Japanese Energy-Efficient Technologies
Progress of Energy Conservation in Japans
In the 1970s, Japan experienced what we call oil crisis and its industrial, commercial, andresidential sectors suffered from oil shortage and soaring energy prices. However subsequently,
the government, industries, companies and even people have committed to promote energy
conservation and conversion activities and have vigorously worked toward energy innovations
to develop technologies, devices, and systems with less energy consumption and higher energy
efficiencies.
As a result, over 15 or so years since 1973, Japan more than doubled its GDP without increasingenergy consumption to the level before 1973. Currently, Japan’s GDP is 2.5 times as large as that of1973 while the total energy consumption only grew 1.1 times. In particular energy consumption inindustrial sector has fallen by 0.8 times (see Fig. 1).
JP Yen trillion, Prices as of 2015

(EJ)

18

600

GDP FY1973-2020
2.5 times

Final Energy Consumption
500

15Transportation
400

12

Residential
91973-2021FY
Transportation

1.5 times
Residential

300

Commercial

1.8 times
Commercial

6200

Industrial

3

100

0
197375

1980

1985

1990

1995

2000

2005

2010

2015

0
2021 (FY)

Fig. 1 Transition of Final Energy Consumption in Japan
Source: METI ANRE Energy White Paper 2023

2.0 times
Industrial

0.9
times

0.8 times
Total: 1.1 times

Primary Energy Supply per GDP (PJ=1015J / JP Yen trillion (Prices as of 2015))

JP Yen trillion (Prices as of 2015)

75

600

70

550

65

500

owth

ic gr

om
Econ

60

450

55

400

50

350

Eﬃci

ency

45

impr

ovem

ent

300

40

250

35

200

30

197375

1980

1985

1990

1995

2000

2005

2010

2015

150
2021
FY

Fig. 2 Trend of Primary Energy Intensity per GDP in Japan
Source: METI ANRE Energy White Paper 2023

When the above circumstances are clarified in terms of the transition of Japan’s GDP versus primary energy
consumption, as presented in Fig. 2, improvement around 40% has been achieved since the oil crisis and energysaving efforts continue to elicit better results.

Global Energy-Efficiency Comparison
The rates of energy efficiency (Energy consumption /GDP) for various countries are comparedin Fig. 3, and Japan ranks among the top in the world. The achievement of such higher energysaving levels largely attributed to the emergence of more energy-efficient technologies, not only in
the industrial sector but also in commercial as well as in residential fields.
6.1
3.5 3.7

3.9

World

Russia

ME

India

2.0

ThailandChina

Non OECD

Canada3.0
2.6 2.7

IndonesiaUSA

1.9 2.0

Korea

OECD

EU27

Australia

Japan

FranceUK

1.0 1.0 1.1 1.1 1.2 1.2
0.6 0.9
Germany

7
6
5
4
3
2
1
0

Fig. 3 Energy Efficiency (Primary Energy Consumption (toe) /GDP (US$)) 2017FY
Source: METI ANRE Energy White Paper 2023

One of the noteworthy initiatives introduced in Japan to rise energy efficiencies is the so-called “Top
Runner Program”, which has successfully led to improve energy efficiencies of various equipment.
This Program was introduced in 1998 by revising the Energy Conservation Law and was intended
to boost energy efficiency in the fields of transportation (vehicles) and home appliances. Under thisscheme, the efficiency target is set to exceed the performance in the most efficient product mode
within a given number of years (from three to ten, depending on the circumstances and categories).
Originally, 11 product categories were nominated (passenger vehicles, air conditioners, electric
refrigerators, lighting, TV sets, etc.), and gradually expanded to others. As of 2023, 32 categories
are covered, including thermal insulating materials, insulation sashes and multi-layered glazing forhouses and buildings.
The categories are chosen based on the following criteria:
1. Products used for daily life.
2. Products with high energy consumption.
3. Products need to increase energy efficiency.
When the categorized products achieve their target efficiency, accredited Top Runner Labels areissued, and the manufacturers can be attached on their products under the law. This labelling helps(environmentally aware) customers select products and incentivizes producers to develop moreenergy-efficient products.
Consequently, efficiencies of passenger vehicles, air conditioners and electric refrigerators were
improved over 20% by the Program.

