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Here is what the acolytes of solar power don't want you to know...
self
| July 15, 2003
| Boot Hill
Posted on 07/15/2003 3:16:56 AM PDT by 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.
TOPICS: Business/Economy; Editorial; Government; Technical; Your Opinion/Questions
KEYWORDS: alternativepower; electricpower; energy; environmentalism; fresnellens; photovoltaiccells; photovoltaics; renewablepower; solar; solarcells; solarpower
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To: Boot Hill
I don't know, my mind gets numb just looking at numbers that big, but it's got to be better than paying farmers to do nothing with all that land. Besides, didn't the american farms in the great plains feed most of the world at one time? That's some huge prodution capacity....
61
posted on
07/15/2003 5:46:30 AM PDT
by
logic
("all that is required for evil to triumph, is for good men to do nothing")
To: FreedomPoster
Yes, but Boot Hill is saying that the plant cost is only 10% of the fuel cost. That brings it up to 3.7 cents a kilowatt-hour. Still along way from 12+ cents a kilowatt-hour.
My real point is that I believe natural gas costs today are much higher than Boot Hill's calculations show.
62
posted on
07/15/2003 5:49:36 AM PDT
by
DB
(©)
To: DB
Let's see, Distribution network, Billing systems, CEO salaries.......
63
posted on
07/15/2003 5:50:43 AM PDT
by
logic
("all that is required for evil to triumph, is for good men to do nothing")
To: Boot Hill
Well here in California they lost money at 10+ cents a kilowatt-hour.
My point being that I think natural gas costs today (and for the foreseeable future) are greater than your calculations show.
64
posted on
07/15/2003 5:52:53 AM PDT
by
DB
(©)
To: logic
Those costs are small relative to generation costs.
65
posted on
07/15/2003 5:56:34 AM PDT
by
DB
(©)
To: DB
I don't think they are much higher. Doing some back-of-the-envelope calculations, at $0.70/therm for natural gas and 80% conversion efficiency, I get $.03/kWh, so in the same ballpark.
66
posted on
07/15/2003 5:58:02 AM PDT
by
FreedomPoster
(this space intentionally blank)
To: Lee'sGhost
To: DB
Well here in California they lost money at 10+ cents a kilowatt-hour Well, heck, there's your problem. When you're not generating your own power, and you have to buy power from 3 states away at the selling utilities' marginal cost of production (i.e. most expensive-to-generate kWhs), no wonder.
68
posted on
07/15/2003 6:01:28 AM PDT
by
FreedomPoster
(this space intentionally blank)
To: FreedomPoster
So interstate trade is bad?
Many states buy California food. Many dont grow their own food. Is that really any different?
Actually I live in a county that generates much more power than the county uses. Diablo Canyon nuclear power plant is here along with other natural gas burning plants.
We (I) simply got screwed.
69
posted on
07/15/2003 6:08:53 AM PDT
by
DB
(©)
To: DB
Delivered natural gas costs for large public utilities are currently less than $5/MMBTU (million BTU). A modern combined cycle, combustion turbine generator typically runs at a heat rate (efficiency) of 6800 BTU (per kW-hr). This means they generate power at 3.4¢/kW-hr.
--Boot Hill
To: Boot Hill
May I hazard a guess that you've never tried solar energy? No, the technology v. $$$ isn't there yet but how about, just for giggles and grins, take a couple hours and set yourself up with a solar oven. If nothing else it might give some quality time with the kids or get them an A in science (or if no kids, get you out of some A/C office into the sunshine). Of course for anything other than smores, don't waste your time or mine when you holler back that small versions like the pizza box type doesn't work. I wish I could upgrade my solar oven to a through-the-wall type.
http://solarcooking.org
To: Boot Hill; newgeezer
This is why windpower rules and solar power drools. But thanks for the platform.
72
posted on
07/15/2003 6:12:20 AM PDT
by
biblewonk
(Spose to be a Chrisssssstian)
To: Boot Hill
BTW, the numbers I gave you in post #70
are California numbers. They were just confirmed for me by a manager at the Moss Landing power plant (2538 MW!!!)
--Boot Hill
To: Radioactive
35 billion dollar blank lung subsidy!
74
posted on
07/15/2003 6:12:55 AM PDT
by
biblewonk
(Spose to be a Chrisssssstian)
To: Boot Hill
You must not have read any of the case studies at the site I linked (which came from your post), and that's not even a recently updated site.
From a business standpoint, solar power devices will simply not keep being installed if they haven't proven cost effective. The market has proven they do have a place as a supplemental or alternative power source.
Reality is flying in the face of your statements, yet you choose to keep plodding along with your mindset.
75
posted on
07/15/2003 6:15:21 AM PDT
by
visualops
(C'mon FReepers, donate donate donate!)
To: Boot Hill
...and what form of energy do you represent?
76
posted on
07/15/2003 6:15:56 AM PDT
by
Consort
To: Boot Hill
Is that supposed to be a joke?
This isn't an "unconcentrated sunlight or low temperature heat" engine that barely moves. I know Stirling engines have been around for a long time, but this is something monumentally different. It's like comparing a two cylinder ICE to a turbocharged V8.
77
posted on
07/15/2003 6:16:09 AM PDT
by
Lee'sGhost
(Crom!)
To: biblewonk; wita
biblewonk says: "...
windpower rules and solar power drools."
wita says: "...the truth is out on wind energy...Wind can only be a backup or 'alternative' due to its inefficiencies." (post #14)
Biblewonk, meet wita. (And may the best screen name win!)
--Boot Hill
To: DB
#73 was for you.
--Boot Hill
To: DB
>>So interstate trade is bad?
It is when you're stuck buying the other guy's most expensive power.
80
posted on
07/15/2003 6:20:46 AM PDT
by
FreedomPoster
(this space intentionally blank)
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