March 24, 2010
| 
22
Editor’s Note: Scientific American ‘s George Musser will be chronicling his experiences installing solar panels in Solar at Home (formerly 60-Second Solar). Read his introduction here and see all posts here.
I had a fun talk yesterday afternoon with Bob MacDonald, the CEO of Skyline Solar, makers of a new concentrated photovoltaic (CPV) array. The thing looks rather like a big solar cooker, with a long mirror that focuses sunlight so that you only need a tenth as many solar cells to cover a given area. CPV may become the first photovoltaic technology to reach cost parity with fossil fuels.
The basic idea, which goes back to the ’70s, is to use fewer solar cells and shine more light on each one. A cell’s rated output is based on straight-on, full-on sunlight, which is about 1,000 watts per square meter at Earth’s surface. In light that is hundreds or even thousands of times brighter, the cell will generate proportionally more current and therefore proportionally more power. (The voltage remains fixed by quantum physics.) Indeed, some types of cells, such as those that capture a wider range of the solar spectrum, perform best under intense light.
The main tradeoff is that the cells then absorb more heat. The Skyline array relies on passive cooling — namely, natural air flow around metal fins mounted on the back of the cells. You also have to factor in the cost of the mirror and, if the panels track the sun, motors. For small residential systems, regular flat panels are still cheaper, but CPV becomes economical for systems bigger than about 50 kW, such as those that are starting to show up on the roofs of shopping malls. For truly gigantic arrays, those bigger than about 50 MW, the cost of silicon begins to add up and solar thermal systems, which heat up a fluid to spin a turbine, become cheaper.
One of CPV’s hangups has been the cost of manufacturing and installation, but MacDonald says his company has come up with a simplified mechanical design that can be built on a converted car assembly line. The units are sized to fit into a standard shipping container and are fully preassembled to make them easy to plug in at the site. A 1 MW array will consume about five acres. The company set up a 27 kW demo system in San Jose last May and expects to start shipping its production units later this year.
Initially, MacDonald says, they will cost about 15 cents per kW-hr, about half the cost of regular solar panels. If so, it is already competitive with nuclear power and closing in on fossil power, which runs about 10 cents per kW-hr (varying with location), not counting its environmental costs.
CPV exempifies how the challenge of solar power these days is not the high-tech lab work but the low-tech, nuts-and-bolts cost-cutting. MacDonald’s description of how arrays must be tailored for their site also made me appreciate how the two ends of the solar market are moving in opposite directions. For homeowners, systems are becoming more standardized to reduce installation costs, make it easier to get permits, and allow DIYers to put up panels on their own. But large farms of solar panels are becoming less standardized. Though their components may be plug and play, their overall design needs to be customized to squeeze out every last watt. "There’s a lot of benefit to be had by purpose engineering," MacDonald says.
22 CommentsAdd a Comment
You must log in or register as a ScientificAmerican.com member to submit a comment.
The "Valley of Death" Looms for 8 Kids With a Rare Disease
It’s not about tar sands – it’s about us
USC Dornsife Scientific Diving: The Guam and Calayan Rails
Sweden Journal: Skogs Livet
Book Review: The Data Journalism Handbook
Crowdfunding for Research Dollars: A Cure for Science's Ills?
YES! Send me a free issue of Scientific American with no obligation to continue the subscription. If I like it, I will be billed for the one-year subscription.
Share
Email
Print
I just had solar panels installed on my home in MA. I used a California company called "Sun Run", and they arranged for a local installer to handle it all for me.
My up front cost was only $1000, and now I just pay Sun Run a flat rate (lower than the utility rate) for the generated power.
The installation took all of two days and was relatively painless. (I did have to wait 2 more days before turning the system on, because I had to wait for the town electrical inspector to stop by).
Now I can see my daily generation online from the SunRun.com website.
It is good for the planet, easy to do, pretty inexpensive up-front, and overtime I’ll save money over what I would have paid the utility for the power.
I strongly recommend it for people with a sunny roof.
Link to thisThe taxpayers are paying most cost of your array, which if perfectly aligned in MA costs about 35 cents a kwh unsubsidized. That compares to the current US average of 3 cents a kwh for nuclear, which is set to drop to under 1.5 cents.
Your aren’t doing your country a favour.
Link to thisI always get a kick out of this magazines oil funded push on renewables.
I guess Musser never thought to ask where MacDonald got his 15 cents a kwh – likely just made it up same as Mussers absurd statement that 15 cents a kwh was competitive with nuclear.
The current US cost for nuclear is 3 cents a kwh according to the OECD.
