Summer electricity shortage countermeasure: Make your own

April 19th, 2011 by Philip Brasor & Masako Tsubuku

Money on the roof

Last Friday night Tokyo Electric Power Co. announced, just in time for the nightly news, that it would be able to provide up to 52 million kW by the end of July. At present, the company can provide a maximum of about 42 million kW. Usually during the hottest days of summer they need 55 million, and if this year’s weather is anything like last summer’s, they could need 60 million.

So if Tepco’s assurance is sincere, there should be no problem with supply for the near future. The government has asked households to reduce their energy consumption by 10 to 15 percent, and consumers have already started getting into the habit of saving electricity. Still, if the crisis has taught us anything, it’s that we can’t proceed under the current system of energy supply. Changes need to be carried out on a national scale, but before that happens individuals with means will certainly look to assure their own electricity needs by themselves, and some manufacturers are only too happy to help.

In terms of cheap, makeshift solutions, one can always buy a portable generator with an AC outlet. Honda makes one for the agricultural market called Enepo at a list price of ¥10,470. It runs on two cassettes of liquid propane gas, the kind you use to run those portable gas ranges, and can produce 900kW for two hours. The main catch is that you’re supposed to keep it outside, but that shouldn’t be a problem in the summer. A representative of Honda told TBS that even since the earthquake orders for the generator have increased tenfold. Also, the retailer Yamada Denki is working with a company called West Holdings to make a large rechargeable lithium battery for home use. The battery can be recharged through a home outlet at night when electricity is plentiful, and then used during the daytime if the need arises.

There are two types. The 1,000-watt model, which takes 3 hours to charge and can supply up to 500 watts an hour for two hours, costs ¥870,000; while the 2,500-watt model, which takes 8 hours to recharge and can supply up to 1,000 watts an hour for two-and-a-half hours, costs ¥1.8 million. Both Toshiba and Panasonic have announced they plan to start selling similar rechargeable devices sometime this summer.

However, households with even deeper pockets and longer outlooks will probably prefer to make their own electricity rather than simply stocking up on Tepco’s. Solar collectors have been widely available in Japan for years. In fact, at one point Japan led the world in the number of solar panels sold to consumers. (Several countries in Europe now buy more than Japan, but they buy from a Japanese company, Sharp.) The chief advantage of home solar systems is that your local power company will buy the electricity that you don’t need from you and thus cut your monthly bill.

TBS visited a two-family home in Yokohama whose solar system allowed them to reduce their bill by up to half. As far as a supplementary system goes in the event of blackouts, solar collectors provide a limited advantage. The Yokohama family happens to have special outlets installed that are connected directly to their solar system, but they can only use up to 1,500 watts during the daylight hours, which is not enough to power all the appliances they normally use simultaneously. Nevertheless, the added value of being able to sell excess to Tepco should boost sales of solar systems, which tend to be expensive, about ¥2.5 million, which means for an average household it takes from 10 to 15 years to pay off in terms of reduced electricity charges.

However, Tepco recently announced that it would double the price it pays for solar-generated electricity from homes, an announcement that angered some consumer groups since it means that households without solar will pay even more for their electricity; but that should mean even more people will be compelled to install the systems, which sounds like a good thing. It should be pointed out that current home solar systems reguire regular maintenance, which costs money. Also, Kyocera sells a portable solar panel on wheels that you can park on your veranda. Eight hours of sunlight will run your PC for two hours, which sounds kind of expensive for the price tag of the unit: ¥289,000.

Wind power is also available to individual consumers, and unlike solar has the advantage of being available as a supplement 24 hours a day, as long as there’s a breeze. The maker of one of the more popular models, the Air Dolphin, says that a wind speed of 5 meters per second will produce 100kW per hour. The drawback is that the windmill is 9 meters high, the propellors are 1.8 meters long, and it’s noisy, which means you might get flack from your neighbors. One company, Zephyr, has devised a new windmill that is much quieter, but each one costs ¥800,000, and that’s not including installation.

Obviously, you need cash and commitment to ensure supplementary electricity for your home, but the government will help. Solar systems receive subsidies of up to ¥500,000 from the central government, the prefectural government, and the local government. But like all consumer goods the more popular a product becomes the fiercer the competition, which means prices come down. So far, the majority of Japanese have not installed renewable energy systems because it didn’t seem that economical in the short run, but crises like the one we’re going through now have a way of changing that sort of thinking.

2 Responses

  1. I know I’m screaming into the void about this, but why aren’t the Japanese requiring that all new residential and commercial construction include solar panels? I know that it’s not the proverbial silver bullet, but it’s certainly a step into the future and if any country needs to develop a greater energy self-sufficient it is Japan.

  2. It is a shame that only solar generated power can be sold by individuals.
    If you generate from water, wind, biomass, geothermal or other recently developed micro power means no power company will buy your surplus.
    All the government funds go into over half a century old atomic plant designs with their centralized, big is beautiful appeal to local politicans.
    If you let individuals contribute power generated by their own design life in the countryside would be much more attractive for people with some engineering skills.
    I do live this dream myself without being able to expand due to the impossibility to sell my product electric power.


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