hey green420 In all honestly man I think you answered your own question. Batteries would have to be kept charged and that uses electricity to keep the batteries charged. And also you could use solar panels to charge the batteries but again this is going to cost some money. What is your reason you cannot afford to run 2 120 lights those should not be very expensive to run compared to say a 600 or 1000 goodluck to you man...........:rasta: