Strategy

Chinese Taipei is surrounded by off-islands that require self-generating power supply. However, power instability, black-outs and high level of carbon emission have been the issues for these islands and waiting for better solution. Limited choices such as diesel generator (DG) or other isolated power supply units are used because of small-sized power system or the distance to better-equipped power provider. Meanwhile, the carbon emission from diesel generator or other independent power supply is also bring uncertainties and concerns not only because of the pollution but also the inefficiency of high cost from fuel transporting over long distance. Therefore, the importance of increasing the usage of renewable energy can’t be more emphasized. It reduces the fuel use, cuts down the carbon emission significantly and eases the burden from budget limits. To optimize the overall efficiency for even better quality in power supply and to further enhance the power stability, the integration of micro-grid technology comes in and works as the solution. As it works as the foundation, it extends the application for renewable energy and trims down the overall cost even more. Reliability, stability, high quality and financial sustainability all come in one place for future development and improvement for electricity supply for off-islands.

Innovativeness

Penghu County Government plans “Carbon-Free Island Demonstration Project – Planning and Designing.” The goal is to introduce the micro-grid system in Dongjiyu. The objectives include, increasing the use of renewable energy, reducing diesel power generation, enhancing the quality of power supply in off- islands and providing low-carbon power supply. The Project includes the use of power generation forecasting for energy scheduling, remote monitoring for load forecasting, and control system for three-phase equilibrium of AC power.

The Origin of This Innovative Technology

Power generation by renewable energy is dependent on weather, seasonal and day/night conditions, therefore, energy storage and back-up power are needed to stabilize power supply for microgrid in islands or remote regions. Meanwhile, due to the inherent intermittency of renewable energy, the power quality is inevitably affected when increased amount of renewable sources are connected to the grid, this means a real-time monitoring, control system and energy storage are therefore required to effectively dispatch and coordinate the distributed energy sources. The overall economic effectiveness of microgrid is critical to end-user market and wide adoption, accordingly, optimization of resource usage and provision of high quality power are important topics for microgrid development.

Proposed Technology

This application is specifically targeted to address the four microgrid issues – supply stability, power quality, economic effectiveness, and increased utilization and penetration of grid-tie renewable-based generation. Our team proposes a total solution, including microgrid design and evaluation, Smart microgrid Monitoring and Energy Management System (“Smart μ-MEMS”), the integration of Energy Storage System (ESS) and existing diesel engine power generator as a Hybrid Microgrid Solution (“Hybrid MS”).

The microgrid evaluation optimizes both sub-system and system configuration and operation requirements based on analysis from environmental and actual grid conditions. This covers the complete life-cycles of the renewable generation sources, other distributed generation and the energy storage solution deployed. Smart μ-MEMS effectively controls the scheduling of different renewable energy, other generations and energy storage systems by matching the needs of end-users. Based on real-time system operating status and information, coupled with requirements on power supply stability and power quality, Smart μ-MEMS optimizes resource allocation – both for regular use and emergency conditions. Hybrid MS, characterized by the combined Energy Storage System (ESS) and diesel generator, improves the power quality issues arising from high renewable energy penetration, PV power supply disruption or feeder lines congestion in urbanized settings.

Chung-Hsin Electric & Machinery Manufacturing Corporation (CHEM) has implemented the microgrid system project in conjunction with the Penghu County Government in Dongjiyu and implemented the project “Penghu Dongjiyu Microgrid Small Power Supply System (PDMS).” Hybrid MS is the core technology of the project. The framework of PDMS is as following:

 

Fig. 1 – The Framework of PDMS

Financial support and public-private partnership

Hybrid MS is the core technology of the project. The advantages are significant. The higher usage of renewable energy reduces the consumption of diesel fuel along with exhaust emission, especially CO₂. By cutting down the consumption of diesel fuel, it saves up to 48% of the cost not only for diesel generators operating but maintenance (diesel cost, delivery and maintenance charges). Meanwhile, high quality and stability of off-island electricity supply is then greatly enhanced via Smart μ-MEMS. For the moment, financial support and potential investors are keen to explore more possibilities because of the positive outcome generated from utilizing Hybrid MS. This is to say that financial investment along with the government’s focus on smart low-carbon power generating system, have transferred into steady and high-quality electricity use for local residents.  A win-win situation for the investors, business operator, government and the residence is therefore guaranteed.

Inspiration of Later or Subsequent cases

The project PDMS is currently part of the county’s low-carbon project. PDMS integrates with the existing diesel power-generating system for regular daily power usage and it effectively facilitates the solution on high cost-reduction on diesel power supply. PDMS also serves as independent electricity provider for domestic use needed from damages caused by climate changes.

Rural village, off-islands or rural none-grid terrain could extensively utilize renewable energy based on local environmental conditions to reduce CO₂ and other greenhouse gases and the dependence on fossil fuels. This project promotes the concept of “Smart-generating, Smart-storage and Smart-feeding.”

Fig. 2 – Smart-generating, Smart-storage and Smart-feeding

The Domain Knowledge Enlightened by this Policy

There are three main direct potential application of our proposed system for adoptions in Chinese Taipei’s grid, as shown in Fig. 3. For each potential application, the PDMS will provide performance data points and the associated economic feasibility aspects that cater to Chinese Taipei’s domestic needs, as illustrated clearly in table 1.

Fig. 3 – Three Main Direct Potential Applications for Adoptions in Chinese Taipei’s Grid

 

Table 1 – Three Application Scenarios

Three Application Scenarios	Direct User	Technology Areas	Economic Parameters
1. Direct connection to feeder-lines	Power System Operator (PSO)	System Specification for feeder line voltage control; Communication protocols	Cost and economic feasibility for corresponding auxiliary services offered
2. Direct couple to existing solar system	Intermittent Generation Sources (IGS) Owner	Response time; Accurate control	Operational cost and economic attractiveness in Chinese Taipei’s adoption
3. Direct connection on user’s end (Distribution)	Customer	System operational stability	Cost comparison with grid-supplied electricity in Chinese Taipei

 

Scenarios:

1. Direct grid connection (e.g. feeder-lines):

With the expected increasing in both the quantity and distribution of Intermittent Generation Sources (IGS) in Chinese Taipei, the Power System Operator (PSO) will need to enact comprehensive control schemes to manage the intermittent nature of such sources since the security and reliability of the power system is not compromised. Specifically, the associated specification requirement on the communication protocols and direct local voltage control are key technology application areas of interest.

2. Integrate via specific set-point of Intermittent Generation Sources/Aggregator:

The aggregated power output of all IGS from renewable sources like solar energy could be potentially modeled and treated as one pseudo generator, for the purpose of assigning regulation and spinning reserves costs. With controllable power output enabled by the hybrid microgrid technologies, coupled with Demand Response Mechanism, this can help further open up IGS players for direct participation of electricity market. The parameterization of response timing and coordination and control mechanisms are key technology application areas of interest, which will be verified and investigated through our PDMS.

3. Direct integration on end-users’ end:

The proposed system can be readily integrated on end-users’ ends (e.g. commercial and industrial facilities) and effectively increase the renewable power utilization and on-site distributed generation capacities, once the system operational stability is thoroughly established and gains market credence.

Transparent channel of public communication

CHEM is willing to share with APEC members in this successful experience. Currently, the information of PDMS is available via TSGIA (Taiwan Smart Grid Industry Association) and the operating data and needed information is also provided to INER (Institute of Nuclear Energy Research) for long-term information collection and research.

The project implementation results have been published in "The Development of Smart Grid Industry and Technology in Chinese Taipei 2016" by Taiwan Smart Grid Industry Association. Up until now, the system improvement is in on-going process, Penghu County Government will be later recommended to disclose the information on benefits and effectiveness along with facts and figures via online resource or the county’s websites.

