Original research
How big is the average American solar system, really
Installed capacity per system by state, and why two credible sources give answers nearly twice apart.
The finding
Key findings
- 1 The installed fleet averages 6.74 kW
34,226 MW across 5,077,543 residential net-metered systems at the end of 2024.
- 2 Systems added in 2024 averaged about 6.9 kW
Derived from the change in capacity divided by the change in count. This is the number that reconciles federal data with marketplace reporting.
- 3 The fleet average rose 25% in eleven years
From 5.38 kW to 6.74 kW, slowly, because each year's larger systems are diluted by a very large stock of older, smaller ones.
- 4 Missouri has the largest systems at 9.15 kW
Against 5.16 kW in Colorado: a spread of 1.8 to one between the state extremes.
- 5 Higher-adoption states have smaller systems, not bigger
The correlation between household adoption and average system size is r = -0.369. Mature markets have older, smaller fleets and tariffs that historically rewarded modest arrays.
- 6 California, the largest market, is below the national average
6.07 kW against 6.74 kW nationally, on 41% of all US residential systems, which drags the national figure down.
Two averages, both correct, constantly confused
Fleet average (6.74 kW): total installed net-metered residential capacity ÷ number of systems. It includes a 3 kW array installed in 2011 and a 14 kW array installed last month, and is dominated by the older, smaller majority.
New-quote average (~12.0 kW): the average size of systems being sold now, from marketplace and installer data. It reflects today’s panel wattages, today’s household loads and today’s EV charging.
Use the fleet average to describe what exists. Use the quote average to describe what you would buy. A page that quotes one under a headline asking the other is the most common failure in this topic, and we have found it in trade coverage as often as in consumer content.
The reconciliation, from a single dataset
The gap between the two figures is usually asserted rather than shown. It can be shown, from these files alone, without reference to any commercial source.
Because EIA reports both capacity and installation counts each year, the change in capacity divided by the change in count gives the implied average size of the systems added that year. In 2024 that comes out at about 6.9 kW, against a fleet average of 6.74 kW, and the two lines diverge steadily across the series.
That is the whole explanation. Systems being installed are considerably larger than the fleet they are joining, so the fleet average lags. Marketplace figures measure the first quantity; federal fleet data measures the second. Both are right, and the difference between them is the age of the installed base.
Fleet average and implied new-system size by year
| Year | Fleet average | Implied size of systems added | Fleet capacity (MW) | Systems |
|---|---|---|---|---|
| 2014 | 5.38 kW | — | 3,453 | 642,276 |
| 2015 | 5.59 kW | 6.0 kW | 5,357 | 958,850 |
| 2016 | 5.77 kW | 6.3 kW | 7,627 | 1,321,277 |
| 2017 | 5.83 kW | 6.1 kW | 9,487 | 1,626,283 |
| 2018 | 5.94 kW | 6.5 kW | 11,357 | 1,911,892 |
| 2019 | 6.07 kW | 6.7 kW | 13,863 | 2,283,702 |
| 2020 | 6.18 kW | 6.8 kW | 16,433 | 2,661,029 |
| 2021 | 6.31 kW | 7.0 kW | 19,929 | 3,157,429 |
| 2022 | 6.51 kW | 7.5 kW | 24,668 | 3,788,427 |
| 2023 | 6.72 kW | 7.8 kW | 30,571 | 4,549,601 |
| 2024 | 6.74 kW | 6.9 kW | 34,226 | 5,077,543 |
HyreSolar calculation from EIA-861. The implied new-system column is derived and noisier than the fleet column.
Figures labelled HyreSolar calculation are computed by us from the EIA source files named below. EIA publishes the inputs; it does not publish these ratios.
Where the big systems are
The largest average systems are in the South and mid-Atlantic (Missouri, Florida, Arkansas, Indiana) where households consume more electricity, air conditioning dominates the load, and the solar market arrived late enough that the fleet was built with modern high-wattage panels.
The smallest are in the mature western markets and the Mountain West. That inversion is the finding most likely to surprise: the states with the most solar have the smallest systems.
