Sunrun's Storage Attachment Rate Hits a Record 74% in Q2 as It Trims Guidance

Sunrun reported on 5 August that 74% of its new systems in the second quarter included storage, a company record and up from 70% a year earlier. At the same time, installed storage capacity fell 15% to 332 MWh and the company lowered its 2026 cash generation guidance.

The headline numbers

In its second-quarter release, Sunrun says it installed 332 MWh of storage, down 15% year on year, and that cumulative networked storage reached about 4.6 GWh at 30 June. It had 1,034,738 subscribers, up 10%, though subscriber additions fell 31% to 19,793.

Cash generation was $23 million, or $45 million excluding $22 million of equipment safe harbor investments. Full-year cash generation guidance was cut to $200 million to $375 million from $250 million to $450 million, excluding those investments.

Why more batteries but less storage installed

Both can be true because the attachment rate is a share of new systems, and the number of new subscribers fell. The release does not explain the drop in storage installed, so this is our reading. A rising share means that most new Sunrun customers now take a battery with their solar. The release does not give a battery unit count, so we cannot say how many homes that is.

The wider US market context is mixed. The American Clean Power Association and Wood Mackenzie reported on 23 June that US residential storage hit a record 1.3 GWh in the first quarter, partly lifted by installations rushed before the Section 25D tax credit expired, and forecast the residential segment to contract 5% in 2026.

Batteries as a grid resource

Sunrun says that in June it signed a non-binding letter of intent with Renew Home and Tesla to deliver over 16 GW of flexible capacity to hyperscalers and utilities. In July it started a pilot placing computing nodes in homes with its solar and storage. Both are early and non-binding or pilot-stage, and we could not confirm any commercial terms.

The idea of pooling household batteries is covered in our report on virtual power plants. Rules for US homeowners are in the United States country guide, and the Tesla brand page covers the Powerwall.

Sources

• Sunrun: Sunrun Reports Second Quarter 2026 Financial Results
• American Clean Power: U.S. Energy Storage Market Q1 2026 Sets Records Across Sectors

Related guides

Keep reading, or check your own numbers:

• Virtual power plants turn home batteries into grid assets
• United States country guide
• Tesla