In order to achieve sustainable high penetrations of solar power into the grid, solar power should be available on-demand, when and where it is needed, in the desired amounts and in a manner that is comparable to or better than conventional power plants.
The Dispatchability activity area aims to ensure that solar power plants based on photovoltaic (PV) and concentrating solar power (CSP) technologies at utility and distributed scales are capable of being dispatched in a fashion that is comparable to or better than conventional power plants. SunShot addresses the issue of dispatchability with a two-pronged approach:
- Extensive analyses to understand the impact of high penetration of solar power plants on the bulk power system and distribution system operations, and
- Research on understanding and enhancing the dispatch capability of PV solar power plants, and investigating the value of varying energy storage capabilities for CSP plants.
SunShot also supports the development of standardized methods for testing grid performance of PV solar power plants, and exploring and demonstrating the value of energy storage.
Under high penetrations of solar power, the constrained availability of solar energy only during the daytime and its associated intermittency and variability results in steep ramps of other types of generation using fuels such as natural gas, hydro, coal and possibly even nuclear, in order to match the total generation profile to the load profile. These ramp requirements from conventional generation are atypical and can be potentially difficult and expensive to accommodate in order to incorporate high solar penetration. Further, challenges arise for the system operator to properly determine the appropriate levels of dispatch for all conventional generation; since solar irradiance and power output must be predicted and cannot be planned with certainty in advance, there is inherent uncertainty in the magnitude and timing of the ramps required due to high solar penetration.
A further impact of high solar penetration is in the capacity value of solar. To enable increasing penetration of solar power on the grid in a manner that is efficient, cost-effective and minimizes curtailment of solar energy, it is critical that solar-generated power is available at any time during the day or night.
|Dispatchability Challenges of High Penetration of Solar|
SunShot’s mission is to be a catalyst to enable dispatchability in solar power plants in order to accommodate and interconnect ANY level of high penetration of solar generation in the grid. Potential pathways for handling high solar penetration include forecasting, supply shifting (energy storage), load shifting and additional load, among others, to ensure that solar power is not curtailed due to its lack of dispatchability. As solar penetration and generation on the grid increases eventually well into the envisioned hundreds of GW of interconnected capacity, all of the approaches must be considered in concert and implemented at varying scale, for reliable and cost-effective integration into the grid.
Achieving SunShot’s Dispatchability target metrics will result in a significant and disruptive improvement in the integration of solar power plants into the grid, supporting more efficient and cost-effective operation of the power system, and helping maintain grid reliability while increasing the proportion of cleaner, renewable generation.
|SunShot Technical Metrics for Dispatchability of Solar Power Plants|
- AWS Truepower: Comprehensive Solutions for Integration of Solar Resources into Grid Operations
- IBM: Watt-Sun: A Multi-Scale, Multi-Model, Machine-Learning Solar Forecasting Technology
- National Oceanic and Atmospheric Administration: Solar Forecast Improvement Project
- National Renewable Energy Laboratory: Operational Analyses, Models and Tools Improvement
- National Renewable Energy Laboratory: Core Competencies for Solar Resource Assessment
- National Renewable Energy Laboratory: Solar Resource Modeling and Measurement Research
- National Renewable Energy Laboratory: Distributed Battery Energy Storage for High Penetration of Photovoltaics
- PHI Holdings, Inc. (PEPCO): Model-Based Integrated High-Penetration Renewables Planning and Control Analysis
- Sandia National Laboratories: Advanced Solar Resource Modeling and Analysis
- University Corporation for Atmospheric Research: A Public-Private-Academic Partnership to Advance Solar Power Forecasting
- University of California | San Diego, CA: Intra-Hour Dispatch and Automatic Generator Control Demonstration with Solar Forecasting