[CliffordK]

Since there is a positive return on the investment...  I'm going to interpret that as indicating that the windmills produce more energy than they consume.  Of course there may be government subsidies, but it appears to be a profitable business.

Apparently there is some competition of selling the electricity though, as the government who has been running several local dams for 3/4 century or so is reluctant to dump more water over the spillways so that they can buy more private wind power.

I'm still not convinced about the benefits of paying a premium for "wind energy".  At the substation, there is really no difference between wind, water, or coal power. 

If, say 5% of the power is generated by wind, and 95% by other sources. 

Then, if 4% of the people pay for "pure wind power"...
Then they get 100% "wind power".
Everyone else gets 1% Wind power, and 99% Other.

It really doesn't change anything.

And, on a calm, windless day...  are those people buying the wind power accepting a brown-out?

[syhprum]

     "I guess LNG is as safe as petrol"
Not if you want to take your car on the Euro tunnel train to the mainland they won't let you on.
I buy my electric from France as I am enthusiast for nuclear power.

[wolfekeeper]

If, say 5% of the power is generated by wind, and 95% by other sources. 

Then, if 4% of the people pay for "pure wind power"...
Then they get 100% "wind power".
Everyone else gets 1% Wind power, and 99% Other.

Yeah, but what happens when 6% demand wind power? The price of wind power goes up, and it becomes more cost-effective to build new wind turbines and then the energy market responds and the price goes back down again. It looks like we're going to be getting 20% wind penetration in the next decade or so anyway; wind power is growing 20+% per annum.

The reason it's growing like that is that the cost of new wind installations is about the same as new natural gas installations per kWh delivered to the end-user, but it's carbon negative and you don't have to rely on foreigners who may push up their prices.

And, on a calm, windless day...  are those people buying the wind power accepting a brown-out?

No, they're buying energy produced by other sources, which lend them the energy. On a very windy day, those sources shut down, and wind power pays it back- with interest. The net effect is strongly carbon negative; that's fuel you didn't have to burn. It's called 'grid storage' and solar panels do the same thing.

Also, if there's a lot of electric cars attached to the grid you can use them as storage; so the wind/electric car combo is particularly attractive.

[syhprum]

How do you rapidly shut down a nuclear plant when the wind picks up ? or will it be easy when all the power plants are fusion (hot or cold).

[wolfekeeper]

Nuclear power is base load power, and very expensive; it's left running at constant power, and doesn't work well with variable loads or variable sources.

[CliffordK]

It is even hard to vary the output of a coal or NG plant, at least with short-term variability.  Presumably one could program it to have peak output at the same time of a predicted peak demand on a diurnal basis.

The government likes to also run the big hydro-electric plants at a constant rate (base load power), but it would seem that hydro would be perfect for variable load power.  Perhaps coupling a large base-load generator with a smaller variable load generator, with the goal of maintaining an average river flow over a 24 hr period.

Obviously average flow rates vary by the season in places like the Northwest USA, but fortunately, in the winter when heating demands are the highest, flows are also generally the highest.

I certainly don't want the government to start discharging my EV car without my permission.  And, my charger is designed as a 1-way device. 

The local power company is discussing variable power rates, with cheaper rates at night, and higher rates during the day.  In that case, I would certainly put a timer on my charger to kick it in at midnight, for example to capture the cheapest power rates.  I may do that anyway.  If they had a buyback, I might consider uploading power at noon (on days I wasn't using the car) and downloading power at midnight.  What would the efficiency be?  80% max?  However, the life of batteries is in part dependent on depth of discharge and cycles.  If my net savings per cycle would be on the order of 1 dollar, I don't think I would choose to allow diurnal cycles as wear on my battery packs would likely be greater than the diurnal cycling.  And, of course, if something came up in the afternoon and my vehicle was discharged, I'd be out of luck.  Rapid 1hr charging might help some, but I don't have that capability. 

Anyway, I'm still convinced that the best place to intentionally vary the power generation is to install a small variable power module in the dams.  Would it cause more silting? 

[wolfekeeper]

You mean Dinorwig, it's a 1.8GW hydro peaker plant in Wales.

http://en.wikipedia.org/wiki/Dinorwig_Power_Station

Also peaker plants in general, are specifically designed to be fast start power generation:

http://en.wikipedia.org/wiki/Peaker_plant

And the idea of the car thing, is that you can CHOOSE to sell (some of) your car's electricity that you bought at base-load cost, back to the grid and make a profit. You don't have to though. Peaking electricity is usually priced at several times higher price.

[Geezer]

I certainly don't want the government to start discharging my EV car without my permission.

It would not be without your permission. There would have to be a system that allowed you to set a price for the energy you supplied. At a certain price, you would be happy to sell it!

[CliffordK]

I certainly don't want the government to start discharging my EV car without my permission.

It would not be without your permission. There would have to be a system that allowed you to set a price for the energy you supplied. At a certain price, you would be happy to sell it!

Like I said, I would be more willing to charge during off-peak hours than to resell the electricity.

However, if the power company offers $1 per discharge cycle on my batteries.
And the battery pack is valued between $3,000 and $20,000.

And, the power company wants to discharge my car at the time I'm most likely to want to use it.

I might choose not to add the extra unnecessary discharge cycles.

[wolfekeeper]

However, if the power company offers $1 per discharge cycle on my batteries.
And the battery pack is valued between $3,000 and $20,000.

I don't think you're quite getting it. At peak load, the power company probably offers more like $0.6-$0.8 or more per kWh, not per discharge cycle. So if it's 50kWh battery, then your battery charge is worth $30+.

The situation is that the power company is desperate for electricity, if they paid $0.2 per kWh nobody would build peaker plants, and nobody would give them any juice!

[Geezer]

The situation is that the power company is desperate for electricity, if they paid $0.2 per kWh nobody would build peaker plants, and nobody would give them any juice!

That's true. The "spot price" for electricity (in the US anyway) can be incredibly high, and it explains why some utility companies have invested heavily in energy storage systems.