May 11, 2007 4:00 AM PDT

Shrinking the cost for solar power

One of the big problems with solar power has been that it costs more than electricity generated by conventional means. But some experts think that, under certain circumstances, the premium for solar power can be erased, without subsidies or dramatic technical breakthroughs.

A sufficiently large solar thermal power plant (also called concentrated solar power, or CSP) could potentially generate electricity at about the same cost as electricity from a conventional gas-burning power plant, experts say.

It's not easy. The plant would also have to come with a large energy storage system, be built next to others and be located close to users. To date, no one has completed a facility that comports to all of these parameters, said Fred Morse, an energy analyst who has studied the issue.

"Solar thermal is available at much more attractive prices than solar photovoltaic. The land mass isn't huge, but it does take a while to build these," said Stephan Dolezalek, a managing partner and co-head of the clean tech practice at venture firm Vantage Point Venture Partners, an investor in Bright Source Energy, which builds solar thermal plants and components.

Both Dolezalek and Jiang Lin, who heads up the China Energy Group at the Lawrence Berkeley National Laboratory, said that solar thermal is likely the most promising technology in the entire alternative-energy field right now.

When asked when solar thermal can hit parity, Lin responded "now."

Thermal by the numbers
Conventionally generated electricity ranges between 5 and 18 cents per kilowatt hour (the amount of money to get a kilowatt of power for an hour) but in most places it's below 10 cents, according to the Energy Information Agency. Solar thermal costs around 15 to 17 cents a kilowatt hour, according to statistics from Schott, a German company that makes solar thermal equipment.

A solar thermal plant would need a facility to store the heat harvested in the day by its sunlight-concentrating mirrors so that the heat could be used to generate electricity at night. "You need the kind of system that can run in the evening," Morse said. At some sites, such as Nevada Solar One, excess heat is stored in molten salt and released at night to run the turbine.

The plant, ideally, should be capable of generating about 300 megawatts of electricity. Those plants can churn out electricity at about 13 cents a kilowatt.

That's still a relatively high price, so utilities would need to group two, three or more 300-megawatt plants together to share operational resources, Morse said. "They could share control rooms or spare parts," he said. That would knock the price closer to 11 cents a kilowatt hour.

"Under 10 cents is sort of the magic line," he said.

Dolezalek puts it another way: the plants need to be around 500 megawatts in size. Most solar thermal plants right now aren't that big. The 22-year-old thermal plant in California's Mojave Desert is 354 megawatts. Utility company Southern California Edison is erecting a 500-megawatt plant scheduled to open in 2009.

By 2014, solar thermal plants located in the Southwest could crank out nearly 3 gigawatts of power, estimated Travis Bradford of the Prometheus Institute for Sustainable Development, a nonprofit based in Cambridge, Mass. That's enough for about 1 million homes.

Costs can then be reduced further by building the plants close to consumers. It costs about $1.5 million per mile for transmission lines, according to statistics from Acciona Solar Power, which owns solar thermal plants. Solar thermal plants work best in arid deserts that get little rainfall. Since some of the fastest-growing cities in the world are located in sun belts, that's less of a problem than it used to be.

But getting to that point isn't easy. Land-use hearings and permits can drag on for years while construction costs rise. The amount of land required can be an issue too: the 354-megawatt plant in California occupies 1,000 acres. Larger plants would need more land, while smaller plants result in higher costs per kilowatt hour.

Even if all of these factors could be completely optimized, solar thermal power plants would likely not produce electricity at a level that would compete with coal plants. Coal plants, however, will likely be hit with carbon taxes in the near future, which will make solar thermal more competitive. Still, at less than 10 cents a kilowatt, solar thermal would be competitive with electricity from gas-powered plants.

Utilities will also likely work hard to lower the costs of solar thermal in the coming decades, Morse added. Utilities are under mandates to increase their renewable energy sources. Citizen groups often complain about wind turbines and the wind doesn't blow at a constant, predictable rate. Several companies are intent on tapping heat from under the surface of the earth to generate power. Geothermal power, however, works best only in certain locations.

"There is an enough flat, unproductive land in the U.S. to power the U.S.," Morse said. "We just don't have the wires to get there. Eisenhower built the national highway system. Some president will build the national grid."

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If you think siting wind turbines is problematical, recall the
knockdown dragout fights against power transmission lines. We're
probably not all going to move to the source, so we will still need
power lines to take major advantage of solar thermal electricity. For
all the talk about alternative energy sources, we still think locally
and act globally.
It is nice to see a solar electric design with a practical energy
storage system built in for the kwh costs cited in the story, though.
Posted by billmosby (536 comments )
Reply Link Flag
Going Green with going Broke
We are all overlooking an important issue here, what can we do as individuals to have an effect on the global energy problem we face today. The answer is Make Solar Power Affordable to the masses. Alternative energy is moving in the right direction to meet the demand but, what effect will it have on homeowners who can not afford it. I recently ran across a company that has removed the tradition cost to Solar Power. They do it with a rental agreement and with an electric rate locked in at or below what you are paying to your electric provider now. They provide a worryfree system, they install it, and maintain it without any addition fee. Imagine every home producing their own electric Solar power on their roofs without going broke. Now the average homeowner in America can take the power back and take action as a collective force with solar power. Think of it, all the energy savings that it would have all across this country not to include the money saved for the homeowner. <a class="jive-link-external" href="" target="_newWindow"></a>
Posted by 2renu (1 comment )
Link Flag
Why are Al Gore, Google, and Wal-Mart putting solar panels on their roofs
If this article is true, why are Al Gore, Google, and Walmart putting Solar Panels on their roof?

We think we know why. In our opinion, it seems these days many are trying to look green even if it cost them. What good would it be if Al Gore put his panels in the Arizona or Nevada desert if no one could see them? He has run a noble race getting the word out about Global Warming. He should do the right thing now and convince himself, Google, and Walmart to use Solar Transfer logic with federal subsidies to put their money to the best use. This is the same federal subsidy that pays you to put panels on your roof in your home state. How can someone in Alaska, New York, or Maine take advantage of that subsidy? They can?t because the sun does not shine with enough power in their state but the federal government would still chip in our share for a losing situation. Now residential solar installers, BP, GE, Arnold Scharzenegger and others may get upset with this logic but it has to be put out there. Missing out on a 4-fold gain is too important. Yes, we calculate a 4-fold return in the power Al Gore and others could generate from the sun by following our logic with the same invested dollar amount. That means 4 times less coal or gas needs to be used to create the same amount of power. A mistake now would cost that much energy savings and GHG reduction over the next 30 year life of the panel investment. We have been trying to drive the solar community in the direction of this article for years. It comes close to our Solar Transfer solution but high-grade photovoltaic chips will still be part of the final mix. Our solution takes the concentrated solution one step further into the mobile fuel industry. Ask your Governor or Senator if they read the Solar Transfer report that was sent to them a year ago. President Bill Clinton sent us a nice letter to keep up the good work, but most other politicians seem to be hesitant on making real energy moves especially those with coal, gas, and oil interest within their state. That is only natural but if we are going to solve this GLOBAL issue they need to see the big picture. That is what we are good at at Solar Transfer, the final solution, the ultimate design. Send this text and ask all those running for office in an email how they feel about renewable energy and Solar Transfer. Solar Power will be the solution once we get enough people to understand our work.
Posted by Manhattan2 (329 comments )
Reply Link Flag
Maine Solar House
I think it is a misperception that you cannot have an effective solar house in Maine?

<a class="jive-link-external" href="" target="_newWindow"></a>
Posted by mados123 (121 comments )
Link Flag
Think long term.
You can't just look at the cost per kwh because that's only part
of the story.

When you use energy that doesn't come from a renewable
source like wind or solar, you add to the demand for
conventional sources. That drives up prices. Conversely, when
you use solar, you reduce demand for conventional power.

