Sunrun’s CalReady: California’s Largest Virtual Power Plant
As California faces hotter summers and more wildfires, the demand for electricity increases. To help meet this demand, Sunrun has expanded its CalReady program. This program connects thousands of home batteries to create a large virtual power plant.
What is CalReady?
CalReady is a program by Sunrun that links home solar batteries across California. These batteries store solar energy and send it back to the grid when needed. This helps reduce strain on the power grid during peak times.
Growth of CalReady
In 2024, CalReady had about 16,000 homes participating. Now, in 2025, it has grown to over 56,000 homes with approximately 75,000 batteries. This expansion allows CalReady to provide up to 375 megawatts of power, enough to supply around 280,000 homes.
How CalReady Works
CalReady operates during peak demand hours, typically from 4 PM to 9 PM, between May and October. During these times, the stored solar energy from home batteries is sent back to the grid to help meet electricity needs.
Benefits for Homeowners
Homeowners who participate in CalReady receive financial rewards. For each battery they share, they can earn up to $150 per year. In 2024, participants earned over $1.5 million collectively. This year, earnings are expected to reach nearly $10 million.
Advantages of a Virtual Power Plant
- Resilience: Distributed batteries reduce the risk of power outages.
- Efficiency: Stored solar energy is used when it’s most needed.
- Cost Savings: Reduces the need for expensive infrastructure upgrades.
- Environmental Impact: Decreases reliance on fossil fuels.
Customer Experience
Participating in CalReady is straightforward. Sunrun manages the battery operations, ensuring that at least 20% of battery capacity is reserved for the homeowner’s use during outages. This means homeowners can contribute to the grid without compromising their own energy needs.
Future Outlook
The success of CalReady in California sets a precedent for similar programs nationwide. As more homeowners adopt solar and battery storage systems, virtual power plants like CalReady could become a common solution to energy challenges across the country.
Summary Table
| Year | Homes Participating | Batteries | Peak Power (MW) | Total Earnings |
| 2024 | 16,000 | ~20,000 | 54 | $1.5 million |
| 2025 | 56,000+ | 75,000 | 375 | ~$10 million |
Conclusion
Sunrun’s CalReady program demonstrates how homeowners can play a vital role in energy solutions. By combining solar power and battery storage, communities can create resilient, efficient, and environmentally friendly power systems. As the program grows, it offers a model for sustainable energy practices nationwide.
For more information, visit the official Sunrun website: www.sunrun.com/calready.
Jonas Muthoni is an entrepreneur and renewable energy expert. He is the editor-in-chief of MicroGridMedia.com, a news outlet dedicated to bringing the latest news and information about solar energy and other renewable energy sources to the public. Jonas is passionate about promoting sustainable energy solutions and educating the public about the benefits of renewable energy. He is a regular speaker at industry events and conferences and is committed to driving the transition to a cleaner and more sustainable energy future.