Ibaraki Sekisui Heim Co Ltd (Mito City) announced Jan 16, 2014, that it will sell houses equipped with a 10kW or higher-capacity solar power generation system in Ibaraki Prefecture, Japan.

Nikkei BP reports that, the "Smart Power Station" houses feature not only a solar power generation system but the "Smart Heim Navi" HEMS (home energy management system) and "e-Pocket" large-capacity stationary lithium-ion rechargeable battery, enabling to generate an amount of electricity equivalent to that consumed in a normal-sized house.

The main products in Sekisui Chemical's "Heim" series of steel-framed houses have flat roofs and make it easy to install solar panels on the entire rooftop, enabling to mount a large capacity solar power generation system. And the maximum capacity of a solar power system mountable on the roof of a 130m2 Heim house is 6.8kW (4.64kW on average in actual situations).

On the other hand, the Smart Power Station series allows to mount a 10kW solar power system even on the roof of a 114m2 house because of its newly-developed "panel-integrated roof" and "long eaves." Moreover, for the "To You Home" series of wood-based houses, the "3.5 cun shed roof," which increases the area of roofs facing south, was developed, enabling to install a 10kW or higher-capacity solar power system even on the roof of a 108m2 house.

With a 10kW or higher capacity, based on the feed-in tariff (FIT) policy, it is possible to choose from two options: "selling surplus electricity" and "selling all the electricity." And a stale income from electricity sales can be expected for 20 years.

The solar panels for Sekisui Chemical's steel-framed houses are tilted 1° so that they can be tightly arranged on a flat roof without making gaps. And the company employed CIS-based solar cells because they can generate the maximum amount of electricity under such circumstances and have relatively low costs.

In regard to houses equipped with a 10kW or higher-capacity solar power system, PanaHome Corp released the "Eco Cordis" detached house, which uses solar panels as a roof, in April 2013. The house was realized by employing Panasonic Corp's "HIT" solar cell, which is one of the highest-efficiency cells in the industry, for its solar panels. According to the company, the income from electricity sales based on the FIT policy can be about ¥515,000 (approximately US$4,936) per year and about ¥10 million or more in 20 years, depending on conditions.

PanaHome's "Eco Corids" (Photo Credit: PanaHome / Nikkei BP)