Or offer free bus service to all and see people voluntary reduce car usage.

That will only work if the free bus service is sufficient. I'm lucky. Where I live I have good, reliable and frequent public transport. Where my sister lives she has one bus service which runs (roughly) "this morning, this afternoon and tomorrow" (unless tomorrow is Sunday, when she has to wait until Monday). That service could be provided free of charge and it would be absolutely no use whatsoever in getting people out of their cars. In fact my sister has a free bus pass but does not use it because she has no buses to use.

I agree that it is not practical to provide frequent bus services across the entire country. But when considering schemes to get people to stop burning petrol or diesel in order to get about, politicians must remember that not everybody lives in Islington.

Or offer free bus service to all and see people voluntarily reduce car usage.

The trouble with simplistic solutions is/are [1] many people want to get to places the buses don't reach, [2] buses are not very convenient when fetching a weekly (or even daily) shop, and [3] it's unpleasant waiting in the rain (or snow) for a bus that may be 10 minutes late.

Those who had £10,000 to put solar panels on their roofs are being paid 40p+ per unit, the cost of which is added to everybody's electricity bills.

We decided to do as described, almost 10 years ago, so we are lucky enough to enjoy the 40p/unit you decry. However you should remember that what we have done in effect is to pay for ten years electricity up-front, so we are only beginning to reap any financial benefit. The high subsidy then was mainly to kick-start the solar-panel industry, which it did.

You might argue that the high tariff should be reduced rather than protected, which I accept.