Learning through theUse of Solar Power
Guidebook on the Introduction ofSolar Photovoltaic Power Generation

Department of Facilities Planning and Administration,
Minister’s Secretariat
Ministry of Education, Culture, Sports, Science and Technology (MEXT)
Educational Facilities Research Center, National Institute for
Educational Policy ResearchWith the cooperation of
Ministry of Economy, Trade and Industry
Ministry of the Environment
andMinistry of Internal Affairs and Communications

Japan

Introduction
Global warming is a concern common to all countries. Of all the world’s issues that require full-scale
efforts, it is one of the most significant. The Kyoto Protocol’s first commitment period started in 2008,and various measures have been taken by many countries so that they may attain their goals of reducing
greenhouse gas (GHG) emissions. Japan aims at a 6% reduction in emissions in the five years ending in
2012, relative to the 1990 emissions level.
In July 2008, the Cabinet approved the official Action Plan for Achieving a Low-carbon Society,setting a long-term goal of reducing GHG emissions by 60 to 80% by 2050, relative to current emission
levels.
In April 2009, the School New Deal Plan was propounded in a policy package formulated to address
the economic crisis. One of the three main pillars of this plan, environment-focused renovations
including the use of solar photovoltaic power generation, is in its implementation phase.
The smooth introduction of photovoltaic power generation facilities into schools nationwide will beenhanced through the use of a guidebook that provides concise information necessary for school
authorities to meet the requirements for preliminary surveys, design, construction and maintenance. The
Ministry of Education, Culture, Sports, Science and Technology (MEXT) decided to prepare such a
guidebook in view of the conditions and characteristics of school facilities. In collaboration with the
Educational Facilities Research Center of the National Institute for Educational Policy Research, andwith the cooperation of relevant ministries and agencies as well as outside experts, MEXT has compiled
this guidebook.
School is a part of life for children. They learn at school, and their experiences there affect their
growth and development in many ways. By implementing environment-focused renovations such as theinstallation of solar photovoltaic power generation facilities at school, school facilities will be places toprovide environmental education to children. Everything they learn and experience at such facilities will
greatly enhance their environmental awareness.
Schools are among the public facilities with which the public is most familiar, being established in all
corners of the country. It is expected that environmental measures will be promoted at the regional level
when environment-focused renovations are implemented at as many schools as possible.
The information in this guidebook was carefully selected to satisfy the needs of school authorities. It
includes examples of photovoltaic power generation programs that are used for environmental
education, the effects of such use, the use process, points to be checked in designing and building thephotovoltaic power generation facilities, and maintenance of the facilities. Specific data and precedingcases are also shown. It is hoped that this guidebook will be fully utilized by school authorities when
they build photovoltaic power generation facilities at their schools.
July 2009

Learning through the Use of Solar Power- Guidebook on the Introduction of Solar Photovoltaic Power Generation
I. Significance and Effects of Photovoltaic Power Generation at School[Contents]…..1

1. The Gift of Sunlight, and Environmental Education(1) Environmental education(2) Reduction of CO2 emissions (Efforts to address global warming)(3) Economic efficiency(4) Emergency power source

…..1
…..1
…..5
…..5
…..5

2. Outline of Photovoltaic Power Generation Facilities…..6

II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities…..8

3. Process for Installing Photovoltaic Power Generation Facilities at School…..8

4. Items to Consider before Deciding on a Solar Power Generation Program…..10

5. Check Items according to Installation Sites(1) On a flat roof(2) On a pitched roof(3) On a wall(4) On window roofs(5) On louver boards

…..12
…..12
…..16
…..18
…..20
…..21

6. Points to Consider with Regard to Regional Characteristics…..22

III. Sales of Surplus Power, and Maintenance…..24

7. Sales of Surplus Power…..24

8. Maintenance and Inspections(1) Daily checks(2) Periodic inspection(3) System service life(4) Repairs

…..26
…..26
…..26
…..27
…..27

9. Checklist for the Entire Process, from Planning to Maintenance(1) Decision of installation(2) Designing(3) Construction and maintenance

…..28
…..28
…..28
…..30

IV. Case Examples…..31

10. Various Photovoltaic Power Generation Facilities at School(1) Installation of photovoltaic power generation facilities for the benefit ofenvironmental education: Environmental education promoted in everyday life,
Kanamachi Elementary School, Katsushika District, Tokyo(2) Installation at every municipal elementary/junior high/special needs school in a city:
Municipal cooperation and coordination,
The City of Kawagoe, Saitama Prefecture(3) Efficient use of the roof of a gymnasium for installation
Senrigaoka Elementary School, Tsu, Mie Prefecture(4) Effective use of an open area on the roof of a parking lot
Tomari Elementary School, Yurihama, Tottori Prefecture(5) Solar cell modules serving as sunshades
Kobayashi Elementary School, Kobayashi, Miyazaki Prefecture(6) Installation without mounting frames
Nakajima Junior High School, Matsuyama, Ehime Prefecture(7) Installation with the roof pitch as the tilt angle
Oshima Elementary School, Inagawa, Hyogo Prefecture

…..31

…..31

…..32
…..33
…..33
…..33
…..34
…..34

I. Significance and Effects of Photovoltaic Power Generation at School

1. The Gift of Sunlight, and Environmental Education
Photovoltaic power generation plays a significant part in efforts to address global
warming, because photovoltaic power is renewable energy and its generation process
does not emit CO2, a greenhouse gas. Photovoltaic power generation facilities at school
will be utilized as educational tools for children and local residents to learn about theeffects and mechanisms of CO2 reductions and energy saving.

(1) Environmental Educationa. Use of solar cell modules(The case of Idogaya Elementary School,
Yokohama City, Kanagawa Pref.)Solar cell modules/panels and devices for displaying theelectricity output are useful for helping children/local
residents to learn about power generation
systems/mechanisms and the effects of CO2 reductions.

The chance for children to gain firsthand experience of solar
cell modules by seeing and touching them is part ofenvironmental education.

(above) Children of higher-grade explain a power
generation system and its mechanism to lowergrade children while touching the module.
(left) Children measure the size of the module.

b. Use of the device fordisplaying electricity output

Children can see the amount of electricity generated each day
on the display unit, which is mounted in a prominent place.

(left) Children look at thedisplay panel to learn about
power generation. (TonamiTobu Elementary School,
Tonami City, Toyama Pref.)(above) Real-time simultaneous display of electricity
generated and electricity purchased* (Shimada-Daini
Junior High School, Shimada City, Shizuoka Pref.)(right) Students use PCs
to learn about daily/
monthly/ yearly changes
in electricity output.
(Yasuzuka Junior HighSchool, Joetsu City,
Niigata Pref.)* Notes:- A type of display unit that shows both generated and purchased electricity in real time is available. When the lights near the display
unit are turned off, children can immediately see that the consumption of purchased electricity is reduced and that photovoltaic
power accounts for a greater proportion of the power consumed by the school. Other types display the amount of electricity
generated in terms of the equivalent CO2 reductions, or the surplus electricity made available by saving on electricity.
- To draw children’s attention to the power generation monitoring system, it is helpful to mount the system at a low position, forexample.
1

I. Significance and Effects of Photovoltaic Power Generation at School

The learning experience of children is shared by their parents andother local residents, who receive reports about the children’s
experience of recharging batteries with the electricity generated by
the photovoltaic power generator

c. Use of the electricity generated(The case of Idogaya Elementary School,
Yokohama City, Kanagawa Pref.)(above) Children understand theuse of photovoltaic power byrecharging batteries. They use therecharged batteries at home.
(left) A report informs parents andother local residents that batteries
can be recharged with photovoltaic
power.

Wall sockets for charging are placed near the solar cell
module.

d. Cooperation of experts(The case of Idogaya Elementary School,
Yokohama City, Kanagawa Pref.)An expert provides an outreachprogram.

By ensuring the cooperation of experts from NPOs andmanufacturers as well as that of local residents, children areencouraged to learn voluntarily; thus, environmental education at
school is further promoted.

Children, under the guidance of anexpert, learn about photovoltaic
power generation, global warming
and resource saving.

The new Courses of Study provide that social studies atelementary schools include study on “electricity saving andefficient use of resources.” It is also required that children learn
about “the function of solar cells and the use of electricity” and“the importance of using energy effectively” in science classes
at elementary schools and junior high schools, respectively.

Children report their learning outcome
to local residents.

School subjects that can include study of photovoltaic
power generation:
Integrated study period, social studies, arithmetic,
science, life environmental studies, domestic science,
special activities, etc.

<<Extracts from the new Courses of Study (notification given in March 2008 regarding elementary schools
and junior high schools and in March 2009 regarding high schools)>>2

Social studies for grades 3 and 4

Children are given opportunities to learn about the efficient use of resources,
including economization of water and electricity.

Science for grade 4 (elementary school)

The children are made to research the function of dry/solar cells so that they
understand the usefulness of electricity.

Science for grade 6 (elementary school)

The children are made to research the utilization of electricity so that they
understand the specific properties and usefulness of electricity.

Social studies (civics) for junior highschoolThe students learn that economic and technical assistance is necessary forsolving the problems of resources/ energy/ poverty around the world.

Science I for junior high school

The students learn that humans use thermal/ hydro/ nuclear power as energy
sources, and they recognize the importance of efficient energy use.

Science I and II for junior high school

The students understand the importance of a sustainable society.

All science subjects for high school

The students’ awareness regarding the importance of a sustainable society isenhanced from a scientific viewpoint.

I. Significance and Effects of Photovoltaic Power Generation at School

Points to remember in using solar cell modules as teaching materials□ Ensure sufficient space around the modules according to the style and content of the learning activities.
□ Apply protective materials and/or set up a fence, where appropriate, to prevent children from suffering
injuries to their heads by bumping against the mounting frame/ support structure of the modules as wellas to prevent them from climbing on the solar panels. Instruct children on matters needing special
attention.
□ When solar cell modules are fixed on the roof, take the security measures of installing a safety net, a fallprevention fence and the like to prevent children from falling from the edge of the roof or a window roof.
(Government subsidies are available for the installation of such nets and fences.)□ When solar cell modules are mounted on the roof, lock the doors to the roof to ensure that children do
not have free access to the roof.
□ Ensure that the ladders of the modules/towers on the roof are properly maintained to prevent children
from climbing them.

Encouraging children to take good care of the solar power generation facilities

Because solar power generation facilities at school are useful for environmental education, school
officials, including those involved in establishing schools, are responsible for educating children to takegood care of the facilities. In the event of any deliberate destruction of the solar power generation
facilities or of other school facilities, appropriate measures should be taken according to the notices
below.
□ Guidance to children/students having behavioral problems: Notice by the Director-General of the
Elementary and Secondary Education Bureau, MEXT, February 5, 2007 (No.1019)□ Arrangements in school to respond to the problematic behavior of children/students: Notice by the
Director-General of the Elementary and Secondary Education Bureau, Ministry of Education, April
30, 1998 (No.313)

Topic

Examples of themes used in environmental education by scholastic year and subject

Environmental education is provided as part of efforts to develop human resources that can help to build asustainable society. In view of this, the Ministry of the Environment selected major items related toenvironmental education from the Courses of Study. Sorting them by subject and year (i.e., lower, middle
and higher elementary grades and junior high school), the Ministry compiled a brochure for use at school.*
A list relevant to photovoltaic power generation is excerpted below from the brochure. The themes in thelist are “the mechanism and the effects of global warming” and “resources and energy.”

3

I. Significance and Effects of Photovoltaic Power Generation at School

Resources and energy
Aim

Lower grades, elementary
schoolMiddle grades, elementary
school・ Recognizing that underground resources and fossil
fuels are finite
・ Understanding the development and current
utilization of natural energy, including solar andwind power・ Considering and practicing a way of life that
reduces resource consumption

The mechanism andeffects of global warming・ Understanding that production activities andlifestyles that heavily depend on fossil fuels
have altered the composition of the atmosphereand have accelerated global warming
・ Considering and practicing in children’/students’
daily lives whatever is possible to curb global
warming

Social studies:z Disposal and reuse of wastesz Securing of drinking water/electricity/gas
z Sciencez Behavior of wind and rubber
z Properties of lightz Flow of electricity
z Behavior of electricity

Science:z Behavior of air and waterz Metal, water and air, and their temperatures

Higher grades, elementary
schoolScience:z Behavior of electric currentsz Use of electricity

Science:z Mechanism of combustion

Junior high school

Social studies:z Regional characteristics of Japan in comparison toother parts of the world (focusing on resources,
energy and industries)
z Issues facing the international community and ourlives (focusing on issues of the global environment,
resources and energy)

Social studies:z Contemporary Japan and the world at present
z Issues facing the international community andour lives (aiming at a better community)

Science:z Electric currentsz Electric currents and magnetic fields
z Aqueous solutions and ionsz Energyz The development of science and technology

Science:z Changes in material statesz Chemical changesz Weather changes
z Living things and the environmentz Conservation of the natural environment and useof science and technology

Industrial arts and domestic science:z Technologies used at home and by industriesz Mechanism and maintenance of energy converters;
design and production by utilizing energy
conversion technologies*Environmental Education at School: A simple guide to themes by scholastic year and subject (Ministry of Environment:
http://www.env.go.jp/policy.nerai/
By combining the themes in this list with other themes, teachers can provide comprehensive environmental education. The Ministry of theEnvironment’s portal site “ECO-learning library” (http://www.eeel.go.jp) is available to those who are interested in environmental education andeco-learning at school, home or work.

4

I. Significance and Effects of Photovoltaic Power Generation at School(2) Reduction of CO2
emissions (Efforts to address
global warming)

The renewable energy produced by photovoltaic power
generation at school replaces some of the electricity supplied bythermal power plants, thereby greatly supporting the efforts byschools and local communities to reduce CO2 emissions.

・ The amounts and percentages of CO2 reduction per school whenphotovoltaic power generation facilities (20 kW) are introduced:
Amount of CO2 reduction: 10 to 13 t per year
Percent CO2 reduction: 8 to 9% (in cold regions); 14 to 17% (inwarm regions)
The CO2 reductions per school are equivalent to the CO2 absorbed
by woods covering an area the size of the Tokyo Dome.
・Electricity generated at a school per day: 50 to 63 kW
The amount of electricity is equivalent to the electric energy
consumed by fluorescent tubes in eight to ten classrooms during theschool’s daytime hours.
・When photovoltaic power generation facilities have been installed atall 36,000 public elementary/ junior high/ high schools nationwide,
their annual output will be about 760 million kWh:The amount of electricity generated is equivalent to the output of asmall thermal power plant, or the annual electricity consumption of
220,000 households.

Notes:
1) The amount of CO2 reduction was calculatedon the assumption that solar panels (20-kW)
are installed at a school of average size
having a total floor space of 5,000 m2.
2) The value (0.000555 t - CO2/kWh) provided
in the Ministerial Ordinance on the
Calculation of Greenhouse Gas Emissions
Resulting from Business Activities bySpecified Emitters (Ordinance by the
Ministry of Economy, Trade and Industry
and the Ministry of the Environment, No.3,
2006) was used in calculating the amount of
CO2 reduction.
3) With the June 2008 revision to the Law
Concerning the Promotion of the Measures
to Cope with Global Warming, theministerial ordinance specifying the CO2
emission factor used for the calculation of
CO2 reduction was also revised.
4) In December 2008, the latest CO2 emission
factor of electric power suppliers was
published. When that factor is applied to
calculation, the amount of CO2 reduction issmaller.

(3) Economic efficiency
When photovoltaic power generation facilities (20-kW) are introduced toschools:・The annual utility power demand per school will be reduced by 12 to
27%, resulting in a savings of 210,000 to 260,000 yen in school
electricity expenses.
・When photovoltaic power generation facilities are installed at all 36,000
public elementary, junior high and high schools nationwide, the totalsavings will be about 8.7 billion yen annually.
・In Tokyo, for example, an annual electric generation of about 20,000
kWh per school is expected.

(4) Emergency powersourceNotes:
1) The amount of CO2 reduction was calculated on
the assumption that solar panels (20-kW) areinstalled at a school of average size having a
total floor space of 5,000 m2.
2) The electric power rate of Tokyo Electric Power
Co., Inc. as of July 2009 was used for
calculating the electricity costs.

Photovoltaic power generation facilities with additional necessary
equipment provide emergency power when power companies areunable to supply electricity due to damage by a large earthquake orother disasters.

By adding a power conditioner with emergency support1, a power line exclusively for emergency load2 andstorage batteries3 to the photovoltaic power generation facilities, electricity stored in the batteries is available
for emergency load when power companies are unable to supply electricity due to disasters such as severe
earthquake. The quantity of stored electricity is limited, as is the number of electric machines/devices to which
emergency electricity can be supplied.
After a disaster, emergency power
Necessary equipment:
1Power conditioner with emergency support: A device for converting DC power fromsolar cells to AC power. When the supply of electricity by power companies is stopped
due to a disaster, this device supplies emergency power that has been stored in and isdischarged by storage batteries.
2
Power line exclusively for emergency load: A line used exclusively for supplying
emergency power. Being independent of the power system that is usually used, thisline is connected to photovoltaic power generation facilities and used when the power
supply is interrupted.
3
Storage batteries: Batteries used when power the supply from power companies isinterrupted due to a disaster.

supply by photovoltaic power
generation is useful for the following:* Lighting facilities and TVs atevacuation centers* Water supply facilities (e.g., water for
drinking and showering, water
purifiers and units for pumping waterfrom swimming pools)* Communications equipment (e.g.,radios, cell-phones, computers andbroadcast equipment)* Rescue activities (in radios, etc.)

Notes:- Whether to introduce storage batteries should be determined from a comprehensive perspective. The initial cost and the necessity for
maintenance/ replacement should be taken into account. (The expected service life of a valve-regulated MSE-type lead battery is 7 to 9 years.)- The plan for installing storage batteries must satisfy the conditions for installation sites, etc. provided in the fire prevention ordinance.
- It should be noted that the amount of electricity supplied to storage batteries varies because the output of photovoltaic power generation
depends on weather conditions.
- Government subsidies are available for installing storage batteries together with photovoltaic power generation facilities.
5

I. Significance and Effects of Photovoltaic Power Generation at School

2. Outline of Photovoltaic Power Generation Facilities
Photovoltaic power generation facilities have no moving parts; thus they are clean
and noiseless.

System configuration

3. Solar cell array
2. Mounting frame

1. Solar cell module
・ Panels for converting solar energy
to electric energy (DC power)・ A frame for setting asolar cell module at apredetermined tilt
angle

・ An array of solar cells. Solar cell modules
are mechanically and electricallyconnected to mounting frames.

11. Actinometerand thermometer・ Devices for measuring insolation
and air temperature

12. Data acquisition
system・ A device for collecting and recording data on
the electricity that is generated. A generalpurpose computer serves this purpose.

13. Display unit

・A device for displaying data that are
useful for environmental education,such as the generated power,
electric energy and insolation.
Standard equipment necessary forphotovoltaic power generation
Equipment that is desirable because it isnecessary for environmental education
Existing facilities that serve the purpose
Equipment to be installed when needed

6

6. Power distribution board/ switchboard
・A device for distributing power to apparatuses in thebuilding
・In this device, the commercial power line and the powerline from the power conditioner are connected.
・A built-in or separate circuit breaker is necessary
exclusively for the photovoltaic power generation
system.

I. Significance and Effects of Photovoltaic Power Generation at School<<Features and points to keep in mind>>
Features of photovoltaic power generation

4. Junction box
・A box for joining wires from solar
cell modules which are set inblocks at multiple places
・It contains lightning arrester
elements and switches usedduring maintenance/ inspectionsof solar cells as well as diodes forpreventing back-flow to solar
cells.
・It can be integrated with a power
conditioner.
8. Commercial power line
・A line for power supply by a power company

9. Integrating wattmeterfor electric power sales

1. It is a clean method of power generation.
Because solar energy is directly converted to electric energy, no physicaland chemical changes are involved, and thus no chemical substances are
emitted. Having no parts that move or rotate, the generation facilities
generate power noiselessly.
2. Unattended operation is possible and maintenance is easy because thefacilities have no moving parts and are not operated at high temperature/pressure.
Maintenance is easy and unattended operation is possible, although theservice life of the facilities should be kept in mind. (ref. 8. Maintenanceand Inspections)
3. Solar energy is inexhaustible.
Photovoltaic power generation provides energy almost perpetually,
because the energy source is solar power.
4. Cell modules are suited to mass production.
Irrespective of the scale of the power generation facilities and the type ofelectric load, solar cell modules are manufactured in the same single
process; thus, mass production is possible.
5. The power generation facilities can be designed in various sizes.
The amount of electricity generated depends on the combined area of thesolar cells, but the power generation efficiency does not. The same
efficiency is ensured whatever the size of the generation facilities.

