Utilizing ICT to Stabilize Energy Use— Comprehensive optimization of the entire factory through visualization —Harutaka Hokahara

Power-Distribution&Energy-Saving Solution Sect., Marketing Dept.
Fukuyama Works, Mitsubishi Electric Corporation

1. Introduction

Concern about countermeasures against global warming
is growing globally, and many countries are moving towardachieving carbon neutrality in 2050. In October 2020, Japan alsodeclared that it aims to achieve carbon neutrality in 2050. As amedium-term goal before 2050, Japan also announced that it aims
to reduce greenhouse-gas emissions in 2030 by 46% compared to2013 levels and that it will further strive to reach an even higher
reduction of 50%. Moreover, fossil fuels (mainly oil, coal, andnatural gas) account for approximately 90% of Japan’s primaryenergy supply (as of 2020), and most of Japan’s supply of mineral
resources (i.e., raw materials) relies on overseas sources (accordingto the Ministry of Economy, Trade and Industry, Agency for
Natural Resources and Energy, Energy White Paper 2022).
To achieve carbon neutrality and stabilize energy use, it isnecessary to further promote energy conservation in the future.
In recent years, it has become essential to promote not only
the conventional rationalization of energy use but also further
energy conservation through (i) energy management that considers
the balance between electricity supply and demand and (ii)
implementation of “factory energy-management systems” (FEMS)
that utilize the Internet of Things (IoT).
At Fukuyama Works, we have deployed a system thatincorporates part of a concept called “e-F@ctory” (our IoTtechnology) as a FEMS to implement energy managementin the factory. The efforts that Fukuyama Works has been
comprehensively undertaking to optimize energy saving in theentire factory using FEMS are introduced hereafter.

2．Mitsubishi FA integrated solution:
e-F@ctory

As Mitsubishi’s factory-automation (FA) integrated solution,
e-F@ctory visualizes sensor-collected data by linking FA andinformation technology (IT) in a way that reduces TCO (total costof ownership) by repeating the plan-do-check-act (PDCA) cycle
at several stages. At the Fukuyama Works, e-F@ctory is being
used to save energy and improve productivity (Figure 1). Thearchitecture of e-F@ctory is divided into three main layers: “shopfloor,” “IT system,” and a middle layer (“edge computing”) thatlinks them.
On the “shop floor” layer, FA-manufactured products such as
sequencers, various devices, and sensors, which are the brains ofproduction equipment, are connected by FA networks, and various

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data are collected in real time. The data are then seamlessly linked
to the IT system for analysis, and the analysis results are fed backfor utilization on the shop floor. However, data obtained on theshop-floor layer cannot be fully analyzed because it contains
special know-how, circumstances, and other causal relationshipsthat cannot be understood if sent directly to the IT system.
Therefore, primary processing, namely, edge computing, is needed
to associate causal relationships to the data and make the data
informative. One of the key features of e-F@ctory is that themiddle (edge-computing) layer between the FA and IT layers is
responsible for not only seamless linkage but also optimization of
the entire FEMS.
■ Figure 1: Conceptual diagram of e-F@ctory

3．Efforts concerning energy saving at
Fukuyama Works
3.1 Background of energy-saving activities
While energy-saving activities have been promoted to comply
with the Japan’s “Act on the Rational Use of Energy” (i.e., “EnergyConservation Act”), recently, companies are required to continueeven more long-term efforts to solve global environmental issues.
We have also positioned environmental contribution as animportant management issue and formulated “Environmental
Vision 2050” to take the initiative in solving environmental issues.
Under these circumstances, aiming to achieve virtually zeroCO2 emissions in 2050, we will respect international trends
toward the creation of a decarbonized society and promote thereduction of greenhouse-gas emissions throughout the entire
value chain—from design and development to raw material
procurement, manufacturing, sales, distribution, use, and disposal.
To achieve the goal, the Fukuyama Plant is promoting energy

