Non-dispatchable Renewable Integration
How will Reclamation, along with the rest of the hydropower industry, adapt to support the successful integration
of non-dispatchable renewable energy such as wind and solar energy?
Need and Benefit
The electric power industry in the United States is in the midst of some profound changes that will change the way
it produces, transmits, and controls electric energy. High energy prices, national security, supply uncertainties,
and environmental concerns are driving public policies and utilities to develop renewable energy sources. As a
result, the US wind energy industry is growing rapidly. Various scenarios have been proposed and studied
regarding the new electrical generation profile. Recently the Department of Energy (DOE) released a comprehensive
and detailed report documenting one of these studies entitled '20% Wind Energy by 2030.' Solar energy is also
expected to make significant inroads in the near future.
For example, to achieve the goal of producing 20% of the United States electric energy from wind will require
about 1.16 billion MWh of wind energy. This will require more than 300-GW of wind generation to be built, which
is equivalent to 150,000 2-MW wind turbines. A majority of potential wind resources are located in the 17 west
western states, the same region that Reclamation serves. Wind generation in this region could be significantly
higher than 20%. The DOE study indicates that this level of penetration is reasonable but will come with
challenges. One of the main challenges is that wind is primarily an energy resource, not a capacity resource.
Capacity resources are generators that are available on demand to ensure generation meets system load to
support the reliability of the power system, ensuring that 'the lights stay on.' Wind is an energy source, but
because of its variability, it contributes little to capacity. Thus incorporating wind energy will require a new way of
managing and scheduling the power system that contains a large energy resource that contributes little to
capacity. Power system reserves which contribute to capacity will become more important in the future power
The limiting value of non-dispatchable renewable energy such as wind and solar is that the available energy varies
and is somewhat unpredictable. Wind and solar cannot be scheduled on the days and times that energy is needed
to meet load demand. Further, wind and solar energy output changes minute-to-minute. Given this scenario,
flexible and dis-patchable generators, such as hydro, will grow in importance to the power system to provide
system capacity, balancing energy, and to match load. In fact, as more wind and solar energy is added to the
power system, additional reserves will be required. Hydroelectric generation is uniquely positioned to facilitate the
integration of non-dispatchable energy sources. Hydro is the only renewable source of electricity presently
available that can support other renewable energy sources by providing the capacity and reserve needs of the
power system. Hydropower is the preferred method to provide system reserves and unlike gas turbines, another
source of reserves, it has zero emissions and zero fuel cost. In fact, hydro resources can have a larger impact on
reducing CO2 emissions than wind and solar resources. Hydro energy CO2 reduction benefit is the same as wind
and solar energy but hydro also contributes to system reserves which further reduce CO2 emissions.
Contact the Principal Investigator for information about partners.
Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Non-dispatchable Renewable Integration (final, PDF,
By James DeHaan
Research Product completed on September 30, 2018