The U.S. Energy Information Administration short-term outlook is forecasting continued growth from non-hydropower renewables generating 8% and 9% of total utility scale electricity generation in 2016 and 2017, respectively.

In recognition that renewable energy will carry an increasingly larger portion of the nation’s load, the Advanced Research Projects Agency-Energy (ARPA-E) is investigating plausible solutions for on-demand energy sources to combat the pitfalls of renewable and distributed power.

The primary concern stemming from the development of renewable and distributed energy sources is power fluctuations. Non-hydropower renewable resources are largely composed of utility-scale solar power plants and wind farms. As these new energy sources carry intermittent production capacity, on demand energy sources are required to help displace peak power demands and balance intermittent power generation.

Future funding of the Department of Energy’s tech incubator, ARPA-E is largely supported by its ability to support innovative technologies that help to revolutionize the power grid. A prime example of how they are able to uphold their motto of “Changing What’s Possible" ARPA-E has addresses the short-comings of non-hydropower renewables by investigating the capabilities of next generations batteries and hybrid fuel cells.

On-Demand Power Generation

On-demand power sources need to be highly responsive. As the power grid operates at or near capacity latest natural gas turbines are designed to be brought up to speed quickly from a standing start. In the minutes it takes to do this the cost saving are considerable against the alternative of keeping turbines spinning but they also prove to be inadequate in resolving the shortcomings of distributed and renewable energy sources.

ARPA-E ‘s funding of hybrid fuel cells offers a new approach to fuel cell development that opens up the possibility of using them as an on demand power source. Fuel cells are akin to batteries as they are an electrochemical device that produces heat and electricity. They differ in that they consume a fuel source in order to produce energy. The hybrid approach is to incorporate fuel cells with built-in charge storage in or near a fuel cell's electrode in order to increase their responsiveness.

Built-in charge storage is what allows a fuel cell to become responsive to power demands. By exciting the electrode with a greater potential the solid-oxide fuel can readily be converted into heat, power, hydrogen, carbon monoxide, and carbon dioxide. This battery mode concept is however a developing technology. The next hurdle is to address capacity while reducing energy losses at the anode, which tend to react with the fuel and dissipate the stored charge.

Redox (reduction–oxidation) flow batteries are a second focal point in an attempt by ARPA-E to balance load from distributed power generation. The flow battery is an energy storage device where a liquid electrolyte flows in both the cathode and anode sides of the cell. The concept was first developed through use of vanadium-based electrolytes, but is being redeveloped with an all–iron-chloride chemistry that greatly reduces their cost.

The bottom line is that APRA-E is into funding competing technologies and not putting all of its cookies in one basket. The unique approach isn’t about venture capitalism and succeeds by taking risks with no immediate return on investment.

Their target is to support the development of energy storage devices that carry a benchmark of $100 per kilowatt hour, with at least 5,000 cycles, while attaining efficiencies that meet or exceed 80%. That is when the developing technologies become competitive, challenge the status quo, and redefine what is possible.

References:

http://spectrum.ieee.org/energywise/green-tech/fuel-cells/challenging-the-lithiumion-boom

http://spectrum.ieee.org/energywise/energy/policy/arpae-under-trump