Environmental Engineering Reference
In-Depth Information
natural gas, and other system components such as transmission facilities
can benefit from well-placed energy storage. The Electric Power Research
Institute (EPRI) lists storage benefits as
• Deferral or avoidance of alternative upgrade or solution net costs
that may include components from the transmission, distribution,
and generation (TDG) sectors
• Energy costs savings (arbitrage) from the displacement of more
expensive peak energy with less expensive off-peak energy
• Transmission peak demand reduction and resulting transmission
demand charge reduction for a separate distribution-based utility
• Ancillary services, specifically regulation control and spinning
reserve
1
Storage should be a more significant factor for electric grids as the penetra-
tion of renewable generation increases. If the benefits available from spatial
and generation diversity and demand response and efficiency are fully uti-
lized, the needs for back-up generation and storage can be minimized. The
energy available from intermittent renewable generation combined with the
capacity value of storage is a complementary match.
Renewable generation in Colorado, specifically from wind power, is devel-
oping rapidly and the development is driving the economy and providing
emission-free energy. Facilitating development by adding capacity value
would be beneficial. Capacity can be added via:
Energystorage
— A storage facility can allow a load to consume excess or
low valued energy and deploy high valued energy on demand.
Demandresponse
— Also known as controllable load, this technique may
be very effective as shown in the ERCOT report of February 26, 2008.
2
Overalleficiency
— While this factor does not add dispatchable capacity,
it is cost effective by reducing baseload.
Increasedcapacityvalueorreliabilityofrenewablegeneration
— This
can be determined by calculating the probability of generation reliability
from spatial and source diversity and optimization planning.
3,4
Additionalnaturalgas(NG)generationcapacityandstorage
— Although
this method is effective, it is burdened with emissions issues. Gas-fired gen-
eration can support only the undergeneration of a system and not overgen-
eration. Moreover NG price fluctuations present economic risks.
Smartgrids
— Adding capacity by utilizing the steps above can be facili-
tated via real-time automated communications.
With the introduction of more wind and solar energy to the grid, the addi-
tion of a variety of energy storage systems is an option that utilities and
developers should consider as a way of increasing reliability and reducing
the costs of providing power when needed. The kind of energy storage to be
installed depends on both the power required to meet transient needs and the
