MIT: Accelerate the deployment of various energy storage technologies

The MIT study spanned more than three years and analyzed the use of various energy storage technologies (electrochemical, thermal, chemical, and mechanical) to store wind and solar power to decarbonize the grid by 2050.

Enabling a climate-friendly grid in the U.S. will require changing planning and operational tools to reflect the transitional systems needed to combat climate change, the report said. It also calls for increased flat fees to make energy storage financially viable.

In addition, the report recommends revising the federal government's current practice of granting intellectual property to private sector partners who share the cost of technology demonstration projects. Public investment in technology demonstrations and early deployment activities is to spread knowledge, the report said.

In the past, the DOE has "stretched" federal funding by insisting that private sector partners share project costs. Because private partners are often awarded intellectual property in return, this practice undermines the fundamental goal of publicly supported technology demonstration projects, which is to disseminate information among all industry players, thereby creating the conditions for effective competition. Federal demonstration projects should include explicit requirements for sharing information with other U.S. entities that are not yet partners, even if this requires a larger federal contribution.

Excess solar and wind output can be stored and power the grid during times of high demand, "in a cost-effective way to maintain reliability - which in turn can support the electrification of many end-use activities outside the power sector," said MITEI Director of Chemical Engineering Professor Robert Armstrong said when the report was released.

Assuming the cost of wind and solar technologies continues to fall, the study's model "identifies a cost-effective pathway to decarbonizing the power system -- reducing emissions by 97%-99% compared to 2005 levels in the U.S.," The study concluded. "Effective decarbonisation will require substantial investment in multiple energy storage technologies as well as in transmission, clean generation and demand flexibility," it added.

“It is helpful to understand where and how energy storage technology needs to evolve and to understand the various trade-offs between energy or capacity cost, round-trip efficiency and duration, etc.,” said Jin Noh, policy director of the California Energy Storage Alliance, in the report. He added that it could guide policies on the development and commercialization of various new energy storage technologies.

Today's dominant grid storage is provided by lithium-ion batteries, which typically have a maximum output of 4 hours, while storage that provides more hours of supply time is needed to meet different grid needs, including weather and seasonally related needs. The Department of Energy is currently developing a research goal to help reduce the cost of energy storage beyond 10 hours. It recently approved $505 million to advance multi-hour storage combined with renewable energy.

The MIT report calls for greater support for longer durations, especially electrochemical storage technologies using widely available earth materials, including those from secondary-use batteries and recycling.

Without substantial private investment support like lithium-ion batteries, more government financial aid is needed to support at least 12 hours of output, the report said. Private financing for these energy-dense, low-cost batteries in electric vehicles "significantly improves the prospects for short-term power system storage," the report noted.

Another challenge, the report said, is that long-term energy storage will be of little value when wind and solar production declines. So, because the characteristics and values of intermittent energy are very different, MIT is also calling for higher flat fees to ensure the storage technology is profitable.

"Our models suggest that, over many hours, the marginal system cost of energy for a decarbonized system dominated by wind and solar power will be zero or low," said Howard Gruenspeccht, senior energy economist at MIT, with the use of Compared to dispatchable generation from fossil fuels, because "future decarbonization systems are likely to have high capital costs and very low variable costs, fixed charges should play a larger role in cost recovery than they do now," he added. This includes charging based on consumers' income levels to "address issues of equity and efficiency".