'There have been attempts by utilities to monopolise the sun'

The battle over the future of net metering is among the most important and complex issues facing the US solar industry.

Pioneered in a handful of US states during the 1980s, net metering programmes allow homeowners to effectively roll back their meters by generating power on-site and then selling it back to utilities at the full retail rate. Such policies create a powerful economic incentive for homeowners to embrace rooftop solar, and have therefore been critical to the growth of companies like SolarCity and Sunrun.

But