Energy Network Team

Research and Verification of Advanced Integration of Renewable Energy Sources

Over View

 To realize high penetration of distributed energy resources (DERs) into energy networks, adjusting the simultaneous balance of intermittent DER supply and energy demand is essential by using existing power plants and energy storage systems. The combination of appropriate DER according to each location is also important, because DERs are strongly depend on local conditions.

Research Target

 To reduce consumption of exhaustible energy resources (fossil fuel and others) and the CO2 emissions through utilization of renewable energy, the team will develop a renewable energy network to reasonably and effectively introduce renewable energy into the existing energy network. In particular, it studies smart control of power conditioners (PCS), utilization of energy-storage systems with hydrogen and batteries, and a technology of system integration for multiple distributed energy resources as technologies for achieving both stabilization of the output and maximization of the electric power generation in introducing naturally fluctuating electric power supplies (PV and wind power generations) into the existing energy network.
 The team proposes a new energy supply model that builds a renewable energy network combining large-scale PV generation and electricity storage with hydrogen and batteries and that builds on the perspectives of electricity users through flexible demonstration facilities and our test platform.

  • Make smarter distributed energy resources (DERs) by using advanced power electronics equipment such as Power Conditioning System (PCS).
  • Optimize system integration by using information and communications technologies (ICTs) with meteorological data.
  • Produce hydrogen from renewable energy and develop technologies related to it.
Solving problems regarding the stabilization and countermeasure costs for mass introduction of renewable energy

Research Outline

 The team is developing a performance test method for elemental technologies such as distributed power sources, power storage systems, and user’s apparatuses and a technology for the integrated use of renewal energy in combination with power storage systems 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 engaged in 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, PV inverter performance tests, field failure diagnosis of a mega solar, etc.
  • Production, storage, and use of hydrogen using renewable energy: a direct electrolysis technology from PV modules (a solid polymer-type water electrolyzer with a fuel-battery function), hydrogen storage by metal hydrides, compression, hydrogen-separation membranes, solar heat utilization and heat storage technologies, etc.
  • Power system coordination and upgrading technologies for distributed energy resources: the team will build user facilities to conduct performance tests of the distributed power sources and performance verifications of EMS that integrate them on an actual scale.
  • International standardization: It aims at rapid international standardization of the above development results through cooperation with international research institutes and the like.
Technological items that the energy network team deal with

Main Research Facilities

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

 On this platform, EMS (Energy Management System) shall be developed and demonstrated through PV systems that consists of different technologies from ten companies, large power grid simulator (Smart DER System Research Facilitiy up to 500 kW). In addition, it is a platform enabling hydrogen-producing technologies with renewable energy in anticipation of hydrogen societies, research and development facilities for distributed batteries as represented by electrical vehicles, and EMS evaluation linked with forecast technologies for the 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 a solar photovoltaic PV power system comprising more than ten types of PV modules and three types of 22 power conditioning systems (PCS), a proton exchange membrane type waterelectrolyte system (with a fuel-cell function), and a hydrogen-storage system using metal hydride; based on this, the team conducted a large number of joint researches. In the future, the team will promote the system research, including the demonstration of system integration technologies through the demonstration of power smoothing utilizing simulation technologies, hydrogen manufacturing with fluctuating renewable energy, and electric vehicles.

2. Advanced monitoring of renewable energy resources
 The team developed a renewable energy power-generation observation system (Fig. 1) to understand the temporal and spatial variability in power generation when PV and wind power generations are introduced with in Fukushima Prefecture on a massive scale through the Fukushima- Prefecture Renewable Energy Next-Generation Technology Development Project (FY2013-FY2014). It allows estimation of the amount of power generation (PV and wind power) in the entire Fukushima Prefecture with a mesh of 2 km and an hour interval and also the forecast of power generation several hours in advance with the same model. In the future, the team will further improve its accuracy to consider the nationwide expansion of this system in Japan.

3. A system of producing, storing, and utilizing hydrogen with renewable energy
 The team developed an operational technique and a water electrolyzer (Fig. 2) to directly connect PV with proton exchange membrane type water electrolyzer to produce hydrogen at the optimal operational point. In the future, the team will be promoting technological development for reducing hydrogen producing costs with renewable energy.
 The team aims at realizing dissemination of FCV and realization of hydrogen societies by developing related technologies.

Fig.1: Renewable-energy power-generation observation system Fig.2: Water Electrolyzer
【Fig. 1】 Renewable-energy power-generation observation system
【Fig. 2】 Water Electrolyzer

Team Member

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