Return to article

Biomass purchase furthers forest rehab project

The benefits of a diverse resource portfolio include reducing pollution, creating jobs, protecting consumers from volatile energy prices and increasing national security. Now Salt River Project's latest renewable acquisition can add "improving forest health" and "protecting homeowners" to the long list.

The Phoenix, Ariz., water and power provider entered into an agreement with Snowflake White Mountain Power to buy 10 MW of biomass power. Under the agreement, at least 80 percent of that power will come from dead and burned forest residue and thinnings in Arizona. SWMP's wood-fired powerplant is scheduled to come online in late 2007.

"We are pleased to be part of a process that will benefit not only SRP's renewable energy supply, but also responds to the state's forest management challenges," commented Richard Hayslip, manager of SRP's Environmental, Land and Risk Management departments.

He added that surplus biomass available from thinning the unnaturally overgrown forest areas is a large renewable energy resource. Carefully planned forest thinning activities can preserve wildlife habitat, minimize soil erosion and reduce the fire danger to homes near the forest.

Powerplant provides disposal

The Rodeo-Chediski fire of 2002 destroyed hundreds of thousands of acres of forest and 426 buildings in east-central Arizona. The blaze left behind tons of burned and dying trees on the Fort Apache Indian Reservation and the adjacent Apache-Sitgreaves National Forest. That charred residue had to be removed to rehabilitate the forest, so the U.S. Forest Service launched the Rodeo-Chediski Fire Salvage Project.

NZ Legacy, SWMP's parent company, purchased some of the USFS timber salvage sale contracts on the Rodeo-Chediski burn area. The contracts allow the removal of dead trees, the larger of which are sold for saw logs while the smaller trees, tops and branches are chipped and ground. The energy developer is also subcontracting on a USFS stewardship contract on several individual community thinning projects. The contract calls for clearing underbrush from wildland-urban interface green forest around Arizona cities.

Both operations produce tons of biomass that must be disposed of in an environmentally responsible way. NZ Legacy is turning that residue into renewable energy, a plan that only works if there is a buyer for the power. "Salt River Project's RFP for 10 MW of biomass power made the Snowflake project happen," said Scott Higginson, NZ Legacy executive vice president. "SRP deserves great credit for its work to clean up the damage done by the fire."

Diverse portfolio adds new resource

Linking forest rehabilitation to renewable energy was an easy connection for a utility that is always on the lookout for new sustainable resources. A series of devastating forest fires had prompted Arizona's governor to launch a task force on forest health and stewardship. "About the same time, we were looking to diversify our renewable portfolio with biomass," recalled SRP Environmental Initiatives Manager Lori Singleton. "Combining the Healthy Forest Initiative and cleaning the forest to provide fuel for the biomass plant seemed good for the overall environment."

Biomass is a relatively inexpensive renewable energy source, even factoring in the cost of transportation. The fact that it is firm power, available whenever it is needed, makes it even more attractive. "SRP is subject to deliver power on demand, not just when weather conditions permit," Singleton said. "That makes it a good supplement to the intermittent sources in our portfolio."

SRP will add the biomass power to an already-diverse renewable portfolio that contains more than 80 MW. Its resources include 50 MW of wind, 25 MW of geothermal, 4 MW of landfill gas, more than 1 MW of solar and 750 kW from a low-head hydropower plant. Customers support renewable development by subscribing to SRP's voluntary EarthWise Energy Program. Currently, more than 4,500 SRP residential customers have signed up for renewable power blocks.

Meeting the RPS

SWMP expects to break ground on the 20-MW facility by the end of the year and begin providing power to SRP no later than January 2008. Although SRP requested only 10 MW, a 20-MW facility proved to be more economical, said Higginson. Arizona Public Service Company agreed to buy the additional generation to meet the state's renewable portfolio standard of 2 percent renewable energy by 2010.

SRP's board of directors voluntarily adopted the RPS in April 2004, and has been acquiring new renewable resources ever since. By 2010, the utility will have to obtain approximately 610,000 MWh from sustainable sources each year to meet the state goal.

That is a big challenge, but the benefits to the community are worth the effort, as the biomass purchase proves. In addition to improving forest health, the deal comes with the usual perks of new jobs for the region and, of course, expanding the diversity and capacity of the Salt River Valley's energy supply. Not a bad day's shopping for the Salt River Project.