He’s copied the basic design of a solar pool heater but managed to do it using ... a PID temperature controller or even an Arduino to make it even better… but it sounds like it works quite ...

Think of solar greenhouse heaters as a way to supplement existing heating systems. They're out there, but some assembly may ...

Essentially, it allows the water heater to get much hotter during times when solar energy is available, and lets it drop to lower values before running the heater on utility electricity during ...