Ontario Wind Energy Plans Costing $1 Billion Annually

[Submariner]

What is turndown ratio?

In this sense of operating on a bulk electrical system, it refers to the ratio between full and minimum load on the generating station. An example from Ontario. The recently shutdown Nanticoke coal units had a maximum output of 500 MW but could reduce to 90 MW and maintain stable operation. So each Nanticoke unit could provide 410 MW of ramping capability. Now look at Halton Hills combined cycle gas plant. Max output is about 650 MW and minimum load about 410 MW. Despite being a bigger generator, the Halton Hills plant can only provide 240 MW of ramp. The coal unit is favoured over the gas unit because it can provide more flexibility to follow load and provide spinning operating reserve at a lower overall cost to the bulk system. This was not a design concern for the combined cycle plants at first, but not that gas has displaced coal to a large extent, it is recognized as enough of a problem that GE and Seimens know this is an issue and are working to improve this. Current generation of combined cycle plants (like Halton Hills have turndown of approximatley 40%. Next generation is shooting for 60% with ultimate goal of 80 percent similar to the retired single stage coal plants.

 

[Submariner]

The technologies needed to store and released energy are not crazy future technologies like fusion. It's things like pumping water up a tower, or compressing air, then driving a turbine from releasing the water or the air on demand. No major breakthrough is required to make these things happen. What's needed are industry standards, fine tuning, economies of scale, efficient manufacturing, and business process development around how to manage the supply.

Fusion crazy? Far from it. It works very very well. Just ask the island in the south Pacific that isn't there anymore. :Eek:

I think you may have missed the point, which was that any secondary energy derived from a storage system will be more expensive than the primary energy used in the first place. So if you start with an expensive expensive energy source like wind or solar, store the energy for later use, then the secondary energy coming out will be even more expensive. It does not matter what storage technology you use or how much you put into improving it's efficiency. Combining storage with wind/solar only solves the problem of when the energy can be used, it does not make wind/solar any cheaper. If we have to pay $140/MWh for wind to produce energy that goes into storage, the energy coming out will cost between $175 and $250 per MWh.

And yes, there is nothing magical about a storage system. But pumping water up a tower? Really? That is pissing in the wind. Ontario that has made use of a significant storage system for almost 50 years. It is in Niagara Falls and is known as the Beck PGS (Pump-Generating Station). For more, see http://www.opg.com/generating-power/hydro/southwest-ontario/Pages/sir-adam-beck-pgs.aspx. The Yanks have an even bigger PGS across the river. The technology is a hundred years old. There are six pump/generators at the PGS. You put them in pump mode to bring the water up into the reservoir when price is cheapest (low demand periods). Then you use the same machine to generate electricity during high demand times. Mechanical and other losses, plus other market costs for pumping (like paying network service charges, etc) means that at the best of times, the energy coming out is between 1.25 and 1.5 times the cost of the energy coming in. If you choose to pump when market prices are cheap (look at this morning ... lots of hours when the hourly price was in the $teens) then the energy coming out is not so expensive, in the $20's. But if you are storing wind energy, you are not paying market rates because you are forced to pay wind $140 /MWh regardless of market prices. The result is stupid expensive power coming out.

By the way, the Beck PGS is about 700 acres in area and can realistically generate about 140 MW. If we want to store 2,000 MW (or more) of wind, how many locations in Ontario do we have that are near a large water supply and significant elevation change that we are willing to flood to that extent?