On June 1, 2017, Shimizu proceeded to a verification stage its system development to supply energy to office buildings, lodging facilities and hospitals taking out power and heat from the surplus photovoltaic power stored by hydrogen as is necessary, which Shimizu had been implementing at the National Institute of Advanced Industrial Science and Technology (AIST) and Fukushima Renewable Energy Institute (FREA).

Shimizu took a particular note on the system to store a surplus electricity of renewable energy in the form of hydrogen as part of the hydrogen energy utilization, and started to develop the system in February 2016. The investment amounts to 250 million yen in total (by Shimizu alone).

The system to verify this time produces hydrogen with water electrolysis using a surplus electricity generated by solar beam and stores it in the tank of alloys for hydrogen accumulation, so that it can be taken out as electricity or heat with the fuel cell when it is necessary.

Shimizu’s energy management system “Smart BEMS” manages and controls the whole system on the basis of the data on the demand of electricity and heat which Shimizu has accumulate.

The system components include photovoltaic power system (output: 20kW), water electrolyzing system (5Nm3/h made by Hitachi), hydrogen storage tank (approx.40Nm3 made by Japan Metals and Chemicals), fuel cell (output 3.5kW made by Toshiba) and storage battery (output: 10kW).

The hydrogen storage alloy used for the verification test is a non-rare metal alloy developed by AIST and it can safely be attached to a building. The facility is designed on the assumption of about 1,000 m2 or so of total floor area.

The verification test is aimed for “to enhance efficiency of hydrogen production,” “to upgrade storage/discharge technology for higher efficiency” and “to optimize management of Smart BEMS.” The test will be made by March 2018.

Dr. Tsuyoshi Nozu, Manager of Shimizu’s Hydrogen Technology Group said, “Shimizu wishes to cooperate to form a hydrogen society aiming for upgrading of Smart BEMS and realizing ZEB (zero energy bill).” Furthermore, Dr. Shigeteru Endo of AIST is enthusiastic saying, “We do wish to commercialize this research and make out a standard with Shimizu on the utilization of hydrogen energy attached to building, aiming to introduce into buildings and the urban areas.”

AIST and FREA is now engaged in its basic study to expand the scope of utilization of hydrogen from a renewable energy in a wide variety. It includes the production technology of hydrogen carrier (e.g. organic hydride, ammonia and formic acid), co-generation technologies and integrated system verification tests to produce and use a hydrogen carrier.

As seen in the National Energy Plan (enacted in April 2014), Japanese government aims for realize of ZEB to make balancing of energy accounts in terms of the average energy of new public buildings by 2020 and new general buildings by 2030. Among them, the power storage and supply with “CO2-free Hydrogen” from a renewable energy particularly draws people’s keen attention. All local authorities and private companies are now carrying out their research and verification experiments.