Updated report and data illustrate trends in distributed solar pricing and design

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We are pleased to announce the release of the latest edition of Berkeley Lab’s Following the sun annual report, which describes trends in distributed solar photovoltaic (PV) systems in the United States, including the growing number of distributed solar-plus-storage systems. The report is based on data from approximately 3.7 million systems installed nationwide through the end of 2023, covering nearly 80% of all systems installed to date and more than 70% of additions through 2023. This year’s report updates key trends related to project characteristics, system design, and pricing, and presents new material based on building and property data integrated into the Following the sun data set.

The report, published in slide deck format, is accompanied by a narrative summary, interactive data visualizations, and a public data file, all available via the link above. The authors will host a webinar on September 4 summarizing the key findings from the report.^and at 10am Pacific. Register for the webinar here: https://lbnl.zoom.us/webinar/register/WN_w4ImuN7yRcWN1TPUvJIEng

Below are some key findings from the latest edition of the report.

Residential systems are becoming increasingly larger, driven by increasing module efficiency. Residential system sizes have increased steadily over the past two decades, reaching a median of 7.4 kW in 2023. System sizes have increased almost in tandem with PV module efficiency, as shown in the left panel of Figure 1. Higher module efficiencies allow for more PV capacity, as residential systems are often space-constrained due to shading, obstructions, and mixed roof orientations. As shown in the right panel of Figure 1, roof coverage ratios (the percentage of roof area used by PV modules) typically range from 20-40% in residential applications and have increased only slightly since 2010.

Figure 1. Trends in residential system size and module efficiency (left) and roof coverage ratios (right) Graph from Berkeley Lab

Nonresidential PV users span a diverse range of sectors as small agricultural systems expand their share. As shown in Figure 2, half of all nonresidential installations in 2023 were installed on commercial properties (including retail, industrial, office, and warehouse facilities), about one-third on agricultural properties, and 15% by tax-exempt (e.g., government, schools, religious, and other non-profit) customers. The share of systems installed on agricultural properties has grown over time; most of these are relatively small systems (

Figure 2. Nonresidential PV customer segmentation. Includes nonresidential rooftop systems and ground-mounted systems up to 5 MW. Larger ground-mounted systems are covered in Berkeley Lab’s companion report, Utility-Scale Solar. Graph format Berkeley Lab

Battery storage rates continue to rise slowly. In 2023, 12% of all new residential PV installations and 8% of all nonresidential installations included battery storage. As usual, Hawaii stood out in a category of its own, with 95% and 88% of residential and nonresidential storage coupling rates, respectively. Residential coupling rates in California rose to 14% for the year. Most of those systems were installed under the state’s old net metering structure, but coupling rates for systems installed under the new net billing rates, which heavily incentivize PV with storage, reached about 60% by year’s end. (Berkeley Lab previously published a deeper analysis of changes in California’s solar market under the new net billing structure.) Residential coupling rates in most other states ranged from 4-10% in 2023. Nonresidential coupling rates also vary widely by state, but are typically quite low (

Prices of residential PV systems decreased year-on-year, but increased for non-residential systems. From 2022 to 2023, median installed prices for residential systems declined by about $0.1/W in real (inflation-adjusted) terms, the same rate of decline as over the past decade. In contrast, median prices for nonresidential systems increased for the first time in 15 years, by $0.1-0.2/W. These small year-over-year changes are sensitive to fluctuations in inflation and the lagged effect on installed prices, which can vary by project depending on the length of their development timeline. In all three customer segments, but especially for residential systems, installed prices consist primarily of business process and other “soft costs.”

Figure 3. Long trend in US median installed prices. These prices represent the initial price paid by the customer for standalone PV systems, prior to receipt of any incentives, including any loan financing costs bundled into the prices charged by installers, and are adjusted for inflation using the U.S. Bureau of Labor Statistics’ “Consumer Price Index for All Urban Consumers, US city average, All items.” Graph format Berkeley Lab

Prices for PV systems vary widely from project to project. For standalone PV systems, installed prices vary by about $2/W between 20^and and 80^and percentile values for both residential and small nonresidential customers, and by approximately $1.4/W for large nonresidential customers (see Figure 4). This price variability reflects differences in project characteristics and local market, policy, and regulatory characteristics. The report includes a multivariate regression analysis that estimates the effects of key price drivers on residential installation prices in 2023. The regression analysis shows the most significant effects associated with battery storage uptake (up $1.4/W), system size variations (down $0.7/W from the 20^and to the 80^and percentile system size) and installations in new-build homes ($0.7/W lower than systems installed in existing homes).

Figure 4. Installed price distributions for standalone PV systems installed in 2023, Berkeley Lab chart

We thank the US Department of Energy Solar Energy Technologies Office for their support of this work, as well as the many individuals and organizations who have generously provided data for this ongoing effort.