Tracking Parabolic Concentrator Solar Hot Tub Heater

Solar powered water heater that provides all the heat for a hot tub. Parabolic trough concentrating collectors. Solar tracker for the concentrators uses Arduino controller. Solar PV and batteries for power. This solar hot water heater is off the grid. Solar Hot Tub Heater is home made using commonly-available parts. There is a new version of this video here: