I can't speak to the UK specifically, but I have 4.8kW system on my south-facing roof in similarly-cloud Oregon. Panels will continue to get cheaper, but likely

I can't speak to the UK specifically, but I have 4.8kW system on my south-facing roof in similarly-cloud Oregon. Panels will continue to get cheaper, but likely the largest part of the cost will be the installation, and that is not likely to become cheaper nearly as soon (though it should gradually, as it's more and more common).