NERC is an international regulatory authority for the reliability of the bulk power system in North America. It assesses adequacy each year in a 10-year forecast, which now includes 260,000 MW of new renewable energy from solar electric, wind, geothermal, biomass and hydro resources. Of this capacity, 96% will come from wind (229,000 MW) and solar electric (20,000 MW), but only 38,000 MW of wind and 17,000 MW of solar are projected to be available at times of peak demand.
“Though not all of these resources may come to fruition, the integration of this volume of energy-dominant resources (or those resources predominately available during off-peak hours) will require significant changes to traditional planning and operating techniques to ensure reliability,” it notes.
Other key issues in the NERC forecast are transmission siting, cybersecurity, climate policy and the smart grid. Of total miles of planned, under construction and conceptual transmission, 35% (11,000 miles) is needed for reliability and another 11,000 miles will be needed to integrate variable and renewable energy generation.
“The variability and uncertainty associated with wind and solar resources make the addition of this variable generation capacity a significant development requiring planners and operators to change planning processes, forecasting capabilities, operating procedures,” the report notes.
NERC also issued a Scenario Reliability Assessment that provides an initial view of the bulk power system with a continent-wide 15% renewable energy portfolio standard, and identifies several possible approaches to meeting that goal. Examples include the northeast integrating new renewable energy resources within the region while the midwest proposes to transport wind power over longer distances from areas of high wind potential to population centres, and “substantial transmission resources would be required in either approach,” it explains.
Reduced economic activity and higher adoption of energy efficiency and demand response programmes have led to decreased projected peak demand for electricity and, as a result, higher reserve margins throughout North America for much of the 10-year period. Combined, energy efficiency and demand response resources will account for 40,000 MW (4%) of the peaking resource portfolio by 2018, effectively offsetting peak demand growth by five years.
“The economic recession has essentially bought us a few years to address capacity and resource concerns across North America, but the 'benefits' of reduced demand growth are expected to be short lived,” says Mark Lauby of NERC. “The time is now to address concerns like transmission siting, secure smart grid implementation and the integration of renewable resources.”
“Federal climate change legislation and state and provincial-level renewable portfolio standards are driving significant changes to the resource mix, resulting in early retirements of coal-fired generation, an increasing reliance on natural gas and large-scale integration of renewable resources,” the report concludes. “Each of these factors will influence reliability over the ten-year period, requiring planners and operators to consider new factors in designing and operating the system of the future.”