303 solar installers ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in Castro Valley: Smart Solar Panel Cleaning Bay Area, CR Score 94/100; 5.0★ from 418 Google reviews; open 24/7.
Best for emergencies (open 24/7): East Bay Solar Cleaning LLC, posts 24/7 hours; ranked #2 of 303.
Most-reviewed: SunPower®, 1,576 Google reviews at 4.5★, the most of 303 ranked; ranked #6.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
303 Castro Valley solar installers are ranked here by CR Score, from 8 published factors. 35 are open 24/7, 153 open Saturdays and 83 open Sundays, based on posted hours. The median Google rating is 4.9★ across 303 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | Smart Solar Panel Cleaning Bay Area | 94 | 5.0★ (418) | Hayward, 4 mi away | 24/7 | Overall |
| 2 | East Bay Solar Cleaning LLC | 89 | 5.0★ (104) | Lafayette, 13 mi away | 24/7 | Emergencies |
| 3 | EnergyAid | 89 | 4.8★ (842) | Fremont, 14 mi away | 24/7 | — |
| 4 | Semper Solaris | 87 | 4.6★ (480) | Hayward, 6 mi away | Sat · Sun · Evenings | — |
| 5 | Solar Pro Energy Systems | 87 | 4.7★ (55) | Redwood Shores, 8 mi away | 24/7 | — |
| 6 | SunPower® | 86 | 4.5★ (1,576) | Richmond, 21 mi away | Sat · Sun · Evenings | Most reviews |
| 7 | Besty Solar Inc. | 85 | 5.0★ (63) | Fremont, 11 mi away | — | — |
| 8 | TN Electrical and Solar Services | 84 | 5.0★ (107) | San Jose, 24 mi away | Sat · Sun | — |
| 9 | SolarSesame | 84 | 4.9★ (126) | Hayward, 5 mi away | Sat | — |
| 10 | Source Energy | 83 | 5.0★ (51) | Walnut Creek, 15 mi away | Sat · Sun | — |
Ordered by CR Score, a 0–100 score from 8 published factors. Paid placement never changes the order.
Ranked #1 because of its Google rating and availability: 5.0★ from 418 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Lafayette, 13 mi away
Ranked #2 because of its Google rating and availability: 5.0★ from 104 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Fremont, 14 mi away
Ranked #3 because of its Google rating and trade focus: 4.8★ from 842 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Hayward, 6 mi away
Ranked #4 because of its Google rating and trade focus: 4.6★ from 480 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Redwood Shores, 8 mi away
Ranked #5 because of its Google rating and availability: 4.7★ from 55 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Richmond, 21 mi away
Ranked #6 because of its Google rating and review volume: 4.5★ from 1,576 Google reviews, the most Google reviews on this list (1,576).
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Fremont, 11 mi away
Ranked #7 because of its Google rating and trade focus: 5.0★ from 63 Google reviews, listed on Google as “Solar energy company”.
Based on 5 of 8 factors; credentials, recency and availability not yet collected.
Based in San Jose, 24 mi away
Ranked #8 because of its Google rating and trade focus: 5.0★ from 107 Google reviews, listed on Google as “Solar energy system service”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Hayward, 5 mi away
Ranked #9 because of its Google rating and trade focus: 4.9★ from 126 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Walnut Creek, 15 mi away
Ranked #10 because of its Google rating and trade focus: 5.0★ from 51 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Dublin, 8 mi away
Ranked #11 because of its Google rating and trade focus: 5.0★ from 128 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Antioch, 37 mi away
Ranked #12 because of its Google rating and trade focus: 4.9★ from 268 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Fremont, 18 mi away
Ranked #13 because of its Google rating and trade focus: 5.0★ from 54 Google reviews, listed on Google as “Solar energy system service”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in San Anselmo, 32 mi away
Ranked #14 because of its Google rating and availability: 4.9★ from 762 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Danville, 12 mi away
Ranked #15 because of its Google rating and availability: 5.0★ from 44 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Livermore, 17 mi away
Ranked #16 because of its Google rating and trade focus: 4.5★ from 172 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Campbell, 30 mi away
Ranked #17 because of its Google rating and availability: 5.0★ from 28 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in San Ramon, 9 mi away
Ranked #18 because of its Google rating and availability: 4.9★ from 111 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Concord, 21 mi away
Ranked #19 because of its Google rating and trade focus: 4.6★ from 135 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Milpitas, 20 mi away
Ranked #20 because of its Google rating and trade focus: 4.4★ from 281 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Dublin, 9 mi away
Ranked #21 because of its Google rating and availability: 5.0★ from 80 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Berkeley, 17 mi away
Ranked #22 because of its Google rating and trade focus: 4.9★ from 45 Google reviews, listed on Google as “Solar energy system service”.
