［ Energy Management System ］

Yokohama Smart City Project( YSCP)
Keywords

Smart grid, EMS, Demand prediction, Optimal control, Demand response

Abstract

The Energy Management System (EMS) is a system that plays an importantrole in building a smart grid. We joined the Yokohama Smart City Project (YSCP)
for the development and veriﬁcation testing of the smart EMS. For Yokohama
World Porters, we built a smart energy system that combines smart Building
Energy Management System (BEMS) and distributed energy resources. Current
results show that the introduction of the smart energy system reduce CO2 emission by approximately 20%. When the master system requires the demand response, we are able to reduce incoming power at the rate of about 40% bymanaging the responses of energy supply facilities and by reducing load witheffective system operation. Going forward, by drawing on the technologies andknow-hows developed through this demonstration project, we will develop businesses of the smart EMS which makes optimal control of distributed energy
resources such as Combined Heat and Power systems and energy storage
systems.

1 Preface
The smart grid is getting increased attention
against the background of such factors as demandsof greenhouse effect gas emission reduction, energy saving, and impacts of the big earthquake inJapan. There is also rising awareness on energy
saving and a serious review on the BusinessContinuity Plan (BCP) and also the necessity for
power system stabilization against the increased
introduction of renewable energy resources. The
smart grid is intended to make an integrated operation and management of information on powertransmission and distribution power network andpower consumerʼs demands. This system is madeby actively using information and a communications
network. The Energy Management System (EMS),
plays a vital role in building a smart grid.
As for our programs for the Yokohama Smart
City Project (YSCP), we conducted veriﬁcation
tests on the smart grid regarding the improvement of the efﬁciency of energy use on the energy
consumer side as well as the handling of the
Demand Response (DR). Drawing on the gained
technical knowledge and know-hows developed
through this demonstrative project, we are developing

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Hironori Shinba,
Tomoaki Hirashima,
Yuji Hori,
Takashi Uyama

MEIDEN REVIEW Series No.169 2017 No.1

EMS businesses.
This paper introduces our programs for the
YSCP and business development for EMS.

2 Our Program for the YSCPThe YSCP is a project selected in 2010 by the
Ministry of Economy, Trade and Industry (METI) as
an area for “Next-Generation Energy and Social
System Veriﬁcation.” It is intended to promote system introduction and veriﬁcation for balance optimization of energy demands and supply in an existing
urban area with buildings such as homes and businesses. As a key member company of the YSCP,
we joined the YSCP and supplied a smart Building
Energy Management System (smart BEMS) to
Yokohama World Porters (“YWP”), a smart Factory Energy Management System (smart FEMS)
to Yokohama Works of the Sumitomo ElectricIndustries, Ltd., and a demand balancing energy
storage system to the annexed site of Tsunashima
Substation of Tokyo Electric Power Corporation. A
veriﬁcation test program was carried out there. An
outline of the veriﬁcation program and the results ofthe veriﬁcation test program at YWP are described
below.

Integrated control forcomplex energy system

2.1 Purpose of Veriﬁcation Test Program
According to the request of the Community
Energy Management System (CEMS) or such an
upstream master system, the smart grid has to provide an arrangement so that energy consumers canactively regulate the power demand. In such a case,compliance decisions based on economic rationality are indispensable. Even in regular energy management, economics and efﬁciency are the basic
requirements and assurance of convenience forenergy consumers is also important. In this veriﬁcation test program, it aimed to build a new energy
system to cope with DR and more efﬁcient DR energy use by best utilizing energy supply facilities suchas distributed energy resources and energy storage
systems installed on energy consumer premises.

Master system

Photovoltaic
power system

Smart
BEMS

Interlinking

Heat load
Power load
Lithium ion storage
battery system

Hot and

Hot waterchilled water
absorption type

Power
Waste
hot
water

Grid power
Incoming
substation
facilityGas
Town gas

EV charging station

2.2 Outline of Veriﬁcation
YWP (total ﬂoor space: approx. 100,000m2), isa large-scale commercial facility located in Minato
Mirai 21. We delivered to this facility two smart
BEMSs and a stationary large-scale lithium ion storage battery system (which was produced under ajoint project with NEC Corporation). Using thesesystems, we established a smart energy system
combining the existing Combined Heat and Powersystem (CHP). Fig. 1 shows the demonstrative system for YWP.
The smart BEMS is intended to realize proper
energy management ﬂexibility under the various situations and conditions including DR. This includes
its role for master system as an information andcommunication terminal. For this goal, the smart
function was added on top of the conventional monitor and control functions and visualization function.
Fig. 2 shows the functional Conﬁguration of the
EMS.
The smart function is composed of functions
such as energy demand prediction, optimal control
of energy supply, and a supporting function for BCP.
The energy demand prediction is used to predictheat and power demands on the next day based on
past demand data and meteorological data. The
function of optimal control of energy supply is used
to minimize energy costs and environmental impact
costs by making an optimal management plan andautomatic control of energy supply equipment
based on predicted demands. In regard to the DR
request from a master system, a management planis made with due consideration to the incentive unit
price. Then the DR acceptance is decided. Fig. 3

