Here is what the acolytes of solar power don't want you to know...

self | July 15, 2003 | Boot Hill

[Boot Hill]

Here is what the acolytes of solar power don't want you to know...

These are the essentials you need in order to appreciate the absurdity of using solar cell power systems as any kind of sensible alternative. After you read this, ask yourself again how much sense solar power really makes.

THIS IS WHAT HAPPENS TO THE SUN'S ENERGY WHEN
WE USE SOLAR CELLS TO GENERATE ELECTRICITY:

	SOURCE	LOSS - %	POWER - W/m2
1.	solar constant	--	1370W
2.	atmosphere	27	1000W
3.	clouds	21	790W
4.	sun angle1	49	403W
5.	night2	50	201W
6.	cell efficiency3	85	30W
7.	dust/reflection4	10	27W
8.	packaging5	20	22W
9.	DC to AC inverter	25	16W
10.	storage	30	11W
Source Notes: 1.   Calculated for both hour angle and a latitude angle of 37º. 2.   See link. Continental U.S. average sunshine is 4.8 kilowatt-hours/       square meter/day, or 200 watts/square meter. That value is nearly       identical with total losses shown for items 1-5 above. 3.   See table on linked page. 4.   Dust, bird droppings, scratches, etc. estimated to be about 4%.       Reflections, per Fresnel's Law, would be another 6%. 5.   See link for data sheet on typical solar panel. Data shows an       overall efficiency of 10.3%, at nominal conditions. This is       nearly identical with total losses shown for items 6-8 above.

Net efficiency = 11.4 Watts/m² or a mere 0.83% (!)

But read on, it gets worse.

• The current average rate of U.S. energy consumption is about 3.3 trillion Watts. Based on the above efficiency data, we would need to cover the entire state of New Mexico with solar cells just to generate this amount of energy!   [+]

• And because of the 2% annual growth rate in our energy consumption, in only 35 years we would also have to cover the entire state of Arizona as well!   [+]

• And the irony is that the environmentalists, who are so obsessed with the use of solar power now, would be the first to scream bloody murder at the idea of such large areas of wild lands being permanently covered over with solar generating plants!   [+]   [+]   (Note: Both articles are written by the same author!)

• Worse still, the entire world-wide production of photovoltaic (PV) cells is so small (300 MW) that it can't even keep up with the annual U.S. growth rate in energy consumption (66,000 MW), much less produce enough PV cells to supply the base amount of energy that we currently use (3,300,000 MW). To do that, PV cell production would have to ramp up over 100,000%!   [+]   (Scroll down to chart)

• The initial capitalization cost of a solar PV generating plant is at least 10 times the cost of a large conventional plant. And that is exclusive of the mammoth land acquisition costs necessary to accommodate the vast expanse of solar cells.

  Here is an example:
  Siemens Solar (now Shell Solar) produces a popular line of large solar arrays intended for commercial, industrial and consumer applications. A big seller is their SP-150, supposedly a 150 watt unit that measures 1.32 square meters. The problem is, it only produces 150 watts under carefully controlled laboratory conditions where the incident light intensity is boosted to 1000 watts per square meter (unrealistically high, see items 2 and 3 in above table) and the PV cells are artificially cooled to 25º C. But when Shell tests that same unit under more realistic conditions of 800 watts per square meter and little cooling for the PV cells, the output drops to 109 watts. When sun angle and night time are factored in (see items 4 and 5 in above table), the average level of power production drops to a piddling 28 watts. (That is only 21 watts per square meter(!) which is nearly identical to the value shown for item 8 in the above table.)   [+]   [+]

  In quantity, this unit sells for $700. That calculates out to $25 per watt. By way of comparison, the initial capitalization cost for a conventional power plant is on the order of $0.75 to $1.00 per watt. That makes the solar "alternative" 33 times more expensive than the conventional power plants of today, and we haven't even figured in the additional cost of the inverters and power storage systems that solar needs (or the land acquisition costs).

  Solar proponents would be quick to point out that, while the capitalization costs may be higher for solar, they don't need to purchase the expensive fossil fuels that conventional plants use. While that is true, what they aren't telling you is that the cost of financing the much higher initial debt load for solar, is greater than the cost of the fuels that conventional plants use. (TANSTAAFL !)

