A Wake-Up Call from Spain
In July 2021, a single fault in Spain’s transmission system caused the grid’s frequency to drop faster than operators could react. Within seconds, protective systems disconnected nearly seven gigawatts of electricity to prevent a total blackout. Millions of people were affected.
The National Renewable Energy Laboratory (NREL) studied this event in detail. Their findings show that as we replace older power plants with renewable energy, the grid loses a natural stabilizing force called inertia. Without it, the system can be more vulnerable to sudden changes. Follow this link to learn more about NREL’s work on this subject: https://docs.nrel.gov/docs/fy20osti/73856.pdf
What Inertia Means
Inertia is the momentum stored in the spinning parts of traditional power plants. When something goes wrong, that momentum slows the rate of change in the grid’s frequency. It gives operators a short window to fix the problem before it spreads.
Think of it like a moving train. Even if the engine stops, the train keeps rolling for a while. That extra time can make the difference between a quick recovery and a major outage.
Why Renewable Energy Changes the Equation
Solar panels, wind turbines, and batteries connect to the grid through electronic controls instead of spinning machinery. This means they do not naturally provide inertia. But they can be programmed to act like they do. This is called synthetic inertia or fast frequency response.
Synthetic inertia uses sensors and software to detect changes in frequency and adjust power output almost instantly. It is not automatic like physical inertia, but it can be placed anywhere on the grid and tuned for different needs.
From Individual Systems to Powerful Clusters
When we group renewable energy systems together and control them as a single unit, we create a cluster. These clusters can take two main forms:
- Virtual Power Plants (VPPs) — Many separate systems, such as rooftop solar, batteries, and small wind, linked by software so they can act like one large power plant.
- Microgrids — Local energy networks that can operate with the main grid or independently during outages.
Both VPPs and microgrids can be designed to provide synthetic inertia and other stability services. This means they can help the grid handle sudden changes while also delivering clean power.
Inertia Vs. Synthetic Inertia
Why This Matters for Solar and Other Renewables
The faster we can add stability services to renewable energy, the faster we can replace fossil fuel plants without risking reliability. Synthetic inertia, VPPs, and microgrids give us the tools to do this.
They allow solar and other renewables to not only supply clean power but also keep the grid steady during disturbances. This makes it easier for utilities and regulators to approve more renewable projects and for communities to trust that clean energy can be dependable.
Benefits of VPPs and Microgrids for the Solar Industry
Next Steps for Solar Industry Professionals
- Learn how synthetic inertia works and how it can be built into solar and storage projects.
- Explore opportunities to join or create VPPs that combine many systems for greater impact.
- Consider microgrid designs for customers who value resilience and independence.
- Share success stories with policymakers and customers to build confidence in renewable reliability.
Bottom line: By understanding and using synthetic inertia, VPPs, and microgrids, the solar industry can speed up clean energy adoption while keeping the grid strong and reliable.
For more information about ProtoGen’s approach to microgrid development, contact our technical team.