Waste heatrecoveryabsorption typeFig. 1

CHP

Demonstrative System for YWP

The smart BEMS and lithium ion storage battery systems wereintroduced to YWP for smart energy system building.

Smart functions
・Energy demand prediction
・Optimal control of energy supply
・Energy BCP planning support＋
Monitor and control functions

Visualization functions

・Power monitor and control
・Air conditioner monitor andcontrol・Trend analysis
・Report・Energy analysis
・Energy consumption monitor
・Establishment of energy saving
evaluation report
・Facility ledger management

Fig. 2Functional Configuration of the EMS

In addition to conventional functions of monitor, control, andvisualization, the smart BEMS is provided with smart functions.

shows image of the optimal control for energy supply. If there is any discrepancy between the demandprediction value and actual value, there is a function
to smart EMS auto-re-plan after automatically correcting the demand prediction value.
The energy BCP response function supports
management of distributed energy resources inemergency case such as a power outage of thereceiving power. We can customize according toconsumer power requirements and facility conﬁguration at each case.
In this veriﬁcation test program, the effectiveness evaluation of this system were conducted by
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Control andmanagement

Energy demandprediction

Management
data gathering

Predicted Predicted
power
heat
demand demand

Deciding
the plan
updating

Deciding theoperational
conditions

Operation plan

Operation
patternfor eachfacility

Amount ofcontrol

Condition
setting

Fig. 3DR
requestLoadoutputvalue

Run/Stop
outputcommandImage of Optimal Control for Energy Supply

0

Fig. 4

Plan
value

Actual
value

3

6

9

12
Time

15

18

21

Example of Graph for Optimal Energy Supply Plan

Based on demand prediction, the system drafts an optimal operation plan for energy supply facilities and makes automatic control. As a result, we aim to reduce both the energy cost and environmental cost.

By the optimal energy supply control, effective use of waste heatfrom CHP can be arranged and efﬁcient energy management
was realized.

building and operating a smart energy system in
YWP.

optimal energy supply plan. This is an operation
plan for the optimal integrated control by the smart
BEMSs for the existing CHP and energy storage
system. The CHP system was designed to makeeffective use of waste heat. In addition, the energy
storage system is used to perform a load shift operation making full use of the difference in electricity
unit prices between nighttime and daytime.
Before implementation of the smart energy
system, the operation of the CHP system wasstopped from 8:30 to 9:30 to prevent reverse power
ﬂow although waste heat recovery of the CHP canbe expected during this time frame. When an energy power storage system was combined withcharging control, however, itʼs possible to perform a
rated capacity CHP operation from 9:00 to 9:30. As
a result, more efﬁcient energy management was
realized.

2.3 Test Items and Veriﬁcation Schedule
Major test items and veriﬁcation schedule areshown below.
( 1) Building a smart energy system (Fiscal 2011)
Two BEMS and a stationary large-scale lithium
ion storage battery system (250kWh) were introduced to this veriﬁcation site. We constructed asmart energy system in combination with the existing CHP system.
( 2 ) Veriﬁcation of optimal control for energy supply(Fiscal 2012 to 2014)
By performing the smart BEMSʼs, optimal control on the energy supply facilities CHP system andenergy storage system, we veriﬁed the effect ofimprovement of energy use.
( 3 ) Veriﬁcation of DR by energy supply facility(Fiscal 2012 to 2014)
Against the DR requests from a master system, automated DR veriﬁcation tests were carriedout by using an adjustment power margin in theexisting CHP system and energy storage system.
( 4 ) Veriﬁcation test program of DR for load reduction (Fiscal 2013 to 2014)
In addition to DR from energy supply facilities,
DR veriﬁcation tests were conducted for load reduction by operation.

