What Sunrun’s 70% Storage Rate Means for Home Solar

Most residential solar companies are still trying to figure out storage. Sunrun just hit a 70% battery attachment rate in Q3 2025 and grew revenue 35% year-over-year while cutting losses by a third.

That single number — 70% of new systems going in with batteries — tells you where green technology is really heading. Solar panels on their own are becoming the default. The real value now is in controlling when and how that clean energy is used, sold, and stored.

This matters because the next wave of clean energy growth won’t come from more panels alone. It’ll come from smarter systems: solar, battery storage, and software working together across millions of homes. And that’s exactly what Sunrun’s results are signaling.

In this post, I’ll break down what Sunrun’s Q3 2025 numbers actually mean, why their “storage‑first” strategy is working, and how this shift affects homeowners, utilities, and anyone building green technology businesses.

Sunrun’s Q3 2025: The headline numbers that matter

Sunrun’s latest quarter shows that pairing solar with battery storage isn’t just good for resilience — it’s starting to improve the economics of residential solar.

Here are the key Q3 2025 figures from Sunrun:

• US$724.6 million in revenue, up from US$569 million in Q2 2025
• 35% year-over-year growth vs Q3 2024 (US$537.2 million)
• 70% battery attachment rate on new residential solar systems
• 412MWh of new residential storage installed in the quarter (up 23% YoY)
• Net loss reduced to US$277.8 million, down from US$412.2 million a year earlier
• US$3.7 million in positive operating profit in Q3, vs a loss over the first nine months
• US$1.2 billion in proceeds in the first nine months of 2025, more than double 2024’s US$557.1 million for the same period

The standout datapoint is that 70% attachment rate. For context, Sunrun’s storage attachment was 14.9% in Q1 2023 and only passed 50% in the first half of last year. That’s a massive behavioral shift in less than three years.

The reality? Residential solar is being redefined as solar-plus-storage by default.

Why Sunrun went “storage-first” — and why it’s paying off

Sunrun isn’t just selling more batteries because they’re trendy. A storage‑first strategy is a direct response to how home energy economics are changing.

The problem with solar‑only systems

Solar alone is great for clean generation, but it runs into three big limitations:

1. Grid rules are changing
   Net metering programs are being scaled back or redesigned in many US states. That means exporting excess solar to the grid is less lucrative than it used to be.

2. Self-consumption is undervalued without storage
   Midday solar often exceeds home demand. Without a battery, that surplus is pushed to the grid when wholesale prices are low.

3. Resilience is becoming a must‑have
   With more extreme weather and grid outages, homeowners increasingly expect backup power, not just bill savings.

Batteries solve all three.

How storage changes the economics

By prioritizing storage attachment, Sunrun is stacking new value streams on top of each installation:

• Higher project value per customer
  A solar‑plus‑storage system carries a larger contract value than solar alone. That supports higher lifetime revenue per household.

• Grid services and virtual power plants (VPPs)
  Connected batteries can be aggregated to support the grid during peak demand. That creates recurring revenue opportunities through utility programs and market participation.

• Tax credit monetization
  Sunrun has been effective at monetizing US clean energy tax credits and transferability options. Batteries increase the qualifying investment base, boosting financial returns.

• Customer retention and satisfaction
  Homeowners feel the benefit of storage immediately during outages and peak pricing windows. That makes churn less likely and referrals more likely.

From a green technology perspective, this is exactly where the sector is heading: hardware (solar + batteries) plus software‑driven optimization and financial engineering (tax credits, leases, VPP revenue) in one integrated model.

70% battery attachment: what it signals for the market

When more than two‑thirds of a major installer’s systems include storage, that’s not a niche anymore — it’s the new normal.

For homeowners and solar customers

If you’re evaluating solar now, Sunrun’s numbers tell you something simple:

Solar without storage is starting to look like buying a smartphone and never connecting it to Wi‑Fi.

It technically works, but you’re missing most of the value. Residential battery systems now:

• Shift cheap midday solar to expensive evening hours
• Provide backup power for outages and storms
• Help avoid punitive time‑of‑use or demand‑based charges

In 2023, adding a battery was still “nice to have” for many households. In 2025, it’s becoming the expectation, especially in:

• States with aggressive time‑of‑use pricing
• Areas exposed to wildfire shutoffs, hurricanes, or grid congestion
• New builds and major renovations where energy design is considered early

For utilities and grid operators

A 70% attachment rate at a national player is a warning and an opportunity for utilities.

• Warning: unmanaged behind‑the‑meter solar‑plus‑storage can reduce peak consumption and complicate load forecasting.
• Opportunity: when coordinated as a virtual power plant, those same systems become flexible, dispatchable resources.

