Landfill gas helps Palo Alto go carbon neutral

A key advantage of landfill-to-gas energy is its dependability

Published September 19, 2013 6:31PM (EDT)

It’s not all about solar for Palo Alto, Calif.

Sure, the Silicon Valley city offers generous installation rebates, has a feed-in tariff program and has contracted for some of the cheapest utility-scale solar known to man, at 6.9 cents per kilowatt-hour. But Palo Alto is also big on landfill gas-to-energy, and a new project 90 miles down U.S. Highway 101 in Gonzales, Calif., is expected to provide the city around 10.4 gigawatt-hours of electricity every year.

image via City of Palo Alto

image via City of Palo Alto

The project takes advantage of gas bubbling up from the Salinas Valley Solid Waste Authority’s Johnson Canyon Landfill. These gases, produced by the decomposition of trash, previously had been flared off to reduce greenhouse gas emissions. That was better than nothing, since it converted the methane to carbon dioxide, a less potent greenhouse gas, but it introduced other potential environmental hazards while also failing to take advantage of the opportunity to make use of the energy in the gas.

The new plant was built by Ameresco, which is becoming a frequent partner of Palo Alto’s. The city is already buying 11.2 GWh/year of energy from the Santa Cruz landfill gas project, 40.7 from Half Moon Bay and 11.8 from Keller Canyon. An additional 51.9 GWh/year is expected from two more projects on the way.

All of this is pointed toward making the city 100 percent carbon neutral. Technically, it can already claim that status, through the use of short-term renewable resources and renewable energy certificates to go along with  committed long-term renewable and hydroelectric resources.

But looking beyond 2016, it wants more longer-term renewable resources, and it expects to get them without spending a lot of money: “The Carbon Neutral Plan achieves carbon neutrality for the electric supply portfolio at a cost expected to be less than one tenth of a cent per kilowatt hour [kWh}  above the already anticipated cost of ~four tenths of a cent per kWh to meet the City’s renewable energy portfolio standard goal,” the city has said.

According to city documents, the landfill-to-gas projects are among the priciest renewable energy sources the city is buying, nearly double what it's paying for its cheapest wind and solar power [PDF]. But landfill-to-gas is a renewable energy resource that has a key advantage that enhances its value: It produces steadily, 24 hours a day, 356 days a year, rain or shine.

By Pete Danko

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California Energy Palo Alto Renewable Energy Solar Power Wind Power