Renewables – Nov 28

November 28, 2006

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Many more articles are available through the Energy Bulletin homepage


Wind, sun, storage, and efficiency

Gar Lipow, Gristmill
previously noted that efficiency is essential to eliminating fossil fuel use, because non-fossil sources have an overall market price cost higher than coal, natural gas, and even oil. This is not as obvious as it seems. Up to a point, renewable energy is competitive with fossil fuels; the problem is, that point is never a majority of consumption.

Take electricity.

You can produce unsubsidized wind power at 4 cents per kWh — cheaper than natural gas, cheaper even than “clean” coal. Unfortunately wind (like most renewables) provides variable power. It can be predicted to some extent, but comes on nature’s schedule, not when wanted. That doesn’t matter much as long as it supplies around 20% or less of total demand. Up to that point, the utility can treat it as negative load; added power when the wind slows or stops comes from existing operating and spinning reserves.

Beyond that point, wind energy without storage requires additional capital, additional reserve-generating capacity. That brings the price up steeply. There are regions that have more wind capacity than this, sometimes a great deal more. But they manage it by exporting electricity to other utilities. If you look at the grid as a whole, and not just local sub-grids, you will find no place where wind supplies much more than 20% of consumption in practice — without storage.

There are non-fossil fuel sources that don’t suffer from this problem, but they are limited. Geothermal electricity is reasonably priced and fully dispatchable, but cost-effective world resources are limited with current technology. (Yes, there are nations like Iceland where that is not a problem, but it is true for most of the world.) The same applies to hydroelectricity. Biomass energy is inexpensive when produced from waste, but still more costly than oil when purposely cultivated on energy farms — with serious water consumption, land use, and net energy issues.

In short, you have to add storage, and storage is expensive.
(27 Nov 2006)
Gar Lipow reviews the storage options and concludes that all have some problems, which is not to say useless — but “efficiency is the key”. One thing which could have been mentioned is dynamic demand control technologies. See Intermittency of Renewable Energy by Chris Vernon for a good intro.
-AF


How mirrors can light up the world
Scientists say the global energy crisis can be solved by using the desert sun

Ashley Seager, The Guardian
In the desert, just across the Mediterranean sea, is a vast source of energy that holds the promise of a carbon-free, nuclear-free electrical future for the whole of Europe, if not the world.

We are not talking about the vast oil and gas deposits underneath Algeria and Libya, or uranium for nuclear plants, but something far simpler – the sun. And in vast quantities: every year it pours down the equivalent of 1.5m barrels of oil of energy for every square kilometre.

Most people in Britain think of solar power as a few panels on the roof of a house producing hot water or a bit of electricity. But according to two reports prepared for the German government, Europe, the Middle East and North Africa should be building vast solar farms in North Africa’s deserts using a simple technology that more resembles using a magnifying glass to burn a hole in a piece of paper than any space age technology.

Two German scientists, Dr Gerhard Knies and Dr Franz Trieb, calculate that covering just 0.5% of the world’s hot deserts with a technology called concentrated solar power (CSP) would provide the world’s entire electricity needs, with the technology also providing desalinated water to desert regions as a valuable byproduct, as well as air conditioning for nearby cities.
(27 Nov 2006)


Spain requires new buildings use solar power

Reuters via MSNBC
Homes must use it for hot water, commercial sites for electricity
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Solar panels are now compulsory on all new and renovated buildings in Spain as part of the country’s efforts to bring its building rules up to date and curb growing demand for energy, ministers said on Monday.
(13 Nov 2006)


China plans world’s largest solar power plant

Reuters, C/net
China, seeking to ease its dependence on coal to fuel its booming economy, said on Tuesday it will build the world’s largest solar power station in the poor but sunny northwestern province of Gansu.

The 100-megawatt (mw) project would cost approximately 6.03 billion yuan ($766 million), and construction would take five years, Xinhua news agency said. .

Xinhua claimed the world’s current largest solar power station was a 5-mw project in Leipzig, Germany, with 33,500 solar panels. But a solar plant in Arnstein near Wuerzburg in southern Germany has a 12-mw capacity, according to its operator, S.A.G. Solarstrom.
(21 Nov 2006)


Green Energy in the North SF Bay

Clark Mason and Michael Coit, Santa Rosa Press Democrate
How alternative resources have gone from responsible to cost-effective
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EB contributor Shepherd Bliss writes:
The mainstream daily The Press Democrat here in Sonoma County, Northern California, published a long front page article on Nov. 26 headlined “Green Energy: how alternative resources have gone from responsible to cost-effective.”

The headline above a large photo of a 300-foot-tall wind generator in nearby Solano County, a model for Sonoma County’s Geysers, “already the world’s largest source for geothermal power,” reads as follows: “From the sun to the Earth: the North Coast is at the cutting edge in making renewable energy an economically feasible option.”

One Sonoma County town, Healdsburg, according to the article written by Clark Mason and Michael Coit, has operated an independent electrical utility for nearly 100 years. It “gets a majority of its power from renewable sources” and delivers “lower rates to its customers than PG&E,” the state’s largest utility, which has only 12% of its energy sources certified as renewable.

The Northern California Power Agency serves Healdsburg, Ukiah in Mendocino County and 16 other cities and public agencies. It advocates not only The Geysers wind farm, but also “a variety of innovative energy sources including tidal and ocean waves,” according to the article.

Many companies, groups, and individuals have been advocating the development of renewable energy here in recent years. Among those mentioned in the article are Fetzer Vineyards in Mendocino County, which this summer installed the largest solar array in the wine industry, and Codding Enterprises, which just installed a massive solar electrical system to redevelop a mixed-use community of 1900 homes in Rohnert Park. Professor Alexandra von Meier at Sonoma State University heads that school’s efforts to teach students about green energy.

Various local small groups also work to educate and advocate renewable area in the region and globally. Among them are the following: Solar Sebastopol, the Energy Transition Team connected to the Leadership Institute for Ecology and the Economy, the Livability Project, Sustainable Petaluma, and Santa Rosa Economic Relocalization.

Author Richard Heinberg also teaches at New College of California in Santa Rosa and has initiated various Powerdown Projects in the area. The Post Carbon Institute recently moved from Vancouver, Canada, to Santa Rosa.
(26 Nov 2006)


Tags: Electricity, Renewable Energy, Solar Energy, Solar Thermal, Wind Energy