Partly to prove the point on it always being windy somewhere (with the cororally that it can’t be wind6 everywhere) there is 24GW of installed wind capacity in this country, and the record for peak output (last Tuesday) is about 18.5GW.
This article is interesting, in that it shows one of the issues with the majority of our wind turbines being located in the northern part of Great Britain.
bloomberg.com said:
U.K. Grid Installs New Kit to Stop Green Power Going to Waste
* Smart valves alleviate congestion on the electricity network
* Technology will free up 1.5 gigawatts of capacity on the grid
By Rachel Morison
May 9, 2021, 7:01 PM EDT
National Grid Plc is installing new technology on the U.K. network that will remove bottlenecks of renewable power and free up enough power to supply a million homes that would otherwise be wasted.
When it’s very windy, too much electricity is sometimes being supplied to the network in one place, with parts of the system reaching maximum capacity while others are below their limit. The so-called smart valves will automatically route power to parts of the grid where there is available capacity.
Reaching carbon neutrality in the grid by the middle of this decade will cost the industry 3 trillion pounds ($4 trillion), according to the network operator. That makes it essential to maximize existing power lines and to use all of the electricity generated from the nation’s wind farms.
The smart valves will allow the company to “harness the full potential of renewable generation and lower costs for the end consumer – all helping toward our ambition of being able to operate the system at zero carbon by 2025,” said Julian Leslie, Head of Networks at National Grid’s electricity system operator unit.
The majority of the U.K.’s wind capacity is in the North Sea. The network can’t always cope with moving all the electricity at once to where it’s needed so National Grid is sometimes forced to pay operators to stop turbines spinning.
National Grid is installing 48 smart valves on five of its circuits at three substations in northern England, making 500 megawatts of new network capacity available at each site. The work will be completed by the end of the year. The company is also considering rolling out the same technology at two more sites in the autumn, which would unlock a further 500 megawatts.
link to article
That’s the same for any type of power station.
Nuclear power stations take a lot longer to decommission and require more energy to do so compared to any other type of conventional electrical power station.
We've run large nuclear stations for decades, the grid can cope with one going off relatively suddenly. Though thermal generators (nuclear/gas/coal/etc.) don't generally go off instantly. Even though the heat source may trip out suddenly, the turbines generating the power spin down more slowly, which allows for other generators to be brought online.
More problematic are the renewables, which use solid-state converters to connect to the grid. Those do trip out instantly.
So as we shift the balance of the grid away from the thermal systems we're losing some of the resiliency we had before. The proper answer is more storage that can be brought online instantly (batteries?) or quickly (hydro?).
But as we've seen this year, there can be extended periods with very low wind and those weather patterns can extend further than just the UK so building more interconnectors won't necessarily save us. There has to be a reliable source of low carbon energy available that doesn't depend on the weather, at the moment nuclear is pretty much the only one that fits.
Back when coal was king, a number of stations were run under capacity so that in the event of a power station dropping off the grid, one or more stations could quickly run up to maximum capacity.
As with any complex system, there are many failure modes. It may not be the heat source (in the case of thermal generators) that fails.
With a system where there are many, many wind turbines, an individual turbine (or a group) dropping out is not significant. The same goes for any distributed power generation system.
Battery systems by their nature have to use solid state converters/inverter systems.
Of course more inter-connectors are not the whole answer. They are however a tool that can be usefully used, as now, if a power network has more capacity than needed and an adjacent power network has a current lack of capacity (or wishes to use spare renewable energy instead of running a fossil fuel station).
The main reason they are run flat out all the time is not because of technical limitations - its because fuel is almost free so there is almost always no point in ever reducing output.
Yes, currently electricity from nuclear power stations is sold to the grid at ‘any price’. But then the current output from nuclear is only 5.36GW, approximately only 13% of the supply.
Given the uncertainty of future prices for electricity generation, if we make the assumption that electricity from renewable sources such as wind turbines will be cheaper than electricity from nuclear power stations, if there is an excess of power generation, what then?
Will keeping a nuclear power station on standby be acceptable?