Showing posts with label renewable energy portfolio. Show all posts
Showing posts with label renewable energy portfolio. Show all posts

Friday, December 26, 2008

Full of powerful wind? Bury it in the ground for later

By Glenn Fleishman

A not-so-new notion is gaining traction for storing power generated at nonpeak times: compress regular air into underground chambers, then retrieve it later to spin turbines.

Wind power can be generated any time the wind is blowing at the same cost day and night. Because there's no efficient way to store power when it's generated but not needed, utilities and wind-power farms around the world are already having to slough off power as wind-based generation scales to something beyond scattered projects.

The New York Times blogs about a variety of efforts focused on using the excess electricity from some wind systems to compress air into sealed underground chambers, such as those left behind from various kinds of pumping and mining operations. The compressed air has potential energy that can be released later.

The current generation of compressed air energy storage (CAES) systems have to burn natural gas to heat the compressed air before the air can be used to turn turbines and recapture a good fraction of the energy used in compression. Future CAES plants are planned that skip the natural-gas input, shunting waste head from compression into the decompression process.

Certain parts of the world are better suited to using CAES for energy storage. In Ontario, the Toronto Star reported a few days ago that there are 50,000 wells in the province of which just 2,000 are still in use. Some of these wells are used for a different kind of stored energy: compressed natural gas, pumped and held until demand requires its release. Others could be used to store compressed air.

The comments on the Times blog entry are particularly interesting, with the author of a significant paper on the technology chiming in, along with a wind industry representative named Michael Goggin. Goggin wrote that storage is unnecessary because other types of generation can be shut down on demand in favor of wind—water can be held behind a dam for later release or natural gas held in pipes for later burning.

But that's surprisingly idealistic. In the real world, the cheapest power is used first. If wind power is generated during nonpeak times, less money is paid for it, even with the subsidies in effect in many countries to encourage wind generation. Goggin's scenario works only if the costs are the same among different forms of generation, or a single utility owns the various forms of generation and chooses a more-expensive method to obtain carbon credits or meet greenhouse gas emission goals.

This view also requires that transmission systems are capable of moving wind power at nonpeak times precisely to where it's best needed. As Sandia National Laboratories researcher Georgianne Peek said (in a press release about an Iowa CAES project) in June 2008, "The wind blows in some areas when electricity is not needed or where the transmission system can't accept all of the energy."

If wind power can be offset from nonpeak to peak times, then it becomes more viable, and thus sees greater use. This could balance green-power principles (more wind generation) with market motivations (lowest cost).

While batteries can also be used to store energy, they are expensive to make, use hazardous and toxic metals and compounds, and can't hold energy for very long. They're useful in specific situations, like home storage and backup with solar systems. Peak shifting, in which power generation is used during off hours to be reclaimed in some form during more expensive daytime uses, involves everything from next-generation flywheels to making ice power air conditioning during the day to providing incentives and for future electric-car owners to charge their cars primarily overnight

Wednesday, November 19, 2008

California Ups Renewable Energy Mandate to 33% by 2020

Written by Timothy B. Hurst

Published on November 17th, 20082 CommentsPosted in Center, Energy, Leader
Gov. Schwarzenegger Signs Executive Order to Raise California’s Renewable Energy Goals to 33% by 2020 and Clear Red Tape for Renewable Energy Projects

In an executive order signed on Monday, California Gov. Arnold Schwarzenegger committed to getting a third of California’s electricity from renewable sources by 2020. Schwarzenegger made the announcement while speaking at a solar panel factory in Sacramento. California Executive Order S-14-08 puts the state’s renewable energy requirement at 33% by 2020, securing its place as the most aggressive renewable energy mandate in the country.

vote nowBuzz up!The order comes Just three days after Schwarzenegger issued another unprecedented executive order to state agencies telling them to make preparations for rising sea levels caused by global warming.

Schwarzenegger’s aggressive target, however, cannot be met without additional changes in the current policy landscape. In fact, just two weeks ago, California voters soundly rejected Proposition 7 which sought to increase the state’s renewable energy standard. Environmental groups were nearly unanimous in their opposition to Prop 7 because it created an exclusion for smaller utilities and power providers. Schwarzenegger said:

“…we won’t meet that goal doing business as usual, where environmental regulations are holding up environmental progress in some cases. This executive order will clear the red tape for renewable projects and streamline the permitting and siting of new plants and transmission lines. With this investment in renewable energy projects, California has a bright energy future ahead that will help us fight climate change while driving our state’s green economy.”

The Governor will propose legislative language that will codify the new higher standards and require all utilities, public and private, to meet the 33 percent target and spread implementation costs across all ratepayers with safeguards for low-income customers. The executive order will also allow for the expansion of eligibility for California’s RPS program to renewable energy generation from other western states.

The Governor made today’s announcement at the site of OptiSolar’s new plant in Sacramento, which will begin manufacturing solar panels in early 2009. When fully built out, the one-million-square-foot plant will be the largest photovoltaic solar panel manufacturing plant in North America.

Image: Lawrence Livermore National Laboratory


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