IRP helps Arkansas River Power Authority plan for future generation
 |
The 4-MW Mercury 50 combustion turbine, the most efficient gas turbine of its size in the world, is not yet available commercially. ARPA member Lamar, Colo., installed a second-generation demonstration model at its powerplant to help offset the rising cost of natural gas. (artwork courtesy of Arkansas River Power Authority)
|
Every five years, Western customers must look into a crystal ball to predict their future electric requirements and the energy resources available to meet them, an exercise welcomed by Arkansas River Power Authority in southeast Colorado.
That crystal ball is integrated resource planning, mandated by the Energy Policy Act of 1992 and Western' Energy Planning and Management Program. The plan requires utilities to forecast their loads and evaluate a wide range of resource alternatives and energy efficiency options to ensure reliable, affordable electric service. With that information, utilities develop an action plan, solicit public comment on it and submit the IRP to Western along with strategies to measure its effectiveness.
It is a work-intensive process, but the benefits are well worth the effort, said ARPA General Manager Jim Henderson. "People sometimes forget to look at all the options," he noted, "but the IRP makes us focus on all the possibilities."
ARPA provides wholesale electricity to seven municipalities: Holly, La Junta, Lamar, Las Animas, Springfield and Trinidad, Colo., and Raton, N.M. Nearly half—48.4 percent—of that power is generated with coal, while Federal hydropower from Western accounts for 26.2 percent and natural gas for 25.3 percent. Integrated resource planning has helped the joint action agency improve the efficiency of its conventional facilities and add more renewable energy to its mix.
Plan addresses ongoing challenges, identifies new ones
Aging generation facilities, the West's worst drought in 350 years and skyrocketing natural gas prices have all affected ARPA's power supply in the years between its first IRP in 1996 and the most recent plan. The first concern is long-standing and will continue to challenge the seven rural communities into the next five years. "The first IRP identified plants and equipment that needed to be retired," recalled Henderson. "Upgrading takes time, so some of those facilities are still on-line and they are five years older."
Based on recommendations in the 1996 plan, the town of Trinidad retired its aging coal-fired, baseload plant in 1998. Supplemental power purchases and three 1,880-kW diesel back-up engines replaced the unit.
One thing the IRP couldn't predict was the spike in natural gas prices, Henderson noted. "In 1996, we were looking at five years of adequate energy supplies at affordable prices. In 2003, natural gas prices have doubled and will probably stay high for the next five to seven years," he said.
To offset the cost of natural gas, ARPA is improving the efficiency of existing facilities. In Raton, N.M., it broke ground in December 2002 on a 7.5-MW, gas-fired internal combustion engine project. The efficient, low-emission unit will provide back-up power for Raton's coal-fired, baseload unit and replace the current backup unit, an outdated 3.75-MW coal-fired unit.
At the Lamar, Colo., powerplant, ARPA arranged for the installation of a highly efficient, 4-MW Mercury 50 combustion turbine, the most efficient gas turbine of its size in the world. Developed through a partnership between Solar Turbines, Inc., and the Department of Energy, the second-generation demonstration unit is not yet available commercially.
When ARPA renews its contract with Western in 2004, the power authority will be looking at a reduced hydropower allocation. Western must periodically reconfigure its resources to accommodate new customers. Drought conditions and reduced Federal spending have also affected the availability of hydropower. Although this renewable resource will continue to be a central block in ARPA's power supply, Henderson insisted, supplemental purchases play a larger role in the latest IRP.
ARPA issued a request for proposals last spring to supply a portion of its energy requirements when its contract with Tri-State Generation and Transmission Association expires in 2004. The IRP recommends that new contracts should allow the flexibility to acquire power through such sources as ARPA-owned generation projects, partially owned large generating facilities and renewable energy opportunities.
Opportunities arise to diversify energy portfolio
The 2003 IRP contains plans for adding more renewable energy to ARPA's portfolio. Some of the agency's members are experimenting with photovoltaic applications, such as powering streetlights and traffic signs. Raton is negotiating a land lease agreement for a potential 25 to 35 MW, independently developed biomass plant. ARPA invited biomass developers to respond to the supplemental power RFP it issued in the spring.
The renewable resource viewed as having the most potential in Baca County is wind, as a source not only of energy but also of economic development. Many ARPA members expressed interest in wind power during the public comment portion of the IRP process. "Farmers see cash from land leases, the county sees jobs and an expanded tax base and utilities see a hedge against natural gas," explained Henderson.
Feasibility studies give good reason for enthusiasm. "This is an incredibly rich area for wind," Henderson asserted. "One site near Springfield, Colo., rates its net capacity factor at 39 percent, with more than 90 percent of the hours in a year producing energy. The studies are available to the public," the general manager added.
ARPA expects to begin constructing a 1.5-MW turbine on the site in January. The unit could supply 41.2 percent of the town's energy needs. Lamar, Colo., is planning its own three-turbine project, in addition to another same-sized unit ARPA will build near the town.
ARPA members hope that these smaller projects will attract large commercial developments to the county, like the 108-turbine wind farm General Electric Wind is building at Gobbler's Knob south of Lamar. That 162-MW operation enabled ARPA and Lamar to get their more modest proposals off the ground. "We are buying the turbines from GE and the same crews that are building the wind farm will install and service our units," said Henderson. "Piggybacking onto that massive project made our small scale plans possible."
Conservation an important component of resource management
It might be expected that a resource management plan for a wholesale power supplier focused on developing renewable resources, identifying supplemental power suppliers and upgrading or building conventional generation, but ARPA's IRP did not neglect demand-side management. Although ARPA does not deal directly with end users, it encourages conservation. Members are already involved in several on-going DSM programs including energy audits for commercial/industrial customers and rebates on compact fluorescent bulbs for residential customers.
Based on a 2001 consumer survey, ARPA is focusing on a conservation information campaign for residential customers. The 2003 IRP recommended a similar survey of commercial/industrial customers to determine what energy efficiency measures they would be most likely to adopt. "Utilities have to encourage conservation of all resources," Henderson stated. "Rural communities understand that society as a whole benefits from using less."
The benefits of conservation, a diversified energy mix and efficient facilities and equipment only come to those who look into the future and have a plan, he concluded. "ARPA is a better utility because of the IRP process," Henderson declared.