Honda and Iwatani, in conjunction with Saitama Prefecture, are to begin trials of a solar hydrogen station in Saitama prefecture. As a Ministry of the Environment project, Honda developed this solar hydrogen station own its own and installed it on the grounds of the Saitama Prefectural office in Saitama Prefecture. The Honda FCX Clarity, a fuel cell vehicle (FCV) equipped with an electric power outlet, will be used for the trial. The company will employ it as a clean power generation facility which emits no CO2 at all. The station has a hydrogen generation capacity of 1.5 kg a day. A high pressure hydrogen tank was installed which can rapidly fill a car in 3-4 minutes.

The primary reason that Honda, a car producer, came to develop a hydrogen station on its own was to reduce CO2 emission. Hydrogen stations are actually a part of the supply infrastructure. The use of electric propulsion for cars (battery electric vehicles (EV) or FCVs are a prerequisite to reduce the CO2 emission from cars completely. This alone is not enough, however. The electric power supplied has to be some form of CO2 free renewable energy. For this reason, since the 90’s Honda has been carrying out research and development concerning CO2 free electric power generation systems such as solar panels or hydrogen generation using electrolysis, mainly in the US.

The Honda’s solar hydrogen station is being handled by an affiliate called Honda Soltec. The station generates power with a 6kW CIGS solar panel. This too is a high pressure hydrogen electrolysis system developed by the company in house. It generates hydrogen, raises the pressure to 35 MPa, and with a dedicated dispenser fills FCVs with hydrogen.

When it was first developed, pressure was raised with a compressor, but due to the motive power for the compressor there was a 20% loss in the power generation efficiency. Because of this, Honda did not use a compressor for the second-generation station but it was built into a hydrogen pressurizing system. For the high pressure hydrogen electrolysis system, only the section which generates hydrogen has its pressure raised, while the oxygen generation section is arranged for emission into the air. The company developed the electrolyzer and the catalyst on its own.

This system was installed at the company in 2010 at its research facility in California, and a long term trial is being conducted. In the US solar stations are positioned as hydrogen filling facilities for home use, with a hydrogen generation capacity of 0.7 Nm3 an hour. Daily it can replenish enough for running the 50km distance sufficient every day for commuting to work or for everyday routine driving. Because it uses solar cells which can only generate electricity during the daytime, a high pressure hydrogen storage facility is required to fill cars which are not used during the evenings.

Although in Japan use for the home is not kept quite in mind as it is in the US, installation of an external electric power source with an output of around 10 kW suitable for consumption by 2 average homes by their FCVs will be under consideration. Evaluation of the performance of FCVs as high volume electric power generators, as well as how to operate them under a municipal environment, will also be looked into.