Yes, installing thermal panels to heat water is always a good idea, because hot water is an energy-intensive resource. If you heat water with gas, you save gas, and if you use electricity, you save electricity. However, thermal panels are positioned differently from photovoltaic panels. They are further inclined and south-facing to maximize heat production, especially during cooler periods.
The argument against thermal panels lies in the fact that the current cost of gas is relatively low, which limits the savings made, given that the saving is on an inexpensive resource. What's more, the heat produced cannot be stored as easily as electricity.
In terms of energy investment,
thermal panels are beneficial, but their economic return can be less attractive.
Although financial incentives are available,
maintenance of thermal panels is more complex due to pipes containing fluids that require periodic purging. In comparison, photovoltaic panels are simpler, with maintenance limited to the electrical cables.
Once installed, photovoltaic panels have a lifespan of
around 25 years, with little maintenance required. Rain generally cleans the panels,
and the main maintenance consists of replacing the inverter after 10 to 15 years. On less sloping flat roofs, cleaning may be necessary every 3 to 5 years.