APF (Annual Performance Factor)

Image of Eﬃciency Improvement(Air Conditioner)
APF: Scale for measuring eﬃciency of the productTarget Level

Highest APF
at the baseyear

Base year

Target year

Fig. 4 Concept of the Top Runner Program
Source: METI ANRE Energy-saving website

Based on these activities, energy conservation has been improved and GHG (CO2) has been
decreased in Japan, as shown in the following figure (Fig. 5). It is analyzed that energy conservationis one of the main factors to lower CO2. For example, during the period of 2013-2019, a reduction in
GHGs of around 6% was achieved through the Top Runner Program, a figure which is set to rise toaround 8% by 2030. **:Meeting material data of the 31st Energy Efficiency and Conservation Subcommittee (March 232021), Committee on Energy Efficiency and Renewable Energy, Advisory Committee for Natural
Resources and Energy, METI

Trends in GHG emissions (FY2020)
1,400
1,300
1,200
1,100

(Mt CO2 eq.)

1,000
900
800

Reduction target for FY2030
Compared to FY2013 : -46.0%*

700
600
500

NF3

400

SF6

300

PFCs

200

HFCs

100
!""0!

1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020

N2O
CH4
CO2

(FY)
*Reference: The Plan for Global Warming Countermeasures

Fig. 5 GHG emissions trend (FY2020)
Source: National Institute for Environmental Studies,Japan’s National Greenhouse Gas Emissions in Fiscal Year 2020 (Final Figures) report April 15,2022

Japan’s national target for GHGs reduction is -46% by FY2030 (compared to FY2013 levels) and it
states to make further endeavors toward -50% by that period and finally to achieve carbon neutrality
by 2050. To meet the goals, stronger policies and measures are introduced.
In 2021 the 6th Strategic Energy Plan which was formulated and in the Plan the target of the energy
saving amount was intensified to set to 62 million kiloliters of oil equivalent. It is to be achieved
through the utmost efforts to reduce energy consumption and improve efficiencies in all sectors.
Further, the Energy Conservation Law was revised and enacted in April 2023. The main points of
the revision were: “revision of the definition of energy” “rationalization of energy use” “conversion
to non-fossil energy” and “optimization of electricity demand”, and non-fossil energy was to be
dealt in the rationalization of energy use, and the definition of energy was expanded by the revision.
Collaborations between countries are important as the carbon neutrality is a goal for the entire
world. Japan is going to contribute to the net zero of other countries in particular in Asian region,
where it is characterized by uneven distribution of renewable energy, underdeveloped grids withmany islands, limited nuclear power generation, and increasing population and energy demand.
To this end, Japanese government has launched the initiative: Asian Zero Emission Community

(AZEC) since 2021 to encourage cleaner energy transition and accomplish carbon neutrality of Asia
in cooperation with other Asian countries. Now various specific activities and projects have been
initiated based on this AZEC initiative, including both immediate and future technologies andmechanisms (energy conservation, renewable energy, biomass, ammonia, hydrogen, CCUS, andfinance and credit systems).

Energy-Efficiency Topics in Industrial Sector: Effective Utilization of Thermal Energy
In the Japanese industrial sector, various efficient technologies have been developed to utilize thermalenergy effectively, such as cogeneration, recovery of wasted thermal energy, high-efficiency furnaces
and boilers, and facilities to use steam effectively. In industrial processes consuming fuel and thermalenergy, given the considerable wasted energy, there is great potential for energy saving by leveraging
technologies to reduce or recover wasted thermal energy. Such technologies usually also elicit otherbenefits, such as a cleaner environment and rapid progress has been made in their implementation.
They can be applied to refine existing processes, as well as for newly built plants.
The features of cogeneration and its prevalence in Japan are shown in Figs. 6 & 7.