Most companies get this wrong. They treat residential storage as a threat instead of as a distributed energy asset that can:

• Shave peak demand during heat waves
• Provide fast response reserves and ancillary services
• Support local reliability where traditional upgrades would be expensive

Sunrun’s growing storage fleet is part of a broader shift toward AI‑driven grid orchestration, where software decides in real time whether a battery should:

• Serve the home
• Support the grid
• Charge up for a forecasted event

That’s where green technology, AI, and energy markets all intersect.

For clean energy and green tech businesses

If you’re building in this space — whether hardware, software, or services — Sunrun’s Q3 points to a few clear trends:

• Storage attachment is now a core KPI. If your product doesn’t support batteries, you’re designing for a shrinking slice of the market.
• Value is shifting from capex to lifetime services. Financing, software optimization, and grid services are where margin lives.
• Tax credits and policy literacy are competitive advantages. Sunrun’s success with tax credit transfers is financial engineering as much as engineering.

There’s a better way to think about residential solar than “sell panels, then upsell a battery.” The winners are designing solar-plus-storage-plus-software as a single product from day one.

The role of AI and software in solar-plus-storage

Solar panels and batteries are the physical layer. The real intelligence — and a big chunk of future profitability — lives in software.

How AI already shapes residential storage

Modern home energy systems are increasingly managed by algorithms that:

• Forecast solar generation based on weather and season
• Learn a home’s typical consumption patterns
• Track time‑of‑use or dynamic tariffs
• Respond to grid signals or VPP dispatch requests

From there, AI can make decisions every few minutes:

• Should the battery charge from solar now or later?
• Should it discharge to avoid peak pricing in the evening?
• Is there a storm coming that justifies holding extra charge as backup?

For a single home, this means lower bills and better resilience. Across tens of thousands of homes, it becomes a virtual power plant that can meaningfully support the grid.

Why this fits the Green Technology series

The Green Technology theme isn’t just about generating cleaner power. It’s about using data and intelligence to squeeze more value out of every clean kilowatt-hour.

Sunrun’s “storage‑first” strategy is a textbook example:

• Clean generation (solar)
• Local flexibility (batteries)
• System‑level optimization (software + AI + grid signals)

That stack is what will enable:

• Smarter, more reliable neighborhoods and smart cities
• Lower system‑wide costs compared to brute‑force grid upgrades
• A smoother, faster transition away from fossil‑based peakers

This is where AI quietly becomes one of the most effective climate tools we have: not by making headlines, but by making every home system a bit smarter every day.

Practical takeaways: what to do with this trend

Here’s how different audiences can act on what Sunrun’s Q3 2025 results are signaling.

If you’re a homeowner or property investor

When you evaluate solar quotes in 2025 and beyond:

• Treat storage as part of the core design, not an add‑on
  Ask for side‑by‑side proposals: solar‑only vs solar‑plus‑storage, with detailed bill modeling.

• Look at lifetime economics, not just upfront cost
  Time‑of‑use pricing, extreme weather, and policy changes all favor systems that can store and shift energy.

• Ask about software and control
  Who controls your battery? How are updates delivered? Can you opt into or out of grid support programs?

If you’re in utilities, policy, or grid planning

Sunrun’s storage penetration suggests it’s time to:

• Design standardized VPP and demand response programs that treat residential storage as a resource, not an exception
• Align tariffs and incentives with flexibility, not just kWh exported
• Encourage interoperable standards so different vendors’ systems can participate in grid services at scale

If you’re building green technology products

Use Sunrun’s trajectory as a roadmap:

• Build products that assume storage and flexibility are standard in homes
• Integrate with existing installers and financiers instead of trying to own every layer
• Focus on data, optimization, and user experience — not just hardware specs

The companies that will stand out are those that make complex energy decisions feel invisible and intuitive to end users while still meeting the grid’s needs.

What Sunrun’s results tell us about the next phase of clean energy

Sunrun’s 70% storage attachment rate and 35% revenue growth in Q3 2025 aren’t just good quarterly headlines. They’re early proof that solar-plus-storage is moving from niche to norm in US homes.

For the broader green technology story, this quarter confirms a pattern:

• Clean energy is becoming distributed, not just centralized
• Intelligence is shifting to the edge of the grid, inside homes and businesses
• Financial and digital innovation are now as important as hardware innovation

As batteries become standard and AI gets better at orchestrating thousands of systems at once, residential solar will evolve from simple bill reduction into a flexible, software‑driven piece of the energy system.

The open question isn’t whether this shift happens — Sunrun’s data suggests it already is. The real question is who will design the smartest, most user‑friendly, and grid‑aware systems on top of it.

That’s where the next wave of green technology companies will be built.