Storing Energy: The race for sustainable solutions
One of the biggest challenges facing the energy sector is how to store our energy when it’s not being used so that we can satisfy the peaks and troughs of our daily energy demands. In cities like Los Angeles (LA), for example, engineers currently need to boost residents’ electricity supply at certain times of the day, using a natural gas-burning power plant to meet the city’s electricity demands. Demand charges are based on peak power, not energy, and therefore energy storage technologies have unique value potential for demand charge reduction.
LA is taking matters into its own hands by making plans to install the world’s largest storage battery, capable of holding and delivering over 100 megawatts of power an hour for four hours. The battery is designed to handle peaks in the city’s power demands, thus requiring less fossil fuels – and reducing customer costs as well.
However, research to find the most efficient energy storage solutions is still at an early stage – and some of the technologies are expensive. Finding sustainable – and affordable – storage solutions is set to become a more pressing issue as we become increasingly reliant on renewable energy sources such as wind and solar power plants that, by their very nature, operate intermittently.
A new paper, “Overview of distributed energy storage for demand charge reduction”, published in the latest issue of MRS Energy & Sustainability, looks at some of the latest developments in the race to find sustainable energy storage solutions that will satisfy our growing demand – and dwindling fossil fuel supplies.
Eminent authors from academia and industry – including Tesla Motors founder and serial entrepreneur Martin Eberhard, along with Said Al-Hallaj, CEO, AllCell Technologies, Greg Wilk, S&C Electric Company in Chicago, and George Crabtree, Director of the Joint Center for Energy Storage Research at Argonne National Laboratory – provide an overview of energy storage technologies that can help reduce demand charges for commercial and industrial customers, as well as residential customers, in the future.
While mechanical energy storage technologies like pumped hydro dominate the total energy storage (TES) capacity at the moment, the authors conclude that these technologies are too large and geographically dependent for wide-scale use. Instead, chemical devices like batteries, and thermal devices such as water heaters or ice storage, have the greatest potential for demand charge reduction.
The authors argue that battery storage is more flexible than TES because it can power any device that uses electricity. They look at the pros and cons of batteries using technologies such as lead acid and conclude that lithium ion batteries have a far broader potential for performance increases.
To illustrate their point, the authors argue that Tesla is currently focusing on lithium chemistries for its energy storage solutions. “Tesla envisions this battery chemistry replacing peak power generators that operate a few times a year at high power,” the authors write.
The paper concludes that lithium ion batteries have the potential to deliver the highest value for demand charge reduction – and the authors point out that prices are decreasing as well. Their research indicates that current lithium ion storage systems could have payback periods below five years when deployed in markets with high demand charges, which could be a win-win solution for the energy sector, their clients and our planet.