Environmental Engineering Reference
In-Depth Information
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Object#
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Name
Upper Reservoir or Forebay
Penstock
Motor Generator
Pump Turbine
Tail Race
Lower Reservoir or Afterbay
FIGURE 3.1
Line drawing of PHES facility.
variable generation will be critical to every operating region. The electric grid
of tomorrow must exhibit flexibility in load and generation management. The
world's generation mix is becoming more diverse and variable. This variabil-
ity is one of the costs for decreased emissions and increased fossil fuel savings.
How can utility companies and other energy providers manage increased
variability? Each operating region will have to assess the resources available
and address the variability inherent in its system. Effective management to
ensure load and generation flexibility will require a series of steps including:
• Improving energy efficiency and implementing demand response
• Utilizing spatial and source generation diversity exhibiting comple-
mentary profiles
• Bringing resources to market via transmission and timely utilization
• Energy storage
• Improving electric utility data communications to integrate the
above steps
Of the five steps for providing flexibility to an electricity system energy, stor-
age is a key step for accommodating variability. A PHES facilitates the align-
ment of renewable generation with loads. Baseload generation has the largest
impact on emissions factors and produces most of the energy. If renewable
generation is to impact electricity-driven emissions in a significant way,
it must be able to affect baseload generation. When renewable generation