Points to keep in mind
・An electric energy meter for measuring the amount of surplus
power for sales. (Some power companies charge sellers of
surplus power for the cost of the meter.)・The type of integrating wattmeter that is needed depends on the
power purchase agreement.
10. Integrating wattmeter forelectric power purchase・ An electric energy meter formeasuring the amount of surplus
power purchased or demanded by apower company
・A conventional electric energy meteris modified by a power company byadding a backstop.
7. Equipment for receiving and transforming electricity
・Equipment for receiving electricity via a commercial
power line (6.6 kV, etc.) and transforming it, whennecessary, to low-voltage power for lighting, etc.
・When electricity is received at low voltage, thisequipment is not necessary.
14. Storage batteries

・Batteries for storing electricity
generated during daytime hours.
Stored electricity is available in
the night or when power supply isinterrupted due to a disaster. (Acontrol unit for discharge/
recharge and a junction box forconnecting to storage batteries arealso needed.)

5. Power conditioner
・A control device for maximizing the DC
power generated by solar cells as well as forconverting DC power to AC power・Some types of power conditioners, though
optional, are equipped with emergency
support to supply power to specified
equipment when the supply of electricity bypower companies is interrupted due to adisaster.

1. The output depends on the insolation.
Power is generated only during the day when the sun is shining. The
amount of electricity generated is determined by the insolation, which
depends on the season, the time of day and the weather conditions.
2. A large area is needed for generating a large amount of electricity.
Because the solar energy density per unit area is small, a large area isnecessary for obtaining a large amount of electricity by photovoltaic
power generation.
3. The cost is relatively high.
Due to the limitations of the current manufacturing technology and the
production volume of the facilities, the cost of electricity generated bysolar power is higher than that of commercial electricity.
4. Direct current power is generated.
Because most facilities require that the power be AC power, a power
conditioner with a built-in inverter is necessary for converting DC power
to AC power.
5. The appropriate tilt angle of solar cell modules should be determined tosuit to each installation site, which preferably is on the south side of thebuilding.
It is necessary to carefully determine the orientation and the tilt angle of
the generation facilities, and the installation site should never be shaded.

Reference:
The expected annual output is calculated as follows:

Ep = H×K×P×365÷1
Ep: Expected annual output (kWh/year)
H: Annual average solar radiation per square meter per day (kWh/m2・
day)
K: Loss factor = about 73% (depending on the type of the module andwhether there is dust, etc. on the light-receiving surface)* Yearly loss due to temperature rise of the cells = about 15%* Loss due to the power conditioner = about 8%* Loss due to dust, etc. on the light-receiving surface and wiring= about 7%
P: System capacity (kW)365: Days in a year
1: Solar irradiance under normal conditions (kW/m2)
Source: “Guidebook on the Introduction of Solar Photovoltaic Power
Generation,” New Energy and Industrial Technology Development
Organization (NEDO)

7

II. Key Points for Consideration in Installing Photovoltaic Power
Generation Facilities

3. Process for Installing Photovoltaic Power Generation
Facilities at School
The process for installing photovoltaic power generation facilities at school isshown below. Well-planned smooth introduction should be aimed at.

Installation Process

M
M
Maaajjjooorrrppplllaaayyyeeerrrsss
School authorities

Decision to launch a photovoltaic
power generation program at school・Consultation with the board of educationand the relevant local government offices
before deciding on solar power generation
and applying for government subsidies
Decision on a solar power
generation program

DesigningArchitectural office (in keepingwith the intentions of the school
authorities)

Contracting
Designing

Procedures for application
to the power company
・One to two months are needed.
Prior consultation with a powercompany is done in thedesigning process.

Construction
・Two to five months areneeded, depending on thescale of the construction
work.

School authorities
Contract
Construction company on behalfof the school authorities
Application procedures

Grid-connected operation
Construction company
Construction

MaintenanceGrid-connected operation
Environmental
education
Maintenance

Environmental education

Power company
Electrical Safety Inspection
Association, power company,
school authorities
School (school authorities,
manufacturers, local residents,
NPOs)

Consultation with manufacturers of photovoltaic power systems and the power company supplying electricity to the region is necessary
before deciding on the introduction of photovoltaic power generation facilities. When a stand-alone system is installed, no consultation
with or application to a power company is required.
8

II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities

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Understanding the significance/ effects ofthe program
Selecting schools for installation
Selecting installation sites and solar cellpanel capacity
Acquiring budget
Confirming installation schedule (fromdecision on operation to completion of
construction/ cooperation with parties
concerned)

・
・
・
・

Significance/effects →pp. 1 - 4
Feasibility →pp. 9, 10
Estimated construction cost →pp. 11, 15, 17, 19,
20
Subsidy programs →pp. 9, 33(Preliminary survey)
・Technical points to be considered forenvironmental education
・Verification of the structural safety of theschool buildings
・
Decision on installation sites
・Checking the surrounding conditions
・
Confirming the types of power lines/
specifications
・
Determining the installation schedule・(Designing)・Power system design
・Solar cell array design
・Selecting peripheral devices
・
Estimating the system cost

・
・
・
・
・
・

Environmental education →pp. 1 - 3
Seismic resistance →pp. 12, 15, 17
Installation sites →p. 9
Orientation/ tilt angle →pp. 13, 15, 18
Snowfall/ strong wind →pp. 21, 22
Schedule →p. 10

・
・
・
・

Waterproofing the roof/foundation →p. 13
Array configuration →p. 14
Safety of children/ students →pp. 3, 12
Things to be checked →pp.27, 28

・・Contract with a construction company

・

Order placement, specifications, etc.
→pp. 36 – 39・・・Consultation with the power company →p. 23
Contract for selling surplus power →p. 23

・

Making necessary applications to the powercompany
Making the necessary reports andapplications to the relevant authorities

・・

Construction
Control of construction schedule and safety

・

Things to be checked →p. 28

・Starting grid-connected operation

・・

Daily check
Periodic check・・・

Maintenance →pp. 25, 26
Service life →p. 26
Warranty period →p. 39

・

Environmental education in cooperation
with the parties concerned

・Environmental education →pp. 1 - 3

・
・
・
・
・

A high-voltage grid-connected system is regarded as electric facilities for private use; thus, it is necessary to appoint a licensed electrician
and to submit to the relevant authorities safety guidelines that are specific to the electric facilities. A low-voltage grid-connected system(under 20 kW) is regarded as electric facilities for general use, and it is not necessary to appoint a licensed electrician or to prepare safety
regulations.
9II. Key Points for Consideration in Installing Photovoltaic
Power Generation Facilities

4. Items to Consider before Deciding on a Solar
Power Generation Program
When a budget and an installation site for the solar power generation program aresecured, the installation of photovoltaic power generation facilities is basically possible.

a. Selecting an
installation site

First, a site should be secured for installing solar cell modules of the desired
capacity.

Points to notice:●Modules are usually mounted on the roof of a school building, but they can be also installed on the wall, thewindow roof or the roof of a swimming pool.
●When modules are planned to be installed on an existing school building, a building that will be used for longer
than the other buildings is preferred. In that case, the service life of each building and possible elimination/
consolidation of school buildings are among the considerations.

b. Acquiring budget

The national government has ample subsidy programs for alleviating the financial
burdens on local governments and private education institutions.

Points to notice:●It is necessary to fully understand the details of the government subsidy programs available for installation ofphotovoltaic power generation facilities at schools. (ref. 1: Government subsidy programs)●Subsidies provided to public elementary schools and junior high schools are also available for the following
purposes: i) Waterproofing of the roof surface, building of a fence on the roof, and other work necessary forsolving technical problems; ii) work necessary for implementing environmental education; and iii) repair workfor energy saving executed at the same time as the installation of power generation facilities.
●The work covered and the grant rates differ depending on the type of subsidy program.

Reference:10II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities

Reference:
Installation schedule
For the second time in fiscal 2009, applications for government subsidies will be accepted in autumn from those
who intend to implement environment-focused renovations. Each accepted applicant will be able to enter into a
construction contract within the fiscal year. It is possible for a local government to place an order for power
generation facilities to be installed at multiple schools.

Points to notice:●As long as the safety of children/students and of their learning environment are secured, it is possible toconstruct facilities not only during the summer vacation but also on weekdays by scheduling the installationof large construction materials and work involving noise and vibration on holidays/weekends.
●A 10-kW system and a 30-kW system take 1 to 2 months and 3 months to install, respectively, including
installation of power generation facilities, inspections and onsite visits by the power company (not including
the period for manufacturing solar cell panels, etc.).
The above-mentioned construction period does not include the time necessary for renovations that are
implemented at the same time as the installation of the power generation facilities.
Example: A program implemented as part of the fiscal 2009 supplementary budget
Jul.

Aug.

0.5 month
Decision on the
program

Sep.

Oct.

Nov.

Dec.

Jan.

Feb.

Mar.

1 monthPreparation of thedesign contract

1 to 2 months
Execution design

1 monthPreparation of theconstruction
contract

Apr.

May.

Jun.

Procedures for carrying
over the construction to
the following fiscal year

2 to 5 months
Installation of photovoltaic power generation facilities (and related works)1
1

Including the manufacturing lead-time (It takes 1 to 3 months to manufacture solar cellpanels, although the manufacturing period depends on the cell capacity.)

Types and sizes of power generation systems
Photovoltaic power generation facilities are largely divided into grid-connected systems and stand-alone systems. The
grid-connected systems include a standard type (with and without reverse power flow) and an emergency support type.
The appropriate type should be selected according to the school’s power demand. The size of the facilities should becomprehensively determined on the basis of installation purpose, the space available, etc.
・The grid-connected systems are connected tothe power system supplied by the powercompany, and the stand-alone systems arenot.
・When a standard grid-connected system withreverse power flow is installed, it is possible
to sell surplus power to the power company.
(ref. 7: Selling of surplus power)・ A stand-alone system is not supplied withelectricity from the power company. With thissystem, it is not possible for the school to sell
surplus electricity to the power company.

