Good for you. Most older U.K. houses are one brick thick (zero cavity) houses which are by their nature thermally dense. Thermally dense houses work by having the heating first heat the fabric of the house which then retains the warmth and radiates it back into the living space. It’s exactly the same principle as early man building structures from large rocks and having large fire pits within them - they didn’t choose large stones for shits and giggles. Heat exchangers don’t generate enough heat to heat the fabric of thermally dense buildings, nor are traditionally built U.K. houses readily suitable for additional insulation - you’re taking dry lining with insulated plasterboard to achieve ‘meh’ level benefits

And that’s current renewables summed up in one post - it’s an extra over = it isn’t enough by itself

Edit to add: it also sums up renewables in the U.K. as a whole. We’ve invested massively in wind power capacity, but the reliability of its output is distinctly meh. Many days it’s tootling along at a few percentage of it’s claimed capacity. But I doubt you, me, or aunty Jan care about that when we want to boil the kettle - we want power and we want it now. The grid recognises that so it keeps gas plants online, however, they’re not permitted to operate efficiently and generating the most efficient amount of power they can for the grid, nope, they’re kept tootling along as back up to the green wind energy ready to pick up the slack when the massive supposed capacity of wind generation invariably comes in at a few percent of claimed capacity. Gas plants operating below capactiy are inefficient and therefor expensive - so it’s uncanny that the cost to consumer of electricity across the board, regardless of where it was derived, is based on the cost of electricity generated by gas….