This is the first in a series of articles in The Institute highlighting Proceedings’ technical topics in celebration of the journal’s 100th anniversary.
A major problem with renewable energy sources, like solar and wind, is that they’re intermittent and not always available on demand. One big challenge for engineers, then, is to convert such energy into a storable form that can be called on when needed. This month’s Proceedings of the IEEE focuses on that issue.
“Once economical sources of fossil fuels approach depletion, we shall have no certain recourse but renewables, primarily sun,” IEEE Life Fellow William F. Pickard and Fellow Derek Abott write in their introduction, “Addressing the Intermittency Challenge: Massive Energy Storage in a Sustainable Future,” the February issue. The issue focuses primarily on solar energy, which the authors point out is the “largest inexhaustible source available to us” and “the most realistic massively scalable future option.” They point out that adding up the energy available from all renewables except solar amounts to less than 1 percent of that available from solar alone.
Spotlight on storage
The February topic was chosen because, the authors say, storing massive amounts of energy from renewable resources presents a host of technical challenges, and the subject has not been investigated thoroughly enough.
Storage systems rely on three key components:
- An input energy-conversion module that receives energy from the grid and converts it to a storable form.
- An energy-storage module that warehouses the energy.
- An output-conversion module that turns the stored energy back into electricity and returns it to the grid.
Energy loss during any of the conversion phases, as well as during storage, poses problems that the journal explores. The goal is to stockpile massive amounts of energy by transforming it into different but conveniently stored forms. Three of those forms—chemical, mechanical, and thermal—are covered in 13 papers.
The issue explores several chemical storage methods including one based on the reversible dissociation of ammonia. Another article considers the strengths and weaknesses of using hydrogen as a storage medium. Articles on mechanical storage describe compressed-air energy storage and underground pumped-hydro storage. Papers on thermal storage focus on the use of different mediums for storing heat, including gravel, molten salt, and concrete.
Other articles in the issue focus on short-term storage, energy policy, and assuring grid stability and power quality. To read the full issue, you need to subscribe to the journal.