|Diagram of a typical wastewater treatment plant|
using the Cambi thermal hydrolysis process
(courtesy of Cambi).
It’s also about saving money.
|Blue Plains, Washington, DC|
The annual savings are expected to more than cover the debt service on the $470
|DC Digester Centrifuges|
The new process also is expected to cut the treatment plant’s greenhouse gas emissions by one-third. Blue Plains has less open land available for solar panels than some other treatment plants, he said. Still, DC Water is considering putting panels on some structures on the 150-acre campus.
The WSSC solar program is a public-private partnership. Washington Gas Energy Systems paid the $12 million to install the solar panels and will operate them for 20 years. The WSSC pays only for the solar power it uses. WSSC expect to save $3.5 million total in electricity costs over the 20 years and cut the two plants’ annual carbon dioxide emissions by 3,200 metric tons — described as the equivalent of taking 665 cars off the road.