When actions speak louder than rock 'n roll. One irony of anti-nuclear rock-concert benefits has been that they are generally high-voltage affairs. But last weekend in San Luis Obispo, Calif., no-nuke musicians Bonnie Raitt and Jesse Colin Young plugged their mikes where their money was going. Light and sound were all solar at the ''We don't need Diablo'' concert, whose money went to support groups fighting the Diablo Canyon nuclear power plant. Power was provided by Solar Genny 1, a trailer-mounted photovoltaic generator with 40 ''pv'' cells on a roof panel that follows the sun. It has a set of batteries that store enough energy to produce 50 amps per hour for 20 hours.
Solar Genny 1 is used more as a gesture than out of practical considerations, but the solar advocates who own it hope it lends credibility to their cause.
The device also powered lighting for an outdoor segment of the TV program ''Knot's Landing'' this week. ''What we're trying to do is capture people's imaginations,'' says Ty Braswell, director of the group that owns the generator.