Electric Cars and Solar Power Kills babies.

jmc · Post by **jmc** » Fri Jul 31, 2009 8:54 am

I'm sure your right about the central steam generator, but I would imagine the bulk of the capital costs would be in laying down the mirrors.

It wouldn't suprise me it the mirrors themsellves could be made to last 100 years plus (maybe with the odd varnish) then it would just be the central steam generator which would have to be replaced every 30 or 40 years, I imagine the capital costs of doing this would be similiar to replacing an equivalent steam generator in a gas power station.

There are certainly plenty of coastal deserts in North Africa, scrubland in spain by the sea. You could use some of the energy from power plant to desalinate and purify enough seawater to act as a coolant.

Regarding Desert storms, I'm sure you could find some way of say turning the mirrors upsidedown and protecting them during storms. The molten salt could keep power generating in the short term. If the storm lasted for weeks you could have a furnace that burnt coal handy along with some coal inventories and use the same steam generator to get electricity from the coal.

MSimon · Post by **MSimon** » Fri Jul 31, 2009 4:12 pm

jmc wrote:I'm sure your right about the central steam generator, but I would imagine the bulk of the capital costs would be in laying down the mirrors.

It wouldn't suprise me it the mirrors themsellves could be made to last 100 years plus (maybe with the odd varnish) then it would just be the central steam generator which would have to be replaced every 30 or 40 years, I imagine the capital costs of doing this would be similiar to replacing an equivalent steam generator in a gas power station.

There are certainly plenty of coastal deserts in North Africa, scrubland in spain by the sea. You could use some of the energy from power plant to desalinate and purify enough seawater to act as a coolant.

Regarding Desert storms, I'm sure you could find some way of say turning the mirrors upsidedown and protecting them during storms. The molten salt could keep power generating in the short term. If the storm lasted for weeks you could have a furnace that burnt coal handy along with some coal inventories and use the same steam generator to get electricity from the coal.

I don't think you have any reasonable idea how harsh the outdoor environment is engineering wise. It is very, very, tough. Murphy always lurks. In every little detail.

Take turning the mirrors upside down. It doesn't help much. You have to put them in a sealed enclosure proof against sand grit (you know - the stuff sandpaper is made of).

Salt water blown off the ocean? One of the most corrosive substances known to man. Desert heat to +120 F cold to -20F (sometimes in one day). And then you have to design motors and mechanical contrivances that can work in those regimes and keep the dust off the mirrors.

Can it be done? Of course. How much money you got?

All this on a square mile of mirrors. Maintenance of a million mirrors (2 m on a side) is going to require a LOT of labor. Some of it more sophisticated than mirror wiping (keep the grit off your wiper cloth).

All this is one reason the initial plants will be in the 10 to 20 MW range. To get experience. 20 MW is nothing.

jmc · Post by **jmc** » Sat Aug 01, 2009 11:29 am

They already did the 20 MW phase back in the 80s.

The largest solar plant currently operating in the Mojave desert produces 310 MW.

Like it or lump it about 4 GW of solar thermal is set to come online in 2 or 3 years time. We'll just have to wait and see whether they've taken all the engineering problems into account.

http://ecoworldly.com/2008/04/12/mega-s ... -projects/

There are stony deserts aswell as sandy desserts, that could solve the dust storms.

MSimon · Post by **MSimon** » Sat Aug 01, 2009 3:18 pm

Nothing solves dust storms. All you can solve is the intensity of the dust.

BTW I never said it couldn't be done. All I said was that I doubted the economics. How much subsidy is going into the plant?

MSimon · Post by **MSimon** » Sat Aug 01, 2009 3:26 pm

And if Desert thermal is such a good thing why do utilities need to be coerced into it?

jmc · Post by **jmc** » Sat Aug 01, 2009 5:49 pm

Because its untried an untrusted technology. Private industry tends to be conservative unless there is a clear advantage.

pfrit · Post by **pfrit** » Sat Aug 01, 2009 6:35 pm

My biggest complaint about solar power plants has always been the fairly intractable problem that they are best where people are not present. In the middle of deserts. You have to ship the power to where people are. I was chatting with someone who mentioned a possible solution. Aluminum. The only method that we have that is really economically feasible of storing electricity right now is to make things that we need anyway with the cheap excess electricity. Large Hydro plants usually have nearby aluminum plants that only run when the electricity is cheap enough. An aluminum plant may stand idle for 8 months at a time and only operate at night. A solar plant, if it produced cheap enough electricty (big if), could support aluminum plants. A solar thermal plant could skip the whole generation of electricity part and power steel manufactoring. Concentrate the heat from the mirrors on the crucibles themselves. That one could be a straight away starter on its own. The issue then is just the cost of the plant. Just an idea.

TallDave · Post by **TallDave** » Sat Aug 01, 2009 9:18 pm

Private industry tends to be conservative unless there is a clear advantage.

And thank God for that. Have you noticed how poor Communist countries are?

Government intervention always comes at a price. Some level of regulation is often salubrious, but if the government is running an industry the results are generally poor.

MSimon · Post by **MSimon** » Sat Aug 01, 2009 10:30 pm

pfrit wrote:My biggest complaint about solar power plants has always been the fairly intractable problem that they are best where people are not present. In the middle of deserts. You have to ship the power to where people are. I was chatting with someone who mentioned a possible solution. Aluminum. The only method that we have that is really economically feasible of storing electricity right now is to make things that we need anyway with the cheap excess electricity. Large Hydro plants usually have nearby aluminum plants that only run when the electricity is cheap enough. An aluminum plant may stand idle for 8 months at a time and only operate at night. A solar plant, if it produced cheap enough electricty (big if), could support aluminum plants. A solar thermal plant could skip the whole generation of electricity part and power steel manufactoring. Concentrate the heat from the mirrors on the crucibles themselves. That one could be a straight away starter on its own. The issue then is just the cost of the plant. Just an idea.

I don't think such a plant can reach temperatures high enough for steel. Processes that use temperatures in the 400 to 500C range might be good candidates. And with such a process you do not take the Carnot hit (60 to 70%).

Of course that means some industries are favored over others. i.e. Aluminum might be cheaper than steel for autos or plastics requiring high temp processing. So essentially you are building a subsidy for a given industry or industries.

Good idea. I don't know how you solve the political problems.

KitemanSA · Post by **KitemanSA** » Sun Aug 02, 2009 12:57 am

TallDave wrote: Government intervention always comes at a price. Some level of regulation is often salubrious, ...

A slanted restatement of Johansen's third law "Like most toxins, government programs are subject to the J-Curve."

jmc · Post by **jmc** » Tue Aug 04, 2009 8:36 am

TallDave wrote:
Private industry tends to be conservative unless there is a clear advantage.
And thank God for that. Have you noticed how poor Communist countries are?

Government intervention always comes at a price. Some level of regulation is often salubrious, but if the government is running an industry the results are generally poor.

Agreed, you don't want to take random risks across the board. Especially if their unnecessary. But in some important key areas where the technology still isn't ready for private industry to take the plunge without support, government funding can help.

Consider all the new gadgets and technology the military has brought into the market place (that's a form of government fuinded research and development, albeit with the primary goal of killing people) commercial airflight would not exist today without earlier military support for the technology. Similarly weather satellites and space technology would not have got off the ground without early government funding. (And the space programme was also an early major driver for the development of solid state transistors.)