Standard
systemGrid-connected
systemWith and without
reverse power flow

Emergency support system (usedtogether with storage batteries)
Stand-alone
systemAn independent system not connected tothe power system of a power company

Notes:
1) It is important to check the existing electric facilities to determine whether the power capacity of the cable connecting the
distribution board to the equipment for receiving and transforming electricity is good enough for receiving power generated by
the installed facilities, and whether the equipment for receiving and transforming electricity should be modified.
2) The standard grid-connected system is the most popular, and power conditioners suitable for such systems are mass produced.
Thus this type of system is recommended for installation in large numbers.
3) Because there is less demand for power conditioners with emergency support (used together with storage batteries), which aresuitable for use with grid-connected emergency support systems, and because only several hundred can be manufactured a year,
an increase in manufacturing facilities is necessary in order for power conditioners of this type to be supplied in large quantities.

11II. Key Points for Consideration in Installing Photovoltaic
Power Generation Facilities

5. Check Items according to Installation Sites
Photovoltaic power generation facilities are designed by an architectural office that
contracts with each school in consideration of the information described below*. It is
recommended that school authorities also understand the same information before
contracting with an architectural office.
*The points to be checked before contracting with an architectural office are elaborated below for each of the
major installation sites: (1) on a flat roof, (2) on a pitched roof, (3) on a wall, (4) on window roof, and (5)on louver boards(1) On a flat roof

Solar cell modules are installed
on a flat roof of the schoolbuilding. Mounting frames arenecessary for tilting the solar
cell panels to ensure maximum
power generation efficiency. A
concrete foundation may beneeded for fixing the mounting
frames.

a. Installation cost
An accurate cost estimate that considers the specific conditions is necessary, but the mean actual costfor constructing standard photovoltaic power generation facilities (10 kW to 30 kW) is 0.9 million to
1.1 million yen/kW*, according to a NEDO field test conducted in fiscal 2006.
*The cost does not include expenses for waterproofing and other renovations.
Investigate the costs!
●Before estimating the necessary budget, the contractor should be asked to give a cost estimate for the planned
facilities.
●The costs for related work, such as for foundations, waterproofing, renovations and reinforcements, need to bebudgeted separately

b. Space for installing the solar cell arrays
Roughly 10 to 15 m2/kW is necessary for installing solar cell arrays*.
* 200 to 300 m2 for 20-kW solar cell arrays12II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities

c. Structural safety of the building
The structural safety of the building needs to be verified in terms of the increase in load on the roof due to theinstallation of solar cell arrays. The verification procedures can be entrusted to an architectural office. Technicalstaff of school authorities may be available for verification.
Building certification* is legally required only when large-scale repairs are executed or when a building isenlarged. Such certification is not necessary for installing photovoltaic power generation facilities on a roof.
*Certification according to the Building Standards Act is required when the solar cell arrays are higher than 4 m above the surface
to which they are fixed.

Check the structural performance!
● Buildings constructed pursuant to the former earthquake-resistance standards:
When seismic reinforcement work and installation of solar cells are executed at the same time, the load of thesolar cells should be taken into consideration in the reinforcement plan.
● Buildings conforming to the new earthquake-resistance standards or buildings otherwise retrofitted against
earthquakes:
In addition to the load of solar cells, the load of i) machinery, such as outdoor air conditioning units, installed on
the roof and ii) children/students when they have outdoor activities on the roof should be taken into consideration
when verifying the structural safety of the building.

Points to notice:
The building is considered to be structurally safe when it is quakeproof, its structural calculation sheets are available,
and the following conditions are satisfied:●The foundation to which to fix the mounting frames of solar cell arrays is basically built above the girders or postsof the building●The total load of the solar cell arrays and their foundation plus the load of i) and ii) above is less than the total live
load of the roof area, namely the load used for structural calculation of earthquake load. It is also useful to set off alarge increase in the load exerted by the solar sell arrays as well as i) and ii) above by reducing the load of otherthings (e.g., by removing the waterproof concrete, relocating heavy loads on the roof to the ground, partiallyremoving the parapet, reducing the roof area available for live load, etc.).
●The total of the weight of the foundation to which to fix the mounting fames of the solar cell arrays and the load
applied to the foundation is smaller than the design live load of the girders/posts on which the foundation is built(i.e., the live load used for structural calculation of the foundation of the girders/posts).
●Safety is secured against things falling as a result of seismic force or strong gusts of wind.
Other than in exceptional cases, evaluation by the local seismic capacity evaluation committee is unnecessary forbuildings that conform to the new quake-resistance standards and for buildings reinforced against quakes.
When structural calculation sheets are not available, safety should be verified by detailed investigation.

Reference:
Notes:
1) In regions with much snow or strong
winds, the mounting frame should be
System load per unit
stronger, which increases its weight.
horizontal projected area
2) When foundation work is necessary for
installing the mounting frames, theAbout 25 - 50 kg/m2
weight of the concrete foundation must
be taken into account.
3) The load per unit area is significant,because the installation area depends on
the installation method and the tilt angle.

Example: A standard frame for mounting solar cell arrays
Capacity

Weight of
the arrays

10 kW

About 1.0 - 1.6t

About 1.5 –3.0t

20 kW

About 2.0 - 3.2t

About 3.0 –6.0t

50 kW

About 5.0 - 8.0t

About 7.5 –15.0t

Reference drawing: Array

Weight of themounting frame

Solar cell array

Access aisle** Access aisles are needed for inspections.

Mounting frame(manufacturer’s
standard)

Access aisle
Foundation

13

II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities

d. Foundation works and waterproof layer on the roof
The state of the waterproof layer on the roof must be checked to determine whether repairs or renovations
are necessary before the foundation works are executed.
Check the waterproof layer on the roof!
●The surface of the roof is covered with a waterproof layer for preventing rainwater seepage. To start with, thestate of the layer should be checked.
●The waterproof layer on the roof of an existing building must be repaired or renovated when foundation works
are implemented for the installation of solar cell arrays. When solar cell arrays are installed on a newly built
building, waterproofing is necessary for the roof.
●An appropriate repair technique should be chosen with consideration of the state of the waterproof layer andalso of whether or not concrete is placed for protecting the roof surface.
Array works (including anchor works
for fixing the mounting frame

Reference drawing:
Foundation works

Foundation works

Photovoltaic panel

Underlying steel: Hot dip galvanizing■ Without sufficient load bearing capacity
Concrete block pavement t 25
Underlying sheet t 7
Insulation (rigid urethane foam) t 35
Asphalt waterproofing

Waterproofing by urethane coating■ With sufficient load bearing capacity

Waterproof concrete
Insulation
Asphalt waterproofing

Spray-on foam insulation (insulation reinforcement)e. Insolation depending on the tilt angle and the orientation
For power generation, it is optimum to orient solar cell modules facing south, but they may also face the due
east or west.
Check the tilt angle and the orientation of the modules!
●The electricity generated by solar cells is maximized when they face due south.
●The tilt angle should be about the same as the annual optimum angle at which the maximum possibleamount of electricity is generated. (The optimum tilt angle differs by region, as shown below.)●On the basis of a thorough understanding of the relationship between electricity-generating capacity andorientation/ tilt angle and in view of the ease of construction and safety, an optimum installation site should
be comprehensively determined.

Annual optimum tilt angle indifferent cities
City

Difference in electricitygenerating capacity by direction
North
Approx. 63%

Annual optimum
tilt angle

Naha
Kagoshima
Osaka

East
Approx. 84%

West
Approx. 84%

Kanazawa
Tokyo
SapporoSouthwest
Approx. 95%

Southeast
Approx. 95%
South
Approx. 100%
(Tokyo, a tilt angle of 30°)

14

II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities

Reference:
Annual photovoltaic power generation in Tokyo by orientation and tilt angle
Orientation/
Tilt angle

Southeast/
Southwest

Due southDueeast/west

0 (horizontal)

100%: the maximum electric energy generated at a tilt angle of 30º and facing due southf. Structures blocking sunlight (effects of shade)
Solar cell modules shouldn’t be in the shade.
Check the shade!
●The amount of electricity generated is reduced when the solar cell modules are in the shade.
●Shadows are their longest on the day of the winter solstice.
●It may be useful to place the modules at some distance from towers, outdoor air conditioning units and otherequipment on the roof to prevent these from shading the modules.
●It is also necessary to ensure a certain distance between the modules to prevent them from shading each other.

Care should be taken to prevent the front-row array from shading the back-row array.
The distance between arrays > (h1 - h2) × K

h1: Array heighth2: Mounting frameheight
K: A factor depending on
the region(Refer to the table below.)

Distance
between arrays

Shadow length factor K on the day of the winter solsticeCity

North latitude

Solar altitude(elevation angle)

Orientation

K (a factor bywhich (h1- h2)
is multiplied)

Naha
Kagoshima/Miyazaki
Fukuoka/Kochi
Tokyo/Nagoya/Tottori
Sendai
Aomori
Sapporo15

II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities(2) On a pitched roof

Solar cell modules are installed on
the sloped roof of a schoolbuilding. Because the modules are
fixed almost flat on the roof
surface, a roof facing anappropriate direction should bechosen. Care may be needed todetermine the module design interms of color, quality of material,
shape, etc., because modules on apitched roof* are conspicuous.

