[clug] OT: Solar power recommendations and advice

Alex Satrapa grail at goldweb.com.au
Tue Apr 20 18:48:36 MDT 2010

On 21/04/2010, at 07:21 , Felix Karpfen wrote:

> If the producers get it wrong, you either get brown-outs (when there is 
> not enough to meet the demand) or waste (when some of the available 
> electricity does not find a buyer).

If we have enough batteries connected to the system, there will never be any waste in the form of generators not putting out as much electricity as they can for however much fuel they're burning. There will be waste in the form of losses due to charging and discharging batteries (lost as heat through the charger and the battery itself).

Batteries can start discharging within microseconds of demand being notified over the smart grid.

Next in line is the hydroelectric system, which is another form of stored power.

After that is the open/closed cycled gas turbine.

Way, way behind in terms of responding to burst demand are the steam turbines which are extremely efficient at producing vast amounts of power at very stable levels.

The way we currently address the problem of burst demand is to run the fuel burners with slightly more capacity than required, which means a large amount of (potential) electricity is simply wasted as heat. I am not aware whether they literally waste electricity as heat by dumping it into resistor baths, or if they just don't load the generator as much as they can. Either way, fuel is being burned to achieve nothing.

For the moment, it's cheaper for a fuel burning plant to burn fuel than to store power in a battery to smooth out demand spikes. For batteries to become common place, we'd need:
 - variable pricing available to small players
 - clear standards for small players to follow
 - mechanisms in place for linesmen to remotely disable the distributed power inputs
 - cost-effective mechanisms for hundreds of thousands of micro-payments for power
 - legislation to regulate all the above
 - feet on the ground to police the legislation

> ... 2nd generation cells (currently 
> marketed in the US) achieve an 18%+ conversion; 

Your roof is currently converting 0% of the sunlight that reaches it into electricity. In comparison, the most inefficient solar panel you can devise will be infinitely better at converting sunlight into electricity.

The efficiency of a panel is only relevant where you care about the space it's taking up: for example if you're planning to convert your wheat farm into a solar electricity farm, in order to export high voltage DC to the next state rather than wheat. You'd want to make enough electricity with the same number of hectares to make more money than you did growing wheat.

> Finally - although this is OT raised to a higher power - the best (and 
> cheapest) way to cut electricity-generated greenhouse gas emissions is to 
> reduce demand.

Exactly! Now we just have to convince 20M Australians to play the piano instead of watching footy on their 150cm flat screen TVs :)

Individually, those of us on the list can take steps such as moving persistent services to low-power devices, or questioning whether we really need to have our home servers on when we're asleep. Turning computers off when you leave home or go to bed is a no-brainer, takes no effort, and starts cutting your contribution to pollution immediately. Then rather than watching TV, learn to play Scrabble (without the new proper nouns rules of course, we're trying to improve education and vocabulary, not celebrate cretinism) or raise some chooks and spend time in the garden.

When we only had a billion people on the planet, we could pollute to our heart's content and the planet would "soak it up" in various environmental sinks. We now have over 6B people on the planet, so we can each only pollute 1/6 as much as people in the 1800's if we want to keep the same pollution levels as we had back then.

To reduce pollution we can use energy sources that produce 1/6th the pollution of equivalent energy sources in the 1800s, or simply use 1/6th the energy that people used in the 1800s. The math is pretty much the same for any point in time - I only pick on the 1800s because that's about the time of the industrial revolution, and I have overly romanticised ideas of C18-C19 being a wonderful environment to live in (sure, we've made huge advances in medicine, but giant backward steps in environmental quality).

And here I am typing this on the second computer on my desktop...


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