Curmudgeon

Funny you should say "Until some cheap, reliable means of storing power becomes available..."

Because while you were writing that I was perusing the Science Weblogs as I am apt to do.

Please read on.

"Near Granada, Spain, more than 28,000 metric tons of salt is now coursing through pipes at the Andasol 1 power plant. That salt will be used to solve a pressing if obvious problem for solar power: What do you do when the sun is not shining and at night?

The answer: store sunlight as heat energy for such a rainy day.

Part of a so-called parabolic trough solar-thermal power plant, the salts will soon help the facility light up the night—literally. Because most salts only melt at high temperatures (table salt, for example, melts at around 1472 degrees Fahrenheit, or 800 degrees Celsius) and do not turn to vapor until they get considerably hotter—they can be used to store a lot of the sun's energy as heat. Simply use the sunlight to heat up the salts and put those molten salts in proximity to water via a heat exchanger. Hot steam can then be made to turn turbines without losing too much of the original absorbed solar energy."

http://www.sciam.com/article.cfm?id=how-to-use-solar-energy-at-night&sc=CAT_TECH_20090218

Now if we could just find a solution to constant negativity...

There is still a lot of manual labour required in assembling a PV panel, hence the high cost.
The author is correct, without substantially higher feed in taffifs the pay back time for a system is over 20 years. This makes the proposition unattractive if you plan to sell your home in a lesser time frame, or if you are in your senior years.
Home owners also need to bear in mind that in states, such as Victoria and Tasmania, there are times of the year when the panels will be fairly ineffective. Despite some misinformation around, these panels require direct sunlight.
Cheaper panels are usually utilising an older technology and are therefore, not as efficient as newer (Monocrystaline) panels.
A good inverter that is IP rated, has no moving parts and a decent warranty (7 years) is expensive. There are cheaper inverters which are fan cooled and only have a 1 or 2 year warranty. Remember anything with moving parts is prone to failure.
A solar system is generally only viable if you are building a new property more than 4kms from the grid. The cost of connecting to the grid is higher than installing a stand alone solar system.

If governements truly believe that CO2 emissions are a menace to our climate then they would have embarked on a Nuclear Power station program. Renewables alone cannot generate all of our power needs. Unless we are going to accept trauma victims being turned away from hospitals at night, when there is no wind blowing. Our lack of water makes hydro electric unviable. All other options require CO2 to be emitted into the atmosphere.

Australia can only radically reduce it's CO2 emissions by replacing coal power stations with nuclear power stations, and using renewable for peak load demand. Without such a plan, Carbon Trading Schemes etc are doomed to failure.

There is clearly a lot of misconceptions and mis-information about PVs- and nuclear power.

The point that I was trying to make in my earlier post was that rooftop PVs are unlikely to ever be economical because, as Liberal in Upwey rightly points out, there are both high labour costs and high "balance of systems" (inverters, batteries, control panels etc) costs which will not reduce much in price. The future for PV lies in meso- and mega systems. It is possible that meso-scale systems- eg factory roofs could be economical, but megascale- perhaps unproductive farmland- will provide the necessary economies of scale. To put this in proportion, one Gigawatt (2% of Australia's electricity) would require about 10 million square metres- ie about 3 km X 3 km- not a large area of farmland, but about 10% of Australia's houses.Economies of scale in installation and much reduced balance of systems costs are possible on this scale.

All of these systems take energy to build- at present that is carbon-based energy- see my article on net energy analysis forum.onlineopinion.com.au/thread.asp?article=8077. It is likely that new nuclear power plants will take more carbon-based energy to construct, maintain and decommission than they will produce. Even then, there is only about 50 years of uranium fuel available at extraction-energy costs that are viable.

The future has got to have a mix of carbon, conservation and a variety of renewables.

[quote]
"Near Granada, Spain, more than 28,000 metric tons of salt is now coursing through pipes at the Andasol 1 power plant."
[/quote]

This is excellent technology. They store heat in the the salt like cold is stored in ice. It's call latent heat, or heat of fusion, it happens during the phase change from a solid to a liquid.

Just like water when it becomes ice. When the salt becomes molten, it can store huge amounts of energy without an increase in temperature. When the sun goes down, they can draw from this heat bank and keep the turbines running. On long periods of no sunshine, the system can be kept going with a raw fuel such as gas, coal, wood, or anything that can produce heat.

Obviously the techs figured steam is the best fluid to run the turbines on those larger systems but an Organic Rankin style system can be more efficient and run at lower temperatures. This system can be scaled down to provide power where high heats are not available.

We could all have one in our homes if someone were to make it and it would be very cost effective compared to PV panels. Just the councils would probably have kittens if everyone had 20sq meters of parabolic dishes on top of their homes. But who knows, maybe in years to come all homes will have to have something like that and councilors will just have to suck it up and bare it!

I should have also pointed out that Australia is one of, if not the best country in the world to use this technology. Bust alas, our lipstick wearing PM is too stupid to know any better. Instead the Milky bar kid would rather give everyone chocolate wagon wheels worth 52 billion dollars and tax them for the privileged!

I am always intrigued that solar panels are judged on their ability to pay for themselves. We don't require that of other appliances. An electric hot water system, for example, is money straight out the door, along with ongoing and escalating running costs as the cost of electricity rises, and no returns at all. Why don't we focus instead on bringing down the cost of solar panels? They are not very complicated and seem unreasonably expensive for what they do. I could have a hot shower from something as simple as a garden hose left in the sun for an hour, so improving solar technology to make it better and cheaper seems the way to go, hand in hand with getting rid of subsidies for the coal industry.