Two key characteristics of solar generation have fundamental impacts to the electric power system as more solar is added to the grid. The first is constrained availability—the fact that the solar energy is available only during daytime, with the highest outputs occurring from mid-morning until late afternoon, whereas load demand levels off during the day and peaks during early evening hours, resulting in the so-called duck curve.The second is generation variability—the fact that solar power production levels can change rapidly depending on the weather.
Solar Plus X refers to a tightly integrated system that may consist of distributed photovoltaics (PV), energy storage, smart building load, electric vehicles, and optimized local control software, among others. By leveraging the inherent flexibility of each technology, Solar Plus X can reduce the total integration and operation costs of these distributed energy resource assets, and also has the potential to provide grid services including on-demand energy, capacity, reliability, and resiliency.
Solar Plus X Challenges and Opportunities
Developing integrated Solar Plus X solutions can be challenging due to the areas of interoperability, control coordination, communication, and scalability. The lack of holistic designs and standard interfaces can result in added integration costs and operational complexity. Advancements in smart inverters, communication and control technologies, among others, offer new opportunities for integrated solutions that are compatible with significantly higher amounts of distributed energy resources on the grid. These solutions can store solar energy for on-demand dispatch, control energy loads for system flexibility, mitigate adverse impacts from solar variability, and provide power during outages.
The Sustainable and Holistic Integration of Energy Storage and Solar PV (SHINES) funding program has six projects that are dedicated to developing integrated PV and energy storage solutions that are scalable, secure, reliable, and cost-effective. Learn more about the six projects.
The Resilient Distribution Systems Lab Call includes a project that is developing coordinated hierarchal solution so in cases of power outages, electricity can be restored using renewable energy. Learn more about the CleanStart-DERMS project.
SETO also funds a storage project with the National Renewable Energy Laboratory to investigate concentrating solar power (CSP) and its ability to increase the overall penetration of solar energy while lessening the variability impacts of photovoltaics. Learn more.