For WaterStillar Works – yes. Any power supply that will bring the system close to boiling point, can be used. We have had requests about this from large CPV-systems that needed cooling; food factories with process heating and geo-thermal plants.
Family can be fitted with an electrical supplemet heater.
Wall in the current configuration can only run on electricity. In future new configurations will be made and it will be possible to use just about any heat source – incl wood and pellets.