Prospector looks back at the Bay Area’s wind power ‘gold rush’

Prospector looks back at the Bay Area’s wind power ‘gold rush’

Prospector looks back at the Bay Area’s wind power ‘gold rush’

Searching for Bay Area wind in the good ol’ days — Sheltering in place has given me an opportunity to sort through several boxes of old stuff, with the ultimate goal of having fewer boxes.

At the bottom of one container was a 1982 report I co-authored at PG&E titled “Wind Energy Evaluations for Solano County and Altamont Pass Areas.”

Forty years ago, I was part of a wind prospecting team. We were similar to the miners of California’s Gold Rush era, but our mother lode was hidden in the low elevation hills between the Central Valley and the San Francisco Bay.

Due to geographic and local climate conditions, strong sea-breeze winds have been prevalent in the Bay Area well before any human observers inhabited the region. Two factors triggered the power-producing windmill era in our corner of the world.

After World War II, air pollution began reaching unhealthy levels. In the early 1970s, the federal government passed the Clean Air Act. In response, the state of California began programs intended to reduce tail pipe and power plant pollution emissions.

At almost the same time, concerns over fuel shortages resulted in the creation of the U.S. Department of Energy. One of this agency’s mandates was to fund programs that would result in increased electricity production from renewable resources such as wind. Research money bloomed like spring roses.

Efficiency vs. size

One of the initial questions for the fledgling wind industry was: What type of wind turbine generates the most cost-effective power over the longest period of time? At that time, there were two schools of thought based on windmill size.

NASA, General Electric and Boeing Industries led the charge for big turbine development. In the late 1970s, they designed and tested several windmills that produced 1,000-3,000 kW.

At the smaller end of the output scale came a wide range of windmill types designed to produce power in the 10-100 kW range. Blade diameter in these machines ranged from 10 to 50 feet in diameter.

In 1980, PG&E purchased one of the first operational Boeing MOD-2 machines. This behemoth windmill used a metal propeller that extended 300 feet from end to end (one football field) and weighed nearly 100 tons. It was erected east of I-680 between Benicia and Cordelia.

PG&E constructed a 300-foot tall weather mast just upwind of the windmill. We collected wind data at several levels on the tower to estimate how frequently winds blew strong enough to turn the turbine.

Another goal was to calculate wind shear, a change in wind speed with height, so that engineers could estimate wind-induced torques that would stress the enormous blade.

After six years of operation, PG&E’s MOD-2 windmill only produced power about 18 percent of the time. Maintenance issues, some due to wind shear events, took a toll and it was dismantled in 1988. Due to poor reliability, only six MOD-2s were built.

The development of wind farms

Prospector looks back at the Bay Area’s wind power ‘gold rush’
This Sacramento radar echo shows windmill clusters north of Antioch and east of Livermore. (Graphic credit: Courtesy of Jan Null, Golden Gate Weather Services)

In Gold Rush terminology, the early large turbines were a “bust.” But smaller windmills proliferated in the early wind rush days. The Altamont Pass area’s windmill population exploded in the 1980s and ’90s.

Wind farm development never occurred on the west side of I-680, but if you are driving north, look to the right just after crossing the Carquinez Bridge. Hundreds of windmills have been erected over the last couple decades in the Montezuma Hills portion of Solano County, just across the river from Contra Costa County.

In another relatively recent trend, technological advancements have resulted in the development of reliable, medium-sized turbines capable of generating 1,000-2,000 kW. As the smaller windmills wear out, large capacity units take their place.

If you took a helicopter flight from Altamont to Montezuma Hills on a windy day, you would be amazed at the number of shiny blades spinning below. There are so many turbines that Sacramento-based weather radar echo maps clearly show the local mother lode of windmills.

As a retired wind prospector, I am happy to see that wind energy, despite some growing pains and environmental issues, seems to have panned out. I wonder what I’ll find in the next box of stuff.

Woody Whitlatch is a meteorologist retired from PG&E. Email your questions or comments to