Average installed system size by state, 2024
| # | State | Avg. system size | Systems | Total capacity (MW) | Household share | Consumption per household |
|---|---|---|---|---|---|---|
| 1 | Missouri | 9.15 kW | 30,022 | 275 | 1.02% | 12,007 kWh |
| 2 | Florida | 8.88 kW | 289,774 | 2,572 | 2.77% | 13,250 kWh |
| 3 | Arkansas | 8.87 kW | 19,146 | 170 | 1.30% | 12,580 kWh |
| 4 | Indiana | 8.69 kW | 11,045 | 96 | 0.36% | 10,814 kWh |
| 5 | Minnesota | 8.40 kW | 22,621 | 190 | 0.88% | 8,548 kWh |
| 6 | Iowa | 8.33 kW | 16,392 | 137 | 1.13% | 9,987 kWh |
| 7 | Maryland | 8.29 kW | 108,428 | 899 | 4.42% | 11,146 kWh |
| 8 | Maine | 8.16 kW | 14,867 | 121 | 2.00% | 6,601 kWh |
| 9 | New Hampshire | 8.06 kW | 22,503 | 181 | 3.45% | 7,428 kWh |
| 10 | Pennsylvania | 8.00 kW | 81,375 | 651 | 1.47% | 9,806 kWh |
| 11 | Illinois | 7.74 kW | 103,145 | 798 | 1.91% | 8,317 kWh |
| 12 | Connecticut | 7.71 kW | 103,824 | 801 | 6.69% | 8,335 kWh |
| 13 | Kentucky | 7.71 kW | 10,069 | 78 | 0.48% | 12,558 kWh |
| 14 | Delaware | 7.67 kW | 14,087 | 108 | 2.98% | 10,928 kWh |
| 15 | Nevada | 7.60 kW | 134,257 | 1,021 | 10.23% | 11,154 kWh |
| 16 | South Carolina | 7.54 kW | 40,055 | 302 | 1.55% | 12,605 kWh |
| 17 | Ohio | 7.44 kW | 27,520 | 205 | 0.54% | 10,146 kWh |
| 18 | Virginia | 7.39 kW | 69,553 | 514 | 1.90% | 12,388 kWh |
| 19 | North Carolina | 7.39 kW | 57,393 | 424 | 1.13% | 12,184 kWh |
| 20 | Oklahoma | 7.38 kW | 16,755 | 124 | 0.89% | 12,949 kWh |
| 21 | Texas | 7.37 kW | 133,501 | 984 | 1.06% | 13,154 kWh |
| 22 | Wisconsin | 7.24 kW | 18,581 | 135 | 0.65% | 7,742 kWh |
| 23 | Washington | 7.23 kW | 59,235 | 428 | 1.76% | 11,465 kWh |
| 24 | Arizona | 7.18 kW | 317,033 | 2,278 | 10.11% | 12,899 kWh |
| 25 | New York | 6.93 kW | 226,979 | 1,573 | 3.06% | 6,854 kWh |
| 26 | Georgia | 6.92 kW | 18,612 | 129 | 0.39% | 12,888 kWh |
| 27 | New Jersey | 6.91 kW | 199,822 | 1,381 | 5.35% | 7,949 kWh |
| 28 | Massachusetts | 6.88 kW | 189,611 | 1,305 | 6.48% | 6,836 kWh |
| 29 | Michigan | 6.63 kW | 23,456 | 155 | 0.52% | 7,419 kWh |
| 30 | Idaho | 6.50 kW | 22,899 | 149 | 2.64% | 11,326 kWh |
| 31 | District of Columbia | 6.35 kW | 17,780 | 113 | 5.58% | 7,672 kWh |
| 32 | Oregon | 6.34 kW | 52,600 | 334 | 2.82% | 10,582 kWh |
| 33 | Rhode Island | 6.12 kW | 17,321 | 106 | 3.79% | 6,802 kWh |
| 34 | California | 6.07 kW | 2,090,983 | 12,702 | 14.71% | 6,039 kWh |
| 35 | Utah | 5.93 kW | 81,115 | 481 | 6.37% | 9,290 kWh |
| 36 | Louisiana | 5.46 kW | 34,417 | 188 | 1.60% | 14,422 kWh |
| 37 | Hawaii | 5.40 kW | 98,418 | 532 | 22.04% | 5,938 kWh |
| 38 | New Mexico | 5.35 kW | 61,209 | 327 | 6.54% | 7,849 kWh |
| 39 | Colorado | 5.16 kW | 179,751 | 928 | 7.03% | 8,091 kWh |
States with at least 10,000 residential net-metered systems. HyreSolar calculation from EIA-861 2024.
Why the biggest markets have the smallest systems
Plotted against household adoption, average system size slopes downwards: r = -0.369. The more solar a state has, the smaller its average system.
Two mechanisms produce that, and they compound. The first is age. A state that has been installing at scale for longer has a fleet containing a very large stock of systems from the era of 250-watt panels; a state that started recently built its entire fleet with 400-watt-plus modules. The second is tariff design. Under retail-rate net metering with steeply tiered pricing (California’s historical arrangement) a system sized to shave the top tier paid back faster than one sized to cover the whole bill. Californians were rationally buying smaller arrays.
The second mechanism has now reversed in California. Under net billing, oversizing to sell power back is unattractive, but sizing to cover self-consumption plus a battery is. We expect the California average to move; the fleet is large enough that it will move slowly.
