Walnut, CA 91788 solar market data
Updated March 25, 2026Provisional score · under 500 installs By The SolarDNA Data Team
Walnut 91788 has 32 solar installations at a median installed cost of $3.16/W, recent growth not yet measurable, and a Market Score of 44 — higher than 62% of U.S. zip markets.
Versus California
How 91788 compares with the state
Installed cost
$1.10/W below
state median $4.26/W
Market score
44 vs 53
California scores 53
Share of state installs
0.00%
of 2.3M tracked statewide
Battery attach
0.0%
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
Growth & pricing
91788 by year
25 installs in the trailing twelve months vs 6 before
Installations by year
Median installed cost, $/W DC by year
Installer comp set
Who installs in 91788
Ranked by systems recorded in this zip
| # | Installer | Installs | 12-mo | Avg kW | $/W |
|---|---|---|---|---|---|
| 1 | SUNRUN | 30 | 24 | 3.23 | $3.16 |
| 2 | SUNPOWER | 1 | 1 | 3.24 | — |
| 3 | SOLARTEC SYSTEMS | 1 | 0 | 2.88 | $6.09 |
Neighboring zips
The nearest zip markets
By distance between zip centroids
| Zip | Distance | Installs | $/W | Score |
|---|---|---|---|---|
| 91789 Walnut | 1.0 km | 2,853 | $4.18 | 49 |
| 91792 West Covina | 3.0 km | 853 | $4.51 | 42 |
| 91748 Rowland Heights | 5.2 km | 1,783 | $4.35 | 45 |
| 91765 Diamond Bar | 5.3 km | 2,593 | $4.08 | 61 |
| 91791 West Covina | 5.8 km | 1,975 | $4.22 | 46 |
| 91744 La Puente | 6.7 km | 2,074 | $4.51 | 39 |
Same city
Other zips in Walnut
Equipment
What gets installed in 91788
Share of systems with a recorded brand
Modules
QCELLS NORTH AMERICA96.9%
ECOSOLARGY3.1%
Inverters
ENPHASE ENERGY96.9%
SMA AMERICA3.1%
Frequently asked
Quick answers about 91788
How many solar installations are there in 91788?
SolarDNA counts 32 active solar installations in Walnut 91788, 32 of them residential, with data through March 25, 2026.
How much does solar cost in 91788?
The median residential system in 91788 cost $3.16 per watt over the trailing twelve months, $1.10/W below the California median.
Is solar growing in 91788?
Recent growth cannot be measured yet for 91788: too few recent installs (data runs through March 25, 2026).
Who installs solar in 91788?
SUNRUN, SUNPOWER, SOLARTEC SYSTEMS lead the 3 installers with systems in 91788. The full comp set is above.
Is 91788 a good market for solar sales?
91788 scores 44 out of 100 (Good, higher than 62% of U.S. zip markets). With under 500 installations the score is provisional.