Friday, October 9, 2009

Energy, the Challenge for the world

Report in the Wall Street Journal of Oct 02:

For more than a century, producing power has been a matter of flipping a switch. Things won’t be that easy as the world goes for energy from renewable sources. Winds tend to blow harder at nights, a problem, since people use electricity mostly during the day. Sunshine can lose its intensity in seconds if eclipsed by a cloud, inconvenient for people who like their air conditioners to run steadily on summer days. Wind and solar energy cannot be stored, as storage technology is still embryonic. And so the search for ways to accommodate the vicissitudes of wind and sun continue to shape up as one of today’s great technological quests.  

Many countries are pledging to produce 20% of their energy from renewable sources within about a decade. This will be a major stretch. Recession has severely crimped renewable energy investment. Proposals to turn over large swathes of desert and coastline to renewable energy generation are encountering angry opposition.

Currently, every wind farm and solar installation has to be backed up by a nearly equivalent amount of conventional fuel to keep the power grid running. That raises costs. Also required is investment in high voltage transmission lines to carry renewable electricity from remote areas to the cities.

In 2008, thousands of wind turbines installed across the US collectively produced only 1.3 % of actual electricity. Most of the wind turbines are located in Bonneville service area at the Columbia river gorge. This Tuesday at 1.00 a.m the wind farms were cranking out 1,550 megawatts. By 7.00 a.m that fell to about 800 mw, just as people were waking up and turning on their lights and toasters. That night, when most people were asleep, wind power topped 2,000 mw.

Most of the electricity in the Bonneville area comes from hydroelectric power. Water release from the dams is reduced to  make use of the wind power, but when wind is blowing hard, Bonneville releases extra water down the spillways without generating electricity to protect the system wires from overheating. And when the wind is so strong that Bonneville cannot ditch enough water, the utility orders wind turbines to shut off.

Texas produces more wind power than any other state. At 3.00 p.m on Feb 26, 2008, wind farms were throwing off about 2,000 mw  electricity, enough to serve about one million households. Then a cold wave blew in making the Texans turn up their heat. However, by 6.30 pm – when energy demand typically peaks – wind production had cratered to about 360 mw.  Ercot, the operator of Texas electric grid scrambled. It cut off power to various industrial customers. To avert situations like these, Ercot has hired a company to provide, an hourly forecast of how the wind will blow at every wind project on the Ercot grid. A very expensive arrangement.

Just after midnight on Christmas morning, 2007, an unexpected wind surge hit Colorado, a state with a lot of wind turbines. It sent power production soaring on the system operated by Xcel Energy. “We were walloped” says the vice president of the company. To compensate, Xcel scrambled to dial down some of its fossil-fuel power plants. Those plants were never designed to ramp up and ramp down at the level we are asking them to do. In this age of renewable energy, “We are learning as we go”.

My question is, if the American are still learning, what hope have we of successfully harnessing wind and solar power at affordable cost. What has not been mentioned in the above report is that water is as much a renewable source of energy as is wind and solar. And we have the technology for harnessing water power to produce cheap and clean electricity.

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