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"As other posters have said, its here now, and its the cleanest we have."

We have cleaner.

you're right.

this technology is useless unless it is affordable. much of the time, space isn't an issue -- it's cost per watt. If this new technology is prohibitively expensive than no customer is going to be interested in it.

along those lines, current solar modules being installed on residential rooftops usually have an efficiency of about 14%, not the 5% that the article claims.

limited life (10% efficiency in 10 years for most designs)

As for your comparison to other semiconductor products, you are confused. Solar cells do not require multiple etching steps; you can grow a doped crystal, cut it into pieces (and save the dust for reprocessing), dope one side of it the other way to create the junction, and add contacts. You're not masking, cutting trenches, sputtering multiple layers of interconnects or any of the chemical-intensive processes which characterize LSI chips, so any claim of pollution which draws on LSI production data is inherently flawed.

What are the chances of 2 Texas oilmen (financially supported by many more oilmen) giving us a coherent national energy policy which frees us from dependency on oil and the Middle East?

If you want your tax dollars to fund alternative energy research, then you should hope that the President shares the agenda of big oil companies to fund alternative energy research. To give three examples among many: BP, Shell, and Texaco.

This notion which you are implicitly endorsing, that oil companies oppose alterntaive energy sources, amounts to crackpot propaganda: It does not agree with fact, which is that oil companies are pursuing alternative sources of energy. It does not agree with reason: Why would oil companies avoid earning profits from alternative energy? Suppose BP could earn 10 billion/year profit by selling photovoltaics? Why would they not want to do that?

Since they never do anything like that on their own...

It's just like the RIAA and the MPAA - when new technology comes out that creates competition for their current business model, they're more inclined to fight the technology, rather than embrace it

Then explain to me why the solar panels on my roof are made by British Petroleum.

The RIAA and MPAA aren't selling a product whose source will eventually run out.

Oil people might differ on when it'll happen, but every oil company CEO knows that eventually we'll run out of easy-to-reach oil and the rest will cost so much to pump out of the ground that it'll be economically impossible to use as a commonplace energy source.

Any oil companies that haven't diversified into other, more sustainable businesses when that happens will be toast, no matter how much lobbying money they spend.

Don't get me wrong, they'll fiercely defend their current business for as long as it's profitable! But there's a limited amount of life left in that business, and they all know it.

The big oil companies, those that really operate on a global basis, are "energy companies" per se but in reallity they are still mainly oil companies..

Then why is one of the largest manufacturers (and promotors) of industrial and consumer photovoltaic solar panels a division of British Petroleum?

BP Solar, to be specific.

Here's one:British Petroleum solar products

When you have 8-12% efficient solar panels

8-12% is a little low. Current product cell efficiency are around 14-18%, and Concentrators w/ multijunctions get 30%. But who cares? Your car gets 15% efficiency in average use, nobody complains about that even thought you pay for the gas. Sun is free. The question is does 15% efficiency do the job? Yes. Even if it gets no better, it wouldn't matter.

six hours per day in the desert without trackers...on a cloudless day... In areas with more cloud cover, shorter days in winter, etc. the numbers drop off dramatically.

Wrong. The average insolation in the US is 6 hours of peak sun per day, no desert required (ie 6000 Wh/sq. meter per day). For a flat panel, the deviation from the best southern nevada site to the worst northern washington state site is only 2-to-1! The rest of the country is suprisingly small devation within this. See rredc.nrel.gov/solar/

Solar cells degrade by 2-5% every year and have a life span of ~30 years

Wrong again. Silicon solar cells degrade less than 10% over 25 years, and are garanteed by the manufacturer to not exceed this over a 20-30 year guarantee - compare that to any other product guarantee! Though, they are guaranteed for 20-30 years, their life isn't limited by it. (see Solarbuzz.com)

Then keep in mind that you have to keep all of those cells clean

Wrong. If you clean them verses do nothing you get a whopping 4% increase. Few people clean PV panels.

And to top it all off, when you cover large tracts of land with solar cells, that land gets less sunlight.

My roof doesn't seem to mind. What land? The average roof has 4-6 times the generating capacity of the average house. 1600 sq ft house = 148 sq meters. 148 m x 150 watts x 6 hours = 133 kWh/day. Average house power consuption 24kWh/day. Beat that with some other form of energy.

after a year with more than average rainfall causes refridgerators to cease functioning and food to rot.

Wrong. When is the last time you noticed the sun failed to come up (yes you still get power in overcast conditions). Further, home PV systems are designed using statistic based on the past 30 years of weather data (see rredc.nrel.gov/solar/). Ask somebody with PV, their power is WAY more reliable than the grid. In fact, most of the comminucation repeaters throughout the western US use PV for this reason.

Now if you come up with a calculation that if you completely covered the sunny state of Arizona with solar cells, it would still not be enough to replace just coal, you're on the right track.

