Cyprus has outstripped all other EU member states in embracing hot-water solar systems, with an estimated 93.5 % of households exploiting the alternative energy form for domestic needs.
The solar thermal systems not only collected solar energy as heat – usually generated through electricity and the burning of fossil fuels – they were extremely cost-effective and had helped spawn an entire industry, he explains.
“It’s been great for low-income families and then there’s the jobs: so many have been generated,” the MP says. “There are the local manufacturers who produce the parts and then all the people who are trained to install them. It’s big business.”
In his role as environment commissioner, Theopemptou pushed hard to make the solar systems obligatory on all newly constructed residential and commercial buildings – a move instituted by Israel back in the 1970s.
That is also true for solar heaters when there is no sun. and there are not many places that have climates where heat pumps cant operate these days.
Also air source heat pumps can have a COP of 3.5 so or higher. so even with a lower efficiency from the PV you might get ahead. You also get gains from the high COP on cloudy days where you might need resistance heating on the thermal one
I dont think you can claim any of them is better without doing the math.
The math depends on where you’re living, but what would you mathematically compare here, available required roof area and roof load limits?
Because the SWH, if put in a place like Cyprus, consumes next to no electricity. Pumps and electronics, but even that is pretty nil if the tank is on the upper floors. So let’s assume a mild sunny climate where the electrical heaters of both the heat pump and the solar heater are off. The heat pump requires power and the water heater doesn’t. As for cloudy days, with proper insulation, a SWH can keep the tank piping hot for a few days.
Personally i don’t see how a heat pump could beat a SWH in costs and benefits over time. Off the gate it already starts at a disadvantage on environmental impact and upfront costs. When it’s sunny, it loses to solar heating, as it’s free vs very efficient. It probably regains some ground during inclement weather and very cold winter days. There’s also the degradation of the solar panel, which happens at a faster rate than the degradation of the solar heater. So i guess in the end it boils down to how bad the weather gets where you live and yeah, do the math. There’s probably a graph of bad weather days with a point where the SWH becomes less attractive than solar powered heat pumps. But for Mediterranean climates, no contest I’d say. You require less area on the roof for a SWH.
And this is only considering available roof area/weight limits, because being honest they’re both free sun energy. But you could use the solar power/money/environmental impact elsewhere.