Where A1 Sun Ranks
Position among installers of home solar in each city, by installations in the most recent three years of records, and how A1 Sun compares with the local market there.
Its strongest market is Berkeley, where it accounts for 9% of the home systems with a known installer.
| City | Rank | Installations | Local share | Price vs. local median | Leased (city average) |
|---|---|---|---|---|---|
| Berkeley, California | #1 | 149 | 9% | 15% higher | 0% (6%) |
| Oakland, California | #9 | 70 | 2% | 9% higher | 0% (17%) |
What A1 Sun Installs
- Typical system size
- 5.3 kW
- Leased or on a PPA
- 0%
- Installed with a battery
- 45%
Mostly sells systems the homeowner owns, paid in cash or with a loan.
Panel brands
- Hanwha Q CELLS (36%)
- Silfab Solar (33%)
- Panasonic (6%)
Inverter brands
- Enphase Energy (98%)
- Enphase Energy (2%)
A1 Sun Prices Compared With the State
Median price per watt of systems the homeowner bought outright, before incentives.
| State | A1 Sun | State median | Difference |
|---|---|---|---|
| California (2023–2025) | $5.45/W | $4.25/W | 28% higher |
Home Installations per Year
Records for the most recent year can be incomplete while utilities finish reporting.
Where A1 Sun Installs Most
| City | Installations (2023–2025) |
|---|---|
| Berkeley, CA | 149 |
| Oakland, CA | 70 |
| Albany, CA | 24 |
| El Cerrito, CA | 19 |
| Piedmont, CA | 13 |
| Richmond, CA | 13 |
| Kensington, CA | 9 |
| San Leandro, CA | 5 |
| Orinda, CA | 2 |
| Alamo, CA | 1 |
| Concord, CA | 1 |
| Corte Madera, CA | 1 |
| Danville, CA | 1 |
| El Sobrante, CA | 1 |
| Emeryville, CA | 1 |
Specialist Rankings
Where A1 Sun ranks among the companies that install the most systems with a battery or with a given inverter brand.
- Solar Battery Installers in Berkeley, CA: #1 (66 systems)
- Enphase Installers in Oakland, CA: #4 (56 systems)
Other Top Installers in Berkeley
The companies ranked next to A1 Sun in Berkeley, by home installations in 2023–2025.
| Company | Installations | Median price | Leased / PPA |
|---|---|---|---|
| Sunrun | 115 | $4.29/W | 70% |
| Sunlight Power | 77 | $6.56/W | 0% |
| Solar Technologies | 76 | $4.95/W | 0% |
| Tesla | 61 | $4.97/W | 0% |
| Save A Lot Solar | 44 | $4.20/W | 0% |
| Got Watts Electric | 40 | $4.82/W | 0% |
A1 Sun: Common Questions
Is A1 Sun still in business?
A1 Sun was still installing home solar in 2025, the latest year in the public records we use, and it is not on our list of installers that closed or went bankrupt. Records lag a year or two, so confirm before you sign: its California license (CSLB #891743) shows whether it is active, and recent Google reviews show whether it is still answering customers.
Does A1 Sun lease solar panels or sell them?
0% of its home systems in 2023–2025 were leased or on a power purchase agreement, and 100% were bought by the homeowner. Mostly sells systems the homeowner owns, paid in cash or with a loan.
What solar panels and inverters does A1 Sun install?
Panels: Hanwha Q CELLS (36%), Silfab Solar (33%) and Panasonic (6%). Inverters: Enphase Energy (98%) and Enphase Energy (2%). Shares of its home systems in 2023–2025 with a known brand.
How much does A1 Sun charge for solar?
In California (2023–2025), homeowners who bought a system from A1 Sun paid a median of $5.45/W before incentives — 28% higher than the state median of $4.25/W. For its typical 5.3 kW system, that is about $28,500. By city: 15% higher than the Berkeley median; 9% higher than the Oakland median.
Does A1 Sun install solar batteries?
45% of its home systems in 2023–2025 included a battery. It ranks among the top battery installers in Berkeley, CA.
Where does A1 Sun install solar?
Most of its recent work is in Berkeley (149), Oakland (70), Albany (24), El Cerrito (19) and Piedmont (13). It is ranked in 2 cities in California.
Before You Sign With A1 Sun
- California license: CSLB #891743 (B, C-46), issued 02/28/2007, registered to A1 SUN INC in Berkeley. It appears in the state's list of active licenses. Check its current status on the CSLB site.
- Reviews and contact details: call (510) 526-5715 (the number on its license) or see A1 Sun on Google Maps, where recent reviews tell you more than any ranking.
- Quotes: get at least three, and compare price per watt, equipment brands and the workmanship warranty — not just the monthly payment.
Compare A1 Sun with other installers
The Berkeley ranking puts A1 Sun next to the other companies that install the most there, with each one's price and leasing share.
Top solar installers in Berkeley →Where These Numbers Come From
Source: Tracking the Sun, Lawrence Berkeley National Laboratory (2026 edition), licensed CC BY 4.0. In New York and New Jersey, recent years come from the state programs' own records (NYSERDA and New Jersey's Clean Energy Program). Company names were standardized and closures checked against news reports by Solar Power Fix. More about our methodology.