Last November SolarCity sold $54.4m of solar-backed asset notes, in a move seen as a breakthrough both for the company and the broader PV industry.

By yoking together thousands of disparate PV systems into a single pool of investments, and selling them on to institutional investors, SolarCity opened an entirely new source of competitive funding -- the lifeblood of companies playing in the booming US third-party ownership PV space.

Analysts