so true as England hardly sees the sun
You'd be surprised. Here in Devon in SW England I've just recouped the entire capital cost of my 14-panel roof array over 7 years in feed-in tariff payments from my energy supplier. The tariff is based on estimated 50% of generation, so the other 50% is net benefit. In the summer I get about 24kwh daily, 3500 in the year.
The system is fine as long as you see it as just one element of a diverse domestic energy portfolio, and don't expect it to provide base load.