2.4 Result of the Veriﬁcation
2.4.1 Veriﬁcation for the Improvement ofEnergy Use Efﬁciency in Facilities
Fig. 4 shows an example of a graph for the04

Heat source
LiB
CHP2
CHP1
Grid power

Quantity of energy consumption

Operation plan

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2.4.2 Veriﬁcation of Automated DR in Energy
Supply Facilities (Wintertime)
Fig. 5 shows an example of a DR graph forenergy supply facility in wintertime. Based on the
aforementioned optimal operation pattern in facilities, this graph shows the results of DR veriﬁcation
tests in wintertime. The outline of DR features in thiscase is as described below.
( 1) DR class: Peak Time Rebate (PTR)( 2 ) Time frame for DR: 17:00 to 20:00( 3 ) DR incentive unit price: ￥10/kWh
According to the plan after the reception of DR
information, the second CHP system was operated
in the DR time frame and both systems maintained
rated operation. This program controlled receiving
power. In addition, the discharge time frame of theHeat source
LiB

Grid power
Reduction rate

5.0
0.0

6

9

12
Time

15

18

21

－5.0

Example of DR Graph for Energy Supply Facility
in Wintertime

The second CHP system is operated in the DR time frame andtwo CHP systems are running at rated operation. In this manner,
we aim to reduce receiving power.

energy storage system was shifted to the DR timeframe for further reduction of incoming power. It wasconsidered that these time frames of operation had
been inefﬁcient unless a DR request was introduced. The economic rationality is, however,ensured by taking into account the incentive bynight and day unit price differences.

2.4.3 Veriﬁcation Test Program of Load Reduction by DR during Operation (Wintertime)
Fig. 6 shows an example of a DR graph inwintertime by load operation. In winter 2013, we carried out DR veriﬁcation test program of “load reduction by operation” in addition to tests of DR fromenergy supply equipment. An outline of the DR tests
in this case is as described below.
( 1) DR class: Capacity Commitment Program (CCP)
for negawatt power bidding by REP (see below (3).)( 2 ) Time frame for DR: 17:00 to 20:00( 3 ) DR incentive unit price: ￥30, ￥30, ￥30, ￥30,
￥10, ￥10/kWh (rate change in every 30min after
17:00)
According to the plan after receiving DR information, the second CHP system was put into operation in the DR time frame and both systems weremade to maintain rated operation. In addition, thedischarge time frame of the energy storage system
was shifted to the DR time frame. Because of theintroduction of incentive unit prices, economic rationality was evaluated and the operation plan was
updated accordingly. The original plan was basedon the plan before receiving DR information.
Primarily, Retail Energy Provider (REP) bidding was

Average reduction rate:
44.4% (plan)Plan
beforeDR info
reception

55.0
45.0
35.0

Plan
after
DR info
reception

25.0
15.0
5.0

0

3

6

9

12
Time

15

18

21

－5.0

Example of DR Graph in Wintertime by Load
Operation

Fig. 6

In addition to DR application by energy supply facilities, DRapplication by load operation was additionally carried out andfurther reduction of receiving power was realized.

Heat source
LiB
Quantity of energy consumption

3

Quantity of energy consumption

15.0
Average reduction rate:
27.3% (plan)0

Fig. 525.0

Receiving power reduction rate
under DR control (%)

Quantity of energy consumption

35.0

Plan
after
DR info
reception

Grid power
Reduction rate
DR time frame

DR time framePlanbeforeDR info
reception

CHP2
CHP1

Receiving power reduction rate
under DR control (%)

CHP2
CHP1

Grid power
Reduction rate

DR time frame

65.0
55.0

Plan
beforeDR info
reception

45.0

Plan
after
DR info
reception

35.0
25.0
15.0
5.0

Average reduction rate: 13.9% (plan)0

Fig. 7

CHP2
CHP1

3

6

9

12
Time

15

18

21

Receiving power reduction rate
under DR control (%)

Heat source
LiB

－5.0

Example of DR Graph in Summertime by Load
Operation

Since energy supply equipment in this veriﬁcation site has no
margin for control in the DR time frame in summer, DR application was conducted only by load reduction through load
operation.

concluded so that the unit price provided by REP
would not give rise to any economic losses. Afterthe tests, the unit price was considered to be proper.
Since the actual energy operation in the YWP
is different from the case shown in Fig. 5, it is impossible to make comparison between both cases.
According to the plan, however, the quantity ofreceiving power is estimated to be reduced on average by 44.4% during the DR time frame.

