City saves green by going green

Phil Castle, The Business Times

Terry Franklin, utilities and streets manager for the City of Grand Junction, demonstrates how slow-fill stations fuel trash trucks with compressed natural gas. The use of CNG in trash trucks saved the city about $25,000 in 2012. (Business Times photo by Phil Castle)

Terry Franklin envisions a day when solar panels fully power the wastewater treatment plant that serves much of the Grand Valley. What’s more, natural gas created at the plant will become a source of energy as well.

That day hasn’t yet arrived. In the meantime, the City of Grand Junction increasingly relies on solar power and compressed natural gas (CNG) to generate electricity, fuel trash trucks and, in the process, cut costs. “We’re saving a lot of money,” said Franklin, utilities and streets manager for the city.

An addition to the solar system at the city water treatment plant is expected to save more than $345,000 in electricity costs over the next 25 years. The city saved about $25,000 in fuel costs in 2012 using trash trucks that run on CNG instead of diesel.

Work is under way on a nearly $191,000 project to install a 55-kilowatt photovoltaic solar system at the city water treatment plant. Counting the new system and the existing, 100-kilowatt system, solar power will generate all the of the electricity needed at the plant, Franklin said.

There are plans to add a 400-kilowatt photovoltaic system at the Persigio wastewater treatment plant, bringing the total solar power system in place there to nearly 500 kilowatts. That would meet about 12.5 percent of the electrical needs at the plant, Franklin said.

There’s sufficient land near the wastewater plant to eventually install enough solar panels to fully power the operation if the technical and financial details can be worked out, he said. The decreasing cost of solar power equipment makes that prospect more feasible.

Meanwhile, the city plans to increase its fleet of trash trucks running on CNG to 12 by the end of 2013.

Trash trucks were an obvious first choice for CNG because the vehicles cover a lot of miles in nearly daily use, but get low gas mileage, Franklin said.

While diesel costs the city about $3.60 a gallon, the equivalent amount of CNG costs about $1. Franklin said he expects local natural gas prices to remain low.

Using federal and state grants as well as assistance from Encana Oil and Gas, the city constructed a CNG fueling facility that includes slow-fill stations for trash trucks, Grand Valley Transit buses and other vehicles. A fast-fill station is available for energy company vehicles and is also open to the public to fuel private vehicles. The CNG station is the only one of its kind between Rifle and Price, Utah, Franklin said.

The initial plan was to use natural gas produced as part of the operation at the Persigio plant to fuel city vehicles and buses.

Franklin estimated the plant produces the equivalent of 400 gallons of gasoline a day in natural gas that’s simply burned off.  It’s a matter of determining how much it would cost to install and operate equipment to clean that gas to remove unwanted components, compress the gas and then pipe it to where it’s needed, he said.

In the meantime, though, Franklin expects the city to save green by going green with the increasing use of solar power and CNG.