Benchmark Study on Green Buildings - Royal Architectural Institute ...

ebates for homeowners who install photovoltaic panels. These subsidies are now being
phased out, but falling prices for solar generating systems may help the industry despite
these lost subsidies. The cost of residential solar power systems has dropped by about 80
percent in the last decade, to around $6,000 US for each kilowatt of generating capacity.
Since 1999, Japanese home buyers have been able to buy a home that requires almost no
outside energy and that results in a near-zero electricity bill (also known as a zero-utilitycost
house or a zero-energy house). The Hybrid-Z home is built by Misawa Homes, one
of Japan’s largest homebuilders, and MSK Corporation, the Japanese distributor for
Solarex Photovoltaics. The Hybrid-Z home features 20 distinguished and comfortable
living designs and offers either a 6 or 12.5 kilowatt solar electric array that covers the
house’s entire roof. The homes use no natural gas or oil, so all energy use is electric,
including household appliances, cooking facilities, and a water heater. Because of
national net-metering, the grid-connected home sells power to the electric utility at retail
rates when the system generates more than the house uses. The solar modules are
assembled at MSK Corporation’s facility in Nagano and are integrated into the roof at
Misawa’s factory. While it takes three days for Misawa to build the modular home, it
takes only eight hours to fully install it on site. Misawa Homes sold approximately 1,500
Hybrid-Z homes in 1999, and expects these strong sales levels to continue. The Hybrid-Z
home is the first residential structure in the world to achieve energy self-sufficiency,
although other manufacturers have since become involved in the zero-utility-cost house
industry. These houses only emit about 1/5 of the CO 2 emitted by a conventional house,
and are also subsidized by the New Energy Foundation in accordance with the subsidy
program for residential PV systems. The subsidy ratio of this program is approximately
1/3 of the total installation cost of the solar roof, which works out to about 3 million Yen
(about $25,000 US).
New Energy Foundation (NEF) programs:
The New Energy Foundation (NEF) of Japan also runs some other subsidy and incentive
programs for the installation of residential photovoltaic power generation systems. From
1994 to 1996, the NEF carried out the “Residential Photovoltaic Power Generation
System Monitor Project” with a fund from METI. The purposes of the project were: to
promote the mass production of PV systems and cost reduction by creating initial demand
for the system, and to establish PV systems best suited to consumer's needs based on the
operation data collected by monitoring. Initially a subsidy covered about 50% of the total
cost of the PV systems. Under this program, 3,590PV systems were installed with a total
power output of 13MW, averaging 3.7kW per system.
In 1997, in place of the above monitoring system, the “Program for Infrastructural
Development of Introduction of Residential PV Systems” was started by the NEF. It
aimed for the large-scale introduction of solar power generation systems for private
residences. This program had its budget increased from 4.1 billion yen in 1996 to 11.1
billion yen in 1997. With the expansion of the budget, applications for the subsidy
increased substantially and installations reached 8,329 in 1997. Owing to the reduction in
PV system prices, the subsidy was reduced to about one third of the actual cost, and the
selection was switched from lot-based one to first-come-first-served basis, so as to accept
87