From the Zero Mass FAQ: >SOURCE is a completely independent drinking water solution; it efficiently utilizes solar power to generate the right amount of electr

From the Zero Mass FAQ: >SOURCE is a completely independent drinking water solution; it efficiently utilizes solar power to generate the right amount of electricity required to run its own system to produce water and charge the battery that ensures you can dispense water at night. So yes, not free -- you have to pay for a solar electric system as part of the package. Manufacture of which itself consumed considerable energy and clean water, somewhere else on the planet.