2.4.4 Veriﬁcation Test Program of Load Reduction by DR during Operation (Summertime)
Fig. 7 shows an example of a DR graph insummertime by load operation. Similarly, as for the
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case in winter 2013, we carried out DR veriﬁcation
test program on “load reduction by operation” inaddition to the tests of DR from energy supply
equipment. An outline of DR tests in this case is as
described below.
( 1) DR class: CCP for negawatt power bidding ofREP( 2 ) Time frame for DR: 13:00 to 16:00( 3 ) DR incentive unit price: ￥50, 50, 50, 50, 50,
50/kWh (in the unit of 30min from 13:00)
According to the plan before and after the
reception of DR information, there is no differencein the operation plan between CHP and energy storage system in the DR time frame. Since the initial
regular operation of CHP, the plan was intended tooperate two CHP systems in the DR time frame andthere was no more margin for control as the energy
storage system was also programmed to discharge
power at the peak time. Since the DR time frame
and the peak time frame were overlapped, there
was no margin for control as a result.
Power demand in the plan after the receptionof DR information is indicated after deducting thesubtraction of the load reduction by operation. This
fact is expressed in the form of reduction of receiving power. As the results, the quantity of receiving
power is suppressed on average by 13.9% during
the DR time frame.

2.4.5 Summary of Veriﬁcation Test Results
We conﬁrmed that adequate management ofenergy supply facilities can be accomplished underintegrated control by the smart BEMS and the energy use efﬁciency is higher than that of conventional
control systems. Based on the result of control on
the CHP and energy storage system, the evaluation
concluded that we will be able to realize the reduction of CO2 emission by approximately 20%. This isalso beneﬁtted by the introduction of the BEMS. In
addition, in Fiscal 2014, the control span was
reduced to a shorter period so that our approach toa higher efﬁcient energy use was advanced. We
could, thus, realize more delicate control and higher
efﬁcient energy use.
In regard to the DR request from a mastersystem, operation checks were carried out on theautomated DR function that is in response to the
incentive-contained DR menu of the PTR and CCP.
As a result, we conﬁrmed its soundness and adequacy. In these veriﬁcation tests, a sequence of
operations, such as demand control in regard to
DR, data exchange, authentication judgment, and

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operation plan updating and control upon receptionof a response, were completely automated and DR
were given without inﬂuencing the load. At the timeof DR veriﬁcation tests in winter, the reduction ofreceiving power for 25% to 30% on average wasrealized by making adequate control of existing
CHP systems in the DR time frame. Further, load
reduction by energy storage system control andoperation was combined to increase the amount of
power reduction. For DR veriﬁcation test in summertime, there was no control margin in CHP and power
storage system, there was no advantage from theDR system. Despite such difﬁculties, however, we
could attain the reduction of receiving power on
average by about 10% as a result of load reduction
by operation while the DR system was used. When
the DR effect of receiving power reduction by wintertime is compared with that by summertime, the former case shows a greater effect. The records at
operation in this veriﬁcation site show that the DR
system can offer a sufﬁcient control margin in
wintertime.
According to industry trends to promote
OpenADR2.0b, (an internal standard for the DRinterface) in Fiscal 2014, we performed DR veriﬁcation test on communication between a master system including “Demand Response Automation Server(DRAS)” and the smart BEMS. We conﬁrmed thatthe DR system was effective at a practical management level even in such an application case conforming to the communication protocol.

3 Business Development in the Future
We have been promoting business development in the ﬁeld of smart energy system. We introduce the smart BEMS for hospitals and universities.
Drawing on our knowledge, techniques, andoperation know-hows developed through the YSCP
veriﬁcation test program, we will continue to improve
the EMS functions in order to increase our supply tobusinesses like hospitals and industrial factory facilities. At the time of proposal to the customer, weinvestigate for optimal facility conﬁguration (kW)and optimal facility management (kWh) based on
customerʼs proﬁle and propose the effect of energy
cost reduction and payback period (year). We will
also offer a comprehensive proposal in regard to reduction of CO2 emission, maintenance efﬁciency,
more speciﬁc BCP planning and its contribution tosociety.

This system is applicable to wide-area energy
sharing by the same energy user like energy delivery over its own transmission line or energy delivery generated by an in-house energy resource
over a transmission line of an electric power company. This was made possible by electricity market
deregulation in Japan. In addition, it can be applied
to optimal management of heat and power by REP
and regional heat supply systems. We will continue
to develop and customize each application.
In addition, electricity market deregulation in
Japan will produce new markets such as supporting
service for a new energy contract scheme, a system
for new REPs, virtual power plants, and ancillary
services. We will also continue to make systemapplication development based on proposals ofsystems and services in response to new businessmodels.

4 Postscript
In the near future, there will be a more substantial introduction of smart grids along with the adventof electricity market deregulation and more introduction of renewable energy resources. We consider that our smart BEMS and smart FEMS developedin the YSCP can be regarded as our basic systems
for smart grid building. We will contribute to a sustainable society through further functional improvements and system extensions.
・All product and company names mentioned in this paper are
the trademarks and/or service marks of their respective owners.

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