• PV cells have a limited lifetime. As a consequence, manufacturers offer only limited warranties on power output, some as short as 20 years.   [+]

• A violent storm, such as a hail storm, can decimate a solar power plant. A storm covering only one square mile (the size of a small 50 MW solar plant) could destroy a half billion dollars in solar panels.

• PV cells have a nasty little habit of loosing conversion efficiency when you put them out in the warm sunlight. A hot day can lower the output power by up to 20%!   [+]

• A solar PV generating plant is not without maintenance. How are you going to wash the tens of thousands of square miles of PV cells of the dirt, dust and bird droppings that will collect over time? How will they be kept free of snow and ice during winter? A 1000 MW solar plant can lose 40 MW of power (retail value, about $50 million per year) by failing to keep the PV cells clean of dirt. Losses would be even greater for snow and ice.

• Solar PV generating plants incur inefficiencies quite foreign to conventional power plants. First, there is no need for energy storage in a conventional plant, as night time doesn't affect generating capacity. Second, there is no need for an inverter to change DC to AC. The inverter is a bigger deal than it first appears to be, because the inverter for a public utility must produce a very pure sine wave and that is much harder to do while still maintaining high conversion efficiency.

• The consumer that purchases a solar power generating system for home installation pays only a small fraction of its real cost, often as low as only 25%. That is because every sale is subsidized by direct payments of your tax dollars and by the government placing un-funded mandates on utility companies, requiring them to push the solar power "alternative". These unfunded mandates are re-paid by the rest of us in the form of higher utility bills.   [+]

Is there any use for solar power that makes sense?
Yes, solar power makes sense in those limited applications where the customer does not have convenient or economic access to the power grid, such as with remote country or mountain top homes. It is also useful for powering mobile or portable equipment such as utility, emergency, scientific devices, etc., where it is not otherwise feasible to hook to the power grid.

But other than those narrow exceptions, it makes no economic, engineering, ecological or practical sense to use solar power as a replacement for, or even as a compliment to, conventional power plants. Solar may have its' own specialty niche, but in no way does that rise to the level of an "alternative" to conventional power plants.

[Publius6961]

Give it up.

The combination of almost total ignorance of science, and a blind devotion to wishfull thinking in the form of a dogmatic religion, makes these folks immune to any logic or to any influence by facts.

"There is a principle which is a bar against all information, which is proof against all arguments and which cannot fail to keep a man in everlasting ignorance. That principle is contempt prior to investigation." – Spencer

[Boot Hill]

Boot Hill says:   "I am an engineer. I've spent a life time in electronics and optics. I am thoroughly familiar with the technology and the economics of solar power."

Wonder Warthog says:   "You couldn't tell it from your vanity post."

Get your mouth and attitude under control.

[Boot Hill]

dark_lord says:   "...you should be able to read it online in a couple weeks..."

Sounds interesting, but if the article is speaking of the Kamen Stirling engine, it is only 20% efficient at converting solar energy to electricity and at the expense of having a large mirror array that must be constantly moved about to focus the light on the engine. Given the area needed for this generator, I'm not sure it would represent an improvement over current PV cell technology and almost assuredly the system cost will not be anywhere close to $1/W. But nevertheless, please post the article when it comes online. It should be an interesting read.

[Boot Hill]

Publius6961 suggests:   "Give it up. The combination of almost total ignorance of science, and a blind devotion to wishfull thinking in the form of a dogmatic religion, makes these folks immune to any logic or to any influence by facts."

You can reach a few. That makes it worth the time and trouble.

--Boot Hill

[biblewonk]

Even Homepower magazing, one of the biggest PV advocates that exists showed similar numbers. Lately they have been showing how much cheaper it is to simply conserve rather than try and produce power with solar panels. They showed how they could save tons of money in a library by simply going to compact florescent bulbs.

Windpower, on the other hand, is perfectly economical and will produce 2-4 percent of the worlds power in 15 years.

[DoctorMichael]

There is only one way to meet the expanding energy needs of the planet: Nuclear Power............and even this might not be enough.

