The sun vs. the redwoods

It could only happen in California.

All the parties in the dispute are as green as nori. (It's made from seaweed. You eat it.)

Richard Treanor and his wife, Carolyn Bissett, live in Sunnyvale, Calif.

And Mr. Treanor and Ms. Bissett care so much about the environment that they drive a hybrid Toyota Prius.

Not to be outdone, their neighbor, Mark Vargas, cares so much about the environment that he recently bought a plug-in electric car.

Mr. Treanor and Ms. Bissett topped that. They planted eight redwoods in their yard, preening that the trees -- which can grow to giant heights -- absorb carbon dioxide, cool the surrounding air and provide a habitat for wildlife.

That's nothing, said their neighbor, Mr. Vargas. Encouraged by the California Solar Initiative, which is offering homeowners and businesses more than $3 billion in rebates over the next decade to install solar-electric systems, he covered his roof and backyard trellis with $70,000 worth of solar panels, meaning he buys little or no electricity generated at environmentally bad, bad power plants.

The months went by. The redwoods grew. And their shade fell upon Mark Vargas' solar panels. So Mr. Vargas asked prosecutors to file charges against his neighbors under California's 30-year-old Solar Shade Control Act, which stipulates that a homeowner can "suddenly become a criminal the day a tree grows big enough to shade a solar panel," explains the defendant, Mr. Treanor, a retired engineer.

Indeed, the law requires homeowners to keep their trees or shrubs from shading more than 10 percent of a neighbor's solar panels between 10 a.m. and 2 p.m., when the sun is strongest. Not a tomato patch that might utilize solar energy to provide a neighbor's family with healthful vitamins, mind you. Just solar panels.

Existing trees that cast shadows when the panels were installed are exempt. But new growth is subject to the law.

Mr. Treanor and Ms. Bissett contend they planted their trees before Mr. Vargas installed his solar panels, in 2001. But is it the date of planting that counts, or the date when the trees grew high enough to shade the panels?

After more than six years of legal wrangling, a judge recently ordered Mr. Treanor and Ms. Bissett to cut down two of their eight redwoods -- the species elevated by Ansel Adams and others to a status equivalent to the Holy Grail in environmental circles.

Residents can be fined up to $1,000 a day for violations, though the judge did not impose any fines against the Treanors.

The couple does not plan to appeal the ruling, because they can no longer afford the legal expenses. They do plan to lobby state lawmakers to change or scrap the law, however.

Bernadette Del Chiaro, clean energy advocate for Environment California, says the solar shade law might need to be revised to prevent similar disputes. Lawmakers might want to "take a look at the policy and make sure it's written in a way that's fair to everybody," she says.

In another place and time, Ms. Del Chiaro might have said, "To make sure everyone's property rights are fully protected."

But this, of course, is California.