Currently O&M and fuel costs for sixties technology ancient and inefficent reactors is 2 cents a kwh.
If a public utility finances a reactor a 4.5% per annum instead of the 15% discount rate Wall Street wants to see from private power companies, the capital cost is roughly .5 cents a kwh for each billion of capital. There are numerous examples of Western designed reactors being sold in Asia for under $1.6B/Gw so far in oneseys and twoseys. It would stand to reason that after a hundred or so of these get built mostly in factories the costs will drop drastically, as both AECL and Westinghouse claim.
Korea has quoted the UAE 1.5 cents a kwh for sixty years on a $40B 5.5 Gw build. AECL quoted Ontario that same 1.5 cents over 60 years on a kwh on a 2.4 Gw build.
Where Musser gets that ridiculous 10 cents a kwh for fossils is another mystery.
Link to thisI admit I’m no expert on the life-cycle costs of various power sources, so I pulled these numbers from Wikipedia, which cites a wide variety of studies (http://en.wikipedia.org/wiki/Relative_cost_of_electricity_generated_by_different_sources) and seems consistent with what a quick Google search turns up. If you think those studies are unreliable, I’d be interested in what you do consider reliable.
As for whether the solar incentives are worth it, that’s a question I’ve discussed in earlier posts. Basically, those subsidies have to be judged on whether they help the solar industry reach grid parity, at which point they can be phased out. The subsidies are already less generous than they once were. Historically, all emergent industries have received public subsidies; many mature industries, including the oil industry, still do. So if you are going to complain about solar subsidies, consistency demands that you also complain about other subsidies.
Link to thisPower from natural gas currently costs around $0.04 per kwh. Solar subsidies are a real waste. There’s nothing to be gained by encouraging high cost energy. Perhaps subsidize a bit of research into solar, but there’s no advantage in making investments in non-competitive technology on a production scale.
Link to thisI’ve been perplexed at how I was going to keep my 70 foot diameter/horizontally spinning fly wheel kept up to speed. If I mount CPV’s on the top side, the juice can run friction motors around the axle. The rotation on the topside will cool the CPVs extremely efficiently allowing maximum output. On the underside I can have my power take off system. I bet I could generate at least interest if not power in the fractions of a cent per kilowatt-hour. Now does anyone have a handle on stopping a 70 ton rotating mass so I can get on to do maintenance?
Link to thisReliable is actual construction costs or sale prices some that I quoted. You can google them and many others yourself. Wikipedia is not a reliable source of anything but can be entertaining reading.
There are numerous examples of Western designed reactors being sold in Asia for under $2B/Gw so far in oneseys and twoseys. It would stand to reason that after a hundred of these get built mostly in factories the costs will drop drastically.
A big task for Energy Sec Chu is to find out why it costs four times as much and takes twice as long to build an identical nuclear plant in the US as in Asia and make it right.
The answer is an out of control NRC.
We have the FAA and DOT regulating the aircraft and auto industries and yet we have no trouble competing with the rest of the world.
But in the nuclear industry we invented and once led the world in we are now a sad joke because of these NRC fools. Americans need to feel the shame and the anger and demand their politicians fix this now.
At this point I can find no current American nuclear subsidies but obviously tens of billions are available for renewables. Hundreds of billions have already been spent worldwide on subsidizing these black hole money pits with very little result.
They are all ten to twenty times the cost of mass produced nuclear.
Link to thisNuclear doesn’t get you off the grid. Although we’d all like to see many more reactors built. However, that will take time, and a lot of it.
Link to thisI have wanted to go solar for a while but the problem seems to be if one area of an array is shaded, the entire array shuts down. I have several trees that I’m not going to cut. My roof is mostly sunny all day long, so I thought maybe a different type of system would work for me. Has anyone else heard of this problem?
One way to avoid this problem is to use microinverters. I have some discussion at http://www.scientificamerican.com/blog/post.cfm?id=invert-your-thinking-squeezing-more-2009-08-26
Link to thisSethdayal, Soccerdad both of you have never shown detailed accounts of what it in your prices. My guess it’s just the nuke core.
The steam engine/electric generator part of the nukes cost about what you say so I have a hard time believing your numbers. So show some real price data instead of numbers with no meaning except to push your points.
Also I get a mix NG, coal and nuke and I pay $.13kwhr for them. Now with PV on homes at $1-2/wt retail if shopped well, sunelec.com it’s cheaper electric for me and many others. Storage is only $10/kwhr/yr so 20kw is only $200/yr which is can make by charging at light and selling at peak. Since solar too happens at peak which here we get $.25/kwhr or more PV is far cheaper, even profitable compared to buying nuke power.
