Posts Tagged ‘solar energy’

Electric cars aren’t just for driving any more

Tuesday, March 13th, 2012

Nissan charged up about giving back to the community.

Late last month, Nissan announced that starting in April its new electric car, the Leaf, would be used as an emergency power supply for a new office-condominium high-rise in Shinjuku managed by Sumitomo Real Estate. In the event of a disaster that resulted in a power failure, Leaf cars could be connected to the building’s electrical system through outlets specially installed for recharging electric vehicles and then the cars’ stored power could be used to supply electricity to the building for up to 42 hours for emergency services such as recharging cell phones and illumination. As a side note, the building also has a special hall that can be converted into a shelter for people in Tokyo who cannot return home during a disaster.

Though this is just a corollary benefit of the Leaf, Nissan’s announcement stresses the idea that electric vehicles could offer a wider range of purposes than just mobility. A number of new housing communities that are being developed with “smart grid” technologies have homes with EV charging stations. As with the Sumitomo building, these stations not only provide electricity for charging the battery of an EV, they also accept electricity from an EV that can be used in the home.

Such news is being stressed as more carmakers enter the EV field. Mercedes Benz Japan said it will start selling its own electric car, Smart, as early as August due to consumer demand. It will be the first foreign EV sold in Japan. At the moment the price hasn’t been determined, but an executive with the company has said it will be competitive with domestic EVs. The Leaf’s sticker price is about ¥4 million, but with the restart of the government’s eco car subsidy, a consumer could take it home for about ¥3 million. The Mitsubishi EV, the MiEV, is even cheaper. After subtracting the subsidy it would cost a little less than ¥2 million.

In related news, Panasonic has said it will start selling a rechargeable storage battery system (chikuden) for the home starting next week. The battery specifically takes advantage of home solar systems, and is mainly being promoted as a stopgap measure for power outages. The problem with solar systems is that they only work when the sun is shining and without a storage device any excess power goes to waste if it isn’t fed back into the grid. This battery can store solar power for the night, for a rainy day, or for blackouts. The battery is a lithium ion type, measuring 45 cm by 15.6 cm by 60 cm. Its capacity is 4.65kW per hour. When fully charged it can supply a house of average size with normal power for two days. The main drawback is the cost, which is ¥2,110,500. It’s cheaper to buy a MiEV.

Solar soon to be heating up in Tokyo

Tuesday, November 29th, 2011

An old solar heating system collector

In the wake of the Fukushima nuclear accident solar energy as a concept has become more attractive to the average person, and the central government’s recent passage of a law to promote renewable energies should help make solar power more widespread. Of course, solar power isn’t perfect, but not so much for the reasons nuclear apologists put forth. For instance, those who say solar energy is basically inefficient point to the fact that the electricity generated by household solar collectors is the equivalent in power of only 10 percent of the energy collected. This is a specious argument since sunlight is, for the time being at least, free, so we’re talking 10 percent of something that is constant and endless and which, untapped, just vanishes into the ether. It’s not like wasting the potential energy derived from gas or oil, since those are by definition finite energy sources.

The problem with solar energy is mainly a political one. According to the renewable energy law, which was sent to the cabinet for approval a day before the earthquake of March 11, power companies are obliged to buy excess energy from home solar systems. Tokyo Electric Power Co. announced last spring that it would buy electricity derived from solar collectors from private homes at double its usual rate. What the utility didn’t say so openly was that this expense would be reflected in electricity bills for all TEPCO customers. One of the main selling points of home solar systems is that, over time, the sale of excess energy to power companies would pay for the systems themselves, which are very expensive, though prices are coming down. People of limited means, which probably describes most households these days, can’t enjoy such benefits because they can’t afford to install solar systems. In the end, they help pay for the systems of the more well-off through their electric bills, not to mention schemes like eco points, which use tax money. So while some may claim that the greater good — greater reliance on solar energy — is worth it, the policy as it’s now carried out is inherently unfair.

A more equitable idea at the household level is using sunlight for heating rather than generating electricity. Solar collectors for heating water have been commercially available for years, and in terms of efficiency — 40 percent — beat out solar collectors for electricity. Since 2009, the Tokyo metropolitan government has been planning to subsidize solar collectors for home heating purposes. They will give people up to ¥500,000 if they install a solar heater in a new house. Condominium builders will also receive some kind of incentive. Recently, Tokyo solicited solar heater manufacturers, 60 of whom applied for approval. Fifty-one were selected whose products will be eligible for the subsidies.

It is the first time a local government has encouraged through subsidies the installation of solar heaters, which have never been so popular even though they are relatively inexpensive and easy to install. The hot water that is produced can not only be used for baths, showers and washing, but also for room heating if the home has a radiant heating system installed in the baseboards or the floors. Such systems, of course, can help households save on energy bills and do not produce extra carbon dioxide, which is the main benefit for Tokyo since local governments have been charged by the government with reducing their carbon output. More important, these savings are not at the expense of other households who do not have the system installed. Solar heating is self-contained, and therefore self-reliant.


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