OT: Solar power

In Australia too. It's used almost exclusively for storage hot water systems - heat up enough water during to night to meet the daytime needs.

But it does run, every night. It's not as if the supplier can say "Oh, the load was rather high, sorry about those cold showers."

That's very different from a system where the power you want to use is unavailable at the time you want to use it.

Sylvia.

I too can see that coming. But municipalities that own the parking meters will extract a pretty penny to charge your vehicle there.

There are moves in Australia towards charing at different rates at different times of day, with the idea being to give consumers a motive to shift some loads to cheaper times (i.e. times when the overall load is lower). However, the rates and times are fixed in advance.

In practice thus doesn't really help much. Any thermostically control system will simply run for longer when turned back on, and it's exactly that thermostatically controlled devices that are the power hungry ones.

That would make sense if they were the only two consumers, but for larger numbers, it quickly evens out anyway, without such control.

Sylvia.

Do most aussies use electric water heating? That's very inefficient.

not to mention gyro effect ...

I don't know about most, but it's widespread.

Australia has lots of easily accessible coal that is readily transportable to the coal-fired power stations that burn it. Selling off electricity cheap overnight for heating water makes it economic to have more coal-fired power stations than might otherwise be the case.

Yes, it's inefficient - the same amount of coal burnt in a water heater would clearly heat much more water - but it's price competive with gas, and solar hot water heating is sufficiently capital intensive that it's only marginally competive even with the available subsidies.

Sylvia.

Except that the solar is a not-always-there-during-daylight, so supply authorities still need the non-solar plant to be there and available, and that plant still has to be capitalised. There is no significant capital saving to the electricity gnerator by having grid-tied solar in their consumer mix.

On the contrary (as Sylvia and others pointed out), the solar-equipped comsumers consume less and therefore pay less towards the capital cost of plant which they still expect to be there when the sun don't shine.

The non-solar consumers are subsidising the solar-equipped ones.

ed to have two electricity meters, one for "off-peak power" and one for reg ular power.

Actually, that's exactly what off-peak water heating is. You store the powe r want to use, in the form of hot water, until the time you want to use it.

If peak power generation occurs during the day, that's when your hot water tank is going to get heated up. The "smart grid" is all about telling appli ances exactly when they can do their thing, and adjusting the minute-to-min ute load to match the minute-to-minute generating capacity.

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Thermal solar power with an array of mirrors concentrating the sun's radiat ion on a single point does depend on a cloud-free atmosphere, and they cons equently only get built in areas that don't see much cloud cover

That one of the reasons that the Germans want to build their solar plants i n the Sahara.

Gas turbines tend to be cheap. In practice the fallback option is likely to be other solar plant far enough away that they are unlikely to be all affe cted by the - rare - cloud cover or sand storms that are blanketing one of them.

There's plenty of agreement that it's high enough to justify solar power. P utting a precise number on the cost is much more difficult.

Nuclear power generation is the technology that isn't solar powered at some remove, and even that depends on the consequences of a supernova at some t ime in the remote past. There aren't any other technologies.

Nuclear fusion just involves setting up your own small copy of the sun.

Basically, if we used any one of the known solar power generation schemes t o generate the bulk of our electricity, the consequent economies of scale i n manufacturing would make the power generated cheaper than mains electrici ty is today. We've gone some way down that road already, and the fact that you can't yet see the next economy of scale is no argument for stopping rig ht now.

Depending where you are. The Germans want to build their solar plants in the Sahara, spread over enough land that most of them are working for most of the time.

Not at the moment. There isn't enough solar capacity to make a significant difference.

To a very small extent. When solar generation starts contributing a significant proportion of the power being generated, the grid will presumably include some pumped storage to cope with this sort of issue.

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n solar or wind output is low, so they need to have a lot of underutilized, ready-to-ramp-up generation capacity sitting around underused. And their d istribution system gets stressed, too.

he distribution system is designed around a few big generators. The distrib ution won't be any more stressed than it is now when the renewable generato rs aren't running, and less stressed when the more widely distributed renew able sources are feeding into the net.

r is moving?

refrigerator (and electric car charger!) when the wind/solar output was lo w.

ded to have two electricity meters, one for "off-peak power" and one for re gular power.

My parents didn't - they had gas-fired central heating which kept the hot-w ater tank hot too.

I do. That's how our flat was set up. Solar hot water heating is popular. O ver lots of Australia it makes sense to install reverse cycle air-condition ing, which cools the place in summer and - very efficiently - warms it in w inter. provided that you don't need a lot more watts of warmth in winter th an you needed cooling in summer. We haven't got that either, because we don 't need enough heating or cooling to make it a worthwhile investment.

On a cloudy day, the air condition system load is also smaller.

Install enough of them, and the whole world would stop spinning. That's far more dangerous than AGW.

My car has a Fastrack transponder. It does auto-pay for bridge tolls, airport parking, things like that. I suppose it will do parking meters some day, too.

Or not run as much. It might be warm indoors in the afternoon, and the loads could be picked up in a controlled way so it's comfortable by dinnertime. System-wide crisies, like when a transmission line or generator shuts down, could be mitigated if loads can be shed all across the system.

Or build enough gas-fired plants and let the market work. Why are we letting politicians do electrical engineering?

You are a walking, talking, unintended consequence!

Not in proportion to the insolation lost. It can easily be 90F and raining. The AC works double.

I would guess that most Americans heat water with electricity, too. The vast majority (based on house hunting over the last five years) in this area heat their homes with electricity (heat pumps), too.

I don't see any advantage to this, either. Though it's used to sell "smart metering".

Yep! Greenies are never honest in their approach.

If you're home during the day, screw you? If you want to save the energy use a set-back thermostat.

Bingo! But the Slowmans of the world *like* it when politicians do the engineering. It's all about the control of the masses.

As a pilot recently announced over the PA after landing, "Please be careful when opening the overhead bins; shift happens."