Here at EnviroWonk, we often focus on gloomy policy news, not because we want to, but because of the cloudy political climate. But here's a sunny bit of news to perk up your day: lawmakers in Hawaii, known for its year-round sunshine and perennial 78-degree weather, have mandated that beginning in 2010, all new homes incorporate solar water heaters.

The heaters, which preheat water running through a heat exchanger on the roof, takes advantage of that lovely tropical sunshine that would otherwise just bounce off the roof. The initial investment is steep - $5,000 for a typical system - but saves so much power that it should pay for itself in just 2.5 years. For a typical four-person house, this should save $150 per month, or about 30-35 percent off the electricity bill. In turn, we bet that results in a healthy savings in greenhouse gas emissions.

It's this sort of thing that we wish we saw more of out of our nation's policymakers. There's no good reason not to incorporate solar heating in the warmer areas of the country, and likewise solar, passive geothermal, and other in-home alternative energy technologies. However, most builders and buyers often shy away due to the high initial investment, even if it ends up being a net money saver.

Libertarians might chafe at the government involvement, and we can understand that argument - but, like airbags for cars and brakes for elevators, we're of the opinion that sometimes, when the benefits of mandating standard equipment are so clear, a little legislation is no bad thing.