OT: Solar power

I liked the announcement "We know you have a choice of bankrupt airlines, so thank you for choosing United."

I worked for the company that had TI develop the fastrak transponders back in the day. Actually, what I really expect is that your CAR would be talking to the parking meter thingie, and say how much juice it needs, how fast it can take it, and who to charge for it!

Den fredag den 27. september 2013 18.54.30 UTC+2 skrev John Larkin:

or give you speeding tickets etc.

-Lasse

Simplistic observation. When it is 40C here and a thunderstorm rolls in, the heat doesn't vanish the moment the cloud cover arrives, and the dehumidification load ramps up faster than the thermal relief.

Off-peak consumption helps flatten the peak/valley ratio of demand. Any load you can shift effectively to off-peak reduces the peak demand and consequently the size of plant. Anything that reduces plant capitalisation will help reduce the electricity cost (or the profit margin for the supplier ...)

Solar is quite popular in Oz, particularly here in W.A. but there was a period after off-peak was introduced here (1977?) that its takeup was significant. Later that tariff was closed off but some consumers still enjoy it under grandfather provisions.

John Larkin can't do numbers. First he worries that Australia exporting 500 million tons of coal would cause the continental plate to shrink away to nothing (it might but not for about 80 billion years, and the planet isn't going to last that long).

Now he's worrying that a few flywheels will cancel earth's rotational momentum.

It ought be a joke, but he's not marked it as comic. Since he claims not to believe that AGW is dangerous "far more dangerous than AGW" could have been intentionally comic, but that's too subtle for him.

That can be borne out in the shipment numbers. I subscribe to Appliance Design, and the electric heaters outship the gas ones at least 4 to 1. Except for the relative cost of electricity vs natural gas, an electric water heater is actually more efficient, as none of the heat goes up a chimney or vent.

-Tom

be

That's never going to be politically acceptable.

Greenie politicians don't usually have much influence on the details of gri d regulation. It's true that Greenie politicians do tend to emotionalise is sues and have been known to over-simplify technical issues, but so have pol iticians of every other stamp.

You'd probably be happier with a warm couple of hours in the middle of the day than you would with a system-wide failure of the generating system. I t hink that after the last US system-wide failure, the MIT teaching generatin g plant had to be used to boot-strap the network, because it was the only o ne that had been sufficiently isolated not to be taken down by the system-w ide failure

For the same reason we don't let electrical engineers do climate engineerin g - there are more issues involved than simple electrical engineering.

Few are as slow as krw, and most have noticed that Soviet-style centralised control didn't work very well. Politicians are there to make sure that the electrical engineers attend to other issues, beyond making sure that krw's air-conditioning works when he wants it to.

I don't think it helps the debate to start twisting the meaning of words. The expression "solar power" is used to mean power generated from sunlight in the short term. It excludes things whose energy derived from sunlight long go, like fossil fuels. It also excludes things that work like the sun, such as nuclear fusion, and things that depended on events in other stars, such as nuclear fission.

I've heard the economy of scale argument over and over. I don't think it holds water. Solar panels are already a multi-billion dollar business. We've had the economies of scale. And some things just appear to be expensive to make - lead-acid car batteries have been around for a century, and have been produced in vast numbers, but they're still not cheap.

Sylvia.

That certainly doesn't happen with water heating. Without off-peak water heating, the coal-fired power stations would be underutilised at night. The operators of those stations will do almost anything rather than reduce their power output. In Australia, we have seen spot prices for overnight electricity actually go negative! That is, generators have been paying for the right to continue generating electricity.

Sylvia.

Perhaps, but it's no sillier than lumping all the various solar power optio ns together and telling us that "Solar is a dead end. Better to spend that money researching other technologies."

But you haven't paid enough attention to what was being said. The rule of t humb is that a ten-fold increase in manufacturing volume eventually halves the cost of manufacturing the individual item being manufactured. A one-hun dred-fold increase cuts the individual part cost by a factor of four.

We've had several rounds of economies of scale. Germany subsidised it's int ernal market enough to halve the cost of solar cells a few years ago, and r ecently China invested enough to halve the cost again - bankrupting a numbe r of German manufacturers, and also some US companies in the process. There are a couple more orders of magnitude increases in volume necessary before photo-voltaic generators could take over as a base load suppliers, and thu s a couple more potential halvings of the unit cost.

You wouldn't go for photovoltaic generators as our base-load source on this basis - there are several different sorts of photovoltaic cells, and until you've seen the actual innovations that provide the economies of scale, yo u don't know which one would be best.

Lead is a rare element - the original supernovas compressed a lot of hydrog en down to iron and elements close to it on the periodic table, but the hea vier elements were all formed after the initial collapse, by neutron captur e, and are correspondingly rarer, and more expensive to dig out of the grou nd.

Battery chemistry is interesting, and still potentially profitable.

All perfectly true, and completely irrelevant to the subject under discussion, which was the willingness of the consumer to adjust their patterns of energy consumption to suit the capacities of the grid.

Off-peak hot water suited coal-fired power stations. The "smart grid" has more to offer grids with significant wind- and solar-powered generation.

Sure there is. smaller lake on a hydro station costs less.

I have not heard of any classic superconductive proposals needing liquid helium or liquid hydrogen. All recent experiments are with "high-temperature" superconductors requiring LN2 (77 K) cooling.

I have seen references to about 1 km long cryogenic cables installed in existing ducts in city centers but no long lines so far.

Extracting heat at 77 K and dumping it at well above 300 K will give a quite low Carnot efficiency and the practically achievable values are even worse. In practice, this must be done in multiple stages and the higher temperature stages need to transfer the heat extracted at 77 K but also the losses (=heat) of the lower temperature heat pumps into the environment.

Exactly the point. Government subsidies are always going to be there, otherwise long term projects would never reach their goal. Today's mind boggling reliability and robustness of integrated circuits would never have been possible without sustained government funding for semiconductor device research at universities and national laboratories over decades.