*Differences from the modules fixed on a flat roof and some supplementary notes are provided below.

a. Installation cost
The cost for installing standard photovoltaic power generation facilities on a pitched roof is almost
the same as that for installing the same on a flat roof, or a little lower because large mounting
frames are unnecessary.
Notes:
1) An accurate cost estimate that considers the specific conditions is necessary.
2) When modules are designed to be fixed at a certain tilt angle, mounting frames tailored to the specifications may be necessary.
3) When a color or a shape different from that of standard types is ordered in consideration of appearance, the installation cost
may increase accordingly.

b. Structural safety of the building
When modules are installed on an existing sloped roof, the structural safety of the building must be
verified by taking into account the load of the modules because such a roof is not usually designed tobear live load.
If need arises, it may be necessary to reduce the weight of the roof by rebuilding the roof with solar
roofing materials.

c. Insolation depending on the tilt angle and the orientation
It is economically efficient to install the modules on a south-facing roof and at a tilt angle equivalent to
the pitch of the roof.
Notes:
1) A sloped roof on the south side is desirable.
2) Avoid a roof that is shaded by adjacent buildings or trees.
3) It is most economical to fix the modules almost flat on the roof. (Power generation is ensured with the modules set at a tilt
gradient of 4/10 ‐ 2/10 of normal roof pitches.)16II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities

d. Space for installation
When solar cell modules are installed on a flat roof, the power conditioner can be placed either outdoors
or indoors. Because the power conditioner must be placed indoors for solar cell modules fixed to asloped roof, the place of the power conditioner must be carefully determined in consideration of theroutes of the electric wiring and piping that penetrate the exterior wall.

Horo Elementary School, Matsue City, Shimane Pref.
(30-kW, installed in fiscal 2004)

Topic

Niikura Elementary School, Wakou City, Saitama Pref.
(10-kW, installed in fiscal 2007)

Types and features of solar cells

Crystal silicon solar cells have been the predominant solar cells on the market, but the market has been expanding
with a variety of solar cells, including thin-film silicon, compound and organic solar cells. The table below shows
the types and features of the solar cells for which subsidies are available under the support program for residential
photovoltaic power generation facilities. Building Integrated Photovoltaics (BIPV) are added because they aresuperior in architectural design and are applicable to schools.

Silicon crystal
Crystal silicon

Types

Features

Moduleconversion
efficiency

The oldest type;consists ofmonocrystal
silicon cells< 15%

Thin-film
SiliconCompound
CIS (CIGS)

BIPV(BuildingIntegrated
Photovoltaics)
A light-transmissive
module suitable forwalls, connecting
corridors, roofs, etc.
of school buildings

Consists ofmulticrystal siliconcells; thecrystallization
process costs lessthan formonocrystals.

A laminate ofamorphous silicon
film andmicrocrystal
silicon film

A thin-film solar
cell made ofcopper, indium
and selenium

< 14%

< 10%

< 11%

Power
generation
characteristics

Power generation characteristics
typical of solar cells; monocrystal
cells produce a larger quantity ofelectricity than multicrystal cells.

Temperature
characteristics

Output performance deteriorates athigher temperatures; superior lowtemperature characteristics

Depends on thecell transmittance

Better performancein the ultraviolet
light range, at hightemperatures and instrong sunshine

Output capacity undera wide range of solar
irradiation conditions,producing a relatively
large quantity ofelectricity

Superior in terms ofarchitectural design
because of the power
generation
characteristics

Superior hightemperature
characteristics
in summer

Midway between
crystal siliconcells and thinfilm silicon cells

Characteristics
depend on thecells that areused.

Modulephotos17

II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities(3) On a wall

Solar cell modules are installed on
the wall* of the school building.
Standard types of solar cell
modules can be used. Modules
with see-through perforated solar
cells or those allowing lighttransmission between cells can beused in windows.

*Differences from the modules fixed on a flat roof and some supplementary notes are provided below.

a. Installation costStandard types of solar cell modules can be used, but the installation cost greatly varies dependingon the building configuration.
Notes:
1) An accurate cost estimate that considers the specific conditions is necessary.
2) Although standardized solar cell modules can be used in building walls, it should be confirmed whether the module
dimensions suit the conditions of the wall in terms of height, pole span, size of wall finishing materials, etc.
3) When repair of the exterior wall is needed and the contractor is determined by tender, the contractor chooses a manufacturer
for the wall materials; thus the dimensions of the wall that can be used for installation depend on the manufacturer. In this case,the installation plan should be formulated for multiple module dimensions.
4) Because the installation of the modules affects the appearance of the building, customization of the solar cell panels may bedesired in consideration of their color, material quality and shape. The installation cost increases in that case.

b. Structural safety of the building
It is important to check whether the additional load on the wall will affect the structural safety ofthe building.
Notes:
1) Because the load added by solar cell modules is not taken into account in the design of the wall, the structural safety of thebuilding must be verified.
2) The design of modules installed on a wall should be based on considerations of the safety of children/students, measures forpreventing modules from falling at the time of earthquakes, etc.

18II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities

c. Insolation depending on tilt angle and orientation
South-facing walls are desirable. On a vertical surface, the modules are basically fixed almost flatto the surface.
Notes:
1) Walls on the south side are desirable.
2) Installation on the west or the east, but not on the north, is acceptable when the installation plan requires it, although lesselectricity will be generated.
3) Avoid portions of the wall that are shaded by adjacent buildings or trees.
4) On a vertical surface, the modules are basically fixed almost flat to the surface, so the quantity of electricity generated is roughly
half that for those fixed on a roof, etc.
5) Power generation efficiency is enhanced when modules are installed on a slightly tilted wall or on louvers.

Tamatsukuri Junior High School, Namegata City,
Ibaraki Pref.
(see-through type, 1.87-kW, installed in 2007)

Higashinose Junior High School, Toyono Town, OsakaPref.
(see-through type, 0.68-kW, installed in 2006)

19

II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities(4) On window roofs

Solar cell modules are installed
above windows on mounting
frames*. The modules serve aswindow roofs and can be used assunshades. The panel dimensions
depend on the manufacturer, andmodules are usually customfabricated.

*Differences from the similar type, i.e., modules fixed on the wall, and some supplementary notes are provided
below.

a. Installation cost
The installation cost is relatively high because the solar cell modules are basically customized.
Notes:
1) An accurate cost estimate that considers the specific conditions is necessary.
2) In principle, modules installed on window roofs are different from standard solar cell modules.
3) Solar cell modules tend to be made of glass laminated with resin, which makes them impenetrable to light.
4) A module for a window roof is made of solar cells placed between two sheets of glass. The transparent resin between the cells
lets light through.
5) For the reason mentioned above and also because modules need to be customized to the dimensions of sashes, the installation
cost is higher than that of other module types.

Sakura Elementary School, Kitashiobara Village, Fukushima Pref.
(3.2- kW, installed in 2007)20

II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities(5) On louver boards

Solar cell modules are installedoutside the windows* or any
openings of the school building,serving as window shades orblinds. They are similar to themodules fixed on window roofs,
in that the panel dimensions
depend on the manufacturer, themodules are usually customfabricated, and the modules areused for shading the sun; however,these modules differ in terms of
where they are installed.
*Differences from a similar type, i.e., modules fixed on the wall, and some supplementary notes are provided below.

a. Installation cost
The installation cost is relatively high, because the solar cell modules are basically customized.
Notes:
1) An accurate cost estimate that considers the specific conditions is necessary.
2) In principle, modules installed on louver boards are different from standard solar cell modules.
3) A module for a louver board is made of solar cells placed between two panes of glass. The transparent resin between cells or
modules lets light through.
4) For the reason mentioned above and also because modules need to be customized to the dimensions of sashes, the installation

cost is higher than that of other module types.

Ueda-Higashi Elementary School, Nagoya City, Aichi Pref.
(10-kW, installed in 2008)21

II. Key Points for Consideration in Installing Photovoltaic Power
Generation Facilities

6. Points to Consider with Regard to Regional
Characteristics
Installation of photovoltaic power generation facilities should take regional
characteristics into consideration.

Measures that take regional characteristics into
considerationa. Snowy regions

Solar cell modules and mounting frames should be designed to support theweight of snow covering them and to let snow that accumulates on themodules slide off naturally.

Points to notice:●The allowable load for each solar cell module and the mounting frame should be confirmed with the manufacturer
to verify that both are designed to bear the weight of accumulated snow.
●It is recommended to consider the adoption of a tilt angle that allows accumulated snow to slide off under its
own weight (50 to 60°), so that snow does not remain on the module surface.
●When modules are installed on a flat roof, the mounting frames should be set sufficiently high to prevent them frombeing buried under accumulated snow or snow that falls from the modules. Power conditioners placed outdoors
should never be buried under snow, either.
●Care should be taken to prevent all equipment and structures on the roof from being destroyed by snow that falls
from the modules.
●The modules and the mounting frames should be configured such that snow manually removed from the modules
does not damage the frames.
●At the time of maintenance work, the modules and the frames should be checked as to whether they have beendamaged or joints have been loosened by repeated accumulation and melting of snow.

Reference:
Snow load:
The average unit load of snow is 20 N/m2 or more. (Unitload of snow: weight of snow per 1 m2 area per 1 cm ofsnow depth.) It can exceed 30 N/m2 in some very snowy
regions.
●Snow load [Pa] =Roof slope factor × Average unit weight of snow [N/ m2] ×
Depth of snow [m]b. Cold regions●Slope factor
Gradient of snow-covered surface≤ 30°> 30° and ≤4 0°> 40° and ≤ 50°> 50° and ≤ 60°> 60°

Roof slope factor

1.0
0.75
0.5
0.25
0

Anti-freezing measures are needed, because rainwater that remains
on the surface of solar cell modules and other parts of the facilities
can freeze in cold months.

Points to notice:●It is recommended to use tilt angle and weep holes effectively to ensure that solar cell arrays and the surroundingarea are free of water.
●At the time of maintenance, the modules and frames should be checked to determine whether they have beendamaged or the joints have been loosened by repeated freezing and melting of water.

22

II. Key Points for Consideration in Installing Photovoltaic Power Generation Facilities

c. Windy regions

Solar cell modules and mounting frames should be designed to use materials thatare able to bear high wind loads.

Points to notice:●It should be confirmed with the manufacturer as to whether the solar cell modules and the mounting frames aredesigned to bear the wind load peculiar to the installation site. A formula for calculating the wind load is shown
below. Calculation is actually very complicated, however, because various factors must be taken into account,such as the region, the installation height and the ground roughness. Thus it is recommended to request that anarchitectural office or the manufacturer check whether the modules and the frames are suitable for the windconditions of the region where they are planned to be installed.
●Construction of a fence is desirable for ensuring safety during maintenance.
●At the time of maintenance, the modules and frames should be checked as to whether they have been damaged orjoints have been loosened by repeated wind load.

Reference:Wind load:●Wind load [Pa] = Wind pressure factor × Wind
pressure [N/m2] × Area of modules [m2]

Tailwind

Headwind●Wind pressure factor (when the modules are installed
on a roof): Obtained by the following approximation
formulae•Tailwind (positive pressure) 0.65 + 0.009θ
•Headwind (negative pressure) 0.71 + 0.016θ
Provided that 15° ≤ θ ≤ 45°

d. Regions affectedby windborne sea
salt

Height from the ground surface
to the center of the modulesurface affected by wind

In regions close to the shore where sea salt damage is anticipated, solar cell modules
and mounting frames should be designed to be made from materials to which
corrosion control measures are applied.

Points to notice:●It is recommended that corrosion-inhibiting materials be used for building photovoltaic power generation facilities.
●Measures should be taken to avoid electrolytic corrosion caused by contact between dissimilar metals used for thefacilities.
●The power conditioner and other equipment should be placed indoors where the ambient temperature does notexceed 40ºC.
●A maintenance plan should be formulated to include periodic washing.

23

III. Sales of Surplus Power, and Maintenance

7. Sales of Surplus Power
Surplus power is efficiently utilized when an electric energy meter for powerinterchange is available. It is recommended that equipment necessary for powersales be installed when a simulation in the phases of prior survey and designing hasverified the feasibility of power sales.

Examples of prerequisites for sales of surplus power:●The photovoltaic power generation capacity is more than enough.
●Electric power is not in great demand at school on holidays and in vacation periods in view of i) the size of theschool, ii) the electric power needs associated with club activities and public use of the school building(depending on the season), and iii) the use of electric air conditioners (depending on the season).

Prior consultation with the power company before starting operation
Work flow on the part of theschool authorities or their agent
Decision to install facilities

Method of connecting to the grid(tentative agreement)

Work flow by the powercompany
Request by the schoolfor prior consultation

Designing

AcceptedContracting

Application for the use of privately
generated power
Application for connection to the grid

Application to the power company

Construction

Agreement on
connection to
the grid

Conclusion of a contract for thepurchase of surplus power
Conclusion of a contract/ MOU
on connection to the grid

Grid-connected operation

1 - 2 months

1 - 2 months(parallel procedures)

Onsite inspection

Maintenance<<Surplus power interchange contract>>

Reference:

Purchase price of surplus power
School authorities wishing to sell surplus power to a powercompany need to consult with the company about powersales and connection to the grid and then to conclude asurplus power interchange contract with the company.
It is recommended that prior consultation with the powercompany about connection to the grid* be conducted as
early as possible after the basic design of the power
generation facilities is finalized.
*Independent consultation with the power company is needed
when photovoltaic power generation facilities are connected to its
utility.

24

The purchase price of surplus power depends on theseason and the power company. Currently, thenational average purchase price is 11 to 15 yen/kWh,almost the same as the price of electricity sold bypower companies. An increase in the purchase priceof surplus power is being considered by the national
government.

III. Sales of Surplus Power, and Maintenance●Estimated installation cost and calibration of the electric energy meter measuring reverse power
flow for sales
It costs about 150,000 to 300,000 yen to install an electric energy meter that measures reverse power flow for sales.
Calibration, which every electric energy meter needs to undergo every 5 to 7 years, costs about 100,000 yen.
Notes:
1) The estimated installation cost shown above is only a rough standard, and the actual cost of installation depends on the power company.
2) Calibration may be needed every 10 years when the electric energy meter is connected to a low-voltage grid.

Topic

Applying the revenue from sales of surplus power to educational activities at school

Not only can the electricity expenses saved by power generation at school be used effectively forenvironmental/energy education and other activities at school, but so can the revenues from surplus
power sales. It is economically inefficient to fail to sell surplus power when such sale is feasible.
Reference: An example in the city of Kyoto (discretionary powers of schools)
1. Budget implementation
To help enhance distinctive education at school, the city allows flexible budget appropriations. Within an annual
initial budget for operating expenses, each school can give priority to the programs regarded as most necessary
for the school, without being bound by a ceiling that was previously set on each budget item.
2. Benefit of reduction in light, fuel and water expenses
Thanks to the flexible budget appropriations program of the city, a sum of money equivalent to the reduction in light, fueland water expenses (as compared to fiscal 2003) has been applied to school library expenses and educational activities. Thishas been made possible by modifying the budget items specified in the initial annual budget during the same fiscal year.

3. Benefit of revenues from surplus power sales
The power company pays the city of Kyoto for the surplus power that the company purchases from schools. The revenues
are designated by the city as miscellaneous income. Thus, it is not possible for schools to use the revenues from surplus
power sales in the fiscal year that the sales take place. The amount of revenue for each school, however, is added to theinitial budget of the following fiscal year; thus, it is available for educational activities.

Reference:

Schools with good sales performance
Shiroi-Daini Elementary School, Shiroi City,
Chiba Pref.
School size: 6 classes
Installed capacity: 30 kW
Annual sales in fiscal 2004: 142, 838 yen

Shibakari Elementary School, Kurume City,
Fukuoka Pref.
School size: 7 classes
Installed capacity: 20 kW
Annual sales in fiscal 2007: 52,269 yen

25

III. Sales of Surplus Power, and Maintenance

8. Maintenance and Inspections
Photovoltaic power generation facilities are basically maintenance-free, but
periodic visual inspections are desirable.

(1) Daily checks

Becauseoperationofphotovoltaic
power
generation
facilities
isautomated, daily checks areunnecessary and there are
no legal regulations for suchchecks. However, it isrecommended that a visualinspection be conducted
once a month for early
detection of any system
malfunctions as well as tomaintain a constant power
output. Please seek advice
from the manufacturer orthe contractor in the eventthat any malfunction isfound.

EEEqqquuuiiipppmmmeeennnttt

Solar cell array

PPPoooiiinnntttsssooofffvvviiisssuuuaaalllccchhheeeccckkk
Dirt, dust, etc. on the surface; damage to the surface
Corrosion or rust on the mounting frame
Damage to external wiring
Corrosion or rust on the outer caseJunction box

Damage to external wiring
Corrosion or rust on the outer caseDamage to external wiring

Power conditioner

Unusual noise/odor during operation
Clogging in the filter of the air vent
Surrounding conditions (no high temperature, no water)

Earth connection
Power generation

Damage to wiring
Normal power generation indicated by instruments/displays(2) Periodic inspection

EEEqqquuuiiipppmmmeeennnttt
Periodic inspections should be
performed by a licensed
electrician pursuant to theoperational safety programs
that were prepared specificallyfor the facilities and submitted
to the authorities concerned.
□Low-voltage system(< 20 kW):
Voluntary inspection□High-voltage system:
Statutory inspection< 100 kW:
Two or more times a year
≥100 kW:One or more times per twomonths

PPPoooiiinnntttsssooofffvvviiisssuuuaaalllccchhheeeccckkk
Dirt, dust, etc. on the surface;damage to the surfaceMmM
meeennntttttteeesssttt
Meeeaaasssuuurrreeem
Measurement of insulation resistanceCorrosion or rust on the mounting frame Measurement of open voltage

Solar cell array

Damage to external wiring
Damage to earth wires, and looseningof earth terminals
Corrosion or rust on the outer case

Measurement of insulation resistance

Damage to external wiring

Junction box

Power conditioner

Damage to earth wire, and looseningof earth terminal
Corrosion or rust on the outer case

Check of display behavior

Damage to external wiring
Damage to earth wire, and looseningof earth terminal

Measurement of insulation resistance
Testing of inverter protection operation

Unusual noise/odor during operation
Clogging in the filter of the air vent
Surrounding conditions(no high temperature, no water)

Earth condition
26

Damage to wiring

Measurement of earth resistanceIII. Sales of Surplus Power, and Maintenance
When the safety management of a high-voltage system is outsourced, it is efficient to add inspections ofphotovoltaic power generation facilities to the safety management contract.
Reference:
Example of safety management fees in the Kanto region (based on data on power receiving facilities and power
generation, as of June 2009)
H
LLLooow
G
Hw
G
Hiiiggghhh---vvvooollltttaaagggeeecccooonnnnnneeeccctttiiiooonnn
w---vvvooollltttaaagggeeecccooonnnnnneeeccctttiiiooonnn
Grrriiidddcccooonnnnnneeeccctttiiiooonnn
Photovoltaic power generation facilities[System capacity (kW)]MonthlyfeePowerreceivingfacilities
Power
generation
facilities< 20

Monthlyfee
Inspection
frequency≥ 20, > 50
7,900 yen/inspection

Voluntary
inspectionFee/
inspection< 50≥ 50, > 100

Depends on the Depends on the
installed capacity installed capacity≥ 100, < 300
Depends on the
installed capacity

Twice/year

Twice/year

Twice/year

Once/twomonths4,000 yen

4,000 yen

7,900 yen

4,000 yen

- The fee may be calculated separately, depending on the facility type and other factors.
- The exact fee should be confirmed with the safety inspection association of the relevant region.
- “Power receiving facilities” means equipment for receiving and transforming electricity.

(3) System service life
The design life of equipment differs by device and manufacturer. In the course of daily operation, it is necessary to check whether
each device is operating normally. The following situations may indicate the end of the service life.
a. A reduction in the power output
b. A reduction in the insulation performance (risk of earth leakage and electric shock)
The expected service life of the major equipment is roughly as follows:・Solar cell module: Expected service life of 20 years or longer
・Power conditioner: Expected service life of 10 years or longer- “Expected service life” means the period in which the equipment performs satisfactorily under certain conditions equivalent orquite similar to actual operation conditions. It does not mean a performance guarantee period.
The condenser capacity decreases gradually over time; thus, this part may need to be replaced in 10 to 15 years.

(4) Repairs
Periodic total replacement or repair of the system is not necessary. An inspection is needed whenever any failure or
malfunction is found. In that case, it is recommended that only the defective part be replaced or repaired.

Topic
Worry-free use of photovoltaic power generation facilities
Insurance plan
Property insurance is available for photovoltaic power generation facilities for
institutional use. It is desirable to choose an insurance plan that suits the regional
characteristics. Almost all movable property owned by a corporate body, including
equipment, manufactured goods and office machinery, can be covered by insurance.
Property insurance covers the following:a. Damage or loss by fire, lightning, burst pipes andexplosionb. Damage or loss by a wind, hail or snow disasterc. Damage or loss by water (e.g., inundation above floor
level)
d. Theft (e.g., theft of a computer)e. Damage or loss by electric fault (e.g., short circuit)f. Damage or loss by mechanical failureg. Other one-time accidents

Coverage examples:
・Snow disaster: A module and part of the facilities fallaway due to accumulated snow.
・Damage by a one-time accident
・Damage by water: Data measuring equipment become
inoperative due to heavy rain.
・Damage by wind or water disaster: A mounting frame
bends and the module is damaged by typhoon.
・Damage by lightning: Measuring equipment burns out
due to lightning.
・Damage by lightning: A power conditioner is damagedby lightning.

Note that wear/deterioration from everyday operation and breakdown resulting from earthquake, tsunami or eruption are notcovered.
27

III. Sales of Surplus Power, and Maintenance

9. Checklist for the Entire Process from Planning to
Maintenance
Please use the check items shown below to adequately follow the procedures fromplanning to maintenance.
The following points need to be checked at each phase in the introduction of photovoltaic power generation
facilities to schools.

(1) Decision of installation
Consideration of installation sites□Where will the photovoltaic power generation facilities be installed? Have studies been conducted to narrow down candidate
buildings and specific sites in those buildings? Will the facilities be installed on a new building or on an existing building?
* Priority should be given to a building having a longer service life.
□What will be the power output level? Is it possible to secure a space large enough for installing the facilities needed for that
output level?
□Are the procedures in place for applying for subsidies to MEXT, METI and the Ministry of the Environment?
□Has the schedule been confirmed with regard to the entire process from the start to the completion of construction?
□Have consultations been under way with and within the relevant local governments and the board of education?

(2) Designing
An architectural office is responsible for designing, but those involved with the establishment of theschool should also check the following:
Arrangements for installation□Have the necessary arrangements been made?
□Have members been selected from the school for an installation project team?
□Has the method for selecting a contractor been decided?
□What will be the bidding method?
□When will the power generation facilities be installed, and what will be the installation costs?
□How will the facilities be maintained? Is a licensed electrician necessary, or will maintenance be outsourced?

Preliminary surveys<Environmental Education>□Are there concrete plans for the use of the power generation facilities in environmental education?
□According to the details of environmental education, necessary technical matters will be checked (from the viewpoint ofsafety, use of the facilities, etc.)<Structural safety of the existing building>□When the generation facilities are built on a building conforming to the former quake-resistance standards, an aseismic
reinforcement plan should be prepared in consideration of the load added by solar cells and other equipment.
□When the generation facilities are built on a building conforming to the new quake-resistance standards or one that has alreadybeen reinforced, structural calculation sheets should be used to verify the safety of the building.
<Surrounding conditions>□Has it been checked as to whether there are structures shading the sun?
□The surrounding conditions will be checked to see whether the power generation facilities will fall under the shadow of abuilding, a tree, a mountain, a chimney, a utility pole, a steel tower, a signboard, etc., and whether fallen leaves/dust
may accumulate on the surface of the facilities.
□Has the depth of snow been checked?
□The depth of snow accumulation should be checked (particularly in a snowy region).
□Has any possible damage by sea salt, lightning, wind, etc. been checked?
□Potential factors for damage to the power generation facilities will be checked in order to select an appropriate
installation site and to determine design specifications accordingly.
<Installation site>□Have the conditions of the building for installation been checked?
□The shape, dimensions, orientation and the surrounding conditions of the installation site should be checked.
□The structure and waterproofing of the floor, as well as the direction/gradient of the drainage piping, should bechecked.
□Routes for carrying in materials and other conditions for construction works should be checked.
□The visual effects/ appearance of the solar cell arrays should be checked.
□The safety of pupils/students while they are using the power generation facilities for environmental education should
be checked.

28

III. Sales of Surplus Power, and Maintenance□Have the conditions of the installation site on the ground been checked (when installation on the ground is planned)?
□The shape and the orientation of the site, surrounding conditions, drainage, ground condition, necessity of groundwork,and routes for carrying in materials should be checked.
□The safety of pupils/students while they are using the power generation facilities for environmental education should bechecked.
<Electric facilities>□Has the current state or the construction plan of electric facilities been checked?
□Onsite review should be done on the basis of electric system diagrams and equipment layout plans.
□What kind of system will be installed? A grid-connected system with or without reverse power flow, or a grid-connected
system with emergency support which necessitates use of storage batteries?
□Is it possible to secure a place for installing peripheral equipment and storage batteries?
□When an existing building is used for installation, is it possible to secure routes for wiring and piping?
□Is a route available for carrying in equipment?
□Is the power capacity acceptable by the main cable connecting the distribution board and the equipment for receiving
and transforming electricity?
□Does the power generation capacity make it necessary to modify the equipment for receiving and transforming
electricity?

Prior consultation□Have the necessary consultations been conducted?
□To determine legal requirements, advice should be sought with the Building Guidance Division of the local government,
the fire department and other authorities concerned, as necessary, with regard to the details of the power generation planand necessary applications.
□MEXT, NEDO and other agencies that subsidize photovoltaic power generation projects should be consulted with regard
to the outline and the implementation schedule of their subsidy programs.
□When necessary, advice should be sought with the power company about grid connection.
□When necessary, advice should be sought with architectural offices/consultants that are experienced in designing ofphotovoltaic power generation facilities. Information should be gathered from manufacturers.

Interim verification□Is the installation plan almost finalized with regard to the building for installation, the installation site, the electric load, the power
output level, the system type, etc.?
□Is there a consensus on the timing of installation as well as on the entire schedule?
□Have the electric-generating capacity and the costs been estimated? Has a draft budget been assembled?

Clarification of the designing conditions□Have the basic principles of designing been finalized?
□Have the specifications of the devices for data display/collection been finalized?
□Where will they be installed?
□Is information shared by all parties concerned, including school authorities and officials?
□What will be the electricity-generating capacity?
□What kind of system will be installed?
□When will the generation facilities start operation?
□What is the budget size?
□Regarding the following, are the designing conditions clear?
□Surrounding conditions□Conditions of the installation site
□Current state of the electric facilities□Legal conditions□Conditions for necessary application procedures

Review and execution of designing□Are the orientation and the tilt angle of the modules optimum? (Both should facilitate generation of as much electrical energy as
possible.)□Are the configuration and the installation method of arrays optimum?
□Are the foundation and the mounting frames designed adequately on the basis of strength calculation?
□When foundation works are necessary to install mounting frames on an existing building, will the waterproof surface of theinstallation site be appropriately repaired?
□Regarding the mounting frames, have the quality of the materials applied and anticorrosion/antirust measures been checked?
□Will the power generation facilities be sufficiently protected with a good offset distance from a lightning protection system?
□Are the earth connections appropriate in view of the technical standards applied to electric facilities?
□Is a power source secured for measuring/display devices?
□Regarding the power conditioner, has it been checked as to whether its installation site and measures against high temperatures are
optimum?
□Is a lightning arrester (surge protection device: SPD) necessary?
□Have legal regulations and requirements been checked?
□Do the details of the designing conform to the aim of the installation of the power generation facilities?
□Are the selected peripheral devices, their installation sites and their surrounding conditions appropriate?
□Have enough measures been taken to ensure the safety of pupils/students?
□Has an installation schedule been prepared? Have the electric-generating capacity and the costs been estimated?

29

III. Sales of Surplus Power, and MaintenanceApplication procedures□Have the necessary applications/ notifications been submitted to the authorities concerned (e.g., director of building and safety)
regarding building certification, notification on facilities plan, etc?
□Regarding the following, have the necessary consultations with the power company been completed?
□Request for prior consultation with the power company regarding grid connection□Application for/ agreement on grid connection (MOU on grid connection, surplus power interchange contract, etc.)

Conclusive confirmation□Have the principal budget and the installation schedule been finalized?
□Have all necessary applications been submitted to the authorities concerned and to the power company?
□Has a construction contract been signed with a contractor selected by appropriate tender procedure?

(3) Construction and maintenanceConstruction is executed by a contractor, but the school authorities and those involved in establishing theschool should also check the following:
Construction□Adequate measures have been taken to keep pupils/students safe during construction.
□There is an appropriate system in place for supervising the construction and safety measures.
□Information has been shared about the commencement and the progress of each construction process.
□The contractor has filed applications and submitted notifications as appropriate.
□Completion inspections have been conducted properly.

Notification□An application has been filed with the Bureau of Economy, Trade and Industry regarding appointment of a licensed electrician
approval for exemption from appointment.)□The operational safety programs, which had been prepared before the start of the construction works, were submitted to the Bureau
of Economy, Trade and Industry before starting the operation of the facilities.

Management□Necessary arrangements have been made and budgetary measures have been taken for implementing daily and periodic checks.
□When applicable, a business trust agreement has been made with the local safety inspection association or the power company for
entrusting safety management to the association or the company.

Conclusive confirmation□The construction works were executed adequately. (The adequateness of the photovoltaic power generation system was verified bycompletion inspections.)□An application has been filed for approval of the appointment of a licensed electrician or for exemption from this, and operationalsafety programs have been submitted to the authorities concerned.
□Appropriate programs for maintenance and safety management are in place.

30

IV. Case Examples

10. Various Photovoltaic Power Generation
Facilities at School(1) Installation of photovoltaic power
generation facilities for the benefit ofenvironmental education

Environmental education promoted ineveryday life
(Kanamachi Elementary School, Katsushika Ward,
Metropolitan Tokyo)

An outline of the photovoltaic power generation facilities at school・School size: 12 classes
・Installed photovoltaic power generation capacity: 2.3 kW
・Installation site: roof
・Orientation and tilt angle: Due south, 30°
・Year of installation: Fiscal 2006
・Characteristics:

In addition to photovoltaic power generation facilities, wind
power/ photovoltaic hybrid power generation facilities, abiotope and a lawn-covered schoolyard are effectively utilized
for environmental education. Photovoltaic power is consumed
in a limited area in the school, and pupils can see on a display
how much purchased power and generated power are
consumed in that area.

Solar cell module facing south,
fixed at a tilt angle of 30°

Wind power/ photovoltaic
hybrid power generation
facilities: Wind power isused on cloudy/rainy days.

