My gas one boiler is almost 50 years old. I have been looking into what I can replace it with when the time comes. I have sufficient ground for a large solar panel array, many more than on a roof. Coupled with a battery system to store the power for nighttime use has a great appeal.
Then Tesla have replacement tiles that are solar, should a re-roof be required that would be interesting.
Insulating a house, so they are suitable for heat pumps, can only be done during the design/build stage. This shows they aren't anywhere as good as the old gas boilers. I understand they can't be turned on and off and must keep pumping. And the pump uses a fair bit of electricity.
Can we have microwave heating that just warms the person?
Short term, in your shoes, before it becomes not allowed, I'd look at replacing that old gas boiler with a new, condensing gas boiler, if it is a big house then probably multiple heating zones, and controls that best suit the situation.
That would deliver heat for about 60% of what it costs at the moment per kWh, simply because of a significant improvement in boiler efficiency.
Solar will never provide winter heating needs in the UK.
Heating the person is not comfortable for very long: churches often use radiant heaters because the buildings are so draughty and hard to heat. Ones head burns and the rest is barely affected!
Approaches to insulation retrofitting that in the past would not even be considered are commonplace these days, driven by the pace of energy price rises.
There is no good answer to reducing the bills for a building that requires a lot of heat, and there won't be in the future either. Use less is the only way forward, whether that is by drastic reduction in thermostat settings, or by insulating/draughtproofing.
In the 1970s, typical UK household temperatures were in the region of 14 degrees C. Anyone under 50 probably doesn't recall, and anyone under 35 probably wouldn't tolerate it! And it is not a good thing to encourage the elderly or vulnerable groups to try.