I think a residential solar panel will be enough for 3 of those. not sure of the cost vs. benefit though. Have you seen the magnetic drivers out there. A European company sells one that is 300KW per hour. They even have a 100kw per hour one that fits into a car with a belt. you come home and plug it into your house and it powers it. Free energy. How much is the cheapest solar panel that produces enough to power to handle 1800 watts?