The Policy

Using Smart μ-MEMS and the integration of Energy Storage System has increased the proportion of renewable energy sources and this satisfies the "Policy for Nuclear-Free Homelands” from Chinese Taipei government. The detail is as below,

Table 2 – New Energy Policy of Chinese Taipei Government

Spread Item	Targets in Year 2025
	Capacity (MW)	Power Generation (G.kWh)
Hydro Power	2,500	5.5
Wind Power
Onshore Wind Power Plant	12,000	3.0
Offshore Wind Power Plant	3,000	10.0
Solar Power Plant	20,000	20.0
Geothermal power generation	600	3.5
Biomass energy generation	1,200	8.0
Total	28,500	50.0
Estimated investment in construction costs	Approx. USD 89 Billion
Total Power Generation in Chinese Taipei	53,691	270.1
The proportion of renewable energy	53.1%	18.5%

Measure:

Power generation by renewable energy is dependent on weather, seasonal and day/night conditions, therefore, energy storage and back-up power are needed to stabilize power supply for microgrid in islands or remote regions. Meanwhile, due to the inherent intermittency of renewable energy, the power quality is inevitably affected when increased amount of renewable sources are connected to the grid, this means a real-time monitoring, control system and energy storage are therefore required to effectively dispatch and coordinate the distributed energy sources. The overall economic effectiveness of microgrid is critical to end-user market and wide adoption, accordingly, optimization of resource usage and provision of high quality power are important topics for microgrid development.

Practicability

Diesel generators are used in most of inhabited islands out from limited choices. Meanwhile, it has presented obstacles in power capacity and stability for development in tourism opportunities and management in a long run. Soon, optimization on solar energy, wind energy and other renewable energy recourses and forming diesel generating as the supporting role in combination in micro-grid will gradually reduce the dependence on diesel or other import fuels. This proactively facilitates the use of green energy, reduces the consumption or waste of fossil fuels, and lessens the greenhouse gas emission (for example, CO₂) for the future goal of “Low-Carbon Island” with our advantages in “Smart-generating, Smart-storage and Smart-feeding.”

Phase I – Effective measure

 

Smart Energy Management are designed and adopted for a smarter micro-grid with less environment impact and better life quality for domestic needs.

“Technology of DG and Solar Hybrid System”

1. This technology is to make DG (diesel generator), which serves as conventional choice for power supply, work as the base power supply, and to use it to integrate the benefits of the PV power system with ESS. This satisfies the domestic power needs from residents and increases the usage of renewable energy while reducing high cost in diesel usage and going further for the goal of low-carbon power supply.
2. Operating cost drops to 50% of the cost from the conventional choice as using solar energy effectively cuts down the high cost in diesel or other fuel supplement.
3. Power supply quality and stability are further strengthened because of the optimized power system, which includes the benefits from integration of smart micro-grid and the conventional choices.

“Intelligent Microgrid Control and Smart Energy Management”

1. Smart Energy Management System (SEMS) works as the platform of integration for information flow, data, power usage and live status from Inverter, MPPT and batteries. The management system uploads the data for power used and generated to cloud system for remote controlling.
2. SEMS manages power based on power source and power generation day and night. In daytime, it controls ESS to store the solar energy and manages the output via Inverter over microgrid for day-time usage. At times when the solar energy source is limited, SEMS continues to manage and allocate the power usage based on night-time needs.

Phase II – Effective measure

“Power SCADA System”

1. The Power SCADA System collects current PDMS information, calculates the information according to the updated information from users and generates the strategies of resource allocation for short, medium and long term goal. By the optimized strategy of resource allocation with the robust calculating result, the automation of scheduling and controlling of PDMS’s power generation and energy storage surely reduces the waste of fuel or diesel and effectively lowers the cost in DG’s operating and maintenance.
2. In order to provide continuous power supply (for Marine National Park Headquarters), diesel generators are planned to be used for primary and daily power usage. Solar energy and batteries for energy storage are allocated to be back-up power supply. Automatic Transfer Switches (ATS) operates automatically and switches to solar energy and batteries for power supply when diesel generators are stopped. While this situation occurs, the back-up power supply system takes over the power load to sustain the reliability of power supply.

