When electric vehicles become popular, even the standard, where will the power come from when people plug them in at night to recharge?

Where I live, we have winds at night, so windmills will work

Solar power would work. It is stored in batteries.

They will be from solar panels.

It will come from power plants of course. 

Keep in mind that even an EV powered by a coal-fired power plant is still lower emissions than a car powered by an internal combustion engine.

In addition, power generation is becoming more efficient / lower emissions. Yes, solar doesn't generate power at night, but it does during the day and contributes to the power grid overall. Coal is decreasing in importance. 

In any case, it will still create emissions, but the point is that it's lower emissions than regular gas-powered cars. 

In the U.K. , we will not have enough that’s for sure. We will end up importing French (nuclear generated) power at whatever price they want. Also they want to ban gas boilers and switch everyone to electric heating.

Costs will at least double , so given that electric is about 5x the cost of gas anyway, my heating bill could go up 10 fold over a few years.

Also, they will need to recoup revenue lost from fossil fuels, so I can see soecial meters being installed for EV charging. It will be like economy 7 in reverse, it will be far more expensive, or all electricity will be charged at a higher rate to compensate. At very least, I think they will makeVAT 20% on it.

You are advantageously failing to remember that it is far simpler to control contamination from a solitary point (power plant) than it is to control it from numerous focuses (engine vehicles). Truly, the sun doesn't sparkle around evening time yet there is another creation called a battery. You may even have seen one. Sun oriented boards are very productive, regardless of whether they are charging for just piece of every day.

Where I live, we have winds at night, so windmills will work

You are conveniently forgetting that it is far easier to control pollution from a single point (power plant) than it is to control it from many points (motor vehicles). Yes, the sun doesn't shine at night but there is a new invention called a battery. You might even have seen one. Solar panels are quite efficient, even if they are charging for only part of each day.

Renewable energy overtook fossil fuels for first time as UK's biggest source of electricity in 2020. Wind, solar, bio-energy and hydro (water) power generated a record 42% of UK power last year, while fossil fuels - mostly gas - produced 41%,.

Very few countries can rely on just one green energy source because as you say the sun does not shine at night, but then water still flows and the wind still blows.  Which is why most countries have combined green energy supplies.

Houses in the UK with solar panels usually generate around 75% of their household electricity needs.  

At the moment around 900,000 UK homes have solar panels, as this number grows the amount of electricity needed from the national grid will continue to drop.  Presumably you know that electricity generated during the day is stored in batteries, it does not disappear when it gets dark?

A company in Australia have just developed an ink which can conduct electricity, which can be printed onto thin durable plastic.  If their tests are successful, this would do away with the need for solar panels and make it easier and cheaper for more homes to install them.

Then of course there are all the wind farms in the UK. On Boxing Day 2020, a record 50.67% of power used in the United Kingdom was generated by wind power. However, it was not the highest amount of power ever generated by wind turbines; that came earlier in December 2020, when demand was higher than on Boxing Day and wind turbines supplied 40% of the power required by the National Grid (17.3 GW).

Those countries leading in the research, development and production in this area are the mega corporations of the future because whatever you think the whole world is moving away from fossil fuels. 

Yes there are challenges and it will take the best and brightest minds to solve them, but they will as man has done in the past.  After four years America is back in the race to lead in the field and take a share in the money and jobs this industry will generate, which is up for grabs.

There is not enough green tech to supply our energy needs now, or projected to be in at least two decades.  Same projections by the way, that were a decade ago under Obama.  We will either have fossils supplying the grids or we will have rolling brown/black out as we rations our energy supply. As is how it works in Ca every summer. You know, that place that has more solar then anywhere else in the US, or should.