PV solar design example

[snip]

Certainly sugar beets are a better approach, but please... a citation that accurately shows cost-to-produce/energy-consumed-to-produce a quantity with the same energy equivalence as a gallon of gasoline... data that would possibly impress me more.

...Jim Thompson

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| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Joel Koltner wrote:>

Andy asks:

Isn't that the same department of energy that is paying subsidies to farmers to make ethanol to replace gasoline, when it takes 1 1/2 gallons of gasoline to produce the energy and fertilizer to make one gallon of ethanol ??

Don't believe all the PR you get from the government ....

Andy in Eureka, Texas

The LLP of any PV solar system will always be above about 0.75. So it doesn't help the grid much.

John

messagenews:85a3$4846a37f$ snipped-for-privacy@news.teranews.com...

energy costs of production in between 3 and 4 years

will pay back even faster. You could shorten the payback

In Australia you can buy solar (or wind) power from excess capacity on the grid for about a 50% premium on the standard price.

In a great move, South Australia just passed legislation that you now get twice the normal rate for solar power fed back to the grid:

Dave.

What's missing is truly free trade of any form of electrical energy. I can only speak for Germany, but I'm sure it's pretty much the same all over the world. The "classic" electric grid is fed from a few huge sources (plants), and distributes power to a few big sinks (industry) and millions of small sinks (households). That's how the grid is laid out, and since the big power suppliers also own and operate the distribution grid, they are not interested in changing any of that.

What we need is an independent and intelligent grid that can be fed into and consumed out of at pretty much any point, to a price that is instantly calculated from supply and demand at that minute. Solar power probably would immediately be economically feasible in regions whose energy demand soars when the sun shines.

It's also important that the generation of electrical energy is calculated at the true cost. Polluting the atmosphere is, in fact, using a ressource that all of us need and therefore it shouldn't come for free.

This would be a self-balancing truly free market. That's why the more right-wing folks don't want it. Big industry likes free markets just as long as the freedom is politically balanced in their favor.

robert

Where I am, the utility is required to buy excess power at the same price they sell it--the meter basically just runs backwards. Almost nobody does it, even at 19 cents per kWh, because it makes no economic sense yet. Cogeneration would be OK in the winter, when the waste heat would go into heating the house, but the maintenance is a problem. (Honey, the furnace just dropped a valve again!)

Self-balancing is the real parlour trick. High winds have caused wind power surges big enough to knock down the grid in the Netherlands a few times, iirc. Base load generation is still needed, or possibly energy storage on a gigantic scale using pumped hydro--which is just about the only storage technology that could conceivably be made big enough.

Re cost for photovoltaics:

A friend of mine at work has a 1 m**2 concentrator PV setup running at

2500 suns, so the cost of the silicon itself can be minimized. (It's based on liquid-metal thermal interface material (TIM) and water cooling.)

Concentrator arrays can be made to stow themselves when it's cloudy, so as to more or less eliminate damage due to wind and hail. That isn't as easy to do when they're installed on a sloping roof, of course, but the real drawback is that they're a headache to maintain.

Cheers,

Phil Hobbs

It's only "economically feasible" with massive public subsidies. And since a bit of clouds can shut off most of the solar power, the conventional utility generators and grid still need to be on standby to handle 100% of the load.

Many places, like California, already have sellback provisions for household solar, with the sellback rate often a lot higher than the usual purchase rate. That still doesn't make residential solar sensible.

A little CO2 never hurt anybody.

The "right-wing folks" don't like distributed solar power because it requires big artificial subsidies to even pretend to be economically viable. If solar makes money on its own, lots of right-wingers will raise money and put up plants.

John

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and it is my belief that all those energy balance items you mentioned are exactly accounted for and captured in the ECONOMICs of MONEY.

If you can save energy with PV or a hybrid car, then that means you are probably saving energy in the big picture. ENERGY =3D MONEY. If the system doesn't save you money, then it probably doesn't save you energy either.

