The National Grid on Renewables  

Technology review has a look at research into how to increase the penetration of renewable energy into national electricity grids - A Sneak Peek of the National Grid on Renewables.

A new $135 million research facility aims to solve a puzzle: how can countries prepare for an energy system that relies heavily on renewable energy? It can also test ways to improve reliability under stress, for example when demand soars in the summer as the air-conditioning load taxes the grid.

Because wind and solar energy supply power intermittently, they create challenges for grid operators. Other new energy technologies are coming online, too, including electric vehicles, energy storage, efficient buildings that cut power use during peak times, and small-scale natural-gas generators and fuel cells. Integrating these technologies on a large scale presents challenges to grid operators.

The National Renewable Energy Laboratory (NREL) in Golden, Colorado, created the Energy Systems Integration Facility (ESIF) to understand how to best operate the pieces of a more diverse energy system. Drawing on a supercomputer and power equipment that can create a megawatt-scale mini-grid within the facility, product engineers and utilities can simulate the impact of new technologies without causing problems to functioning grids.

Regions with a high percentage of wind and solar now rely on daily forecasts and stand-by fossil-fuel power plants to maintain reliable service. But once renewable energy is more than 20 percent of capacity, grid planners need more sophisticated tools, says Benjamin Kroposki, director of energy systems integration at NREL. “We saw this big shift. If we are successful in reaching cost targets for individual technologies, then what? You need to start doing systems integration,” he says.

An NREL analysis published last year found that, with a more flexible system, the U.S. could get 80 percent of its electricity from existing renewable energy technologies by 2050 (see “The U.S. Could Run on 80 Percent Renewable Electricity by 2050”). Germany and Denmark already have about 20 percent renewable electricity and Germany plans to achieve around 80 percent renewable energy, in both electric power and transportation, by 2050.