ELWA is not only much easier, but also much cheaper than solar thermal systems. This applies both in a single-family home and in apartment buildings. The advantages over solar thermal are multifarious: Due to the elimination of the pipes you can save up to 90% valueable copper No cost-intensive components like pumps, valves, expansion tanks, frost protection mixtures, insulations,... Photovoltaic heating even works with low solar irradiance No lossy start-up procedures (clocking, loop warm-up) Maintenance-free (frost protection) No material fatigue during system downtime Efficiency independent from system temperature More efficient at lower ambient temperatures Nearly loss-free energy transmission from the roof to the boiler Mounting in the boiler/tank quickly and not complicated, even when tank is filled Nearly no internal consumption (2W) Grid feed-in of the energy surplus instead of stagnation (with AC ELWA and AC ELWA 2) Cost development and technical development of photovoltaics are rapid ELWAs can be used decentrally, thereby no distribution losses in multi-family houses. The solar energy is converted into heat right where it is needed!