It's becoming well-accepted that doing stuff like retrofitting your home to make it more energy-efficient pays for itself over the long haul. It's just that the long haul is, well, long—a lot of homeowners don't have the upfront cash to splurge on efficiency projects or solar panels, even if they'll reap dividends ten years out. In theory, banks could step in and devise some sort of clever financing mechanism that would help homeowners pay for this, but that hasn't happened yet. (Electric utilities could also step in and assist with the financing, but only if they have incentives to reduce their power load, through decoupling laws and the like.)
So it's worth checking out what the city of Berkeley's doing: As the mayor's former chief of staff, Cisco DeVries, explains over at Grist, the Berkeley FIRST initiative, which gets underway next week, will let property owners install solar systems without paying the hefty upfront cost—instead, the city will issue a municipal bond to cover the installation, which is then paid back over 20 years via a new line item on the property owner's tax bill. (If the property is sold, the tax is just transferred to the new buyer). The beauty of the thing is it's entirely voluntary—no taxes, no mandates; it's just that, if you do want solar power, it's easier to finance. If Berkeley's scheme ends up being popular, I'll be curious to see if the private sector starts cobbling together similar offers.