Cracking the PPA:
Renewable Energy Projects
and Energy Storage
Overcoming challenges associated with adding
energy storage to existing solar and wind farms.
or solar project and the services provided by the battery, but other projects keep
the storage project as a separate resource, which can signifcantly complicate matters.
For example, if the battery
charges from a solar project
such that the off-taker no longer receives that power, how
does that affect the PPA obligations? And in either case,
what happens when the battery takes power off the grid?
Who is responsible for that
BECKY DIFFEN AND NELLI DOROSHKIN, McGuireWoods
Colocating energy storage with renewable generation resources seems like a natural partnership to reduce the intermittency of renewable generators. Several projects have been built
across the country combining storage with wind or solar projects. While the co-location of such facilities can yield many
benefts, there are a number of legal and practical issues that
need to be considered when deciding to acquire and co-locate
storage facilities (particularly battery projects) with existing or
new renewable generation.
The primary issue with co-locating a storage project, particularly with an already operating wind or solar project, is
considering how the storage “add-on” will affect the renewable development. From an implementation standpoint, constructing or setting up a storage facility next to existing
renewable generation can disrupt the existing resource’s performance. The operating project will likely need to be taken
out of service for at least some of the construction phase of the
storage project, which will impact revenues and contractual
Further any existing power purchase agreement (PPA) or
offtake agreement will need to be modifed to account for performance changes due to the co-located storage. Sometimes
these agreements are amended to include the storage project,
so the off-taker now receives both generation from the wind