conservation by replacing aging facilities with high-efficiency
equipment, using renewable energy sources such as solar-power
generation, and implementing EM (“energy-loss minimum”)
activities to detect and reduce energy loss in production activities
through the use of FEMS.
3.2 Overview of energy saving
The Fukuyama Works aims to both improve productivity andsave energy by utilizing control technology from the productionequipment field and measurement technology developed in thefield of power distribution and reception. The products that
we manufacture are circuit breakers, meters and gauges, smart
meters, uninterruptible power supplies (UPS), and energy-saving
support equipment, which is installed at various locations aroundthe factory and utilized in energy-saving activities throughvisualization of sensor data (Figure 2).
■ Figure 2: Overall diagram of the energy-management
system at Fukuyama Works

Our energy-saving activities are twofold. The first activity
is “target management” (i.e., “demand management”) that uses
measured energy usage to set and manage target values. As for thesecond activity, we set production lines as role models for energysaving activities. We then collect their production volumes andmeasure their energy consumptions and determine their specificconsumptions from that data. These activities are then constantly
managed by using specific consumption. Moreover, the automatic
assembly line for circuit breakers measures energy consumptionof each individual facility, collects the production volumes, andcorrelates production-related data (such as product quality, errors,and results) as an indicator for managing energy consumption.
Energy saving through specific consumption management
involves four steps: “measuring,” “visualizing,” “reducing,” and“managing.” When measuring energy consumption, it is important
not only to collect energy-use data on the shop floor but also tocollect data in conjunction with production information such as
production volume.
In the visualizing step, the measured energy and production
information is visualized by using IT, the data is analyzed, points
at which energy loss occurs are identified, and those points arehandled in the reducing step. In the reducing step, for example,
operations are improved by utilizing energy-saving drive products
such as inverters and high-efficiency motors, stopping idling ofequipment on standby, and optimizing the startup and shutdownof equipment.
In the managing step, energy usage and specific consumptionof lines and equipment are monitored in real time, and thoseactual values are managed so that they do not exceed the target
values. To improve in terms of productivity and energy saving,
four consecutive steps, “measuring”, “visualizing”, “reducing”, and“managing,” are repeated multiple times along with each PDCA
cycle.
Recently, focusing on five key points for energy saving(equipment-start-up time loss, equipment-shutdown time loss,
utility time loss, production intensity, and production-loss timeratio), we are utilizing one of our products, “EcoAdviser”, anenergy-saving analysis-and-diagnosis application equipped with
our AI technology, “Maisart” to extract notices of energy loss
automatically from data on power consumption and production
volume measured and collected at the transformer production line.
The insights that we gained from this process have led to energysaving improvements.
3.3	Energy saving through target management (demandmanagement)
Fukuyama Works received ISO14001 “EnvironmentalManagement System” certification in 1997, and we started
energy-saving activities from that time. Utilizing the ISO 14001
organizational structure, each department manages electricityconsumption targets to ensure that actual results do not exceed
the targets. The amount of electricity used at each location ismeasured by a measuring device at that location, and themeasurement information is transmitted to an energy-saving datacollection server (one of our products, EcoServerIII) via B/NETtransmission (a field network for power distribution and controlof equipment) for data collection. The web-server function ofEcoServer III connects to the Fukuyama Work’s network systemand discloses the collected data on the web server. In this way, we■ Figure 3: Energy-management system

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have created an environment in which workers can monitor theirenergy use (Figure 3).
As for management of power demand, electric-power pulses
supplied from transactional watt-hour meters of the electricity
utility providing our electricity are used, and the number of pulses
is imported into EcoServer III, which uses its demand-monitoring
function to monitor demand. When the demand reaches theenergy-saving level, the energy-saving level is sent as a “demandsignal” to AE-200J centralized air-conditioning controllers,
which send a “power-saving-operation signal” to inverter-type
air-conditioners installed in the factory and offices to achieve
automatic energy-saving operation (Figure 4).
■ Figure 4: Energy-saving control of air-conditioners basedon energy-saving level

