Renewables – July 21

July 21, 2007

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A German City’s Long Focus on the Sun

Paul Burkhardt, Associated Press
FREIBURG, Germany – Rolf Disch has harnessed the sun in his city of Freiburg, starting with his own house.

It looks like an upside-down Apollo spacecraft and serves as a testing ground for ideas dreamed up by the 63-year-old solar architect.

0719 10The home slowly turns with the sun to charge a billboard-sized solar panel on the roof, and the waterless toilet emits an occasional malodorous whiff. Hanna Lehmann, Disch’s wife, says she doesn’t mind these features but admits she’d like to have a freezer, except that it would eat up too much electricity for her husband’s liking.

“I miss my Campari on ice,” she said.

Disch and his city are pioneers in energy-saving, and a growing number of eco-tourists flock here to admire his house, known as the Heliotrope, from the Greek words for “sun” and “turn.” Across the city, solar panels are on everything from the soccer stadium to entire neighborhoods with homes that produce more energy than they use.

“Energy was too cheap for people to take it seriously, but with the rise in energy costs and the IPCC report people see that they have to look for other solutions now,” Disch said, referring to the U.N.’s Intergovernmental Panel on Climate Change, which documented scientific evidence for global warming.

With its focus on solar energy, Freiburg demonstrates the progress that can be made by promoting, developing and using renewable energy. But the city of more than 200,000 in the sunny southwestern corner of the country also is an example of how far technology in the solar sector has to go _ it produces less than 1 percent of its electricity from the sun
(19 July 2007)


Hot off the grid
Solar ovens utilize nature’s rays for energy-efficient, everyday cooking — even in foggy San Francisco

Tara Duggan, San Francisco Chronicle
..Sun-heated ovens are nothing new. The idea has been around for centuries, and people of a certain age may remember using ragtag cardboard-and-foil contraptions to bake carrot-lentil loaf back in their hippie days. But with today’s new versions that produce results comparable to conventional ovens, solar ovens are poised to move into the mainstream.

“For people who are interested in being carbon-neutral or being green, the idea of using something like a Sun Oven is very appealing,” says Paul Munsen, president of Sun Ovens International, based in Elburn, Ill. He expects to sell 5,700 ovens in the United States this year, up from around 1,000 in 2004.

Lynn Langford of Ross purchased a Sun Oven a year ago and uses it to prepare dishes such as baby beet salad with walnuts and feta. Instead of boiling the beets on her stove and toasting walnuts in her oven, she places the beets in a dark pot, wraps the nuts in parchment paper and tucks both into the oven to cook in her sunny backyard.

“When you care about not heating up the whole planet, it’s a fun and easy way to do it,” says Langford, who says her electricity bills dropped by 30 percent in the first month of using her solar oven about three times a week. ..
(11 July 2007)
Long article concludes with recipes and additional notes on history and potential of solar ovens. -LJ


Photovoltaic for Australia

Tom Wayburn, Dematerialism
In the United States, which is the only country I know enough about to suggest policy, which is not to excuse jingoism of any stripe, the applicability of photovoltaic solar cells (PV) is limited by the total area suitable for PV divided by the number of people. Australia has an area nearly as large as the area of the US and a much smaller population; therefore, enough area per person can be devoted to solar to satisfy the personal energy budget of every person, provided the political will can be found to overcome the huge energy debt that must be incurred before payback begins and, possibly, to accept a complete change in political economy to keep the EROI as high as 3.0, a number that might not include the costs of commerce. This is explained in “Energy in a Mark II Economy. ..

In the first two spreadsheet models we needn’t concern ourselves with energy units or with the actual energy requirements of the Australian economy. The purpose of the following exercise is to determine if anything can be done to prevent the disqualifying deficit incurred by straight-forward exponential growth for solar cell production. It occurred to me that a one-time subsidy of energy – or, more likely, completed solar cells produced elsewhere – would be sufficient to jumpstart new production facilities powered by the output of the existing cells. The results are summarized in Table 1 below.
(18 Jul 2007)
The product of an ongoing debate/discussion on the ROEOZ list. I’m not yet sure I can make much sense of it. Elucidation is welcome. -LJ


Arizona shouldn’t waste public money on impractical photovoltaic cells
(Guest opinion)
John Kromko, Arizona Star
About 30 years ago, a great wave of interest in solar energy swept through the state Legislature. Being a former engineer, I realized that the numbers didn’t quite add up. But I went along with the near unanimous vote to set up several solar-energy programs, hoping that economies of scale would kick in and make the programs feasible.

Grants, rebates and credits flowed profusely, and the only result was that the state and many of its citizens lost many millions of dollars. The cycle has been repeated several times, the most famous being the alternative-fuels disaster that could have bankrupted the state.

Now it looks as if we’re poised for another round.

Repeating history has demonstrated that whenever politicians act with undue fervor or without sufficient knowledge, slick operators will appear to take the money and run.

…Installing 2-kilowatt arrays on individual homes is not nearly economically feasible and almost certainly never will be. On the other hand, solar turbine-generator technology is economically feasible, environmentally superior to photovoltaic, and is ideally suited for Tucson’s climate.
(19 July 2007)
Contributor Steven Lesh writes:
This is a debate that really needs to be conducted nation-wide. The time and resources to do something about global warming are getting very short. Homeowner-installed PV appears to have been uncritically accepted by politicians and the media without proper consideration of its economics and the overall manageability of the resulting system.

I bought into the promise of homeowner PV (4kw DC) and have no regrets especially come power bill time. Take that back. For all the trouble and expense involved, I’m left with the knowledge it did NOTHING to reduce the amount of greenhouse gases my utility is pumping into the air to produce my electricity.


Tags: Electricity, Photovoltaic, Renewable Energy, Solar Energy