Geothermal energy is a form of energy using the inherent warmth of the ground to create power in primarily the form of heat. Roughly six to seven feet below the surface of the ground, the temperature of the Earth is regulated. By exchanging liquids between above and below ground areas, temperature regulation can be achieved. This is mostly seen in residential situations.
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Renewable Geothermal Energy / Geothermal Power
The renewable energy future
Remember rain?
As Los Angeles creaks through its driest year on record and nervously awaits its next explosive wildfire, many wonder if global warming is already taking a toll. Nobody really knows; California has always had intermittent droughts, after all. But climate models predicted this situation. Changes in ocean temperatures and currents driven by things such as the melting of the Greenland ice shelf -- which is happening a lot faster than scientists expected -- will probably produce an even more desert-like climate in L.A.
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Future Power
Where on Earth can our energy-hungry society turn to replace oil, coal, and natural gas?
Freedom!
I stand in a cluttered room surrounded by the debris of electrical enthusiasm: wire peelings, snippets of copper, yellow connectors, insulated pliers. For me these are the tools of freedom. I have just installed a dozen solar panels on my roof, and they work. A meter shows that 1,285 watts of power are blasting straight from the sun into my system, charging my batteries, cooling my refrigerator, humming through my computer, liberating my life.
As National Geographic reported in June 2004, oil, no longer cheap, may soon decline. Instability where most oil is found, from the Persian Gulf to Nigeria to Venezuela, makes this lifeline fragile. Natural gas can be hard to transport and is prone to shortages. We won't run out of coal anytime soon, or the largely untapped deposits of tar sands and oil shale. But it's clear that the carbon dioxide spewed by coal and other fossil fuels is warming the planet, as this magazine reported last September.
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Clean Wind Energy for Year
Citizens for Pennsylvania's Future (PennFuture), an environmental nonprofit, has launched a year-long contest for Pennsylvania residents in which it will give away six compact fluorescent bulbs each month to a monthly winner and a grand prize of one year's supply of clean wind energy. (Enter here.)
Perhaps more importantly, every entrant in the contest will receive a free copy of a PennFuture brochure, "Ten Quick Actions to Help Stop Global Warming."
Great idea, happy to see...
New York Sees Renewables Progress
The summary of a report on New York's Renewable Electricity Standard (RES) makes for some interesting reading. Some highlights:
NYSERDA is planning a third solicitation this fall, and says, "Considering the large number of wind projects under development, a significant number of potential bidders are expected, and consequently, reasonably priced bids are anticipated."
What is happening in New York is a good example of what can happen with strong leadership at the state level. Former Gov. George Pataki (R) and current Gov. Elliott Spitzer (D) deserve enormous credit for pushing this effort forward.
kkarthikeyan
Storing Solar Power Efficiently
Thermal-power plants that store heat for cloudy days could solve some of the problems with solar power.
Solar proponents love to boast that just a few hundred square kilometers' worth of photovoltaic solar panels installed in Southwestern deserts could power the United States. Their schemes come with a caveat, of course: without backup power plants or expensive investments in giant batteries, flywheels, or other energy-storage systems, this solar-power supply would fluctuate wildly with each passing cloud (not to mention with the sun's daily rise and fall and seasonal ebbs and flows). Solar-power startup Ausra, based in Palo Alto, thinks it has the solution: solar-thermal-power plants that turn sunlight into steam and efficiently store heat for cloudy days.
"Fossil-fuel proponents often say that solar can't do the job, that solar can't run at night, solar can't run the economy," says David Mills, Ausra's founder and chairman. "That's true if you don't have storage." He says that solar-thermal plants are the solution because storing heat is much easier than storing electricity. Mills estimates that, thanks to that advantage, solar-thermal plants capable of storing 16 hours' worth of heat could provide more than 90 percent of current U.S. power demand at prices competitive with coal and natural gas. "There's almost no limit to how much you can put into the grid," he says.
Major utilities are buying the idea. In July, the Pacific Gas and Electric Company (PG&E) signed a 25-year deal with Ausra competitor Solel Solar Systems of Beit Shemesh, Israel, to buy power from a 553-megawatt solar-thermal plant that Solel is developing in California's Mojave Desert. The plant will supply 400,000 homes in northern and central California when it is completed in 2011. Florida Power & Light, meanwhile, hired Solel to upgrade the 1980s-era solar-thermal plants it operates in the Mojave.
Ausra, meanwhile, is negotiating with PG&E to supply power from a 175-megawatt plant that it plans to build in California, for which it secured $40 million in venture financing this month.
What distinguishes Ausra's design is its relative simplicity. In conventional solar-thermal plants such as Solel's, a long trough of parabolic mirrors focuses sunlight on a tube filled with a heat-transfer fluid, often some sort of oil or brine. The fluid, in turn, produces steam to drive a turbine and produce electricity. Ausra's solar collectors employ mass-produced and thus cheaper flat mirrors, and they focus light onto tubes filled with water, thus directly producing steam. Ausra's collectors produce less power, but that power costs less to produce.
One megawatt's worth of Ausra's solar collectors has been producing steam in New South Wales, Australia, since 2004; the steam is fed into the turbines of a primarily coal-fired power plant. The final piece of the system--a proprietary heat-energy-storage system--should be ready by 2009.
SOLAR ENERGY AS CHEAP AS COAL!
Energy company Sunrgi recently announced an astounding new solar system that will break our grids free from the fossil fuel lockdown. Their Xtreme Concentrated Photovoltaics promise a low-cost, high-efficiency system with an incredible projected energy pricing of 5 cents per kilowatt. This breakthrough puts solar on par with the cost of coal, natural gas, and other non-renewable energy sources.
If solar energy is ever going to live up to it’s world-changing potential, it’s going to have to mesh with our existing energy infrastructure, competing with coal and natural gas on price point. While traditional photovoltaic arrays span great expanses and struggle to keep costs down, Sunrgi’s system proposes a novel idea, making better use of fewer expensive materials.
The XCPV system is based on a principle blinding in its simplicity: use a magnifying glass to concentrate the sun’s energy into a single high efficiency solar cell. Each unit features a lens that magnifies the sun’s rays 2,000 times, focusing it onto a solar cell that converts more than 37% sunlight to energy. The result is a system that maximizes the potential output of each solar cell while minimizing cost and space required.
The units are modular and thus easily deployable on or off-grid, and they can be easily upgraded to accommodate future advancements in solar cell technology. To deal with the tremendous temperature of focused sunlight (more than 3,000 ºF!), Sunrgi has developed a proprietary cooling system that keeps the panels safe and sound. Rounding out the tech is a sun-tracking system and a PV cell composition that doesn’t depend on the world’s depleted silicon reserves.
Craig Goodman, president of the National Energy marketers Association, has stated that “Solar power at 5 cents per kWh would be a world-changing breakthrough. It would make solar generation of electricity as affordable as generation from coal, natural gas, or other non-renewable sources, without require and subsidy.”
Sunrgi has built and tested working prototypes, and has announced plans for commercial production in 12-15 months.
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