In our five-story office building (General Administration
Building), where general affairs, sales, and design staff work,
electricity consumption for air-conditioning, lighting, officeautomation (OA), and outlet circuits on each floor is measured.
This measurement information is collected by EcoServerⅢ andcan be checked on the web, so it is possible to manage targets
based on the measurement data. Energy-conservation measurescover lighting and air-conditioning; as for the former, lights areturned off before the start of work and during lunch breaks. Asfor the latter, we are working to ensure “schedule management”(e.g., shutting down operations before and after work hours) and“temperature management” (28°C is the target for air conditioning
and 20°C is the target for heating). To avoid going back to theprevious energy-conservation (energy saving) measures, thecompliance status of the countermeasure-applied operations ischecked with the measurement data collected by EcoServer III(Figure 5).
3.4	Energy saving through production-intensity
management
Energy use on production lines increases in proportion withproduction volume. Managing energy usage only is insufficient
to determine whether energy is being used efficiently, so it isnecessary to manage trends in energy usage while comparing
it with production information. At the Fukuyama Works, welink production volume to energy consumption and practiceproduction-intensity management. On performing production-8

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■ Figure 5: Energy management of the office buildingintensity management, we construct energy-saving model lines bytargeting lines that are likely to be effective when improvements
are made. The targeted lines include lines that consume a lotof energy, lines that can be expected to be expanded laterally
after being improved, and lines with significantly fluctuatingproduction volume due to changes in types of products
manufactured. A case study of one of these energy-saving modellines, namely, a production line for printed circuit boards in ourelectronic-module factory, is introduced hereafter. An EcoServer
III, the above-described energy-saving data-collection server, isconnected to the line, measurement devices are installed at theswitchboards of the production line and used to measure theelectricity consumption of the entire line, and sensors are installed
along the production line and used to collect production figuresand visualize production intensity (Figure 6).
■ Figure 6: Energy-managementsystem for electronicmodule factory

By linking the amount of electricity used on the line with thenumber of products produced, the energy-management systemfor our electric-module factory (as shown in Figure 6) manages
specific consumption by using the amount of electricity consumed
to produce one product (kWh/item) as an index. In small group
activities, which are improvement activities undertaken at
production sites, we check the temporal fluctuations in production
intensity, analyze the factors that exaggerate the points along theline at which the production intensity exceeds the target value, anddiscover points at which production intensity can be reduced. Asshown in Figure 7, items for improvement were hidden at points
where specific consumption exceeded the target value, and specificconsumption was improved through small group improvement
activities.
■ Figure 7: Example of analysis using production intensity
graph

To reduce specific consumption, it is effective to improve andincrease productivity as well as to reduce energy consumption, andby promoting these activities in conjunction with improvement
activities at production sites, the efficiency of production lines
can be improved. By accumulating improvement activities toaddress the identified improvement points, we reduced production
intensity by 61% compared to before we implemented the smallgroup activities (Figure 8).

management for each line, only rough production information andenergy information was available, so it took a huge amount of timeand effort to analyze the factors that worsened the production
intensity. And it was difficult to identify which piece of equipmentin the line was making the production intensity worse (i.e.,increasing it).
In 2010, when the automatic-circuit-breaker assembly line wasupgraded, we introduced production-intensity management foreach piece of equipment comprising the line (as shown in Figure9). This upgrade allowed us to (i) identify the equipment that wascausing the energy-consumption rate to increase immediately and(ii) collect information on production, quality, and equipment
errors (short stoppages) from the sequencers used to control thatequipment. Then, by comparing the collected data with theproduction-intensity data, it is possible to analyze the causesof the increase in the production-intensity. As for the featuresof the energy-management system, energy consumption andproduction information for each unit comprising the production
line is measured. Data on energy consumption is collected andintegrated by EcoServer III, and production information collectedvia the sequencers is collected and integrated by EcoAdviser, anenergy-saving support application installed on MELIPC (ourindustrial computer).
■ Figure 9: System for collecting energy and productioninformation from automatic-circuit-breakerassembly line

