AIST FREA

産総研トップへ

Energy Network Team

Research and Verification of Advanced Integration of Renewable Distributed Energy Resources

Over View

In order to provide stable energy in the case of widespread use of variable renewable energy resources, it is essential to adjust the simultaneous balance of power supply and demand by using existing power plants and energy storage systems. A suitable combination of renewable energy resources for each location is also important, because distributed energy resources (DERs) are highly dependent on local meteorological conditions.


Research Target

The team has been developing a renewable energy network to reasonably and effectively introduce renewable energy into the mature legacy power grid system. This will reduce the consumption of finite energy resources (fossil fuels, etc.) and reduce CO2 emissions. We focus on advanced control and grid support technology for a smart inverter (PCS).
This research topic aims to develop integration technology for both stabilizing and maximizing multiple DERs, especially PV and wind, by using energy-storage systems (ESS) such as hydrogen and batteries in the case of naturally fluctuating electricity conditions due to the metrological environment. The team proposes a new energy supply system based on a renewable energy network with renewables and DERs. It will be built by combining utility-scale PV generation and ESS including the hydrogen system. This approach will create a new energy supply model from the perspective of electricity users, through flexible demonstration facilities and our test platform.

  • Realization of smart distributed energy resources (DERs) through the use of advanced power equipment such as the smart inverter or PCS.
  • Optimization of system integration through the use of information communications technologies (ICTs) and meteorological data.
  • Hydrogen production from renewable energy and development of related technology.
Solutions for widespread use of renewable energy and cost-effective grid stabilization technology

Solutions for widespread use of renewable energy and cost-effective grid stabilization technology

Research Outline

The team is developing a performance test method for elemental technologies such as DER, ESS, and users’ equipment in addition to a technology for the integrated use of renewal energy in combination with ESS and heat utilization technologies in order to realize a renewable energy network.
This will improve the power supply value and the economic value of renewable energy and promote various introduction plans such as 100% renewable energy use.
The team is mainly working on the following research and development topics:

  • Comprehensive evaluation of a PV generation system: predicting the annual amount of power generation of various types of PV modules, conducting PV inverter performance tests and field failure diagnosis of a utility-scale PV system, etc.
  • Hydrogen production and storage technology using renewable energy: Technology for direct electrolysis from a PV system (solid polymer-type water electrolyzer with a fuel-battery function), hydrogen storage using metal hydrides, compression, hydrogen separation membranes, solar heat utilization and heat storage technologies, etc.
  • Grid support and smart technology for DER: We provide a smart test platform for energy management systems (EMS) as a user facility and keep developing performance verification test procedures and updating environments.
  • International standardization: We seek prompt international standardization of the above development results through cooperation with international research institutes, etc.
Technological items handled by the Energy Network Team
Technological items handled by the Energy Network Team

Main Research Facilities

Distributed energy resources (DER) demonstration platform【figure below】

This platform will be used for the development of an energy management system (EMS) and its demonstration through PV systems (consisting of different technologies from ten companies), a large power grid simulator (Smart DER system research equipment consisting of a 500 kW AC grid simulator and two sets of 300 kW DC simulators). In addition, the platform enables hydrogen production technologies using renewable energy in anticipation of the hydrogen society, research and development facilities for distributed batteries such as electric vehicles and EMS evaluation linked with forecast technologies for solar irradiation and wind velocity (EV demonstration facilities, 20 kW class PV + water electrolysis demonstration facilities, etc.).

  *DER: Distributed Energy Resources

DER demonstration platform
DER demonstration platform

Activities and Achievements

1.System integration technology and energy management
The team conducted a performance analysis of individual elemental technologies, including ten different types of photovoltaic (PV) systems with three types of twenty-two inverters (PCS: power conditioning systems), a proton exchange membrane type water electrolysis system (with a fuel-cell function), and a hydrogen storage system using metal hydrides; based on this, the team conducted a large number of joint research studies. In the future, the team will promote system research through the demonstration of system integration technologies using power smoothing simulation, hydrogen production with fluctuating renewable energy, and electric vehicles.

2.Advanced monitoring of renewable energy resources
The team developed a renewable energy power generation observation system to better understand the temporal and spatial variability in power generation when PV and wind power generation is introduced in Fukushima Prefecture on a massive scale through the Fukushima Prefecture Renewable Energy Next-Generation Technology Development Project (FY2013‒2014). The system makes it possible to estimate the amount of power generation (PV and wind power) in the entire Fukushima Prefecture using a 2-km mesh and an interval of one hour, and to forecast the power generation several hours in advance using the same model. The team will continue to improve the system’s accuracy and examine the possibility of its nationwide introduction in the future.

3.Hydrogen production, storage and utilization system using renewable energy
In response to the problem of power output suppression in the case of introducing a large amount of renewable energy, we have developed a hydrogen energy system consisting of a water electrolyzer, storage unit and fuel cell system. We developed the water electrolyzer using photovoltaic output and succeeded in converting 15% of the solar energy into hydrogen energy by direct coupling between photovoltaic and electrolysis【Fig. 1】.
We are aiming to put the stationary hydrogen energy system into practical use in residential areas. We are developing hydrogen storage using a metal hydride that can store hydrogen safely and easily. Furthermore, we aim to utilize CO2-free hydrogen for fuel cell vehicles, through the development of technology related to high-pressure hydrogen.

Fig. 1: Unitized reversible fuel cell Fig. 2: High-pressure hydrogen device for fuel cell vehicle application development
Fig. 1: Unitized reversible fuel cell Fig. 2: High-pressure hydrogen device for fuel cell vehicle application development

Team Member

Title Name
Leader Kenji Otani
Senior Researcher Tetsuhiko Maeda
Researcher Jun Hashimoto
Researcher Naruki Endo
Researcher Nguyen Duc Tuyen
Researcher Ustun Taha Selim