Numerical Goal for Reference

1. Maximum penetration rate of solar energy ＞80%
2. Average daily penetration rate of solar energy＞40%
3. Operation costs reduction > 48%

Replicability for International Use

Penghu County’s support and our team’s investment in this project will enhance the current power quality, and improve the operation performance for PDMS. In the short-run, as the economic benefits of PV and energy storage technology improve, the operational experience of PDMS can be expanded and transplanted to specific off-grid and environmentally protected areas in South East Asia, as well as other areas to improve the distributed energy systems’ efficiencies. In the long run, further technology development around these key areas would effectively enable higher integration of solar and other distributed power generation into needs. The strategic collaboration between Chinese Taipei enterprises and institutes would help develop microgrid-based total solution for the region, bolstering Chinese Taipei as a center of excellence for high value-add microgrid system design and engineering domestically as well as the emerging Asia markets.

Responsible organization

Fig. 4 – Responsible organization

 

Cost-Effectiveness

The parameters and results of the 20-year average cost of this system are shown in uploaded file ”Appendix 1-1 Levelized Cost of Electricity (LCOE).pdf.” The cost details include the equipment cost, the construction cost, the fixed annual expense and the equipment replacement that has reached the end of the service life. The formula for calculating the Levelized Cost of Electricity (LCOE) is:

LCOE = (Sum of Present Value of Annual Expenditure) / (Sum of Product of Solar Power Generation and Discount Factor)

According to the above-mentioned calculation results, LCOE of Dongjiyu Solar Power System with Energy Storage System is USD 0.1826 / kWh, as shown in uploaded file ” Appendix 1-1 Levelized Cost of Electricity (LCOE).pdf.”

Reduction of Carbon Emission

The locations of measured points are shown in Fig. 5. (a) 4 power meters are used to measure 4-loop power supply of the diesel generator set. (b) 3 power meters are used to measure 3-loop power usage of electricity by villagers (c) 5 power meters are used to measure power generation of 5 sets of solar power systems. On the island, the main power source comes from diesel generators and solar power system. Therefore, increasing the supply of green energy is then able to reduce the power output of diesel generators and carbon emission generated by DGs. Statistical green energy output and reduced carbon emission can be quantified as follow:

Reduced Carbon Emission

= green energy output (kWh / year) * 0.528 (kg-CO₂ / kWh)

= 109,581 (kWh / year) * 0.528 (kg-CO₂ / kWh)

= 57,859 (kg-CO₂ /Year)

Carbon emission: 0.528 kg-CO₂ / kWh (Cited in Bureau of Energy, Ministry of Economic Affairs.)

Fig. 5 – Meter Allocation

Consistency with Energy Policy and Strategy

To promote further growth of renewable energy-related development efforts in sustainability, Chinese Taipei government has already enacted aggressive policies and initiatives to scale-up its PV generation targets, with the Ministry of Economic Affairs, Bureau of Energy (MOEA-BOE) commissioned plan to scale-up the PV capacity installation from 615.2MWp in 2014 to 20GWp in 2025. To address the issues arising from intermittency of solar power generation, MOEA-BOE has already proposed the strengthening measures to manage such intermittent generation sources, and plans to increase the grid’s tolerance and capacity for increased intermittent generation sources through the use of grid-tie energy storage.

Our project goal is in accordance with the goal of Chinese Taipei energy policy.

1. Energy generating: the project promotes penetration rate of solar energy by the way of building an island-type microgrid of high proportion of renewable energy sources.
2. Energy storage: the project expands the power storage for photovoltaic power generation with SEMS; it increases the penetration rate of renewable energy, and reduces power generation cost by power scheduling.
3. Smart system integration: PDMS consists of renewable energy full-day power forecasting program, full-day load forecasting program, generator and energy storage unit optimization scheduling program, scheduling & real-time control program to achieve the goal of low-carbon energy dispatching for Dongjiyu. PDMS covers forecasting, scheduling and energy allocation. The project starts from low-carbon energy plan and power supply system development, aims to integrate the island's existing diesel generators and 86.4kWp solar power generation system.
4. Cost reduction: The project aids to ease the problem of high cost in power generation and to help the island becomes a demonstration site for low-carbon power generation.