Cogeneration

Difficult-to-use
waste heat
ThermalenergyGas plant

Pipeline

Cogeneration

Electric
energyArea of demand
Electric energy 45-20%
Thermal energy 30-60%

Difficult-to-use waste heat 20-25%

Total efficiency 75-80%

Difficult-to-use waste heat 56%

Conventional system

Total efficiency 40%
Total loss 4%(Internal loss, transmission loss, etc.)
Electric energy 40%
Difficult-to-use
waste heat

Thermal power plant

Power transmission line

Area of demand

Electric
energyTotal loss

LHV standard

Fig. 6 Features of Cogeneration
Source: Advanced Cogeneration and Energy Utilization Center Japan (A.C.E.J) Website

(104kW)
1,500

1,332
Commercial

1,250

1,064

Industrial
908

1,000
750

581
355

500
205
250

70

0
1987 1990

1995

2000

2005

2010

2015

2020 (FY)

Fig. 7 Trend on Cogeneration installation in Japan
Source: METI ANRE Energy White Paper 2022

Energy-Efficiency Topics in Commercial and Residential Sectors
As already seen in Fig. 1, Japanese energy consumption has steeply risen since mid-1980s incommercial and residential sectors, due to growing living standards across the country as well as
commercial activities deployed in new sectors. The “Top Runner Program” was crucial to reducing
energy consumption in these sectors, as highly energy-efficient electrical home appliances and officedevices were developed and supplied to the domestic market. Thanks to these effects, growth ofenergy consumption in these sectors has been curbed for the past 15 years or so.
One key niche within these sectors is highly refined thermal transfer technology for heating,cooling and refrigerating. It is sometimes referred to as “heat-pump” technology because it involves
the transfer of heat energy and it has been applied to air conditioners, refrigerators, water heaters
and other devices; combining not only thermal transfer technology but also highly efficient control
technology based on inverter technology and environmental parameters, including temperature.
This heat-pump technology has prevailed widely in Japan.

(kWh)
1,600
1,400
1,200
Air-Conditioner

1,000
800
600
400

Refrigerator

TV(Braun tube type)2000

TV(LED type)
1995

2000

2005

2010

2015

2021 (FY)

Fig. 8 Average Electricity Consumption of Air-Conditioner and Other Home Appliances
Source: METI ANRE Energy White Paper 2023
Note:
Air-conditioner; Wall mounted cooling and heating units with the cooling capacity of a 2.8kW-class model.
Simple average values for representative models of energy conserving-type products
Refrigerator; 400-liter type (average 401-500 liters).
Yearly electricity consumption (measurement method revised in 2015 (JIS))LED TV; 32-inch, yearly electricity consumption

Eﬃciency ratings of available AC units by regional metric
Last updated 16 Oct 2020

IEA、The Future of Cooling, Eﬃciency ratings of available AC units by regional metric、2020/10/16
Fig. 9 Comparison of energy efficiency values of air conditioners by area and countries
Source: 4th Working Group on Judgment Standards for Air Conditioners and Electric Hot Water Appliances, Energy
Conservation Subcommittee, Energy Conservation and New Energy Subcommittee, General Resources Energy
Investigation Committee Oct. 18, 2021

In Japan, for air conditioners (all-season types: for cooling and heating) are concerned, COP(Coefficient of Performance) is one of the indices for measuring product efficiency, as well as the APF(Annual Performance Factor). Both COP and APF indicate the cooling/heating capacity (kW) values
per 1 kW of power consumption. However, the latter takes power consumption at the rated time
into account as well as load conditions such as buildings where air conditioners are used, the outside
air temperature while cooling or heating and the efficiency of the air-conditioner depending on
the differing capacities of inverter devices. This makes it possible to evaluate energy consumption
performance regardless of utilization. There are many scales to evaluate performance of air
conditioners, but APF is being introduced in foreign countries as a common benchmark to measureefficiency. The level of energy efficiency values for air conditioners in Japan is about same level as
Europe area (top level), although differences in measurement conditions make direct comparisonsdifficult. (Fig. 9)