Based on 5 of 8 factors; credentials, recency and availability not yet collected.
Based in San Jose, 25 mi away
Ranked #23 because of its Google rating and availability: 5.0★ from 11 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in San Francisco, 19 mi away
Ranked #24 because of its Google rating and trade focus: 5.0★ from 38 Google reviews, listed on Google as “Solar energy company”.
Based on 6 of 8 factors; credentials and recency not yet collected.
Based in Benicia, 32 mi away
Ranked #25 because of its Google rating and availability: 5.0★ from 14 Google reviews, open 24/7.
Based on 6 of 8 factors; credentials and recency not yet collected.
#1 to #25 are shown in full above. Here are #26 to #50, in CR Score order; each links to its profile. We publish the top 50 of 303 ranked solar installers here; the rest are on their profiles.
20 more solar installers within 40 mi that we can't rank yet: too few reviews, or a trade we couldn't confirm. Listed A to Z.
| Business | Google rating | Distance |
|---|---|---|
| Borrego (Oakland) | 4.0★ (2) | 13 mi |
| Castle Electrical Services | 5.0★ (2) | 13 mi |
| Contra Costa Sun | 5.0★ (2) | 15 mi |
| Eagle Shield | 3.0★ (2) | 8 mi |
| Estrada Exterior Cleaning Corp | 5.0★ (2) | In Castro Valley |
| GHESolar Company Fremont | 5.0★ (2) | 12 mi |
| Good Guy Electric and Solar Inc | 5.0★ (1) | In Castro Valley |
| Optivolt | 5.0★ (2) | 18 mi |
| Phils Electric Company | 5.0★ (2) | 15 mi |
| Solar Sense PV, Inc. | 1.0★ (2) | 9 mi |
| SolarPanal EranNSave Danville | 5.0★ (2) | 12 mi |
| Spartan Home Services | 5.0★ (2) | 10 mi |
| Sunvalley Solar | In Castro Valley | |
| Synergy Power | 5.0★ (1) | In Castro Valley |
| Total Home Solar | In Castro Valley | |
| Triad Power Solutions | 5.0★ (2) | 8 mi |
| TwineSpot | In Castro Valley | |
| Universe Solar Panel Oakland | 3.0★ (2) | 9 mi |
| Vonnegut Electric & Solar | 5.0★ (2) | 4 mi |
| West Coast Solar & Water Heater Repair | 5.0★ (2) | 7 mi |
Typical prices in USD, adjusted for California with a published regional index. Each row names its basis and month.
| Job | Low | Typical | High | Basis | Checked |
|---|---|---|---|---|---|
| Solar panel installation | $29,770 | $33,680 | $36,640 | Per system: about 12 kW at about $2.60 per watt, before incentives. US national range × 1.08 Pacific factor (2025 Cost vs. Value Report) | October 2026 |
We scored 303 Castro Valley solar installers on 8 factors, weighted as shown. A business is ranked when its trade is confirmed and it has 3 or more Google reviews or a claimed profile. Unknown factors are left out of the score, not counted as zero. Scores last refreshed October 22, 2026.
Paid placement never changes a rank or score. Featured businesses are paid, labelled, limited to 3 and shown above the ranking, outside it.
| Factor | Weight | Computed from | In Castro Valley data |
|---|---|---|---|
| Reputation | 35% | Bayesian-adjusted Google star rating | Measured |
| Credentials | 15% | Active state license 0.6, bond 0.2, workers’ comp 0.2 | Not yet collected |
| Review volume | 10% | log10(reviews + 1) against the list maximum | Measured |
| Recency | 10% | Share of reviews from the last 12 months | Not yet collected |
| Availability | 10% | Weekly open hours, Saturday, Sunday, 24/7 or same-day | Measured |
| Trade focus | 10% | Google main category 1.0, business name 0.7, additional category 0.5 | Measured |
| Proximity | 5% | 1.0 when based in the city, falling to 0 at the trade’s radius | Measured |
| Completeness | 5% | Website, photos, description, hours, claimed profile (0.2 each) | Measured |