Mary Powell, the CEO of Sunrun, believes that residential solar panels and battery storage can help stabilize the U.S. grid, which is currently struggling to keep up with increasing electricity demand. She sees transforming more homes into their own power generation sites as a quicker solution compared to connecting large-scale wind and solar farms to the grid, a process that can take years. Sunrun hit a milestone last month by installing solar and battery systems in a million homes, totaling at least seven gigawatts of installed power-generating capacity and two gigawatt hours of energy storage.
Powell, who is recognized on Forbes’ inaugural Sustainability Leaders list today, aims to grow the number of homes that serve as small-scale virtual power plants. Sunrun, the largest U.S. solar installer, is increasing its battery deliveries, focusing on Tesla Powerwall units. Average residential projects for Sunrun typically include 7.5 kilowatts of solar panels and batteries with at least 13-kilowatt hours of storage. The cost of such systems can exceed $20,000, but federal tax credits and state rebates can help offset the cost. Powell emphasizes the importance of affordability in scaling up residential solar and energy storage solutions.
The residential solar power industry has seen a significant increase in the adoption of batteries in recent years, allowing customers to store excess power generated during sunny days for use at night or on cloudy days. Currently, 54% of Sunrun’s customers are using batteries with their solar panels, reducing their reliance on the grid. However, the U.S. electrical grid is not being upgraded fast enough to keep pace with rising power demand. Powell warns that infrastructure spending is insufficient, and consumers may face rate hikes if the grid is not modernized.
A significant increase in residential solar and energy storage installations could help local utilities manage growing demand more effectively. However, the permitting process for new systems remains cumbersome, with various entities involved in the approval process. In states like California, where there is a surplus of solar generation but not enough battery storage, the state has curtailed incentives for new residential solar projects under new net metering rules. This has led to a decline in new installations, impacting companies like Sunrun.
Sunrun’s revenue fell by 11% in the second quarter of 2024 due to the changes in California’s net metering rules, but the company expects to install up to 1.1 gigawatt hours of battery storage in 2024. Powell emphasizes the importance of federal support for solar and battery projects, especially targeting low-income residential, community, and tribal installations. She believes that standardizing guidelines at the state and utility levels can accelerate adoption and make distributed power generation and storage more accessible.
The potential of distributed power generation and storage to scale quickly and benefit both consumers and utilities is gaining attention. Powell envisions Sunrun as an orchestrator of smart, controllable home and electric vehicle loads for utilities. As the U.S. power grid faces challenges in meeting increasing demand, residential solar panels and battery storage could play a crucial role in stabilizing the grid and creating a more sustainable energy future.
