Large Scale Rapid Response Energy Storage and Electrical Energy
(Funded by BU's Ignition Award)
Prof. Uday B. Pal, Dr. Peter Zink, Prof. Srikanth Gopalan, Prof.
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Energy Storage and Electrical Energy Generation System
Ignition Award: The Ignition Award Program awards funds to
Boston University faculty to bridge the gap between government-funded,
discovery-oriented research and the follow-on development work performed
by external commercial or non-profit entities. By enabling researchers
to generate relevant data, reach key milestones, develop a prototype,
or test an implementation strategy the Ignition Awards will help bring
raw technology and business concepts to a mature enough state where
they can be either licensed, form the basis of a new company, or create
a new, non-profit social enterprise.
In this program we are developing a cost-effective and innovative
rapid response large-scale energy storage and recovery system at less
than $100/kWh for grid-scale application. The energy storage is based
on an exceptionally high energy density system, W/WO3 (20 kWh/L of
tungsten based on LHV of hydrogen), cycled between the tungsten (W)
metal and its oxide during energy storage and recovery cycles, respectively.
In the next phase of the program, the storage system will be integrated
with a reversible solid oxide electrochemical cell (RSOEC) stack.
The solid oxide electrochemical cell will have the same architecture
as a solid oxide fuel cell (SOFC). During the energy storage cycle,
the cell stack will electrolyze steam using renewable or off-peak
sources of electrical energy to produce hydrogen which will reduce
WO3 to W (WO3(s) + 3H2(g) = W(s) + 3H2O(g)). The steam coming out
of the storage system will be fed back into the electrolyzer to continue
the process until the required amount of energy is stored as W metal.
And during periods of peak demand or to maintain base load conditions
for renewable energy sources, the RSOEC will operate as a fuel cell
stack. It will use hydrogen generated by reducing steam with the W
metal and converting the W metal back to WO3 (W(s) + 3H2O(g) = WO3(s)
+3H2(g)). The by-product steam coming out of the fuel cell will continue
the above reaction until all the stored energy from the W is recovered.
The storage system will thus store energy when the electrochemical
cell stack is operated as a steam electrolyzer, and generate electricity
from the stored energy when the cell stack is operated as a fuel cell;
the novel storage system avoids the need to store hydrogen. This will
address the intermittency and ramping challenges for the transmission
of renewable electric energy and variations in peak demand. The proposed
system will accelerate adoption of renewable energy technologies and
reduce GHG emissions from the electricity generation sector.