I have installed a solartwin panel for water heating. combined with Akvaterm tank this works well. Using gas to top up water heating less than once a week in August.
Windsave turbine not as effective, It produces a lot less than we had hoped for. I suspect that despite the lower theoretical efficiency a vertical axis turbine would be more efficient in an urban environment.
Have a guage to tell you the water temperature in your tank. During the winter, using this so we could turn off the gas water heating when the desired temperature was reached enabled us to halve our consumption.