How beneficial are solar panels? Ultimately the goal is to get electricity providers to go 100% renewable and shut coal plants, a separate matter, but you can be part of the effort to move us away from fossil fuels

The biggest buyers of RECs (renewable energy credits) are power companies looking to satisfy state-mandated clean-energy requirements, known as renewable portfolio standards. In effect, the power company pays for the right to claim the climate benefits of the panels on your roof. It sounds like an esoteric distinction, but it matters: By selling the RECs instead of keeping them for yourself, you could just be helping the utility meet a goal it was already mandated to meet — thus helping excuse it from building more solar capacity itself. In other words, your direct net contribution to reducing greenhouse gas pollution is nil.
“A lot of individuals buy green power because they want to know that the power they’re buying wouldn’t be there unless they bought it,” says Jennifer Martin, executive director of the Center for Resource Solutions, a nonprofit firm that certifies RECs’ authenticity. But if that’s what you think, and you don’t hold onto the RECs, “you’re not getting what you’re paying for.”
So does that mean you should skip the panels altogether? Hardly. There are still many good reasons to go solar, including the possibility to save money on your electric bill. Meanwhile, the more people who adopt solar panels, the more the price drops, as panel manufacturers and installers get more efficient. This is already happening, as the cost of solar has plummeted 73 percent since 2006 and could soon be equal to or less than the cost of other electricity in many states. Industry insiders have a rule of thumb that every time production of panels doubles, solar prices drop 20 percent.

Then there’s the powerful “Prius effect,” wherein the conspicuous use of a green product like an electric vehicle or solar panels prompts neighbors to follow suit. That growing customer base can be a source of pressure on governors and state legislators to ramp up their climate ambitions. Politicians who see solar on their constituents’ rooftops are “going to be encouraged to dream big,” said Nathanael Greene, director of renewable-energy policy at the Natural Resources Defense Council. California, the country’s leading solar state, recently boosted its renewable portfolio standards to one of the most ambitious in the country, requiring utilities to get half of their power from renewables by 2030. By 2045, Hawaiian utilities will get 100 percent of their energy from renewables, in accordance with a law passed last summer.