Laboratory tests on a small (56 kWh)
battery established a DC roundtrip efficiency averaging 97 percent and better
than 95.5 percent for any power rate.
This stability at different power rates
ensures consistent performance. Field
testing on the 3 MWh ESS confirmed
the efficiency, showing that performance
and functionalities measured on small
systems represent full scale operation.
Owners and operators of power plants
must have complete confidence that their
ESS is consistent, predictable and the
right size. To achieve this, they must
recognize that ESS operational profiles
are complex and multi-functional and
sizing is an iterative process involving the
battery and EMS.
especially in facilitating the integration of
intermittent renewable generation within
power networks by making it both predictable and grid compatible.
Saft delivered a fully integrated turnkey ESS based on three Intensium Max
20+ containerized systems. Together, the
three units deliver 3 MWh of power to
help smooth peak demands on substations and compensate for the intermittent
production of wind farms and PV installations, as well as deliver ancillary services
to control network frequency and voltage.
The project has confirmed that a SOC
algorithm (developed by Saft for its battery management system) corresponds well
with the measured energy integration.
THE ACCURACY OF THE SOC
ALGORITHM CONTRIBUTES TO:
• Effective cell balancing
• Effective use of capacity to generate
• Permanent operation at partial SOC
without need for a maintenance charge
enhance performance and optimize the
total cost of ownership.
OPTIMUM ESS FOR PUERTO RICO
A 10 MW PV plant in Puerto Rico
successfully optimized an ESS (Figure 7).
The grid code required that ramp rates
be limited to no more than 10 percent in
output change per minute. In addition,
the operator required support to grid
frequency by up to 5 percent.
Modeling was used to identify the
optimum ESS as having 1. 3 MWh energy storage capacity and 5 MW power
rating. Saft delivered a solution comprising three Intensium Max 20 P high power
containerized systems. This balanced
both the peak power and customer’s requirements. It also anticipated a
drop in power over the lifetime of the
ESS due to electrochemical aging. This
should ensure that the ESS will continue to meet the operator’s minimum
technical requirements even at the end
of its lifetime.
ENDESA GRAN CANARIA—ENSURING
SOC ALGORITHM ACCURACY
A 3 MW ESS has been installed on the
Spanish Island of Gran Canaria as part
of Endesa’s pioneering STORE (Storage
Technologies of Reliable Energy) project
to demonstrate how energy storage can
promote the integration of renewable
energy within utility networks.
A main aim of the STORE project is to
demonstrate the technical and economic
viability of large-scale energy storage,
Michael Lippert is marketing and business development manager for Saft’s
Energy Storage Business.
He holds a degree in European business studies in
France and Germany and has been working
for more than 20 years in different international
sales and marketing positions at Saft focusing
on railway, traction and stationary markets. His
current responsibilities cover strategic and operational marketing for industrial battery markets,
in particular market and product development
for renewable energies and smart grids.
FIGURE 7: Schematic of 10 MW PV plant in Puerto Rico
Modeling is an iterative process that starts
with a first estimate of battery specification
that is combined with the other inputs to the
EMS to deliver a cost profile.