Solar Energy: Not So Clean Afterall

I wrote about Michael Asher at Dean’s World. When I wrote him a bit of fan mail, I asked him about solar and wind power. Here’s the conversation…

> How do solar proponents propose we use solar energy given the fact that
> the earth rotates? It would seem to me that you would need to store the
> energy somehow for use at night, which would mean that you would either
> need huge batteries OR you would need to electrolyze H2O to get
> hydrogen, then store that to burn it at night. Are either methods even
> feasible?
>

> Just curious.

Scott,

Energy storage is indeed the achilles heel of
both solar and wind power (winds rarely blow 100% of the time).
Environmentalists get around this in the usual manner, by refusing to get
pinned down on details. They simply make fuzzy claims that these should be
“part of” the overall energy picture—but what’s the other part? Solar and
wind may one day supply a reasonable fraction of residential energy
needs…but they’re almost comically unsuited for heavy industry. That’s
probably why they’re so favored by those who believe “manufactured goods”
should stop at tie-dye shirts and bean sprouts.

As for specific means of energy storage, right now there just isn’t any
practical means, period. Batteries come closest, but battery-arrays able
to thousands of megawatt-hours have never been built. They’re technically
feasible in theory at least, but the cost would be astronomical, the
environmental footprint very large, their safety questionable, and finally,
they’d lose anywhere from 20 to 40% of the power put into them due to
coloumetric charging losses. Hydrogen storage would have a much lower
up-front cost, but generating the gas, compressing it for storage, then
finally oxidizing it can easily mean you’d lose 2/3 of the power thus
generated. When you consider “daytime” solar power is already upwards of
40X more expensive than a well-run nuclear plant, a solar system capable of
providing nighttime power might be 100X or more costly.

Incidently, whenever you read statistics about solar plants, remember a
little ‘numbers game’ is usually played with them. Coal and nuclear power
usually have about a 95% availability factor…meaning a 1000MW nuclear
plant will provide 95% of that much power on a regular basis. But solar
power has closer to a 30% AF, due to cloud cover, the day/night cycle, and
other factors. So when you see a news report that some new solar array is
“capable of powering 5,000 households”, remember to divide by three in your
head….the total power generated is actually much lower.

Best regards,

Mike Asher
Dailytech

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5 Comments

  1. Ryan:

    Obviously, this person did not understand other methods of storing energy. Just because you’re trying to convert wind/solar/whatever energy into electricity, doesn’t mean you can’t convert it to other forms to store it (of course there is some loss in doing so). Hybrid cars convert mechanical into electrical storage into batteries and super-capacitors. That might not work for solar, but what about hydroelectric dams? Can’t we pump water into storage tanks to store kinetic energy? Some companies are considering that. Also, generating energy from wave technology, tide changes, etc. What about flywheel technology (this would be ideal for small organizations, and is almost lossless)? Also, some solar collectors that convert heat into gas can store kinetic energy thermally either in the ground or through some transfer fluid contained in tanks and is very effective.

    You have to think outside the box before you attack this question.

    My personal opinion is that you generate electricity cheaply using vertical windmills. They are way more efficient and not as ugly as traditional windmills. Plus they are way easier to fix and maintain, and don’t make a lot of noise.

    Check the link below:

    http://www.popularmechanics.com/technology/industry/1288371.html

    Solar energy can supplement our energy during the day, when we use it most.

    Ryan

  2. Scott Kirwin:

    Ryan
    No, he does understand other methods. What he’s talking about is centralized power generation; what you’re talking about is a decentralized model. The problem with the decentralized model is that you lose efficiencies of scale. You also have problems with our grid because our grid is built on a centralized model.

    If you have solar arrays large enough to power a city, to replace say, a 4,000 MW coal fired power plant, where are you going to store the energy you’re going to need after sundown? I doubt that you would be able to build a flywheel or set of flywheels that would be able to power that city at night.

    As for hydro, I like rivers – undammed rivers. So do salmon and bass. I’d rather fire up a nuclear reactor than dam up a river.

  3. Scott Kirwin:

    One more thing I just realized.
    With a decentralized model you could also probably do away with AC. I believe that the only reason we went the AC route was for transmission over distance. I suppose that we could avoid the power loss associated with inverting from DC to AC by going with a straight DC system.

    Unfortunately I don’t know how you would transform the grid in time for this to make a difference with global warming. If the alarmists are correct, we don’t have that much time to change our power generation and use. We need to act fast – which means switching to non-polluting centralized power generation that’s available 24/7.

    That says “nuclear” to me.

    But then again, I personally don’t believe the alarmists.

  4. Jasmine Ward:

    hybrid cars are energy efficient compared to diesel or gas powered cars.;-’

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