The Nebraska Public Power District’s (NPPD) 2013 integrated resource plan (IRP) calls for increased levels of renewable generating resources and energy efficiency to meet NPPD’s customers, if electrical growth is higher than expected, or if significant costs on carbon dioxide emissions become a reality.
NPPD’s board of directors on June 14 approved the 2013 integrated resource plan (IRP). The utility modeled 19 different resource plans that would be implemented in the next 20 years
The utility has forecast summer electric demand to grow at an average rate of 1.1% annually between 2013 and 2018, and 1% annually between 2019 and 2032. Winter season demand is forecast to grow at an average rate of 1.3% annually between 2013 and 2033.
The base case load forecast used in the IRP analysis assumes that NPPD’s summer demand requirements will grow at an average rate of 1.1% annually between 2013 and 2018. Demand requirements are forecast to grow at an average rate of 1.0% annually between 2019 and 2032. NPPD’s base case energy requirements are forecasted to grow at an average rate of 1.4% annually between 2013 and 2032. These growth rates reflect the moderate level of energy efficiency.
Off-peak periods are now typically higher than on-peak periods, due to the success of NPPD’s demand response program, the utility said. The majority of savings come from irrigation load control by wholesale customers, which accounted for 600 MW to 650 MW of demand reduction from the summer of 2011 to the summer of 2012.
“[I]n 2011 and 2012, the official ‘off-peak’ peaks were 120 MW and 367 MW higher than the ‘on-peak’ peaks, respectively,” the utility said.
In the summer of 2012, drought conditions and extreme heat caused “unprecedented” heat loads in NPPD’s service territory, largely due to irrigation effects. The region’s “anytime” peak of 3,030 MW was 360 MW higher than the previous high, set on July 30, 2006.
“In addition, NPPD’s peak set during billable hours of 2,663 MW was nearly 140 MW higher than the previous all-time high set in 2011,” NPPD said. The utility attributed the peaks to irrigation loads that hit unprecedented levels, but noted that with a return to more normal weather conditions, NPPD will have planning capacity surpluses of 200 MW to 300 MW for the “next few years.”
For 2012, 45% of NPPD’s generation was from coal, 34% from nuclear, 4% from hydro, 4% from wind and 2% from gas and oil. The remaining 11% was supplied through purchases, over half of which came from WAPA.
In 2012, NPPD executed power purchase agreements (PPAs) with wind developers for 68 MW of wind and in 2013 has executed PPAs for an additional 105 MW from two wind farms, 30 MW from the Broken Bow II and 75 MW from the Steele Flats Wind projects. Assuming the wind projects are operational in 2014, NPPD’s native load customers will have 9% of their annual energy requirements met by wind resources.
NPPD has also authorized a nuclear uprate to add 146 MW of capacity at the Cooper nuclear station in the fall of 2018.
Carbon dioxide emissions have dropped 18% to 20% “over the last several years,” according to NPPD.
NPPD has a goal to obtain 10% of its generation from renewable resources by 2020.
NPPD’s transmission system includes more than 4,400 miles of transmission lines in the state of Nebraska, comprising 1,067 miles of 345-kV, 642 miles of 230-kV and 2,763 miles of 115-kV facilities. NPPD’s electrical system, including transmission and subtransmission grids, comprises more than 5,100 miles of power lines.