El Cajon, CA 92021 solar market data
Updated April 17, 2026 By The SolarDNA Data Team
El Cajon 92021 has 6,149 solar installations at a median installed cost of $4.26/W, installations down 19.8% over the trailing twelve months, and a Market Score of 43 — higher than 58% of U.S. zip markets.
Versus California
How 92021 compares with the state
Installed cost
$0.00/W below
state median $4.26/W
Market score
43 vs 53
California scores 53
Share of state installs
0.27%
of 2.3M tracked statewide
Battery attach
5.8%
state 12.7%
Statewide momentum
▲ 1.1%
residential solar added in California, 12 months through Jul 2026
Statewide market
2.3M systems
30.9% of homes · utility-reported through Jul 2026
Next-12-month outlook: 164–200 installs (midpoint 182)
Trailing-12-month installs carried forward at half the observed growth rate (capped at ±30%), with a ±10% band. Not a forecast of permits or policy.
Growth & pricing
92021 by year
202 installs in the trailing twelve months vs 252 before
Installations by year
Median installed cost, $/W DC by year
Installer comp set
Who installs in 92021
Ranked by systems recorded in this zip
| # | Installer | Installs | 12-mo | Avg kW | $/W |
|---|---|---|---|---|---|
| 1 | SUNRUN | 1,263 | 49 | 5.8 | $4.67 |
| 2 | TESLA | 353 | 8 | 7.1 | $5.12 |
| 3 | SEMPER SOLARIS | 329 | 0 | 6.54 | $4.09 |
| 4 | BAKER ELECTRIC SOLAR | 287 | 0 | 7.53 | $4.11 |
| 5 | BRIGHT PLANET SOLAR | 204 | 10 | 5.2 | $5.44 |
| 6 | SOLARTECH ENERGY SYSTEMS | 180 | 0 | 7.94 | $3.74 |
| 7 | SUNPOWER | 88 | 0 | 31.14 | $4.85 |
| 8 | SULLIVAN SOLAR POWER | 83 | 0 | 7.86 | $4.29 |
| 9 | STELLAR SOLAR | 81 | 6 | 13.41 | $4.05 |
| 10 | SUNGEVITY | 75 | 0 | 6.58 | $3.86 |
| 11 | JAMAR ELECTRIC SAN DIEGO | 73 | 0 | 5.22 | $3.21 |
| 12 | ASI HEATING AIR | 70 | 0 | 8.11 | $3.75 |
Neighboring zips
The nearest zip markets
By distance between zip centroids
| Zip | Distance | Installs | $/W | Score |
|---|---|---|---|---|
| 92040 Lakeside | 4.3 km | 6,414 | $4.15 | 48 |
| 92019 El Cajon | 4.5 km | 5,676 | $4.09 | 50 |
| 92020 El Cajon | 5.0 km | 5,062 | $4.17 | 54 |
| 92071 Santee | 6.9 km | 7,992 | $4.22 | 46 |
| 91942 La Mesa | 9.8 km | 3,308 | $4.27 | 46 |
| 92119 San Diego | 9.8 km | 3,511 | $4.19 | 46 |
Same city
Other zips in El Cajon
Equipment
What gets installed in 92021
Share of systems with a recorded brand
Modules
QCELLS NORTH AMERICA15.5%
LG ELECTRONICS13.2%
SUNPOWER12.0%
CSI SOLAR5.9%
YINGLI ENERGY CHINA5.2%
Inverters
ENPHASE ENERGY35.1%
SOLAREDGE33.3%
SMA AMERICA7.8%
SUNPOWER6.5%
ABB3.5%
Frequently asked
Quick answers about 92021
How many solar installations are there in 92021?
SolarDNA counts 6,149 active solar installations in El Cajon 92021, 6,068 of them residential, with data through April 17, 2026.
How much does solar cost in 92021?
The median residential system in 92021 cost $4.26 per watt over the trailing twelve months, $0.00/W below the California median.
Is solar growing in 92021?
Installations in 92021 are down 19.8%: 202 in the trailing twelve months versus 252 before.
Who installs solar in 92021?
SUNRUN, TESLA, SEMPER SOLARIS lead the 497 installers with systems in 92021. The full comp set is above.
Is 92021 a good market for solar sales?
92021 scores 43 out of 100 (Good, higher than 58% of U.S. zip markets).