Wrong. Solar is a reasonably dense form of energy wirelessly transmitted through a light "grid" in a usable form almost everywhere on the earth. If you wanted to compare space needed to produce all the electricity consumed in the US it would be a small 100 mile square (see picture for scale www.energycooperation.org/solarh2.htm). In fact studies have shown coal uses as much space due to the space required for strip mining. Try strip mining on top of your roof!

Repeat after me: It doesn't matter how much you are willing to pay. Solar and wind alone cannot do the job.

Wrong. What would it cost to pay for solar electricity? Try the cost of the Irag war. Seriously, do the math (including new military spending) and that would be enough over the next 3-5 years to t

All the solar energy in a 10x10 mile square is not enough to power the US.

10x10 = 100 sq mi ~= 260 million sq meters

The sun puts out (very roughly) 1000 watts of energy per square meter. This means our square will produce 260 GW (million KW). According to Google, the all the US power plants combined at full capacity produce 690 GW. So we're off by factor of almost 3, even assuming: 100% efficiency, constant direct sunlight round the clock.

A more accurate estimate would use this reference: "In Baltimore, Maryland, USA, for example, a flat array will receive about 1400 kWh/m2 per year." This means

1400/(365*24) ~= 0.16kw per sq meter.

This gives us 41.6 GW for the square. Off by a factor of over 15!

So, it's way off, but not ridiculously so. Consider that the numbers would be pretty close if we used a 40x40 mile square (665 GW).
The real problem, of course is storing all that energy for use at night!

It's very rare today to hear of a major company throwing money at a research project since the '80s.

Of COURSE it's rare for an oil company to fund any research into alternative energy sources.

We already have replacements for oil. We don't use them because oil is CHEAP.

Of course it's cheap when the price-point of solar panels is $10/watt. Even then they pay for themselves in about 10 years at consumer price for power (note I'm talking Australian figures here, but I believe the US figures are not dissimilar).

Have a look at the names of the big solar suppliers. Solarex and BP - oh, except BP purchased Solarex a couple of years ago. I guess it's just BP Solar then. What else are BP known for? Gosh.

Either they're preparing a migration path from oil, or supressing solar to retain oil profits. As with most big companies, I imagine it's a bit of both.

And as you say - oil is cheap, especially if contries are not charging large royalties for removing a non-replaceable resource - but there's politics for you, and it's not a good idea to start charging too much for your oil when you don't have a squeaky-clean record, because it might be convenient not to have you around any more.

It really demonstrates the effect that these large oil corporations have on our world, when there are much better cleaner alternatives to fossil fuels, yet these are being ignored for the sake of the oil companies.

Oil companies like BP, ChevronTexaco, and Shell, right?

Last time I priced solar power it was about $25,000 for my residence before rebates. Knock $6000 off for rebates, and it's still almost $19,000 out of pocket. It would take an estimated 27 1/2 years to pay for itself (assuming no maintenence since I don't know what that would cost). By all means, keep up the research on this, but to expect joe sixpack to adopt solar power right now for a household is just not realistic.

It's not that I'm opposed to solar power, but until something can be done to bring the price out of the stratoshere, it's simply not economicaly plausable right now. I generaly try to be environmentaly sensitive, but I shouldn't have to be a millionaire to make a significant contribution. All of which disregards the energy spent making the things and the fact that used solar panels are bad for the environment! I think I'll stick with nuclear energy for now.

British Petroleum (the BP gas stations) has apparenlty dedicated very much to solar energy: bpsolar
A testimonial on that site claims that their system had a 5-year payback; in other words, it cost the same as 60 months' worth of electric bills (anywhere from $6,000 to $18,000).
Just like space tourism, more people will use it once it becomes practical.

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Step 1> Convert computer glare into useful electricity. Step 2> ??? Step 3> PROFIT!

I'm appalled at the lack of imagination shown by most of these posts.

First off if you read the PDF (15M) report to Nasa prepared by Bradley C. Edwards to satisfy the requirements of his $500 000 grant you will readily see that this is totally feasible.

Next check out the website - where they are calling for people to express interest in working on this project. They expect to be hiring in the next year or so. You'll also see that serious people are taking this seriously. Do you want a job?

Next understand that $17B is not very much money. Considering that BP just spent $6.7B on a oil company in Russia and has plans for more purchases.

I meantion BP because they have a plan to move beyond oil.... BP Solar is BP's attempt to become a broader energy company (check out their new sun logo) instead of an oil company. The High Lift systems news page says: -

BP Solar - a subsidiary of British Petroleum, currently doing $300M in annual sales. Our discussions have focused on BP's interest in using the SE for deployment of a solar energy satellite. Several items that came up included possible collaborative efforts, the performance of our system and the possibility of BP using our system. They are considering writing a letter of endorsement

If BP with the cash they have can throw $6.75 B at Russia they could, over 5 years, finance a large share of the Space Elevator. Who needs the Government? In fact Nasa would make sure it costs more to build than it should. Nasa is a bureaucracy, not a business, and is ill-suited to the sort of cost control required of economically viable business decision. Only communists would argue that a Space Elevator should be built and controlled by government.