Use of photovoltaic power generation
The power lines in this school are divided between those for purchased power and those for photovoltaic power.
The latter is consumed by lights installed in the main entrance and the corridors on the first and second floors on
the north side of the building. The power consumption of the lights in these places is shown regarding bothpurchased energy and generated energy. Because the number of lights involved is limited, pupils can tell easily
how many fluorescent lamps are being powered by the energy generated at school.

Efforts for environmental education
Because information and reports on environmental efforts are posted at various places in the school, both pupils andteachers have become more interested in natural energy, being more aware of the importance of energy/resourcesaving. As part of the continued efforts for encouraging children to learn more extensively about environmental
issues as well as for fostering children who are considerate and value natural environment, a brochure forenvironmental education was prepared and the school has been working together with pupils’ families in promoting
environmental education.

Purchased energy and generated
energy are shown.

A brochure is available, and information on
the environment is posted at many places inthe school.

31

IV. Case Examples(2) Installation at every municipal elementary/ Municipal cooperation and coordination
junior high/special needs school in a city
(The City of Kawagoe, Saitama Prefecture)
An outline of the photovoltaic power generation facilities at all elementary/juniorhigh special needs schools in the city
●Number of schools in the city: 33 elementary, 22 junior high, 1
special-needs●Installed generation capacity:
3 kW: 31 elementary schools and 22 junior high schools
10kW: 1 elementary school and 1 special-needs school
30kW: 1 elementary school●No. of schools installed: FY 1998: 1; FY 1999: 1; FY 2000: 10;
FY 2001: 16; FY 2002: 15; FY 2003: 12; Fiscal 2006: 1●Characteristics:

At all elementary and junior high schools in
Kawagoe, pupils/students and local residents
are familiar with solar cell modules.

Most of the schools that installed a 3-kW system used their existingbuildings for installation. 10-kW systems were installed concurrently with renovations of buildings at two schools. A 30-kW
system was installed in a school when it was rebuilt as part of a complex, which was built also for a community hall and alibrary that were relocated from elsewhere. The small 3-kW systems were installed in large numbers because their capacity,
being the same as that of the system used at home, was considered to be useful for providing environmental education tochildren and for raising local residents’ awareness of photovoltaic power generation.

Background of the installation at all elementary and junior high schools
In fiscal 1996, the City of Kawagoe launched a 1% power saving campaign with the aim of using the financial resources that were
saved through the campaign for the benefit of the citizens. Since then, the city has been working on various measures and policies forcurbing global warming. For the purpose of enhancing local residents’ awareness of environmental conservation and of promoting
environmental education to school children, the city decided to install photovoltaic power generation facilities at a greater number ofpublic facilities, and finally established a policy of “installing photovoltaic power generation facilities at every newly built public
facility as well as at all public elementary and junior high schools because of the importance of such facilities for environmental
education.” The plan for installing the facilities in all schools was implemented successfully and was completed in 2006.

The four-year plan and priorities for installation
The city formulated the “plan for promoting regional introduction of new energy.” Based on the plan, photovoltaic power
generation facilities were intensively built at all municipal elementary and junior high schools in the city over the four years fromfiscal 2000 to 2003. To implement the plan efficiently, it was decided that i) photovoltaic power generation facilities would beinstalled concurrently with the repair and waterproofing works that had been separately planned, and ii) installation would takeplace at various places in the city within each fiscal year, so that local residents would be exposed to and informed of thephotovoltaic power generation facilities.

Installation costs
The costs were borne solely by the city only for the facilities installed at the two schools in fiscal 1998 and 1999. The installation of
3-kW systems at the other 51 schools was approved as a regional project that ensured scheduled installation in the entire city area;
thus, it was implemented under a grant from the NEDO Project for Promoting the Local Introduction of New Energy.* The twoschools that installed the facilities concurrently with relocation or renovation of school buildings were certified under Eco-school
Pilot Model Project, and they were subsidized by the NEDO Field Test Project on New Photovoltaic Power Generation Technology.
In fiscal 2003 and 2006, subsidies were also available from the Green Power Fund of Greater-Kanto Industrial Advancement Center(GIAC).
*In fiscal 2009, subsidies were provided by the New Energy Promotion Council.

Cooperation and coordination among the municipal government’s departments
Roles were shared by multiple departments in the municipal government to make all-out efforts for promoting the installation
project. For example, the board of education made various arrangements with each school and took budgetary measures, theConstruction Department was responsible for installation works, and the Environment Department applied for subsidies/grants.
Left:Tsukigoe Elementary School,
Kawagoe, Saitama Prefecture (A10-kW system was installed when
the building was renovated.)

Right:Kasumigaseki-Kita
Elementary School, Kawagoe,
Saitama Prefecture (A 30-kW
system was installed when theschool was relocated andrenovated.)32

IV. Case Examples(3) Efficient use of the roof of a gymnasium for installation(Senrigaoka Elementary School, Tsu, Mie Prefecture)●School size: 20 classes●Installed photovoltaic power generation capacity: 10.4 kW●Year of installation: Fiscal 2005
●Annual output: 12,200 kWh●Characteristics:

The solar cell modules installed on the roof of the
gymnasium are made of amorphous silicon, and no glass isused on the surface. This material fits well with the vaulted
roof and is superior in visual appearance.
The electric energy generated is displayed at conspicuous
places in the shoe locker area for pupils and at the entrance
for visitors, so that the effects of environmental education
using the photovoltaic power generation facilities will
spread to local residents.

Solar cell modules on the roof of a gymnasium(4) Effective use of an open area on the roof of a parking lot(Tomari Elementary School, Yurihama, Tottori Prefecture)●School size: 10 classes●Installed photovoltaic power generation capacity: 20 kW●Year of installation: Fiscal 2004
●Annual output: 15,700 kWh●Characteristics:

The open space on the roof of a parking lot is effectively
used for installing solar cell modules.
The electricity generated is used to power fluorescentlamps and is displayed on a unit placed beside the schoolgate; thus, pupils can tell at a glance that electricity is
generated each day and that they benefit from it.

Solar cell modules on the roof of a parking lot(5) Solar cell modules serving as eaves(Kobayashi Elementary School, Kobayashi, Miyazaki Prefecture)●School size: 23 classes●Installed photovoltaic power generation capacity: 5 kW
●Year of installation: Fiscal 2006
●Annual output: 6,000 kWh●Characteristics:

Solar cell modules serve as eaves. They help to curb a risein the indoor temperature by protecting classrooms fromdirect sunlight in summer; thus, they improve the school
environment.
A unit for displaying the electricity generated is placed in
the entrance and used for environmental education for
pupils.

Solar cell modules serving as eaves were installed on
an existing school building.

33

IV. Case Examples(6) Installation without mounting frames(Nakajima Junior High School, Matsuyama, Ehime Prefecture)●School size: 4 classes●Installed photovoltaic power generation capacity: 10 kW●Year of installation: Fiscal 2006
●Annual output: 13,500 kWh●Characteristics:

Installation of the solar cell modules on a roof without
mounting frames helped to reduce the load on the roof.
A unit for displaying the electricity generated is placed
inside the school building for use in environmental
education, and surplus power is purchased by a powercompany.
Mounting frames were not used, even though the roofis almost flat(7) Installation with the roof pitch as the tilt angle(Oshima Elementary School, Inagawa, Hyogo Prefecture)●School size: 7 classes●Installed photovoltaic power generation capacity: 10 kW●Year of installation: Fiscal 2006
●Annual output: 11,300 kWh●Characteristics:

The tilt angle of the solar cell modules is the same as theroof pitch. A unit for displaying the energy generated isplaced in the entrance so that children are always aware of
the power generation at school. They learn about thecharacteristics of solar cells, including seasonal changes in
the power output, through year-round observation ofphotovoltaic power generation. Surplus power is sold to a
power company.

34

Solar cell modules installed almost flat on a pitched roof

IV. Case Examples

Topic

Long-range outlook for CO2 reductions according to different scenarios at school

The Action Plan for Achieving a Low-carbon Society approved in a Cabinet meeting on July 29, 2008, aims at
reducing CO2 emissions by 60-80% by 2050 as compared to the current emissions level. CO2 emissions fromschool facilities in 2050 were estimated according to various scenarios. In comparison with the emission level in
1990:
a. CO2 emissions will increase by 10% when only standard energy-saving measures are taken; andb. A significant reduction in the CO2 emission will be possible when state-of-the-art environmental measures,
future environmental measures which will be made available by technological innovations, and efforts by theelectric industry are combined with energy-saving measures. (There are many factors, including cost, to consider.)An outline of various environmental measures
Scenario
1

Maintenance of the Status Quo

2State-of-the-art
environmental measures

3

Medium-to-long-term
environmental measures(facilitated by technologicalinnovations in the future)

4

Efforts by the electric industry

Description
Underuse of insulation, energy-saving devices, renewableenergy, etc.
Use of daylight, insulation, energy-saving devices, renewableenergy, etc.
Use of daylight, super insulation and high-efficiency energysaving devices, and increased use of renewable energy, etc.

Reduction of CO2 emissions per unit of output through efforts
by power companies

To increase the use of renewable energy, it is critical to promote installation of photovoltaic power generation
facilities in as many schools as possible.
・The estimates shown above are included in the Policy regarding the Promotion of Environmentally Friendly
School Facilities (eco-schools): The Role of Schools within a Low-Carbon Society (final report prepared by
Prof. Ikaga in March 2009) of MEXT.

CO2 emissions [million t- CO2/year]

10% increase from the 1990 level

Universities/ CollegesHigh schools

State-of-the-art environmental measures

22% reduction from the 1990 level

Mid- to long-term environmental measures

47% reduction from the 1990 level

Efforts by the electric industry

70% reduction from the 1990 level

Junior high schools
Elementary schools

year
Estimated CO2 emissions from school facilities

35

[Contact for inquiries]
Educational Facilities Research Center, National Institute for Educational Policy Research -Japan
Address: 3-2-2 Kasumigaseki, Chiyoda-ku, Tokyo, 100-8951, Japan
Phone: +81-3-6733-6991
Fax: +81-3-6733-6966
URL: http://www.nier.go.jp/English/departments/menu_11.html