Batteries, which cover a range of technologies, are suitable for stationary grid storage applications both at the utility-scale and for community and other distributed storage applications near the consumer end of the distribution network.
In the future, growth opportunities for innovative grid connected stationary energy storage will drive demand for batteries, attracting new companies that are developing batteries for the specific demands of grid storage.
For instance, Primus Power, a five-year-old venture capital-backed startup, is developing a more efficient flow battery and has announced that it has raised a further US$20 million in funding. The funding will be used to introduce its innovative battery technology to its first utility and power customers this year.
A more efficient flow battery
Primus Power is in the business of making “flow batteries” which store energy like the batteries in your laptop do. However, these batteries have the electrolyte (the substance that acts as the medium for the charging and discharging) separated out of the battery cell in liquid-filled tanks. The systems utilize a pump to transfer the liquid electrolyte over the electrode, which in turn stores energy.
Flow batteries are not new to the market but Primus Power’s flow battery is supposed to be more efficient because it uses one tank, one flow loop, one pump, and no separator (many current ones on the market use two tanks and a separator). Primus’ electrode is also made of metal, compared to the felt or plastic electrodes of some competitors (so higher conductivity) and the electrolyte itself — that flows through the system — is zinc-based.
This design has a number of benefits-flow batteries can be more cost-effective, they are easily refillable, and they can provide prolonged amounts of energy storage when compared to traditional enclosed batteries.
Primus Power’s flow batteries are supposed to be able to provide energy storage for over a period of four or five hours, while a lithium ion battery can provide energy storage for about an hour. This is according to Primus Power’s CEO Tom Stepien.
Primus Power sells an “EnergyPod,” which is basically a shipping container that’s filled with about a dozen flow batteries which are stacked on top of each other. Each EnergyPod has the capacity to store 250 kW of energy for a cost of US$500 per kWh. For large installations, a utility can install multiple shipping containers and manage them with the computing and software that Primus Power also provides.
Power companies are looking to add energy storage technologies like batteries and flow batteries to the grid as a way to store energy generated by renewable energy sources like solar and wind which are intermittent in nature. The idea here is that a flow battery can store energy from a wind turbine when the wind is blowing particularly hard. The battery can then release the additional energy over four to five hours when the wind stops blowing.
The battery market set for growth
Other startups that are building the next-generation of low cost batteries for the power grid include Ambri, Eos Energy, Aquion Energy and others. Several of these companies are aiming to commercialize their technology this year.
Primus Power has raised a total of US$35 million from investors including Kleiner Perkins, Chrysalix, DBL Investors and I2BF Global Ventures. The new round was led by South Africa-based resource developer Anglo American Platinum Limited. Primus has also received US$20 million worth of grants from US government agencies, like the Department of Energy.
Primus Power is looking to use these latest funds to deliver their first EnergyPods to customers. Customers include a utility in Modesto, California, the Bonneville Power Administration in the Pacific Northwest, and a microgrid at the Marine Corps Air Station in Miramar, California.
California is set to host a number of these new and innovative power grid energy storage solutions since the state has made a decision to support a large amount of energy storage projects by 2020. This is in support of its renewable energy goals. [Read our article, California’s Energy Storage Mandate-Will Others Follow?]
Compressed air energy storage solutions are also beginning to emerge. Startups like LightSail Energy and SustainX are all working to reinvent compressed air energy storage.As countries around the world work towards attaining their renewable energy targets, a greater need for energy storage solutions will come about. In addition to this, the full benefits of distributed generation and microgrids will only be realized once storage solutions become cost-effective and plentiful. The storage of distributed generation in commercial and industrial sectors is picking up and appropriate solutions will be snapped up. [Read our articles, Drivers of the Commercial Energy Storage Market and Energy Storage Sector Targets Commercial Customers.]