GREEN CITY Atop Bernal Heights, winds speed at 25 mph, enough to prematurely slam doors, disperse heat, and power Todd Pelman's Roscoe Street house with 100 watts of electricity at any given moment.
The 34-year-old engineer has pioneered the city's first permitted microwind project, a six-foot-tall cylindrical turbine that currently sits on his roof and sends juice into the energy grid, offsetting some of his dependence on Pacific Gas and Electric Co. Now his company, Blue Green Pacific, is working to put the turbines on the market in the next year.
"It's aesthetically not going to be disruptive in an urban environment," Pelman told the Guardian, referring to the generator, which resembles the double helix of a DNA strand when it spins.
It is microprojects like this that could help support the Community Choice Aggregation program passed by the Board of Supervisors last month, which aims to have the city partner with its residents to generate a greener power portfolio over the next 10 years.
Bernal Heights Sup. Tom Ammiano, who codrafted a plan for CCA with Sup. Ross Mirkarimi, considers Pelman's project a grassroots step away from PG&E, which he regards as a "wolf in sheep's clothing."
"When people see how fruitful and utilitarian this is, we'll wind up calling the shots," Ammiano told us. He amended the planning code for Bernal Heights to permit structures to reach more than 30 feet high, thus allowing the current and future use of wind turbines in his district.
Pelman's turbine will generate between 300 and 600 kilowatt hours of energy per year, or about 10 percent of a typical home's energy needs, he told us. His vertical-axis turbine is a natural propeller system that spins on its axis a contrast from the windmill-style horizontal-axis turbines characteristic of rural areas. It's made of steel, aluminum, and plastic and contains no sharp blades that might endanger birds.
Urban wind, though plentiful, has not been widely used, mostly due to aesthetics and the space constraints of turbines, according to Johanna Partin, the Renewable Energy Program manager of the San Francisco Department of the Environment.
"The micro and small urban wind market is still in the early stages of development," Partin said, pointing out that Chicago, the notorious Windy City, only recently started a residential permitting process.
Pelman's turbine became the first in the city to receive a residential permit for use last Oct. 5 after numerous bureaucratic back-and-forths with the Planning Department.
His rooftop turbine captures wind energy coming from the coast and going east and sends it to an inverter in his garage that converts it to usable energy, which then travels into an electrical panel.
"Think of the turbine as the heart of the system and the inverter as the brain of the system," Pelman said.
While Pelman's turbine may catch people's eyes, he claims it does not do the same to birds. "It coexists very peacefully with the pigeons and the hawks," he said, mentioning a couple of Bernal Heights' bird species.
He is working with the Audubon Society to make sure he can live up to his assertion. Due to the turbine's opaque appearance, no birds have attempted to fly through and meet their doom a problem frequently noted with the large, horizontal-axis turbines at the Altamont Pass Wind Farm.
A one-turbine system will cost around $5,000, though Pelman estimates that rebates will reduce the price by $1,500. It's an "emotional purchase," he said, that will at least partially satisfy a green conscience.
Chris Beaudoin, one of Pelman's first customers, decided to make wind energy his green cause.