Contents
- Residential solar installations statistics: U.S. annual capacity additions and market shifts
- Residential solar installations statistics: quarterly capacity and seasonal patterns
- Residential solar installations statistics: system size, homes and equipment
- Residential solar installations statistics: storage attachment and system sizing
- Residential solar installations statistics: financing and installed prices
- Sources
Residential solar installations statistics: U.S. annual capacity additions and market shifts
The U.S. residential photovoltaic (PV) segment added 4,742 megawatts of direct-current capacity (MWdc) in 2024, down 31% from 2023. The annual figure measures installed capacity, not the number of homes or projects, so it describes the total rated power added rather than how many households adopted solar. The reported decline was broad: 42 states experienced lower annual residential installed capacity in 2024. California, a major residential market, recorded a 45% year-over-year contraction. These state and national results show that the slowdown was not confined to one market, though the size of the California change stands out. SEIA, U.S. Solar Market Insight 2024 Year in Review Executive Summary, p. 12.
The available figures establish the direction and scale of the annual change, but they do not give a count of installations or a complete explanation for the national decline. SEIA attributes California’s contraction to the transition to net billing; that statement applies to California and should not be treated as a complete explanation for all states. Capacity additions can also move differently from project counts when system sizes vary, so the MWdc total alone cannot say whether fewer systems were installed, systems were smaller, or both.
Residential solar installations statistics: quarterly capacity and seasonal patterns
Residential PV added 1,155 MWdc in the fourth quarter of 2024, around one quarter of the 4,742 MWdc added over the full year. That places Q4 in context, but a single quarter does not establish a seasonal pattern. To identify seasonality, the quarters would need to be compared across multiple years, with attention to market-specific changes and reporting periods. SEIA, U.S. Solar Market Insight 2024 Year in Review Executive Summary, p. 12.
The quarterly number is still useful for distinguishing the final-quarter contribution from the full-year result. It should not be read as the number of installations: it is capacity, expressed in MWdc. Nor does the year-end total indicate how much capacity was operating throughout the year, since it reports additions during the period.
Residential solar installations statistics: system size, homes and equipment
In Berkeley Lab’s sample of U.S. residential installations from 2024, the median PV system size was 7.2 kilowatts (kW), while the average was 9.3 kW. The middle half of observed system sizes fell roughly between 4 and 11 kW, represented by the report’s 20th-to-80th-percentile band. Because the average exceeds the median, larger systems pull the average above the size of the midpoint system; the percentile range also makes clear that installations vary considerably. Berkeley Lab, U.S. Distributed Solar and Storage: 2025 Data Update, p. 4.
California’s median in the same report was 5.7 kW, below the national sample median. This comparison describes system sizes in the 2024-install sample, not the number of systems installed in either geography. Differences in median size also do not, by themselves, explain California’s decline in annual capacity additions.
Building type and equipment provide further context for what a residential system typically looks like. In the 2024 sample, 92% of residential installations were on single-family detached homes. Module-level power electronics, including microinverters and DC optimizers, appeared in 87% of residential systems. The report also puts median residential module efficiency at roughly 21%, with a reported percentile range of 20.5% to 21.5%; the update does not specify the endpoints of that percentile band in the cited narrative. These are characteristics of sampled installations, not estimates of all homes or equipment in the U.S. housing stock. Berkeley Lab, U.S. Distributed Solar and Storage: 2025 Data Update, pp. 5, 10.
Residential solar installations statistics: storage attachment and system sizing
Battery pairing varied sharply by state in 2024. In California, storage was paired with 57% of new residential PV installations, up from 14% in 2023. Hawaii had an 85% attachment rate, the highest reported for any state. Across states other than California, the combined rate rose more modestly, from 5% in 2023 to 8% in 2024. Berkeley Lab describes rates below 5% in most states that year. The figures are shares of new PV installations paired with storage; they are not the share of existing solar homes that own a battery. Berkeley Lab, U.S. Distributed Solar and Storage: 2025 Data Update, p. 6.
Among residential PV-plus-storage systems in the 2024 sample, battery capacity had a median of 13.5 kilowatt-hours (kWh), and most systems were in the 10–20 kWh range. Median storage duration was two hours across the report’s three customer segments, including residential. Capacity and duration describe different things: kWh measures stored energy, while hours describe how long storage can deliver power under the report’s measure. These sample statistics do not indicate how long a battery would run a particular home, which depends on the home’s demand and the system’s operating conditions. Berkeley Lab, U.S. Distributed Solar and Storage: 2025 Data Update, p. 7.
Residential solar installations statistics: financing and installed prices
Third-party ownership (TPO) accounted for a larger share of sampled residential installations in 2024 than in 2023: the reported rate rose from 26% to 43%. TPO systems are owned by a provider rather than the host customer; the statistic describes ownership structure, not a direct comparison of household savings or total lifetime cost. Berkeley Lab, U.S. Distributed Solar and Storage: 2025 Data Update, p. 11.
For host-owned, stand-alone residential PV installed in 2024, Berkeley Lab reports median installed prices of $3.5 per watt for cash purchases and $4.7 per watt for loan-financed systems. These are inflation-adjusted gross installed prices before incentives or tax credits. In the combined cash-and-loan host-owned group, the median was $4.0 per watt of direct-current capacity (2024 $/Wdc), with the 20th-to-80th-percentile range running from $3.0 to $5.2 per watt. The cash-purchase mode—the most common price level—was below $3 per watt. The median and mode answer different questions: one marks the midpoint, while the other identifies the most frequent price level. Berkeley Lab, U.S. Distributed Solar and Storage: 2025 Data Update, pp. 8, 35.
Adding storage changes the price comparison. In 2024, the median cash price per watt of PV capacity for host-owned residential systems paired with storage was $1.7/W higher than for stand-alone systems. From 2023 to 2024, that paired-system median fell by $0.6/W for cash purchases in inflation-adjusted terms, while the median for loan-financed paired systems rose by $0.5/W. These are separate financing groups and paired-system comparisons; they should not be combined into a single direction of price change. The per-watt figure is based on PV capacity, so it does not represent the total battery cost or a complete measure of a system’s value. Berkeley Lab, U.S. Distributed Solar and Storage: 2025 Data Update, pp. 8–9.