Of course the convesion factor between money and energy is changing with time as oil becomes more expensive so it is not a static problem.

Mark

Only if you have zero batteries...

Having a solar/grid-tied system with no batteries is good for folks who want to sell power back to the utility company, but I would agree that realistically it doesn't help with power outages that much. (Although depending on where in the country you are and the time of year, LLP without batteries may get closer to 0.5... still not a huge difference, of course.)

I had a co-worker who was seriously looking into doing this, and he stopped at the point when it became clear he'd be paying something >$5k in the cost of approved transfer switches/line protection equipment and the cost of a licensed electrician to make it all kosher. Initially it had looked quite appealing, since he figured he'd be spending no more than, say, $1k in parts and had the skills (and free time, unpaid of course) to wire it/weld it all together himself.

This would only be true if the power companies implemented infrastructure to provide 100% of the expected loads 100% of the time (or some number very, very close to 100%). This is no longer true today, in most places: During "peak demand" season (usually hot summer days with lots of air conditioners going), rolling blackouts are not at all uncommon. They make people upset and usually "something" is then done to try to prevent them, but it's no longer considered "completely unacceptable" that they happen. Of course, one technique to prevent them is how (in many places) people can voluntarily have a widget attached to their AC which gets shut off if the grid is being stressed. Many big companies that draw significant power (mills, foundries, etc.) have a similar provision -- the electric company can cut them off with, e.g., 20 minutes notice and a big check that apparently covers the lost profits of the company but is far cheaper than building additional infrastructure.

Convenient how PV typically works best in the very same conditions where you need a bit of a "boost" to the grid, isn't it?

---Joel

Well, sure, if you keep in mind that a lot of what makes "economic sense" has to do with the political winds of the day and not so much what objectively costs the least *right at any given interest*. And this is how it should be: Taxes and subsidies are meant to influence behavior so that while it'd be cheaper *right now* to build power plants with no concern whatsoever for, say, effluent discharges, it would also tend to mean that we'd be (potentially) degrading the rivers and waterways which many people don't put a "price tag" on until it becomes polluted... at which point cleaning them up is far more expensive overall that if we'd avoided the problem in the first place (can you say, "Superfund site?").

But when it comes to energy policy, everything is highly political since there's a lot of money involved, foreign nations to deal with, and lots of environmentalists with varying degrees of "real" science to consider as well. It really isn't a simple matter, there are plenty of vested interests out there who will downplay technological advances in energy production if it means that their current technologies will become less valuable.

---Joel

Here's some articles about a home ethanol production system:

An NPR reporter dug into the economics of this process. It turns out that $1.00 per gallon ethanol is possible, but only based on world sugar prices (not available here in the USA). If you buy sugar in bulk (by the truckload) US prices, it'll run you about $6.00 to $8.00 per gallon IIRC.

If I can find a summary of the analysis on-line, I'll post it.

--
Paul Hovnanian	paul@hovnanian.com
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Have gnu, will travel.

Then ask Uncle Sap for a government grant - everyone else got their snout in the trough so why not the P.P.?

If it were economic, yes. But you can build a gas turbine peaker for a fraction of the cost per watt, and not depend on the schedule of sunshine.

The really sensible wey to generate electricity is with nukes. Fossil fuels are too valuable (or too dirty) to waste making electricity.

John

If there were any really good battery technologies, the whole power industry would change. But no luck so far.

John

Yeah, definitely agree there. Happily the push for longer laptop/cell phone (and now cars, to a very small extent) battery life has put many millions of dollars into battery research with no government investment needed... If the CEO can't finish that Excel spreadsheet on the jet to Paris, heads will roll, after all! :-)

Stuff like underground carbon fiber flywheels are always intriging, dunno how practical they are though...

When they ramp up ethanol production, will there be any security issues?

I mean, what do you think a tank truck full of moonshine would go for on the black market? >:->

Thanks, Rich

I wonder what's going to happen when Joe sixpack discovers that ethanol is pure moonshine?

Cheers! Rich