Renewable Or Nuclear Energy? That''s Just One Question
By the end of next year, motorists coming into San Antonio on Interstate 37 will be met with an awesome sight: more than 200,000 shimmering solar panels turning the scorching sun into clean electricity to help power the city.
The project will make CPS Energy the state leader in solar power, a lofty position the company proudly touts along with its title as the nation”s top public utility for the use of wind power.
But when it comes to the biggest decision facing CPS – how to meet the energy shortage looming in the next decade or so – utility officials are adamant that renewable resources like solar and wind are not yet ready to shoulder the lion”s share of the load.
The proposed solution instead is to add two nuclear reactors to the South Texas Project. Utility officials insist the proposed $5.2 billion investment is cheaper and more reliable than solar or wind.
The situation has the local anti-nuclear coalition Energia Mia and statewide renewable energy proponents outraged.
Some insist CPS is flat wrong that solar and wind are not ready to lead San Antonio into the future. Others say that, right or wrong, CPS Energy has not produced the analysis to back up its contention.
CPS officials believe they are getting a bad rap for an energy plan that, in their estimation, is reasonable and balanced.
“Our plan embraces all forms of energy, wind, solar and, yes, nuclear,” said Mike Kotara, executive vice president for energy development at CPS Energy. “It”s not a matter of either-or.”
National experts at the Energy Department”s research laboratories support much of CPS Energy”s view of renewable energy. Solar and wind still are unreliable compared with conventional sources like nuclear or coal, according to the DOE. And the vaunted technology to store the power produced by the sun and wind so it is available when needed, is, in many cases, still in its experimental stage and very costly.
However, things are changing quickly with renewable energy, particularly solar.
The Bureau of Land Management has opened up its vast tracts of land in the Southwest for solar proposals, with an eye toward eventually producing as much as 100,000 megawatts of solar – more than 20 times San Antonio”s peak power needs.
The Energy Department is working on making solar thermal power – which focuses the sun”s heat through a series of mirrors – one of the most cost-effective power options by 2015. And closer to home, a Florida company last month announced plans to build a 300-megawatt solar plant in West Texas, a project that would be the biggest in the state and one of the biggest in the country.
CPS isn”t a buyer of that power, but it just announced a 30-year agreement to buy power from the 14-megawatt project being developed by the Colorado-based Juwi Solar off I-37. That facility will produce enough electricity to power about 1,800 houses a year.
In June, CPS signed a 20-year agreement to buy power from the 27-megawatt solar plant Tessera Solar is developing in West Texas.
Announcements like these are making people wonder what the energy landscape will be like in five or 10 years, when San Antonio could be committed to the new nuclear reactors.
“To me, the solution is solar power and wind power,” said Energia Mia member and former City Council member Patti Radle.
Beyond the cost of nuclear, Radle is concerned about safety issues and the problem of storing waste.
“San Antonio has plenty of solar and South Texas has plenty of wind,” she said.
Given its size, locale and climate, Texas has more potential for renewable energy than any other state.
It has harnessed the wind more effectively than any other, filling huge swaths of West Texas with wind turbines, and recently started to build wind farms on its gusty coastline. It is also investing $5 billion in transmission projects to help it move power from the desolate wind centers in the west to the cities.
The problem is that the wind doesn”t blow all the time, and in West Texas it tends to pick up at night when power needs are not critical.
This makes it a tricky proposition for a utility worried about meeting its peak power demand, which usually occurs during the hot summer months when people get home from work and crank up their air conditioners and appliances.
In June, for instance, wind output in Texas often dipped below 20 percent of capacity, and sometimes even below 10 percent, during peak demand, according to the Electric Reliability Council of Texas.
The solution proposed by many, and one brought up often at the public debates over San Antonio energy, is to store the power by a variety of methods to make it available when it is needed the most. Ideas being tested include batteries or the use of compressed air or water to store the energy.
The Energy Department believes so strongly in the potential of wind that it has set a goal of producing 20 percent of the nation”s energy by wind by 2030. But the federal government isn”t near as bullish on storage, said Ben Karlson, wind integration lead at the DOE”s Sandia National Laboratories. It”s not even part of the plan.
“The capital cost is so high, it doesn”t make sense,” he said. “We”re talking $150 per kilowatt hour (for storage). That”s huge.” At that price, it”s cheaper to build new power plants, he added.
Storing solar thermal
The potential for energy storage changes drastically when talking about solar thermal energy. Here experts believe they soon can produce storage systems at one-tenth of the price quoted for wind storage. That would make solar thermal one of the most inexpensive forms of energy available.
San Antonio, which has among the lowest electricity prices in the nation for a major city, charges its residential customers about 9 cents a kilowatt hour. And CPS wants its new nuclear plants to produce energy at about 8 cents a kilowatt hour. If the DOE hits its target with solar thermal, it will beat both those costs by the middle of the decade.
The agency has set a goal of producing solar thermal energy for about 7 cents a kilowatt hour by 2015 with up to six hours of storage, and 5 cents a kilowatt hour by 2020 with 16 hours of storage, said Brad Ring, manager of the solar program at the DOE”s field office in Golden, Colo.
“It”s an exciting time,” Ring said. “There is a lot of effort being put forth with some promising results.”
These goals are set for the best areas in the country for producing solar thermal energy, which are generally found in the Southwest. But some parts of West Texas also are considered suitable for this technology, said Nathan Siegel, a senior member of the technical staff at Sandia Laboratory.
What makes solar thermal most appealing for storage is that it depends on heat to generate electricity, and heat is much easier to store than electricity itself, Siegel said.
Generally, these plants use thousands of trough-shaped mirrors to focus the sun”s heat on pipes that contain fluid or oil. The fluid, which reaches temperatures of more than 700 degrees, is used to heat water, which creates steam that runs turbines to create electricity.
Several plants using this technology are operating in the U.S., including the 64-megawatt Nevada Solar One plant started in 2007.
The heat also can be stored in insulated tanks full of molten salt and used to create energy for a period of hours after the sun has set. Currently, the cost of solar thermal is about 16 cents a kilowatt hour, Siegel said. He expects large plants using storage to come online soon.
“The issue now is one of financing,” Siegel said “The technology is basically at the point where somebody could take it and run with it.”
Arizona Public Service has announced plans to build two large solar thermal plants of just under 300 megawatts each. The utility expects the plants to be operating by 2012 and 2013. Both plans boast storage.