Yes the wind is free and windmills work. But as I already have explained, they need to be matched with a back up, whether that is used or not.
What will be the back up?
If it's fossil or nuclear, then that is what the country pays for electricity.
Two points:
You actually don't need a 100% capacity backup - that is a red herring and for the birds - usually an idea that is proposed and floated by climate deniers and lobby groups through paid mouthpieces. The UK and it's territorial waters cover several degrees of latitude and the wind has never, ever been zero at all latitudes. "Weather underground" website is a decent resource (wunderground.com) for historical data - go have a look for yourself. Offshore wind is usually more effective at generation, because of the more consistent winds offshore, but the costs are higher for construction and maintenance.
Nobody is proposing a fully 100% wind generation capacity - but it does form a large part of a complete energy solution. Other parts can also be carbon zero.
Other discussion:
Technology is most certainly being funded, researched and implemented. Several things have caught my eye over the past year or so. I posted recently on the battery installation being built in central Scotland. Other large scale battery developments exist already and more are being proposed.
Long-range power connections that can supply a country from large scale solar from thousands of miles away is also in late stages of consideration and proposal - and before the detractors jump in and cal out "inefficiency", the very fact that it is being developed as a VIABLE method of supply simply shows that it is considered VIABLE as an energy source by the engineers working on the project.
So long range connections are on the cusp of development, and clearly show promise in supplying a zone where it is night time from a place where the sun is still shining - moderating the "can only get solar in daytime" detractor argument, because it is always daytime somewhere on the planet...
Small modular nuclear is also coming into vogue right now - but my personal view is that the downsides of nuclear are significant.
Then we also have domestic home-scale generating capacity being adopted - with homeowners themselves investing in solar and battery capacity. I'm looking at this myself, but currently not in a position to move forwards. It is definitely apparent that the revolution is accelerating here - with domestic solar and battery suppliers struggling to keep up with demand at the moment and I think this is only going to accelerate further... If we ever get to a large proportion of UK homes with battery storage then the dependency on large scale industrial battery storage will reduce significantly. Wind generates at night time (although not quite as well as in daytime - see details below if interested) so can be stored from wind-powered-grid in domestic batteries overnight to feed daytime use - and solar can top up in the day to provide evening high-domestic-demand-time power.
Battery EVs can also take advantage of excess wind overnight.
Other types of battery can be used to store excess night-time wind generation including pumped hydro. I personally used to loathe the idea of fossil-fuel energy being used to power pumped-hydro despite understanding the logic behind peak and off peak demands, but now with renewable being used to power renewable pumped-hydro, this is another virtuous circle that makes sense. As written above - heavy fluids are being developed to increase the energy storage capacity from pumped hydro, and is another layer in the mix.
All of these things combined together will form the overall mix of domestic and industrial supply, they all form part of the overall solution... and the mix will be engineered to work, despite the detractors saying blinkered things like "but the wind doesn't always blow".
The overall point is that the green revolution is most definitely underway - and the UK would do well to get in on the ground floor while it can. This isn't "virtue signalling" or "virtue talking", it's simply how things are currently moving forwards. The more and more energy the globe can generate in renewables means that the objects we produce to create renewables can be produced using renewables - and this sets up a virtuous circle of clean energy. China is investing heavily in renewables and drill-baby-drill USA will probably lose out in this long-term endeavour, leaving a potential vacuum of investment that the UK is well placed to tap into.
[Short meteorology lesson on horizontal air movement:
The wind at the surface/ground level is not as strong as the wind at around 2,000 feet above surface level. The wind at 2,000 feet is called the "geostrophic wind" or "gradient wind".
Wind strength is greater where isobars are closer together. UK met charts typically have isobars spaced at 4 hectoPascal (hPa) intervals (4 millibars in old money). Hence storms which are depicted on a surface pressure chart show isobars in circles that are closely stacked together, and it is this close spacing of isobars that creates very strong winds.
Friction is the reason for the wind strength decreasing below 2,000 feet. Friction between air movement and the ground is (typically) greater than friction between air and water for two reasons - ground is "rougher" than water and water is also consistently level and flat. Turbulence is also created by undulating terrain/obstacles/trees/buildings/etc. That said, in hilly terrain, it is better to place turbines at hill tops, because the venturi effect created by squeezing the horizontally moving air upwards helps to reduce the effects of friction.
Friction between air and surface is greater at night due to the ground being colder, which cools the air and makes it more dense/heavier to move, therefore the pressure gradient force moves it more slowly.
Wind direction also varies between surface and 2,000 feet gradient wind. This is because it is moving more slowly and the other force experienced by moving air - the Coriolis Force - which deflects air movement to the right in the northern hemisphere - and the reason that wind flows along the isobars at 2,000 feet, rather than at right angles which you would intuitively expect - the Coriolis force is reduced by slower moving air.
Daytime reduction in wind surface wind speed compared to gradient wind is typically 20-25% during daytime and typically 30-35% during night time.
Wind direction is typically 20deg "anticlockwise" from gradient wind during daytime and 30deg anticlockwise night time.
Wind direction is said to
veer if it changes in a clockwise direction (viewed top down on a map) and said to
back if it changes in anticlockwise.
The phrase "backs and slacks due to friction" ius useful in remembering how the wind varies from gradient wind to surface wind.
Surface wind is therefore not exactly along the isobars, but
backed slightly.
Buys Ballot's Law (a real person's name) states that if you stand with your back to the wind in the northern hemisphere, the low pressure will be on your left.
One more factor on air movement is the sea breeze effects during an otherwise windless or low wind day. The
Thermal Wind. Land heats quicker than water in daytime sunlight. Even though the air in contact with both land and sea at the coast is at the same pressure - therefore no pressure gradient force to drive winds - the thermal heating of the air over the land expands the air column over land more than that over water. The entire air column over land expands and becomes less dense. This creates a pressure differential,
at height, between the two different air columns and causes horizontal air motion to start flowing
at height from land to sea. A circulation effect is created from the warm air rising over land, flowing out to sea, and cooler air moving in from sea to land at surface level to "replace" the warm air that has risen away from the surface. This sea breeze typically flows strongest in the afternoon periods of hot summer days where there would otherwise be very little wind.
This is another reason why offshore wind can harness energy from otherwise slack wind days.
I think that's all I can remember to write down for now...]