Trenching vs Overhead Wire Runs (2026)

What's actually in the trench

A typical ground-mount-to-house trench runs:

• 2–4 inch conduit — usually Schedule 40 PVC for direct-bury, or rigid metal conduit (RMC) where required by AHJ
• 3+ wires: two phase conductors + ground (residential) or three phase + ground (large commercial)
• Optional: monitoring conduit — data cable for inverter communication if not using cellular/WiFi
• Underground warning tape — required ~12 inches above conduit by NEC 300.5
• Concrete encasement in some jurisdictions for shallower runs

Trench depth requirements (NEC 300.5)

Why ground-mount trenches are so expensive

1. Excavation labor. 100–200 feet of trench at 18–24" depth is 5–15 cubic yards of dirt. At $80–$150/hour for a mini-excavator + operator, plus hand-finishing around obstacles, plus tree-root navigation — easily $1,500–$4,000 in excavation alone.
2. Conduit + wire. 200 feet of 2" PVC + #1/0 AL or #4 CU conductors + ground = $400–$1,200 in materials.
3. Concrete encasement if AHJ requires it (~$300–$800).
4. Restoration. Re-grading, re-seeding, replacing landscape rocks, fixing irrigation lines — $500–$2,000.
5. Permit and inspection. Electrical underground inspection (open trench), then re-inspection after fill.
6. Voltage drop sizing. Long runs require larger conductors to keep voltage drop under 2%. A 200-foot run at 30A often needs #1/0 wire vs #4 for short runs — conductor cost roughly doubles.

Total: a 100-foot trench typically runs $3,500–$8,000 added to system cost. 200 feet runs $6,000–$15,000. For long-distance runs (500+ feet from a barn / shed solar to the main house), trenching can easily exceed $20,000.

Overhead alternative

For longer distances, overhead wire on poles or strung between fixed structures (existing poles, barn-to-house) can be 30–60% cheaper. Pros and cons:

Overhead is most common for rural ground-mount systems (barns, sheds, free-standing arrays where the path between the array and the house is long and trees aren't blocking).

Aerial messenger cable (in between)

A middle option: aerial messenger cable strung on existing utility-grade poles. Used commonly by farmers running solar from a remote barn to the meter. Roughly 50–70% the cost of trenching. Requires AHJ approval and proper pole anchoring.

Cost-saving tips

• Trench during other excavation. If you're already digging for landscape, irrigation, or septic work, adding a solar conduit run is incremental cost — not a separate $5,000 project.
• Run extra conduit. While the trench is open, run a 1” spare conduit alongside. Cheap insurance for a future EV charger run, monitoring upgrade, irrigation control wiring.
• Use directional boring for crossing under driveways without tearing them up — expensive per foot but cheaper than driveway replacement.
• Right-size the conductor. Don't oversize "just in case" if voltage drop math allows the smaller wire.
• Let the homeowner DIY backfill if they have time — saves $500–$1,500 on labor (after the inspector signs off the open trench).

Frequently asked questions