For the most part hot water heat pumps have superseded solar hot water systems. Roof are better suited to photovoltaic panels and electricians to be. Frank are a lot lighter than plumbers. Iâ(TM)d much rather have electricians running around on my roof than Plumbers hot water heat pumps work better in cloudy winter conditions which are often the design conditions for a future, renewable energy grid as there is less solar and wind resource in winter than in summer as a general rule Sanden, for example, or SanCO2 as itâ(TM)s known in the states has a heat pump that goes down to -18Â Celsius, still having a positive, cop