Solar water heater for farm water trough?
Another trade show question, we are doing a farm show and we get farmers asking for a way to keep the water trough out in the field from freezing. I don't really know how this can be done economically with PV because they need the electricity exactly when the available sunlight is the lowest. I was thinking some thermal set-up as it is so much more efficient? They only need to keep the water from freezing.