Saturday, November 15, 2008

Will we make a difference?

Now that construction has started and some pressure has shifted to our contractor, I can get back to reflecting on the bigger picture. When we are up and running, our $3.5 million project will produce up to six million kilowatt-hours of electricity annually. That's almost unnoticeable in the utility world--about one day's output from a typical natural-gas-fired power plant.

However, to get that much power from another renewable resource, you would need one large wind turbine (like the Vestas V80 above, one of many on PSE windfarms) or a few acres of photovoltaic panels. A 1.5MW+ wind turbine would cost about the same as our anaerobic digester, but it would have to be located somewhere in the southeast quarter of Washington to produce its full potential. A solar photovoltaic installation could be located in Western Washington, but it would have to extremely large and spectacularly expensive to produce six million kWh each year--30,000 panels costing at least $40 million to install. Moving the installation to California or some other sunny location would cut the size and cost in half, but solar is still the priciest option.

So manure power will make a difference in Western Washington because we have few options here for renewable energy. But more importantly, a digester does much more than just collect the sun's rays or spin in the wind; our project will also be providing free cow bedding to dairy farmers, cutting methane emissions, and reducing manure odor. In the future, we may find valuable uses for all of our extra hot water or discover some new service that we never even imagined the system could do. An anaerobic digester is the Swiss army knife of renewable energy, and we can't wait to get ours up and running!

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