Renewables – Oct 24

October 24, 2006

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Many more articles are available through the Energy Bulletin homepage


Khosla stumps for solar, California ballot initiative

Rick Merritt, EE Times
The big opportunity for solar energy is in utility plants, according to Vinod Khosla, who gave back-to-back keynotes on the subject here Tuesday (Oct 16.). The iconic venture capitalist who has started his own alternative energy investment company also stumped for California’s Proposition 87, which would fund research into so-called clean technology.

“I now believe that thermal solar will be cheaper than coal-fired electricity plants. It is far more risky to build a coal-fired plant than a solar thermal one today,” said Khosla, speaking at the Emerging Ventures conference.

Photovoltaic cells have made significant advances with thin film, multi-junction technology. Utilities represent an opportunity for solar energy that could amount to hundreds of billions of dollars, said Khosla, who earlier in the day he delivered a keynote at a solar power conference a block away that attracted an estimated 7,000 attendees.

Although many developers are pursuing the low-cost solar cells, Khosla said “that’s exactly the wrong way to go.
(24 Oct 2006)


Ethanol: blessing or bane?

Greg Burns, Chicago Tribune
Plants offer promise of prosperity, but some fear bubble may burst
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…The ethanol boom is spreading money around the heartland like so much fertilizer. Billions of dollars in new government subsidies have touched off a flurry of private investment at biofuel operations across the Midwest. Tired towns where opportunity has slipped away for decades now see their salvation in the giant distilleries that turn corn into alcohol for the gas tank. Almost every rural hamlet has a plant in its sights, or so it seems.

Yet the benefits of ethanol fall unevenly, and some longtime rural interests stand to lose ground even as corn farmers and many others gain.

If the local crop gets used for ethanol instead of exports, then grain elevators, loading equipment and barges used to ship corn down the Mississippi could become obsolete. If grain is less readily available for feed, Midwest livestock producers such as Asay could be squeezed out. If ethanol plants emit excessive levels of pollution, their nearby neighbors could be in for a rude surprise.

And what if the ethanol boom goes bust? What if oil prices, already down sharply from their summer peak, head back to $20 a barrel? What if some cheaper raw ingredient takes the place of grain? What if ethanol plants really belong near their customers in big cities, instead of small towns in corn country?
(23 Oct 2006)


Energy from Wind: A Discussion of the EROI Research

Dr. Cutler Cleveland, The Oil Drum
TOD editor: This is a guest post by Cutler Cleveland. Dr. Cleveland is a Professor at Boston University and has been researching and writing on energy issues for over 20 years. He is Editor-in-Chief of the Encyclopedia of Earth, Editor-in-Chief of the Encyclopedia of Energy, the Dictionary of Energy and the Journal of Ecological Economics. He has particular interest and expertise in the field of net energy analysis.

As the world transitions from fossil based energy systems to a larger portfolio of renewables, the tradeoffs between energy quantity, energy quality and environmental impacts will increasingly need to be compared using meaningful metrics. Wind energy seemingly provides high returns, high quality energy (electricity) with minimal large scale environmental impacts.

Wind energy is one of the fastest growing energy systems in the world. In Europe and the United States, wind-powered generating capacity increased by 18 percent and 27 percent, respectively, in 2005 alone. While the rate of increase is impressive, wind still accounts for less than one percent of the world’s electricity generation.

The surge in wind energy is due to a combination of factors, including reduction in the cost of wind turbines, volatile prices for conventional forms of energy, the demand for non-carbon forms of energy to mitigate the effects of climate change, and generous government subsidies such as feed-in tariffs in Europe and the production tax credit in the United States.

One technique for evaluating energy systems is net energy analysis, which seeks to compare the amount of energy delivered to society by a technology to the total energy required to find, extract, process, deliver, and otherwise upgrade that energy to a socially useful form. Energy return on investment (EROI) is the ratio of energy delivered to energy costs.

…Does the high EROI for wind power presented here guarantee that wind will assume a major role in the world’s power generation system? There are a number of issues surrounding wind energy that require resolution before that happens.

The dramatic cost reductions in the manufacture of new wind turbines that characterized the past two decades may be slowing.
(19 Oct 2006)
Cutler summarises: “This article reviews 112 wind turbines from 41 different analyses, ranging in publication date from 1977 to 2006. This survey shows average EROI for all studies (operational and conceptual) of 24.6 (n=109; std. dev=22.3). The average EROI for just the operational studies is 18.1 (n=158; std. dev=13.7). This places wind energy in a favorable position relative to conventional power generation technologies in terms of EROI.”

Encouraging findings. This post is also available over at the new Encyclopedia of Earth website.
-AF


Outsourcing Solar Roofs

Peakguy, The Oil Drum: New York City
Based on much of what I’ve read and heard lately about renewable energy sources, I am becoming much more positive about Solar. While it’s very small right now, Solar power is one of the few renewables that can scale to meet a large proportion of our energy needs. It is one of the few area that I can envision technology getting better and less expensive over time, unlike the physical limitations of biomass derived energy.

The major barriers for many residential and commercial buildings to place solar on their sun drenched roofs is the upfront costs. People and businesses have budgets for buying the electricity they need, but rarely do they have the resources to make a large upfront investment in something that will take years or decades to pay back. Creative financing and outsourcing to specialized firms is the answer.
(22 Oct 2006)


Power lunch: Bacteria turn leftovers to energy

Edie Lau, Sacramento Bee
With the help of billions of hungry bacteria, a University of California, Davis, engineer has cooked up a system to extract energy from table scraps.

At a ceremony today expected to draw hundreds of people, the campus will formally introduce its $1 million “biogas” plant.

The plant can swallow between eight and 10 tons of food waste a day, feeding tanks of microbes that, in turn, excrete hydrogen and methane — gases that can be burned to generate electricity or fuel vehicles.

“This is a real commercial-size system,” said Ruihong Zhang, the UC Davis professor of biological and agricultural engineering who invented and patented the system after eight years of tinkering.

“This is 20,000 times larger than what we’ve been working with in the laboratory,” she said.

At full capacity, the plant can produce enough electricity for 10 average California households a day…
(24 Oct 2006)


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