Eleven years, eight markets
The state paths show the same story from another angle. Late-arriving markets enter the series already at a high average and stay there. Long-established markets climb slowly from a low base as new installations gradually outweigh the legacy fleet.
What this does not tell you about your own roof
Nothing on this page is a sizing recommendation. The right size for a specific house is set by its consumption, its roof area and orientation, its shading, its utility’s tariff and interconnection limits, and whether it charges a car. Those vary far more between two houses on the same street than between two states.
A kilowatt is also not a fixed amount of electricity. A 7 kW array in Arizona generates materially more than a 7 kW array in Maine, so equal-sized systems in different states do not offset equal shares of a bill. This dataset contains capacity, not generation, and cannot speak to output.
A kilowatt is not a kilowatt-hour
One distinction is worth making explicitly, because it is the source of most misreadings of a table like this. Capacity is not generation. Every figure on this page is nameplate capacity in kilowatts (what an array can produce at peak) not the electricity it actually produces over a year.
The same 7 kW array produces materially more in Phoenix than in Portland, Maine, because of irradiance, and more on a south-facing unshaded roof than on an east-facing one with a chimney. So a state with larger average systems is not necessarily a state whose solar households offset more of their bill; it may simply be a state whose households consume more, or whose roofs are newer and larger.
The consumption column in the state table above is the closest proxy this dataset offers. States with the largest average systems (Missouri, Florida, Arkansas) do broadly have higher household consumption, which is the sizing logic working as it should. But EIA-861 contains no generation figures for these systems, so nothing here can be converted into output, savings or offset percentage, and we do not attempt it.
Methodology
Calculation
Average size = residential photovoltaic net-metered capacity (MW × 1,000) ÷ residential photovoltaic net-metering installations, both from EIA-861, summed to state level. EIA publishes both; it does not publish the quotient.
The implied new-system size = (capacity in year t − capacity in year t−1) × 1,000 ÷ (installations in year t − installations in year t−1). This is a derived quantity and inherits all the noise in both differences, including any reclassification. It is shown as a trend, not quoted as a point estimate.
AC or DC: the largest limitation on this page
EIA-861 records a Type field of AC or DC per utility filing, and utilities do not all report on the same basis. State totals therefore mix AC-rated and DC-rated capacity. DC ratings are typically 15–25% higher than AC for the same array, so a state whose utilities report predominantly in DC will show a larger average size for reasons that have nothing to do with the arrays on its roofs.
We have not corrected for this, because correcting would require assuming an inverter loading ratio we cannot observe, and an assumption inserted into a table of measurements is how a study stops being a measurement. It affects the cross-state ranking more than the national trend, since the reporting mix within a state is broadly stable year to year.
Inclusion floor
States with fewer than 10,000 residential net-metered systems are excluded from the ranking. Averages computed on a few hundred systems are dominated by a handful of unusual installations.
What this is not
Not a quote size. If you are sizing a system, the relevant number is what your roof and consumption support, which is typically well above this fleet average and closer to the marketplace figure.
Not a measure of generation. A kilowatt in Arizona and a kilowatt in Maine do not produce the same energy, and this dataset contains no generation figures.
Not comparable to utility-scale statistics, which are reported on entirely different schedules and in different units.
Terms used on this page
- Fleet average
- Total installed capacity divided by total installed systems, across everything currently connected. What this page primarily reports.
- Implied new-system size
- The year-on-year change in capacity divided by the year-on-year change in system count. A derived estimate of what was installed that year.
- kW (kilowatt)
- A measure of capacity, not energy. It describes how much power an array can produce at peak, not how much electricity it generates over a year.
- DC vs AC rating
- DC rates the panels; AC rates the inverter output. DC figures typically run 15–25% higher for the same array. EIA-861 contains both, mixed.
- Inverter loading ratio
- The ratio of DC panel capacity to AC inverter capacity. Needed to convert between the two ratings, and not observable in this data.
Citation, reuse and corrections
How to cite this study
Full citation. HyreSolar Research, “How big is the average American solar system, really”, September 2026. Analysis of US Energy Information Administration Form EIA-861, 2014–2024. Available at https://hyresolar.com/research/system-size-by-state/
In text. “according to a HyreSolar analysis of federal utility filings” — with a link to this page.
In a chart or table. “Source: HyreSolar analysis of EIA-861 (2024)”.
What you may reuse
The underlying data is a public US government dataset and carries no restriction. The analysis, rankings, derived ratios and charts on this page are ours, and you are welcome to reproduce them — including the charts — for editorial, academic and non-commercial purposes with attribution and a link to this page.
