Demonstrators protesting continued installation of PG&E SmartMeters around Northern California closed down a company service and payment center in Santa Rosa on Thursday after blocking the entrance.

Police said the demonstration on Stony Circle was generally peaceful, and PG&E opted to close the customer service office for the day rather than seek arrests, spokesman Paul Moreno said.

A leader of opponents to the wireless transmission meters, meanwhile, said some of the protesters were ready to go to jail if necessary to make the point that PG&E and the California Public Utilities Commission have an obligation to fulfill demand for more thorough studies into health concerns related to radio frequency emissions from the meters.

"It's not fair to ask the consumers to do the kind of investigation that the CPUC should be doing," said Sandi Maurer of Sebastopol, co-founder of the EMF Safety Network, which has led opposition to SmartMeters.

About 25 critics gathered early Thursday to protest outside the Rohnert Park equipment yard for Wellington Energy Inc., which has a contract with PG&E to install the meters.

But for the second time this fall, workers had cleared out the yard and failed to turn up for work on the day protesters had designated to picket, Maurer said.

So protesters went to the Stony Circle service center, where they demanded to speak with a customer outreach specialist to ask about peak emission data, Maurer said.

When he did not come out — Moreno said he wasn't there initially — some protesters blocked the entrance.

Moreno said the group was asked not to block the path of customers, but did so anyway.

Moreno said PG&E is evaluating alternatives to the current SmartMeter program because of concerns raised by some consumers even though the great weight of scientific evidence says our SmartMeters are safe."

At a distance of 10 feet from a SmartMeter, the power density is equal to about 1/1,000th of a cell phone, Moreno said. It only transmits for about 45 seconds a day, he said.

People with questions about the new meters can call PG&E's SmartMeter hotline, (866) 743-0263, he said.