Blogs, Solar

Japan’s Tipping Point Blog 4: Solar Hot Water

This is my fourth blog on the Japanese renewable energy situation, based on my book, Japan’s Tipping Point: Crucial Choices in the Post-Fukushima World.  I will focus here primarily on solar hot water.

 While in Japan, in June 2011 I visited the boosters of solar hot water, the Solar System Development Association – to American ears sounding like a sci-fi outfit that is colonizing Mars and Jupiter, but typical of the strange English that the Japanese often use. The offices were hard to find, the entrance down a dingy alley, and the view out the window is the facade of a skin clinic across the road.  In contrast to the 118 industries that belong to the Japan Photovoltaic Energy Association, there are only 13 members of the solar hot water organization.

 Even though producing hot water from sunshine is a well-established, proven technology that (ignoring subsidies) costs less than PV panels, it is unpopular and has a terrible image in Japan, as I had already heard from officials in various Eco-Model Cities.  In Kitakyushu, for instance, despite a subsidy of 10 percent of the purchase price, only two people in fiscal 2010 applied for a solar hot water installation.  So city officials are terminating the subsidy, giving the entire budget to PV panels. 

 Thermal solar sales swelled in the 1980s, following the second oil crisis, spurred by low-interest government loads.  But aggressive salesmen gave the industry a bad name, as Mitsumi Taga, the director of the Solar System Development Association, explained.  Because of the moderate climate in all but the northern island of Hokkaido, many consumers opted for an inexpensive system that uses only water.  As the pipes are heated by the sun, the hot water flows into a tank on the roof and can then be drawn into the house by gravity.  On nights when the pipes might freeze, owners must drain the water and refill it the next day.  Unscrupulous salesmen could easily spot the rooftop tanks and would tell homeowners that their system needed maintenance and special chemicals. 

 The SSDA was founded in 1978 to represent both PV panels and thermal solar, but in 1987 the photovoltaic association split off, probably to get away from such scandals.  The pipes for the hot water systems began to crack and fail in 15 years or so, and by that time many manufacturers were no longer in business.  From 2002 to 2005, the Japanese government gave subsidies to both solar hot water and PV panels but then terminated both of them.  Now PV panels are an upscale status symbol, while people don’t want an ugly tank on their roof.

 Manami Mizutani, in charge of public relations for the association, explained that there are three types of solar hot water system.  The down-scale water-only systems cost a bit over $3,000.  Others use a form of anti-freeze in the rooftop panels that passes through a heat pump in the house, where the water is heated.  A small pump circulates the cooled anti-freeze back to the roof.  These units cost about $10,000 without subsidy.  Finally, there are systems made by OM Solar that are more expensive and can only be installed in new homes. This third approach heats and circulates hot air that provides radiant floor heat as well as hot water.

 Back in Vermont, I have recently had the anti-freeze-type system installed on my roof.  A tiny solar panel runs its small pump.  With federal and state tax subsidies, it cost about $6,000.  During the warm summer months, I was able to disconnect my back-up electric hot water heater completely, and we had more than enough hot water, even with houseguests.  It will probably pay for itself in a few years. 

 In Japan, however, businesses are pushing all-electric eco-homes.  The popular EcoCute produces hot water from the air via a heat pump and is indeed relatively energy efficient.  But EcoCutes cost about $9,000, and they add more than $60 to the monthly electric bill, whereas hot water is essentially free once a solar thermal system is in place.

 To encourage sales, the SSDA has made a deal with the devil, the fossil fuel Tokyo Gas Company, to offer solar hot water systems along with natural gas heat, in a joint effort to combat the electricity boosters.  Companies such as Yazaki also offer hybrid rooftop systems, with both PV and solar hot water panels.  But sales are still very slow.  The Tokyo Metropolitan Government has given subsidies for solar hot water for the last two years, with few takers.  For fiscal 2011, Tokyo is sharply increasing the subsidy, but Shoji Kobayashi, the head of Tokyo’s Renewable Energy Policy Division, isn’t sure it will help.  “People think the hot solar water panels are ugly, even in a hybrid system with PV panels,” he told me.  I said this was crazy – the anti-freeze type panels look as slick as those that generate electricity.  That doesn’t matter.  “People associate them with the old style,” Kobayashi concluded.