And wind is even more cost effective.
Link to thisMy nuclear costs can be simply confirmed with Google. They are sale prices or completed costs.
The latest ultra efficiency NG plant is $1B/Gw + 3 cents a kwh at the current ultra low $4.1kcuft gas price.
The latest coal plant is $3B/Gw + 2.4 cents a kwh at the latest ultra low coal price.
Currently the OECD has US nuclear costs at 3 cents a kwh. Google it. Mass produced new nukes are predicted at $1B/Gw + 1 cent a kwh.
The 13 cents a kwh US retail price comes from inefficient US utilities being required by Wall Street to earn usurous 15% rates of return. Public power like in Seattle is 6 cents a kwh.
You have to pay sombody to install your roof, get the permits and the grid connect equipment.
Using an actual solar 5 kw solar Watson House, Massachusetts with a fire sale grid tie package ratioed up to 5 Kw we get.
panels,ship,inverters $18K, labor $6k, 5500 kwh annual actual (confirmed with PVWatts), loan 6% 25 years 8% cost.
2400000*.08/5500 = $.35/kwh
Because of the collapse of the Spanish solar market there are solar panels being dumped by the container load, hence the current fire sales.
A solar panel is really no more than a home depot skylight with solar cells glued to it. If the cells were free the cost would still be $2 peak watt..
I have no idea where you are getting your absurd storage costs but do tell. Love to see your reasoning/sources.
Latest Chinese build Texas wind farm – 56 sq miles of concrete, roads and steel, $1.5 billion. 125 Mw(avg), excluding storage, transmission, and millions annually for load balancing natural gas. $12B/Gw.
Link to thisMy nuclear costs can be simply confirmed with Google. They are sale prices or completed costs.
The latest ultra efficiency NG plant is $1B/Gw + 3 cents a kwh at the current ultra low $4.1kcuft gas price.
The latest coal plant is $3B/Gw + 2.4 cents a kwh at the latest ultra low coal price.
Currently the OECD has US nuclear costs at 3 cents a kwh. Google it. Mass produced new nukes are predicted at $1B/Gw + 1 cent a kwh.
The 13 cents a kwh US retail price comes from inefficient US utilities being required by Wall Street to earn usurous 15% rates of return. Public power like in Seattle is 6 cents a kwh.
You have to pay sombody to install your roof, get the permits and the grid connect equipment.
Using an actual solar 5 kw solar Watson House, Massachusetts with a fire sale grid tie package ratioed up to 5 Kw we get.
panels,ship,inverters $18K, labor $6k, 5500 kwh annual actual (confirmed with PVWatts), loan 6% 25 years 8% cost.
2400000*.08/5500 = $.35/kwh
Because of the collapse of the Spanish solar market there are solar panels being dumped by the container load, hence the current fire sales.
A solar panel is really no more than a home depot skylight with solar cells glued to it. If the cells were free the cost would still be $2 peak watt..
I have no idea where you are getting your absurd storage costs but do tell. Love to see your reasoning/sources.
Latest Chinese build Texas wind farm – 56 sq miles of concrete, roads and steel, $1.5 billion. 125 Mw(avg), excluding storage, transmission, and millions annually for load balancing natural gas. $12B/Gw.
Link to thisI just happen to know the cost of electricity produced by a large size gas fired power plant from business dealings with the plant. My company buys power from the plant near cost and we get if for about $0.04 per kwh with no help from the government.
Link to thisDesert Solar Thermal power is inexcusable stupidity. A total scam. The latest & greatest Ivanpah Solar Thermal plant in the Mojave desert is $1.37B for 392 MWpk, 125 MWavg. 30% of that comes from NG used as an adjunct to the Solar Energy. So that’s $15.6k per kwavg Solar Electricity. Add to that the quadruple oversized long distance power transmission line and peak output NG pipeline, both paid by the public, and we are up to over $18k per kwavg.
And now we still need fossil fuel guzzling NG or Coal to supply the balance of the Electricity or about 70% of the total. Again paid by the public. Add another $3k per kwavg for that. So we are up to $21k per kwavg. Plus O&M costs for the Solar Power plant, about 2 cents per kwh, plus NG fuel costs for the Solar Power plant, about 2 cents per kwh at certain future NG prices, plus O&M for the Coal or NG shadowing power plant of about 4 cents per kwh.