Implementing organization

The team of this project is comprised of notable enterprises and institutes in Chinese Taipei, including TIER, INER, CHEM and others. The microgrid evaluation and microgrid smart control algorithm, developed by INER, will be used for system testing and impact evaluation, while CHEM and supporting vendors will lead the development and integration of hardware equipment for SMART μ-MEMS and Hybrid MS.

Fig. 6 – Implementing organization

All of the participating organizations have committed resources and express strong interest to support technology development and qualification efforts on validating and further business case of microgrid growth in the Asia Pacific region. Below is a brief profile summary of the implementing organizations, while detailed info on these organizations will be given in uploaded file “Appendix 2 Team member CV.pdf”.

1. Penghu County:

Penghu County's permanent establishment is responsible for promoting the use of renewable energy sources in similar, inhabited off-islands, such as Wangan, Qimei, Tongpan, Hujin, etc. These include the total of nineteen inhabited off-islands.

2. Chung-Hsin Electric and Machinery Manufacturing Corp. (CHEM):

Founded in 1956, CHEM is an established industry player serving the power sector with a strong yearly revenue of USD 3 billion. CHEM’s core products range from Gas Insulated Switchgears (GIS), AMI Meter, Smart Grid equipment to associated commissioning systems. CHEM started investing in new energy areas since 2008, and has completed notable product milestones including 5kW methanol-based fuel cell, smart inverter, hybrid DC/AC microgrid and smart microgrid Energy Management System (EMS).

CHEM is committed to further its technology development in microgrid, and aims to enhance and further such technical exchange through international collaboration partners. It is envisioned that through the participation of PDMS, CHEM will assist in further co-development of an internationally certified microgrid solution that is suited for Chinese Taipei and Asian countries.

3. The Institute of Nuclear Energy Research (INER):

The Institute of Nuclear Energy Research (INER), established in 1968, is a government agency with a history of credibly safeguarding dedicated to the research and development (R&D) on nuclear safety, nuclear facility decommissioning, radioactive waste treatment and disposal technologies. Moreover, INER also bears the mission of developing radiopharmaceuticals for the public well-being. Nowadays, Chinese Taipei’s energy policies are ensuring nuclear safety and waste reduction, building up green energy and a low carbon environment, and working eventually toward creating a nuclear-free homeland. In conformity with the national energy policy, INER has expanded its researches in recent years to including the development of green energies such as new and renewable energies, energy conservation and carbon emission reduction, in addition to participating in the energy-related economic policy research.  Its expertise conventional generation, transmission and distribution, smart grids, and sustainable energy use, as well as energy markets and regulations.

4. Taiwan Institute of Economic Research (TIER):

Taiwan Institute of Economic Research (TIER) was established on September 1, 1976 as the first private independent think tank in Chinese Taipei, whose main purpose is to actively engage in research on domestic and foreign macroeconomics and industrial economics to promote Chinese Taipei’s economic development. Division 1 of TIER is currently commissioned by Ministry of Science and Technology to conduct new energy technology strategy’s overall efficiency evaluation, and is also commissioned by the Bureau of Standards, Metrology & Inspection. to conduct specific feasibility study of testing and certification of smart grid program and international cooperation programs.

Performance:

The combination of diesel generators and smart micro-grid will not only improve the power quality and stability, but also enhance the penetration ratio of renewable energy resources by introducing the automatic controlling function. Significant reduction of fuel consumption will also be a major plus generated from this innovative technology.

