Landfill gas facility to double its power

July 24, 2014 0 By Tami Hood

Landfill Gas - Seattle renewable energy

Waste-to-energy plant will produce more electricity for businesses and homes.

The Waste Management Columbia Ridge Landfill and Recycling Center, a landfill gas power plant south of Arlington, Oregon, will be doubling its capacity, enabling it to generate more power for Seattle businesses and homes that are 260 miles away.

An estimated 2 million tons of garbage is handled by the landfill plant annually.

Of the 2 million tons of trash that the Columbia Ridge Landfill and Recycling Center receives every year, about one third of it comes from Seattle Public Utilities. Once the trash has been deposited at the dump site, the organic waste begins to breakdown and methane gas is released as a natural byproduct of the decomposition process.

The gas is collected at Columbia Ridge using a system that is made up of 85 wells. The gas is fed into an onsite power plant where it is utilized as fuel for electricity production. Recently, four new engines were added to the facility, which are to commence operation in August. This expansion will boost the landfill energy system’s capacity from 6.4 MW (megawatts) to 12.8 MW. That translates to about enough electricity to power over 12,000 homes.

All of the electricity that will be generated at Columbia Ridge will be purchased by Seattle City Light, which is the tenth biggest public electric utility in the United States, serving over 400,000 consumers.

By investing in landfill gas, Seattle City Light has a better chance of meeting state renewable energy laws.

Large utilities that were developed after 1997 are required by Washington state law to obtain 15% of their electricity from renewable sources. The agreement that City Light has made to purchase all of the energy produced at Columbia Ridge, helps it to reach this green goal.

Scott Thomsen, a spokesman for City Light said that “It’s one of the strictest (energy) portfolio standards in the country, if not the strictest.” He added that “This project helps us get a small piece of that requirement taken care of.”

Thomsen also said of the landfill gas agreement that City Light is pleased to take advantage of a product that would otherwise be wasted. “You’re literally taking people’s trash, and turning it into a valuable resource,” he said.