Energy-Efficiency Topics in Commercial and Residential Sectors:
Zero-Energy Buildings (ZEBs)
When thinking about the world’s energy use, buildings, particularly in urban areas, are consuming
vast amounts of energy, hence there is a need to focus on this sector. The lifespan of buildings isanother aspect to consider. Buildings generally stand for 40 to 100 years or more, meaning that abuilding constructed this year will likely remain in use, even at least in 2060. Therefore, actions
should be taken right now for the future and then the concept of ZEB ((net) Zero Energy Building)that energy input and output for buildings should be ultimately equal by introducing energy efficientand renewable equipment has been emerged.
Before 2015, there were few Zero Energy Buildings in Japan and most were still experimental or
prototypes. But at the end of 2015, the concept of ZEB was defined and future measures for promoting
it were revealed by the ZEB Roadmap Examination Committee sponsored by the Ministry of the
Economy, Trade, and Industry (METI), then the ZEB was receiving considerable attention.
The Japanese government (Japan’s Strategic Energy Plan adopted at the Cabinet Council in April2014) set the following goals to realize and facilitate ZEB:-Realize ZEB in newly constructed public buildings by 2020 (This target has been achieved)-Realize ZEB in newly built public and private buildings by 2030 on total cumulative average
To achieve the above, the ZEB Roadmap Examination Committee has started to examine (1) how
ZEB is defined and evaluated, (2) the feasibility, and (3) measures to promote ZEB. and developed
additional definitions for ZEB as follows:(Signiﬁcant energy saving,
more than 50% compared
to benchmark)(Net energy saving not 100%but exceeding ZEB Ready)Energy savings of at least 50, 75, or 100% earn ZEB Ready, Nearly ZEB, and (net) ZEB statusaccordingly.

In Japan, the definition of “ZEB oriented” was added to the ZEB series for buildings with 10,000
sq. meters in 2019. And in ASEAN, the ZEB Ready Award has been added in the ASEAN EnergyAwards since the same year for disseminating ZEB among ASEAN member states.
Now is the time to promote ZEB in every country and reduce CO2 emissions dramatically to
mitigate climate change. And to disseminate ZEB in each country, policies and supporting mechanisms
promoting ZEB are essential. To support policies and efforts to facilitate measures for each country,
TS23674, the technical specification of ISO (International Organization for Standardization), waspublished in September 2021, the title of which is “Methodology for achieving nonresidential zeroenergy buildings (ZEBs).”
In Malaysia, a guiding design document based on TS23764 is already under development, andcertification on ZEB has also been initiated, although a voluntary basis. And it is no longer justtheory, but actual demonstration projects have been started to convert existing buildings to ZEB.
In addition, the Philippines, Vietnam, and other countries have also begun their ZEB initiatives,and it is becoming a major trend in the building industry in Asia.

Roadmap for Worldwide Utilization
Highly developed energy efficiency and renewable energy technologies can bring considerable
advantages to save energy. Currently, international efforts and activities have been made, basedon prevailing energy-efficient and renewable energy technologies. The purpose of this booklet isto help disseminate highly developed technologies in area of energy efficiency, renewable energy
and decarbonization by showcasing relevant Japanese products & technologies and explaining theirfeatures and effects.
The products and technologies are listed in nine categories: “Factory,” “Industries,” “Office,
Building”, “Residence”, “Construction, Transportation & Logistic”, “Power Generation &Distribution”, “Renewable Energy & Storage Battery”, “Energy Solution Service” and “Award
Winning Technologies (Best Practices)”. Also noted is the fact that all technologies in this book areenvironmentally friendly, given scope to lower energy consumption and (sometimes) improve theenvironment directly. Moreover, the Japanese technologies in this booklet are also characterized ashaving “quality” and “durability,” which achieve lifetime impacts in the area of energy efficiency.
This booklet also outlines the contact points which help when studying feasibility and planning foradaptation.
The booklet also references companies and associations capable of integrated realization via thecited technologies or with scope to consult on overall energy reduction planning, basic designs ofvarious plants or renovating for energy efficiency and renewable energy in the context of industrial
estates. Since the Paris Agreement came into force, global nations have established greenhouse gas
reduction targets and launched full-scale efforts toward net zero carbon.
To achieve this globally, it is crucial to ensure the penetration and take-up of various tried andtested technologies, including energy saving and renewable energies, across the board worldwide.
Amid growing global interest in the UN Sustainable Developing Goals (SDGs), Japanese companies
are expected to continue actively engaging in climate change and carbon neutral measures andstriving to expand various advanced technologies and products accumulated to date that will help
save more energy and promote renewable energies and decarbonization to the rest of the world.
It is our hope that this booklet will help disseminate and leverage sophisticated technologies in
the areas of energy efficiency, renewable energy and decarbonization throughout the globe.
(Written by JASE-W)