We ask for the link rather than a bare mention because the methodology and the limitations live here. A figure quoted without them is easy to misread, and several of the numbers on this page carry conditions that change what they mean.
Who produced this
The HyreSolar research desk. We do not attach an individual byline to these studies, because the work is a scripted analysis of a public federal dataset rather than an authored opinion, and a personal byline would imply a kind of authorship that is not what happened here. What is accountable instead is the method: the source files are named, the arithmetic is stated, the extraction is scripted, and the validation is published.
HyreSolar is an independent analysis and matching service. We are not an installer, a lender or a utility, and no installer pays for placement, ranking or mention in this research. See the editorial policy.
How this study is built
Annual Form EIA-861 workbooks for 2014–2024 are downloaded from EIA and parsed by script into a single dataset. Every figure on this page — in the prose, in the tables and in every mark on every chart — is read from that dataset at build time. Nothing is typed by hand.
That is not a stylistic preference. It means a number in a sentence and the same number in the table beneath it cannot drift apart, a chart cannot disagree with its own caption, and next year's EIA release updates the entire study by regenerating one file rather than by someone editing 4,000 words and hoping they caught every instance.
The workbooks are not consistent between years — sheet names change, header rows move, a measure is renamed, a column appears in one year only, and one large utility is filed under two different spellings. The extraction addresses columns by their header meaning rather than their position, and keys utilities on their EIA number rather than their name, because every one of those inconsistencies silently produces wrong output if ignored.
Corrections
If you find an error, tell us and we will fix it on the page with a dated note rather than silently. That includes disagreements about method: the inputs are public and the arithmetic is stated, so the argument can be had on the evidence.
Update schedule
EIA publishes final Form EIA-861 data for a year in approximately October of the following year. This study is rebuilt against the new release and republished at the same URL, so links do not break and the accumulated citations stay attached to the current numbers.
Questions
What is the average size of a home solar system?
Why do sources disagree about average solar system size?
Which state has the biggest solar systems?
Why are California’s solar systems small?
Do states with more solar have bigger systems?
What size system do I need?
Is a bigger system always better?
Written and audited by
HyreSolar Research
Primary-source research, data analysis and fact checking
We are a research desk, not a sales floor. We read the statute, the tariff, the code section, the federal filing or the manufacturer data sheet ourselves, and we publish the figure with the document it came from and the date we retrieved it. Where a number cannot be traced to a primary source, we publish the shorter page and say what we could not verify. That rule has cost us whole sections, and it is the reason the rest can be trusted.
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How this desk works
- Primary sources only. Statutes from the legislature’s own publishing system, federal data from the agency that collects it, code text from the adopted edition, manufacturer claims from the data sheet. We do not cite an article that cites a source; we go and read the source.
- Every figure carries its provenance. A named document and the date we retrieved it, so you can check it and so you know how old it is. Retrieval dates are not decoration: an EIA rate from May is a different fact from an EIA rate from August.
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Data as of EIA-861 2024 final release. Authorship on this site is organisational: the analysis belongs to the desk rather than to a named individual, and we do not publish credentials we do not hold. Our editorial policy sets out how we source, date and correct what we publish.
Sources & retrieval dates
- US EIA, Form EIA-861 — Net Metering (annual files, 2014–2024) — Utility-level net-metered capacity, installations and energy sold back by state and customer sector, plus PV-paired battery capacity and installations from 2023. Downloaded as the published annual ZIP archives. Retrieved 2 September 2026.
- US EIA, Form EIA-861 — Sales to Ultimate Customers (annual files, 2014–2024) — Utility-level residential revenue, sales and customer counts by state, used to derive the average residential price and to count the households a state actually meters. Retrieved 2 September 2026.
- US EIA, Form EIA-861 — Distributed Generation that is not Net Metered (2024) — Residential photovoltaic capacity served under buyback, feed-in and utility-owned arrangements rather than net metering. Capacity only; this schedule collects no installation count. Retrieved 2 September 2026.
- US EIA, Average Price of Electricity to Ultimate Customers by End-Use Sector — EIA’s own published state price series, used only to validate our derivation. Agreement across all 357 overlapping state-years is within 0.005¢/kWh, i.e. EIA’s own rounding. Retrieved 2 September 2026.
- EnergySage marketplace data, 2026 — Average size of residential systems quoted through the marketplace (~12.0 kW), used here only as the contrasting new-quote population. Not used in any calculation on this page. Retrieved 6 August 2026.
What size system does your house need?
Fleet averages describe the past. Your consumption and roof decide the answer.
HyreSolar is an independent analysis and matching service. We are not an installer, lender or utility. When a reader asks to be introduced, installers may pay us a referral fee. That fee never buys ranking, scores or placement in research. Our editorial policy sets out the rules.