Becca Jones-Albertus, acting deputy director for the U.S. Department of Energy Solar Energy Technologies Office, recently gave a talk hosted by the MIT Energy Initiative (MITEI) in which she discussed how energy storage advances and grid integration can boost the growth rate for solar energy. A seasoned solar technology researcher, Jones-Albertus provided data on cost reductions, storage options, and grid modernization. Following the event, she spoke with MITEI to offer a glimpse into the potential future of solar.
Q. What do you envision for the future of solar energy in regard to its cost effectiveness and ability to compete with conventional fuels?
A. Solar energy costs are rapidly declining, enabling solar to grow from just 0.01% of the U.S. electricity supply in 2006 to roughly 1.5% today, with a total capacity of over 47 gigawatts. By the end of the next decade, baseline projections are that solar will supply 5% of U.S. electricity. But with more rapid technology innovation and advances in energy storage, there is potential to significantly expand solar deployment beyond these numbers.
In 2011, the Department of Energy launched the SunShot Initiative with the goal to drive down the costs of solar electricity to be cost-competitive with conventional fuels by 2020. It set what were considered aggressive cost targets at the time, but rapid declines in costs have enabled the industry to achieve the utility-scale cost target of 6 cents per kilowatt-hour three years early.
As a result of this success, the office has set a new cost target—to further halve the cost of solar by 2030. Achieving a 50% price reduction in utility-scale solar would make it among the least expensive options for new power plant generation. At this price, solar would fall below the variable cost of many existing generators, enabling lower electricity costs for all consumers.
In addition, with the recent rapid growth in solar penetration on the grid, cost reduction is no longer the single most important challenge for solar technology. Accordingly, the Solar Energy Technologies Office is expanding beyond cost reduction to include an emphasis on grid integration and enabling solar technologies to support grid reliability and resilience.
Q. What is solar-storage synergy and how does storage impact the solar market?
A. The solar-storage synergy signifies that as the amount of grid-connected solar continues to increase, so does the market opportunity for storage. Similarly, increases in the penetration of storage on the grid could also increase the market opportunity for solar. Further, installing solar and storage in combined systems may offer cost reduction opportunities compared to installing either in isolation.
Solar energy can only be produced when the sun is shining—but that doesn’t always match up with when electricity needs to be used. Storage enables solar energy to be used whenever it is needed. Battery storage costs are falling quickly, and if that continues, low-cost storage would enable significantly greater solar deployment.
These projections are developed from the National Renewable Energy Laboratory’s Regional Energy Deployment System model, which incorporates a wide-range of factors, including the value of energy technologies in various time slices, in order to project the evolution of the U.S. electricity system through 2050 based upon grid balancing requirements and lowest cost optimization for electrical capacity expansion.
The National Renewable Energy Laboratory’s Distributed Generation Market Demand model simulates and projects the adoption of distributed energy resources for residential, commercial, and industrial entities in the continental United States through 2050.
Q. What opportunities and challenges face the solar industry as solar is integrated into the grid?
A. The nation’s electricity delivery system was designed to move electrons in one direction from large power generation stations to customers. This one-way system is now a two-way superhighway. From smart devices to variable generation systems like solar, electricity is being moved on and off the grid at multiple speeds and locations.
A modernized grid must have the ability to dynamically optimize grid operations and resources, rapidly detect and mitigate disturbances, engage millions—if not billions—of intelligent devices, integrate diverse generation sources with demand response and energy-efficiency resources, enable consumers to manage their electricity use, participate in markets, and provide strong protection against physical and cyber challenges.
There are many opportunities for solar to contribute to the resiliency of the nation’s grid. For example, researchers at Lawrence Livermore National Lab, funded by the Solar Energy Technologies Office and the Grid Modernization Lab Consortium, are working to demonstrate that distributed solar PV and storage can help communities recover quickly from a major disaster like an earthquake, hurricane or flood.
Currently, once electricity is lost, restarting the grid is performed manually using special generators. It’s an extremely slow process that does not account for electricity that could be generated by distributed sources. Using “agile islanding“—forming microgrids around local solar customers—solar electricity can help to restart local power supplies and jumpstart critical grid functions.
The electricity industry is facing unprecedented challenges from a changing energy mix and a changing society. Solar electricity can play an important role in ensuring that this transition makes the critical electricity grid more reliable, secure, and resilient.