Solar energy will eventually be more cost effective than oil, but
in the mean time it can and does save us all money. Even those
of us not using it!
Posted by Macsaresafer (802 comments )
Link Flag
I'm glad you didn't link to your website this time
It's one of the least professional and devoid of content sites I've ever seen. It makes it look like the concepts haven't gotten out of the designers head, or the designer is too paranoid to share anything about it for fear of someone stealing the idea.
If the solar transfer report was anything like the website, I'm sure nobody got past the first page.
Posted by skrubol (181 comments )
Link Flag
How valuable is desert land anyway?
In this article, one of the costs taken into consideration is the
land needed for solar panels. Why would the price of desert
land be so significant? Solar seems to be a means to put
inhospitable land to good use. The more arid the land, the less
it costs; not to mention the more efficient solar becomes.
Obviously, solar power can't be used everywhere in the US, but
for those regions near arid climates, it would be the best source
of power. Even if it is not the most cost-effective power, solar
energy is clean and would not require a nonrenewable fuel. Coal
and natural gas may be the best options today, but the costs of
all fossil fuels will only go up. Once solar becomes competitive
with those fuels, it's time to transfer to the more reliable power
for the future.
Posted by Battleshipagincourt (14 comments )
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I would like to see a study that incorporates the land costs for conventional energy... one that includes the area needed to mine for coal, oil, or gas, the plants to refine it, and the power plants to convert it into energy. the 1000 acre solar field in California does seem like a lot of land, but i kinda imagine it's about the same if you take into account all the other factors to make "conventional" power. Heck, I was just traveling in Bahrain and saw way more than a thousand acres of land with oil and gas pipes crisscrossing through the desert. BTW 1000 acres is 1.5625 sq miles. I'm new to looking at this stuff, but what about a Hybrid system that helps to make solar more efficient?
Posted by fauja (1 comment )
Link Flag
Solar power satellites?
In the recent, resurgent interest in solar power there has been no mention of the solar power satellite concept. I saw a presentation in the late 90's that claimed the basic engineering is done and shows it is a viable solution. The next step is to build a prototype and work out the kinks, but no one seems to be talking about this?
Posted by C.Schroeder (126 comments )
Reply Link Flag
Goes back further than that
Back to Peter Glaser in 1974. The biggest perception problem, after
figuring out how to get the things into orbit, was the microwave
power transmission back to Earth. Diffuse it may be, but scary to
some folks all the same. Gerard K. O'Neil had solar power satellite
manufacturing as one use for the space colonies he imagined in the
mid to late 70s. They would be made from lunar material and
originate much closer to the needed orbits, in an energy sense,
than they would if made on Earth. Same for the colonies.
Posted by billmosby (536 comments )
Link Flag
Al Gore
Gore is making this feeble effort because the plitical fallout of a 42 room non-green house was too high. if Al really believed in his pitch he would have done this first.
Posted by Joe Johnston (1 comment )
Reply Link Flag
Grow up.
Anyone can build an efficient house. It's more difficult, but more
important to improve the efficiency of the much larger number of
older homes. Gore is taking an existing house and doing just that.
Solar is only one part of that effort, and unfortunately, he had to
fight to get permission to install it.

Lame attempts to discredit him for his efforts are childish. You
should be ashamed of yourself.
Posted by Macsaresafer (802 comments )
Link Flag
Look at it this way. We appreciate all efforts. Platonic Dialogues help.
We simply look at the earth as one. Not broken up by country, or state boundaries. We are not indebted to big oil, or to a local politician. Collect the power where it gets the most energy and distribute it as close to that location as possible for limited losses. Then email/wire a solar Transfer credit for the pioneers who bought the panels. That is true carbon offsetting at it's finest, that is Solar Transfer, and it is time it gets it?s own discussion going.

We hate to turn people off of solar because every little bit counts but look at it this way. If you are talking Photovoltaic solar panels keep them off roofs. The panels fixed to the roof can have a poor angle to the sun (relative to the southern exposure and pitch). The solar constant in Maine is lower than in Nevada or Arizona! (That?s the most important thing). Also Dual tracking for individual installations does not spread the cost.

Reduce cost by eliminating batteries that have to be replaced. Sell your power to Vegas. Vegas pays you for your panels energy production. That comes to about 3-4 fold improved return on your investment and more importantly reduced carbon emissions. It is all about Location, Location, Location and watts per dollar invested. We are not on something, we are onto something, I promise! Hopefully you will agree and email a copy of this posting to Al Gore, Google, and Wal-Mart. They are all planning local photovoltaic installations. It is a good start but they could be doing better!
Posted by Manhattan2 (329 comments )
Reply Link Flag
Geothermal resources can be tapped to produce power at a net cost of 5-8 cents per kilowatt. The plants are so low key that people pass them on the highway and don't even notice them. There is no waste (no fuel burned.) So you have all the advantages of solar at 1/2 to 1/3 of the cost. No coal mining. No oil burning. No oil importing. No giant windmills killing birds. No unsightly panels on roofs. No need for batteries (the earth is hot all the time.) Just clean, quiet, inexpensive power.
Posted by rgrayson268 (2 comments )
Link Flag
It's got to be near population
Most of the desert isn't well populated. IIRC, on average 40% of the power generated is wasted by transmission and distribution (loss in step-up transformers, transmission lines, step down transformers, distribution lines and more step down transformers.) Solar is too expensive to waste anywhere near that and still be competitive. In general, land near large populations is expensive and cheap land would suffer too high losses.
Posted by skrubol (181 comments )
Reply Link Flag
Make Hydrogen
Whatever might be the solar power source -- make hydrogen -- although far from an original thought -- and hydrogen can't easily be piped or stored -- it is the perfect ingredient for converting carbon containing substances. Importantly, capital cost for the synthesis facility would be high but even such simple things as carbon monoxide and carbon dioxide can then be converted to any carbon containing fuel. Satisfies two problems -- make methane or other hydrocarbons and use it in real power generating systems and gets rid of carbon dioxide and monoxide ? all renewably, so to speak
Posted by dglickdr (5 comments )
Reply Link Flag
IMO so called "environmentalists" are the main enemy of the environment. Face it, solar power or wind power will *never* become viable considering exponential increase in demand. Would anyone want to pay 5x more for the same electricity? And in the meantime we (esp. countries like China) are burning more fossil fuel to make electricity than ever.

We'd be far better of investing the money into anything that has a potential to provide high amounts of energy and hopefully aim for displacing energy from fossil fuel altogether. This could be clean nuclear, geothermal,... but certainly not solar or wind.
Posted by atici (63 comments )
Reply Link Flag
If only...
More nukes would be great! Seems not to fly politically, thought.
Posted by billmosby (536 comments )
Link Flag
Let's make it even easier. Let's say Al Gore has 3 houses.
Let's say Al Gore has 3 houses.

We truly do appreciate Mr. Gores efforts. We just use his name as a hypothetical because it gets people from both sides of the isle to read our logic. If he has not put the panels up yet please try to get this to him.

One of his houses is in Tennessee and is nestled into the woods and uses 15,000 kwh of power each month.
Let's say another house is in Arizona but his roof there does not have optimal angle to the sun and he only uses 2,000 kwh at that location.

Let's say his third house is a doublewide trailer in Nevada close to the grid and the town folk don?t mind him using his 2 acres for a solar installation. He only uses 1,000 kwh of power because he does not like the accommodations.

OK Let's say he has $50,000 to spend on photovoltaic panels. Does he put them in Tennessee were people will be able to see he is doing his part. Does he put them in Arizona were they are shaded from the sun most of the day? Or does he put $50,000 worth of solar panels around his trailer tilted toward peak sun?

The Political answer may be to put them in TN. The Global Warming solution / Solar Transfer solution is to put the panels or some form of a solar investment near the doublewide. He can back feed any extra power he doesn?t need and get a credit to help pay for the Tennessee electric bill. You see it is more significant to get every little bit of power we can get from that solar investment to help the planet, and for the republicans out there that are on the fence with this issue especially if it is going to change their way of life, he just made 4 times more money by placing his solar investment out in Nevada.

Now forget the fact that he might not have a house in Nevada. Solar Transfer will find a way to get someone else who does have a doublewide with 2 acres to grant us access to the land.

How do we sell this to the Federal government so they would still contribute $2500 toward the installation cost in Nevada even though Mr. Gore does not have a house there? Ask your Senator to make it happen!
Posted by Manhattan2 (329 comments )
Reply Link Flag
Solar power is good, but it costs three times the rate per kilowatt as GEOTHERMAL power. Geothermal offers clean power (nothing is burned). Geothermal is continuous (no need to store power at night). No giant wind mills needed. No unsightly roof arrays. Geothermal power plants are so low key they can be located next to a highway and people will drive by without knowing there is a power plant. No buring coal or oil. No importing from our enemies. The western United States has enough geothermal potential to take care of the United States electrial power generation for decades. We have two great souces of power -- the earth and the sun. It makes sense to go with Mother Earth.
Posted by rgrayson268 (2 comments )
Reply Link Flag
Wow, years later, people are still at this! I think it's time for everyone to get involved with CSP as it is the BEST form of energy storage, period. Molten salts have been used in the nuclear industry with Brayton cycle generators. Unfortunately, people are too scared of closed cycle fission which produces but a thousandths of the long term radioactivity as today's simple minded "once through system". Thorium can also be used to greatly reduce weapons proliferation issues, anyhow, graphite also is a heat storage medium used in the aluminum industry. Heat storage (on a large scale) is much more efficient than any other medium except possibly pumped water. Oh, one more thing, I am for widespread solar mirrors ONLY if the land is not bulldozed!
Posted by fireofenergy (18 comments )
Reply Link Flag
We think at that in the near future the cost of electricity from the grid is going to be higher than the solar or wind power so we should be prepared and help our planet the sooner the better.
Posted by rozuga1 (1 comment )
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