Originally Posted By: Joshua_Skinner
Yes, wind integration is problematic. In the NW it's working reasonably well because of the hydro balancing reserve. Large scale demand side balancing is coming on line.
Solar is easier to integrate, but still no cake walk.
One big problem is that large base-load thermal plants aren't flexible enough to ramp up and down production as needed.
If you think these issues aren't being worked on and won't be solved please turn over all the computers in your car and retrieve a set of breaker points. There is a sea-change happening in the utility industry, but I don't think that's your area of expertise. Change would be happening faster, but there are huge capital expenses involved.
I like the fact that you've presented that wind and solar are difficult(ish) in the market, but not sure on where you get the idea that thermal plant isn't flexible.
35-100% is a pretty typical range for a black coaler, gas thermal (devil's work, should never use gas for thermal power stations) can do lower. Brown coal and nukes certainly don't have the turn-down.
Wind and solar are harvesters, and can't be "dispatched" like thermals and GTs
Wind blows, and sun shines, and you get power, but then you need a grid and thermals to control (actually to provide) system frequency, control that frequency, and to provide power factor correction (latter can be done with static VAR compensators, or synchronous condensers, but no-one wants to pay for that service, although it's essential).
South Australia keeps making headlines as the state that regularly provides all of it's capacity as wind.
This particular day was intereresting
http://reneweconomy.com.au/2015/how-south-australia-coped-without-any-baseload-power-65138
on a couple of fronts, a brown coaler had an explosion, and 4 people were injured (some of the media seemed to take delight in that fact), and the state "survived solely on wind power". Repeat on the news ad nauseum.
Can see the event below (BTW, that "gas" is all open cycle GT, and Gas fired thermal)...firstly, it's not a big market...and secondly the gas was ignored. Note which of the two remaining sources could be intentionally ramped up to meet the demand...gas, as the wind dropped later that day.
What they didn't report was that the state is connected at the other end to a mass of brown coal fire thermal at the end of a transmission line, and should the line have gone down, the whole state would have been black...
Great renewables story, but the missing details are that the state was on a knife edge...if it lost access to the thermals, then it could not self start. The windmills don't make the grid start.
What also wasn't reported was that two days later, there was no wind in that state, it's interconnectors were maxxed out with the station still shut down, and the wholesale price was $100s/MWHr (normally $30-$45), which naturally encouraged the demand side to keep their consumption down. 1,000MW wind gen one day, and three days later less than 100.
The station got back in after the investigations were completed, and prices stabilised, the state became it's usual import/export self, with normal prices...they are still one of the most expensive states to buy electricity in.
Good news (in certain circles who glee in that news) is that Station will be closing down within the next 8 months, and the state gets to demonstrate how reliable its wind is. Half of that gas power shown in the chart is due to go as well.
It's all economic and shareholders. The wind gets first access, and drives down the power price, but there's no money in providing the systems that keep the grid up.
Traditional radial feeds are now having power reversals, making huge problems with system stability, frequency control, and power factor.
As you correctly say, these things are being worked on, but they are an expense that the grid companies are having to pay for, not the wind generators...it ends up on your electricity bills, but not apportioned to the sources that have displaced traditional sources, while only providing one of the half dozen or so things that thermals provide to the grid.
