The push for the use of more renewable energy on power systems around the world reached a new level this year with the COP21 agreement signed by national leaders world-wide, to help reduce the global carbon footprint. This is an important step in paving the road for the future of wind, solar and other renewable generation integration into the grid.
While the will to do it may be one of the most critical components to drive greater levels of renewable integration, we also need to make sure the integration is technically feasible with today’s existing grids; and, if it is, does it make economic sense to do it.
GE’s Energy Consulting group has been an industry leader in helping utility customers and industry stakeholders answer these questions and what we’ve learned is that there is not a hard limit. Power grids can accommodate substantial levels of wind and solar with appropriate operation and system changes.
To illustrate this finding, we recently launched an interactive infographic with details and additional key findings from three case studies from our work: the Hawaii Renewables Portfolio Standards (RPS) study, with our customer the Hawaii Natural Energy Institute (HNEI); the Western Wind & Solar Integration Studies (WWSIS), with our customer U.S. National Renewable Energy Laboratory (NREL); and the PJM renewable integration study.
The Hawaii Wind & Solar studies utilized modeling tools, including GE’s MAPS, PSLF and MARS, to identify and evaluate cost-effective ways to support the growth of renewables on the islands of Oahu and Maui. The goal of these studies was to identify how to meet renewable targets and standards while maintaining grid stability and reliability. The studies found that, to improve grid reliability and stability through the integration of renewables, there were certain operating changes that would need to be made to the current system:
- Include reserves to handle wind and solar variability;
- Reduce minimum operating levels on thermal power plants;
- Remove must-run constraints and allow cycling of baseload units, and
- Use wind and solar to provide reserves.
The WWSIS studies investigated the operational impact of renewable penetrations of up to 35 percent annual energy on power systems operated by the WestConnect group of utilities — which includes companies in many western states. The studies determined that the Western Interconnection can successfully meet more than 30 percent of the region’s electrical power needs by integrating wind and solar.
The PJM Renewable Integration Study examined what impact increased renewable penetration would have on grid performance in all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia. This study, which was initially commissioned in 2011, found that to achieve the 14 percent renewable portfolio standard (or 40 gigawatts of renewable power), it would require a minimal annual transmission investment of approximately $4 per megawatt-hour of delivered renewable energy to the system. Further, the study found that the fuel cost savings from renewable generation could offset the costs of necessary transmission investments over time.
These three examples demonstrate the potential for the integration of substantial amounts of renewable energy on three grids that operate under very different conditions.
While these studies demonstrate what’s possible today, we believe the future has the potential to be even brighter for renewable integration with the right focus and continued collaboration between companies like GE, the electric power industry, and key regulators and policymakers globally.