Completeness

The existing power generation system on Dongjiyu is composed of 4 diesel generators, namely 3 sets of 200 kW and 1 set of 300 kW, with the total installed capacity of 900 kW, and 86.4 kWp PV system. The annual power generation of PV system is evaluated according to the investment parameters, as shown in the uploaded file “Appendix 1-2 Investment Parameters.pdf.”

The PV module area is 1.63m²; the maximum power of PV system is 86.4kWp with 85.71% of performance ratio (PR); the PV module efficiency is 15.4%. On the other side, Dongjiyu’s average annual amount of insolation from 2007 to 2014 is approximately 1476.6kWh/m2. These mean the annual power generation of PV system in Dongjiyu shall reach 109,582.6 kWh as the annual power generation per PV module goes to approximately 317.08 kWh.

Measurable Achievement Scale

In most of scenarios, lead-acid batteries are recommended to be set up to complete the system arrangement. The recommended Depth of Discharge (D.O.D.) of lead-acid batteries is 50% to avoid shorter life time of the batteries caused by frequent over-discharging.

The formula for calculating annual power generation of 86.4kWp PV system is:

Annual power generation of PV system

= (Module Quantity) * (Annual Power Generation per Module)

= 345.6 * 317.08 (kWh)

= 109,582.6 (kWh)

As shown in uploaded file “Appendix 1-2 Investment Parameters.pdf”, annual power generation of 86.4kWp PV system is about 109,582.6 kWh.

Achievement

The proposed project of PDMS (https://esci-ksp.org/project/penghu-dongjiyu-microgrid-small-power-supply-system/), aims to achieve the following KPIs for quality and effectiveness:

1. To design the system model and complete the associated analysis via Microgrid Evaluator to achieve an optimized parameterization for Smart μ-MEMS.
2. To develop and implement the proposed Smart μ-MEMS, which provides the use of power generation forecasting for energy scheduling, remote monitoring for load forecasting, and control system for three-phase equilibrium of AC power to aim at lowering the operation cost of Dongjiyu microgrid system.
3. To develop and implement the proposed Hybrid MS to mitigate the intermittency of PV generation.
4. To achieve power generation for 300 kWh each day within 12 months, with the new generation cost below USD$0.1826/kWh.
5. To improve current microgrid system stability, e.g. maintaining voltage levels within 0.99%-1.01%.
6. To reduce greenhouse gas emissions by 57.86 metric tons/year.

Verifiability

According to the micro-grid operation data collected and recorded so far from Donjiyu Monitoring System, the data covers two main parts. Firstly, on power generation and consumption, the data indicates solar energy generation, green energy output from grid-tied inverters, energy generated from diesel generators and also, power consumption from residents over the island respectively. Secondly, it also reveals the percentage of domestic power usage for local residents from green energy and diesel generator. Green energy takes up to 40% of daily usage while 60% of daily usage comes from power generation of diesel generators. See the figures below.

Fig.  7 – The Penetration Ratio of Green Energy for 60kWh/170kWh Battery Capacity

 

Fig. 8 – Weekly Data of Power Supply/Electricity Usage

Fig. 9 – Percentage of Power Usage from Green Energy and Diesel Generator

Impact

The key driver for development of smart grid comes from the maturing energy storage technologies.  The rapid declining cost of ESS is set to render and boost up the commercial readiness of massive adoption for renewable energy applicationand integration. Assuming similar microgrid integration schemes as PDMS can be applied in Chinese Taipei main grid system, it could potentially boost up the Intermittent Generation Sources (IGS) capacity from 4.07GW to 28.5GW, as calculated with an overall generational capacity increasing of 24.43GW in year 2025. This domestic source of clean energy of 50 G.kWh amounts to an effective NTD 2.85 Trillion market-sized industry. This is essentially an effective boost for domestic GDP. Given Chinese Taipei’s current huge reliance on import of energy for power generation, this can also further strengthen Chinese Taipei’s energy security. Moreover, the corresponding environmental impact decreasing offered by this domestic clean energy is also significant.

Multiple Operational Areas for Application

Fig. 10 – Multiple Operational Areas for Application