Solar and Heat Pump Hot Water

Choosing solar or heat pump   - http://www.energy-without-carbon.org/SolarOrHeatPump

Best alignment for solar collectors   -  http://www.energy-without-carbon.org/BestAlignmentForSHW

Selecting solar HW size  - http://www.energy-without-carbon.org/SelectingSolarHotWaterSize

Efficiency of heat pumps  COP  - http://www.energy-without-carbon.org/HeatPumpEfficiency