Heres an interesting article

TonyS

<a href="http://www.bloomberg.com/news/2011-09-29/utilities-giving-away-power-as-wind-sun-flood-european-grid.html">http://www.bloomberg.com/news/2011-09-29/utilities-giving-away-power-as-wind-sun-flood-european-grid.html</a>

LarryC

Sounds like storage is the answer.

Sounds like an efficient means of energy storage and redeploying is an answer.



Where are the high efficiency high mass flywheel generators?  Million kilo, high speed, magnetic bearing, vacuum enclosed, motor generator sets with energy conversion efficiencies in 90+ % efficiencies, and millisecond response times.

Jean-David Beyer

Storage is the answer?

I suppose storage is the answer. My parents did this on a small scale in France. In France, the electricity is distributed on one grid, but they charge two rates. There are two meters, and one, that has the high rate, is available 24/7. The other, that runs at a low rate, can be switched on and off remotely by the power company (government monopoly when I was there) when the load on the system was too high, but they guaranteed a certain number of hours in any 24 hour period.



Their apartments (they had two in one building) were heated by forced hot air. The "furnace" was powered by electricity: resistance heaters. What the heaters did was heat the box that was mostly filled with rocks. The box was pretty well insulated. When ther thermostat felt cold, it turned on a blower that moved air through the rocks and into the apartment.



This was in the south of France where it rarely got below 40F in the winter. If it got colder, they could have used more rocks. In their case, they could throw a switch and get power anytime, but paying the higher rate. I do not suppose this would work well if their main use was to run an aluminum refinery or something really big.

LarryC

Dual rate power

As far as I know, they still do that in the UK, Europe and New Zealand. The electric water heaters are on the "night rate" meters. Here in New England, most of the older buildings still have dual meter boxes where the second meter was for a service controlled by a clock.  This second meter was for high current loads like stoves, water heaters, and electric dryers. For some large industrial facilities, they have a special rate tariff with the power company where the power company can actually turn off the facilities power in times of very high demand. In exchange, the facility gets a huge break in their electric pricing rates.



One of my concerns with intermittent power sources like solar, wind, and to a lesser degree, hydroelectric generators, the customer is expecting 24/7 reliable power. They don't want the power to go out because the wind stopped blowing or the sky became cloudy. Reliability comes at a price.



Big steam cycle thermal plants like nuclear, coal, and biomass, are not nimble power generators. They have definite ramp up and ramp down limitations. They do not turn on and off like a light switch. Some of them require a day or longer to heat up to come on line. Expecting someone to maintain a thermal plant in hot standby to come online in 15 minutes or even in a hour because a storm front came thru and idled the wind farm is not cheap. Someone has to pay for the fuel. Even gas turbine plants take several minutes to come on line.



Here in the North America, we are lucky in that we have limited ability to import or export power up to 1500 miles away. That allows us to spread the generation and consumption out over a larger area and a larger population. Usually a surplus in one locale can be exported to another area rather easily. Same with a loss of generation, the affected area can import power quickly and easily.



Until recently, each country in Europe maintained their own power system mostly independent of their neighbors. With a much smaller footprint each power grid was susceptible to local conditions with limited access to back up power from their neighbors. That is why they were so concerned about load leveling and encourage off peak usage by giving severe discounts to off peak users.



If an economical, efficient (95+ %), fast responding ( less than 10 millisecond), long duration (5+ Hr at rated output), large scale (1 - 1000 MW hr) energy storage scheme can be developed, a lot of the risk associated with intermittent power sources could be reduced.  They could be charged up during periods of low demand and export power during times of high demand. 

Pumped hydro storage does that at Nigra Falls but it only occurs at night after the tourists go to bed.



Let me apologize about the size of the post. I tend to over explain things at times.