So here you have it, $21k per kwavg capital cost plus 8 cents per kwh O&M costs, for a GHG belching, unreliable, ecologically destructive power source, that requires huge quantities of precious desert cooling & washing water:
"…To maintain the efficiency of the process, all of the 40-foot-high mirrors-ten million square feet of mirror surface-must be washed every five days or so, plus a high-pressure wash every ten-to-twenty days…"
"….[Andasol 1] It will use 560 million litres/year of fresh water, [20 MWavg] mostly for cooling the steam circuit, drawn from local ground water …"
Compare this with Nuclear, $4-6k per kwavg, for First-Of-A-Kind power plants, with a 90% capacity factor. Reliable 24/7, rain or shine, winter or summer power with only recycled ocean water needed for cooling. Short, fully utilized, power transmission lines straight to the major load centers. O&M costs are currently 1.7 cents per kwh. Nuclear produces 71,000 GWh/HA of Land Area vs the Solar Thermal of 31 GWh/HA. Minimal Environmental impact for the Nuclear. And Factory production hasn’t even been done yet for NPP’s. That would bring capital costs down to $1-2k per kw.
The only reason the Wacky Desert Solar Scam gets any funding at all is because of back room influence from Fossil Fuel lobbyists, who know it will not make a dent in Fossil Fuel consumption, while presenting a Feel Good Publicity Stunt for gullible politicians, the technically illiterate public
Link to thisand Oil/NG controlled publications, like Sci-Am.
More about this Desert Solar Scam. So 30% of its Energy comes from NG. This will be converted to electricity at 30% efficiency in the Thermal power plant, including long distance Gas & Electricity Transmission losses, maybe 27% efficiency. The same NG could produce electricity at 62% efficiency in a CCGT, located close to the load, not way out in the desert. And I thought that California was big on Energy Efficiency. Huge amounts of precious stored chemical energy wasted – at 30% eff. vs 62% eff. Yep, but they put in LED street lights, a 5% improvement over HPS at 10X the cost – that’s efficient. IDIOTS!
So now, the Desert Thermal with the shadowing NG power plants, we have Baseload Power that uses NG for 76% of total energy supply. That is INSANE!
The #1 priority use of NG is to supply peaking & standby power generation, and to supply the very high winter peak heating energy needed in Northern regions.
The #2 priority use of NG should be to replace imported Oil – which is rarely used for power generation, by converting it to Methanol/DME and using it as a transportation fuel.
Also of course as feedstock for the chemical Energy.
It is INCREDIBLE, that in one breath, renewable advocates are willing to spend huge amounts of capital, like $400 per kwh, and $2k per kw for energy storage (like batteries or pumped hydro) and in the next breath want to throw away our already cheap NG Chemical Energy storage on baseload power generation – which can much better be done with Nuclear.
NG supplies are highly limited. The USA has to import 14% of it’s NG. And the latest EIA forecast is a 13% increase in NG production by 2035. While Total USA energy consumption will increase by 15%. So NG won’t even be able to keep up with Energy Consumption Growth, never mind replacing Imports, Never Mind replacing Filthy Coal.
WE MUST USE NUCLEAR & HYDRO EXCLUSIVELY FOR ALL BASELOAD POWER GENERATION. USE OF NG IS A CRIMINAL ACT that will cause NG prices to explode, shortages to become frequent, and real pain for the consumers WHO ACTUALLY NEED the NG, like homeowners in Northern regions, for their Winter Heating Peak Load.
Link to thisMore problems with Solar Thermal power, from Ted Rockwell and William Tucker:
http://tedrockwell.typepad.com/files/nuclearenergyfactsreport-2010jan22.pdf
http://www.terrestrialenergy.org/
"…On August 31, 1986, 240,000 gallons of therminol caught fire and burned, destroying the tower and its equipment. A new tower was built, and the system ran until it shut down permanently in 1988. Solar One had no way to store either heat or electricity, so it had to shut down every time the sun went under a cloud. Literally…"
"…On January 10, 1990, a series of explosions rocked one of the cooling towers and ignited large quantities of therminol. Thirteen engine companies needed 1500 gallons of foam to quench the flames. Then on February 27, 1999, almost a million gallons of therminol caught fire, destroying considerable portion of the facility. The flames released toxic fumes, and a half-square-mile had to be evacuated. The Federal Aviation Administration also set up a no fly zone around the facility…"
Chuck Devore, a state assemblyman from California said this about solar thermal power:
"…And you need to honestly take a look at what’s happening out in the desert. I’ve visited the solar fields out at Cramer Junction. They produce as I recall about 135 MW of power. They are solar thermal fields that have been up probably for about 20 years now. In other words not very much power. And they cover about 1000 acres or so. And what I was struck by when I went out to visit them was the fact that there was no plant or animal life whatsoever underneath those panels. The entire 1000 acre area was a dead zone, because the plants are a fire hazard for the parabolic trough mirrors. And they spray, like an herbicide to keep the plants from growing and to keep the dust down because the dust and sand abrade the mirrors and increases their maintenance costs. And so what I found somewhat interesting was that in that entire area it was devoid of any life. Now people who don’t live in the desert may think that’s all well and good, there’s no life out there anyway, but as a guy who has spent a lot of time out in the eastern High Sierra I can tell you there’s a lot of life out there…. How much of the desert are we willing to cover? Because the energy density of solar power is so minimal compared to the energy density of something like nuclear power where you can produce hundreds of times the amount of electricity on a much smaller imprint on the ground…"
And the panels do effect desert climate adversely, in uncertain ways.
Link to thisI don’t remember saying anything about desert solar thermal…..
As for oil and natural gas "controlling" Sci Am, if you saw the sorry condition of our offices (not to mention our salaries), you’d immediately realize that we’re not controlled by any deep-pocketed interest.
Link to thisGeorge Musser – where else are you going to put those huge monstrosities? The desert is bad – most anywhere else is worse. The economics are even worse for smaller commercial rooftop installations. And then you’re even more so relying on shadowing fossil fuel power plants – paid by the taxpayer or utility customer. A total loser.
So you’re telling us Shell Oil is cheap with it’s disinformation / advertising budget. It doesn’t take a rocket scientist to figure out what is going on at SciAm.
Energy Blogs are humming with discussion on these four Energy Technologies:
The LIFTR, Liquid Fluoride Thorium Reactor:
http://www.youtube.com/watch?v=AZR0UKxNPh8
http://home.comcast.net/~robert.hargraves/public_html/AimHigh.pdf
The IFR, Integral Fast Reactor:
http://www.skirsch.com/politics/globalwarming/ifr.htm
The Polywell, IEC Inertial Electrostatic Confinement Fusion:
http://www.youtube.com/watch?v=FhL5VO2NStU&feature=related
http://nextbigfuture.com/search/label/iec%20fusion
Dense Plasma Focus Fusion:
http://nextbigfuture.com/2010/02/lawrenceville-plasma-physics-fusion.html
http://video.google.com/videoplay?docid=-1518007279479871760&q=Google+tech+talks+lerner&pr=goog-sl#
Do a search in the Sciam website, for any of the above HOT Technologies, you won’t find ZIP. Do the same for the Renewable’s SCAMs being promoted relentlessly by Oil/NG interests AND SCIAM (drop the I – what does that spell?). Unlike the renewable SCAMs, the above tech could actually SOLVE the Global Warming, Peak Fossil Fuel crisis. And a whole lot more – like unlimited Space Travel, cheap Potable Water, power for UnderSea & Arctic Habitat, and cheap, zero emissions Ocean Cargo Vessels.
So George, start writing articles in SCIAM about realistic Energy Tech that can really make a difference – and then we might believe you aren’t lackey’s of Fossil Fuel Vested Interests.
Link to thisThe big problem is storage. We’ve spent the last fifty odd years and billions of dollars finding mew ways to generate power and not a relative dime’s worth in storage technologies. The attempts to sequester carbon into limestone may turn out to be an energy storage method too. I bet my flywheel, for the same amount of ground area, can store more energy than a wind turbine could generate. Forget the mini-inverters, mini storage in place overcomes the series problems encountered with shaded panels. We need to learn how to pump the water back up behind the dam fellas.
Link to thisdwbd, I can see your point. Solar collecting systems do poorly at distances. These are systems set in place by those wishing to make profit from it and governments who don’t understand the mechanics behind what they invest in. The alternative is to place these systems at the end user such as residential, commercial, industrial and any building requiring electricity. Even as we speak improvements in solar collecting and distribution systems are happening and are being adopted in progressive nations while we look at these systems as money makers for utility companies and don’t look to help the rest of us… if it was the intent to place solar collection on ever roof top in the nation as mandated from government at their expense it could be done… believe it or not DC voltage can be used to power many of our systems without converting to AC voltage. Beyond a building needs the excess could then be converted and used by local utilities to be paid at market prices… we all benefit. Just as good as any tax breaks, would help those who are in over their heads with mortgages that are crippling many a home buyer.
Link to thisYou may not have mentioned the word "desert", but where else would one locate a concentrated solar collecting array to wring out a very poor economic result as opposed to a catastrophic economic result?
I will defend you on the charge that SciAm is on the payroll for the energy interests. The coverage of GW is far too slanted to make that claim.
Link to thisI guess solar technology is still so new that we’ll have do our own research on potential costs and savings. Certainly sounds like nobody here is agreeing on much.
Link to this