[Boot Hill]

He's not even getting the 800W that he claims to be getting from that 2m^2 PV array. Not even close. Guarantee you.

--Boot Hill

[RightWhale]

With solar cells still at $5 per watt, it's still a limited sector of the power industry. What do you think of England's new project to replace the need for 6 new nuke power plants with wind farms? Expensive, no doubt.

[Boot Hill]

I believe you are correct about the nuclear option.

--Boot Hill

[Boot Hill]

I hadn't heard about that English project for the 6 nuke plants, but since nuke plants are typically in excess of 1000 MW in size, the question that comes to mind most readily is how are the English planning to get 6,000 MW of electricity out of wind farms.

--Boot Hill

[RightWhale]

There is some current news floating around the media, I'll keep my eye out for an article. They are going to build offshore, a massive installation.

[DoctorMichael]

I have a 'Projected Energy Needs' table at home so I can't quote it right now. Its from Zubrin's (the pro-exploration and -colonization of Mars guy) ENTERING SPACE and I can't offhand remember what government agency he got it from.

The numbers he shows can only be met by nuclear power; there is NO WAY these "enviro-friendly" technologies can keep up with 'Need'. Even going full-bore with old-tech stuff like generating power by burning coal, natural gas, damming more rivers etc., etc., etc. that are 'proven' technologies does not keep pace.

The numbers for the 'growth of energy needs' are staggering. Specifically, they only get worse when you start throwing in the industrialization of places like China, India and other highly populated Third World countries. I'll try and remember to post the Table tonight.

[FreedomPoster]

No, it's something a utility does. Here in the South, with a Summer, daytime-peaking utility, you pump water from reservoir #1 up the dam to reservoir #2, typically at night using your large base-loaded coal and nuclear plants. This keeps them running full-tilt all the time.

During the peak load afternoon hours, your let the water run through the dam turbines from #2 to #1, making hydropower. Hence "hydro pumped storage".

It's pretty much a large utility option only.

[RightWhale]

An assumption for projected energy needs is that the earth is a single planetary surface, closed system. If, however, heavy manufacturing is thrown up into orbit, a large chunk of the energy requirements go with it. Industrialization needs a huge chunk of power. Put the factories in orbit and let them produce their own power. We can live in pretty good comfort with a much reduced power grid once industry is taken out of the race. This isn't woodstoves, it is technology and a lot of employment for competent engineers.

[null and void]

Right you are. It's a 7.4 m² array. This works out to about 10% efficiency at noon.

[null and void]

And how many watts at midnight, with a new moon, in mid-winter? In other words, what is the average output over a full year, which would tend to average out daily, seasonal, and weather variation?

It's usually clear weather in San Jose. That being said, the best answer I can give is "enough". Enough to defray 90 to 95% of my energy bills. Call it an average of about 1/3 the peak 800 W. About 2 MW-hr/year.

At that rate the system will pay for itself in a mere 25-30 years, assuming constant energy rates.

I have a small array because the state of California forbids selling electricity to PG&E, but only allows credit towards usage. Our ever clever Governer Grayout now wants to TAX solar energy...

[Boot Hill]

When you say 800 watts, are you referring to the manufacturer's installed, peak power rating? Or are you referring to having made an actual power output measurement? If it is the former, what model and manufacturer do you use?

--Boot Hill

[null and void]

The system was installed by a local contractor:

MC Solar Engineering
2362 Walsh Ave.
Santa Clara, CA 95051
(408) 496-6226
www.mcsolar.com

The grid connected inverter, Model GC1000 is made by:

Advanced Energy Systems
P.O. Box 262
Wilton, NH 03086
(603) 654-9322
info@advancedenergy.com

Sorry, I don't know who made the actual arrays. They are single crystal silicon.

[DB]

Okay, whatever.

"Efficiency" can mean a lot of different things depending on the context.

Energy conversion efficiency is one thing. The size of the generator vs. the actual usable output is another.

Efficiency could just as well be in terms of the dollars in verses dollars out.

But hey... I don't know what the word means...

[DB]

The inverter the other person said he used in his system has a specified nominal efficiency of better than 90%.

http://www.advancedenergy.com/gc1000.htm

Significantly better than the 75% you've been posting.