A
battery electric storage system is currently being installed at our Wastewater
Treatment Facility. The system, owned and operated by Viridity Energy, will help balance the
relationship between our renewable energy projects and the electrical grid.
Renewable
energy sources are more intermittent than traditional sources like natural gas
or coal, and existing electrical infrastructure is still adapting to handle them.
Batteries are one tool that will help ensure renewable energy and the electrical grid
can work together reliably and effectively by managing supply and demand.
Our
Wastewater Treatment Facility has received more than 60 percent of its
electrical demand from our 7.5-megawatt wind and 500-kilowatt solar projects
since 2006. When more power is generated than we need, it gets sent back to the
electrical grid. Once the batteries are in place, that excess energy -- up to one
megawatt -- can be stored in the batteries instead, which will help ease
pressure on the grid.
Battery project construction site at our Wastewater Treatment Plant (December 2017)
In times
of high demand, the grid can pull energy from the battery for use.
Additionally, in the event of a power outage, the battery could provide up to 15
minutes of backup power for the plant.
Because wastewater
treatment is an energy intensive process, a one-megawatt battery is unable to fully
store all the excess renewable energy generated, or to act as a long-term
resiliency tool during outages. However, future battery projects will allow critical
infrastructure, such as wastewater treatment plants like ours, to run 100
percent on renewable energy and be independent from the electric grid.
The batteries are expected to be in operation by February 2018. The project is a small-scale version of what will likely be an important tool
in supporting the growth of renewable energy across the U.S.
Additional
resources and articles on battery storage: