For the time being, all homes built in the Del Webb Orlando and Del Webb Stone Creek retirement communities will include a pre-installed 2kW rooftop PV system – and homebuyers will have the option of upgrading to an 8kW system.

The 2kW system would save the average homeowner $300 annually on their electricity bill, Del Webb says.

The deal is groundbreaking in focusing on homes built on speculation and then later sold – rather than targeting existing homeowners, as is the case with most third-party PV lease arrangements in the US.

SolarCity would own the systems and essentially act as a mini-power utility to the homeowners – taking additional profit by selling unused electricity back into the grid and pocketing existing state...