A report published by the Materials Research Society (MRS) says that increasing the market share of variable renewable electric power generation in the U.S. from the present 4% is both technically and economically feasible.
Nevertheless, certain assumptions about the role of storage and transmission infrastructure should be reconsidered if a radical energy transformation is to materialize.
The costs of interconnecting renewable energy sources are likely to be higher than the costs of building new natural gas combined-cycle plants, the research shows. Furthermore, the cost of utility-scale storage – widely seen as a remedy to the variability of renewable energy sources – is likely to remain a significant barrier to adoption.
Published in MRS Energy & Sustainability – A Review Journal, the report is the result of a four-year study conducted by a team of technical and policy experts at Carnegie Mellon University, the University of Vermont, Vermont Law School and the Washington environmental law firm Van Ness Feldman.
The main findings of the research are as follows:
- The seasonal variability of wind power is beginning to be understood, as are the sources of error in its day-ahead forecasts;
- Geographic aggregation of wind and solar power has long been proposed as a method to smooth their variability, but for wind power, it has been shown that there is little smoothing at timescales where the magnitude of variability is strongest; and
- It has also been shown that the point of diminishing returns is reached after a relatively few wind plants have been interconnected.
According to Jay Apt, author of the report and a professor at the Tepper School of Business and Department of Engineering & Public Policy at Carnegie Mellon University, the latest generation of efficient and fast-ramping natural gas plants have come on the market that can operate with very low air pollution emissions while compensating for the fluctuations in wind and solar generation.
The report also concludes that geographic concentration of renewable energy sources with the aim of displacing dirty power plants would make wind and solar more valuable. In this regard, uniform national policies, such as a federal renewable portfolio standards, would be less effective than specific incentives for wind and solar power in locations where they would displace high-pollution power, the report says.
To read the report, click here.