Elon Musk-chaired Solar City, the biggest name in residential solar power, is now offering loans to allow their customers to own their solar panels for cheaper than their current lease offerings.

The loan option, called MyPower, is structured like an energy payment, in that the customer pays off the loan by paying their energy bill — and it's a win-win, because these payments can end up being cheaper than your traditional power bill. And after 30 years, the power is free.

Here's how it works, according to SolarCity founder and CEO Lyndon Rive: customers take out a 30-year loan on a solar power system at 4.5% interest. SolarCity installs and maintains the system at no cost to the customer, and the customer pays for the power — and in the process, pays off the loan.