What would BP Solar do? Build Power Sats....

These are High Lift's vision for the main use for the Space Elevator. Imagine a fleet of these beaming power to anywhere on earth. Every country on the planet could get cheap electricity without the huge national grid infrastructure required now. Without the huge investments in time and resources to build power stations - and without the fossil fuel use.

Use your imagination.

These ideas have been the subject of SF for decades - but the Space Elevator is now possible due to those nifty Carbon Nano-tubes.

When your imagination focussed by the reality of this thing actually being built in the near term (5 years) everything changes - and it'll change for us not our children. It'll change our careers.

Imagine this - an electric airplane that is powered by a Powersat beaming microwaves to it. No fuel to carry, super efficient travel - and at what speeds?

These guys are planning for the Space Elevator to be operational SOON - they have realistic timelines.

What I want to see here is some discussion of the uses that could realistically be made of a space elevator. We're the generation that will built it, use it and be changed by it. I like the parallel to be made with electricity, or flight, or the steam engine - in the early stages everyone probably dismissed it - and the world changed despite them.

What would you realistically (with a nod towards economic viability) do with the low launch costs they're projecting - $10/LB...

Ideas anyone?

BP Solar says a "typical" household system would cost anywhere from $10,000-$40,000. That alone is the biggest obstacle to homeowner photovoltaic energy creation. That's a huge investment for most Americans to make, let alone the rest of the world.

Do you know how much energy it takes to make a solar panel?

I'm afraid I don't know, though I'd be surprised if a single 100W solar panel exceeded the 3.65 Megawatt-Hours it can generate over the course of its service life.

They are energy carriers, because it takes more energy to produce them than you get from burning them.

I'd also like to note that, with the same calculation, a theoretical 100% efficiency solar panel of 8m^2 (or about 9'x9') could power a large house with air conditioning and have room to spare. (alternative energy advocates frequently point to how great their house is because it uses so little energy, but they also fail to mention that air conditioning is the first thing to go since it is such an energy hog. I prefer to compare to the current average homeowner's situation, for a more realistic picture) That's calculated as 1.0kW*5H*30days*8m^2=1200kWH/month assuming only 5 hours/day since a fixed solar panel isn't always exposing a 100% cross section to the sun.

Can't speak for the American Oil crowd, but I know for a fact that the Euroeans are looking very seriously at all sorts of alternative/renewable energies. BP and Shell are two fairly big players in solar, biomass, geothermal, and forestry.

The green-leaning unwashed masses aren't the only ones who are aware that we're burning dinosaurs faster than we're making them. Forecasts vary on the catastrophic oil-running-out deadline (the USGS forecasts are held in fairly high repute). There are many more you can find, with wildly varying dates.

However, a fact much more interesting to an Oil company is when it's going to stop getting cheap to recover oil. All these businesses know it is definately going to get more expensive to extract oil. They also know it's a real posiblity it's going to get more expensive to buy it from countries which make it cheap (OPEC getting its shit together, and other "disaster" scenarios).

So yeah, they thought of that. They reckon that as companies who've got a pretty good idea how energy is used, they're pretty qualified to in this area. Anyone heard any oil company propoganda on fuel cells?

1. Stay away from used motor oil in your system. Stay away from oil, period. If you have a leak or a line rupture, you could have a hazmat/groundwater pollution problem that's worth more to clean up than your house and land combined. Stick with water and ethylene or propylene glycol; they are easy to handle, easy to pump and biodegradable.
2. Before you think about solar heating systems, think about insulation. Every watt of heat you can keep from leaking out of the house is a watt that does not have to be generated or captured.
3. Many solar panels are laminated onto plate glass. I don't know how much hail these are able to stand. This panel is rated for one-inch hail, but I wouldn't expect it to handle two-inch. The only way to protect a panel against hail is probably to put it on a tracking stand and turn it vertical (edge-on to the hail) when your conditions were bad. Making a hail-detector that can trigger the stowing process soon enough is probably a problem with no off-the-shelf solution. If you are talking about a solar-thermal panel for heating water, it's likely to have its cover glass busted in a hailstorm. You might be able to deal with this using a plastic top layer, but I have no idea who makes such things. Try doing a little research.
4. Solar (photovoltaic) panels love the cold. The cell voltage improves as the temperature goes down.
5. If you have strong winds in the winter, definitely think about a wind generator. You can probably heat your house with the power generated during winter gales; a 10 KW machine is good for better than 30,000 BTU/hr if you dump the output to heating elements, and several times that much if it runs a heat pump.

Question: Who's the world's largest solar electric company?

Answer: BP Solar (BTW, BP="British Petroleum").