■ Figure 8: Improvement effect through productionintensity management

Moreover, by building a system that visualizes energyand production information for each manufacturing facility,
we were able to make more detailed improvements in specificconsumption, improve productivity, and achieve optimal use ofenergy. In the above-mentioned case study (as shown in Figures
6 and 7), we implemented production-intensity management on aproduction line basis, and factors that worsened the consumption
rate and improvement measures were identified through small
group activities. However, in the case of production intensity

The collected data is displayed as energy and production
information on a dashboard, one of EcoAdviser’s functions, on alarge monitor that is set up on the shop floor, as shown in Figure
10, and the monitor is used to share information with the shopfloor workers. To manage productivity, a ranking of first-passyield by process and number of “pass” or “failed” products for eachprocess is displayed in a manner that makes it possible to identify
bottleneck processes easily. The number of equipment errors
and cycle time are also managed, so it is easy to link awarenessof processes that need to be improved to improvement actions.
As a result of daily improvement activities, production intensity(kW/unit) was reduced by approximately 30% (compared to 2012figure).
As for a recent initiative, on our transformer production line,
as shown in Figure 11, EcoAdviser, the energy-saving analysis anddiagnosis application equipped with our AI technology Maisart,

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9■ Figure 10: Dashboard
of EcoAdviser on the circuit-breaker automatic assembly line

is being used to measure and collect electricity consumption andproduction volume for each piece of equipment on the production
line, automatically diagnose energy loss, and make improvements
based on the insights gained from these measurements.
■ Figure 11: Energy-management system of production linefor transformers

First, from the preheating furnaces, pouring equipment, andcuring furnaces on the transformer production line, the curing
furnace with the highest electricity usage was selected as thetarget for improvement. As a step toward improvement, thegraph function of EcoAdviser is used to determine the electricity
usage of the furnaces from various graphs plotting (1) numberof products and energy by furnace, (2) production intensity byfurnace, (3) overall production intensity and vacancy rate of thefurnace, and (4) energy consumption by operating status as shownin Figure 12.

and (ii) power loss due to waiting for workpieces to be loaded.
These findings have enabled us to improve the efficiency of the
production line for transformers.
The “energ y-loss automatic-diagnosis function” ofEcoAdviser—which focuses on f ive key energ y-saving
perspectives (equipment-start-up-time loss, equipment-shutdowntime loss, utility time loss, production intensity, and productionloss time ratio)—is used to automatically extract “energy-loss
notices” from the data on amount of energy consumption andproduction volume for each curing furnace. We focused on twoof those perspectives, namely, equipment-start-up-time loss andproduction intensity, which are the most-common energy losses,
and proceeded to understand their current status we determined
and analyzed their status as explained hereafter.
As a countermeasure for equipment-start-up-time loss, as
shown in Figure 13, we found that the start-up time of thecuring furnace was earlier than the production start time. As for
production intensity, we found that among several curing furnaces,a particular furnace routinely showed about three-times-higher
consumption than that of the others. After checking the on-site
curing furnace in question, we found that hot air was leaking fromthe product-loading door, so we fixed that leak; consequently, wereduced CO2 emissions by approximately 50 tons per year.
■ Figure 13: Energy-loss diagnosis screen■ Figure 12: Graphs for energy-saving operation of curing
furnaces

4．Conclusion

A case study of a factory that uses FEMS to optimize energy
use comprehensively throughout the entire factory and reduceenergy consumption in the utility and production systems wasdescribed. We will continue our efforts as described in this casestudy to achieve the goal of carbon neutrality by 2050.
Analyzing the information obtained from the graphs revealed(i) a furnace with poor furnace efficiency (large vacancy rate)

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＊This article is only a case study of Fukuyama Works, which may
not necessarily be applicable to our overseas works.