Mitsubishi to Supply Solar Electricity to Skyscraper

2014/04/02 20:51
Kenji Kaneko, Nikkei BP CleanTech Institute

Mitsubishi Estate Home Co Ltd announced that it will meet about half of the contract demand of the "Shin Marunouchi Building" near Tokyo Station with electricity generated by using biomass, biogas and solar power from April 2014.

Mitsubishi Estate Home concluded the "contract for electricity purchase by proxy" with Eneres Co Ltd, which mediates electricity trade, etc. In the contract, the Shin Marunouchi Building is the demander. Eneres will procure electricity in accordance with the demand of the building by using the "partial supply" scheme, which purchases electricity from both a general power supplier and a PPS (power producer and supplier).

First, the PPS, Iwate Wood Power KK (Miyako City, Iwate Prefecture), purchases renewable energy-derived electricity from power producers. Then, Eneres buys power from Iwate Wood Power and a general power supplier and supplies it to the Shin Marunouchi Building.

The renewable energy-derived electricity is purchased from (1) a biomass power plant that uses forest thinnings and waste from timber mills and is located in Miyako City, Iwate Prefecture, (2) a biogas power plant that uses inflammable gas generated by fermenting food wastes produced in Tokyo and (3) a mega-solar (large-scale solar) power plant that Mitsubishi Estate Home built in Sakura City, Chiba Prefecture.

Mitsubishi Estate Home is considering the following operation procedures. As a primary power source to be used around the clock, electricity purchased from the general power supplier is used. During daylight hours, when power demand increases, electricity generated by using biomass and biogas is used. And from 13:00 to 17:00, when power demand peaks, electricity from the mega-solar power plant is used.

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The renewable energy-derived electricity is expected to be certified as "low-carbon electricity" for the "2nd Planned Period" for the Responsibility to Reduce Total Emissions of the Tokyo Municipal Government's Environmental Securement Policy, which the government of Tokyo plans to implement in fiscal 2015.

Mitsubishi Estate Home has been meeting 100% of the power demand of the Shin Marunouchi Building with renewable energy sources especially wind and hydraulic power since April 2010. However, in the wake of the implementation of the feed-in tariff (FIT) policy, etc, it became difficult to purchase electricity with the previous scheme. By employing the partial supply scheme, it became possible to use renewable energy-derived electricity to meet half of the contract demand.

The new scheme that uses electricity from the mega-solar plant located in Sakura City, Chiba Prefecture, for the Shin Marunouchi Building enables to benefit from the peak shaving effect of the solar power plant near the demander.

In an urban area, there is a large peak demand due to air conditioning systems. Because the amount of electricity generated by a mega-solar power plant increases in those peak hours, it can be easily used for peak shaving. Under such circumstances, PPSes are actively purchasing electricity from mega-solar plants near the Tokyo metropolitan area with a premium.