Solar vs. Grid-Tied Lighting

The following analysis is based on actual project figures from a 40-light commercial parking lot installation in Southern California, modeled against a grid-tied LED alternative of the same scope. Every number below is real — drawn from actual equipment costs, the official SCE TOU-GS-1 tariff effective January 2026, federal tax benefit calculations (C-Corp taxpayer assumed), and documented maintenance schedules. This is not a hypothetical comparison. It is a real project, a real decision, and real money.

The Scenario

A commercial facility in Southern California — a high-traffic distribution and logistics operation — needed to light its parking lot for security, safety, and operational purposes. Dusk-to-dawn operation was required. The evaluation came down to two options: solar-powered units with portable bases, or a conventional grid-tied LED system requiring trenched underground conduit connecting back to SCE.

The financial model was built from three inputs: actual installed equipment costs, the official Southern California Edison Schedule TOU-GS-1 Option E tariff (effective January 1, 2026, at $0.31/kWh for off-peak commercial service), and real federal tax benefit calculations. Electricity escalation was modeled at 10% annually. SCE raised commercial rates 12.9% in a single month — October 2025 — alone, so 10%/yr is a conservative, defensible assumption.

Source: SCE Schedule TOU-GS-1 Option E, effective Jan 1, 2026 (Advice 5725-E, Resolution E-5217). Tax benefits assume C-Corp taxpayer; consult your tax advisor for actual eligibility.

Cost & Feature Comparison

Cumulative Cost, After Tax, By Year

Solar starts higher — $195,000 upfront versus $122,000 for grid-tied. But after the federal Investment Tax Credit (30% ≈ $58,500) and first-year bonus depreciation (≈ $35,000), the effective net cost of solar at the end of Year 1 is approximately $102,000. Grid-tied, after its own $26,000 in depreciation benefits, nets to ≈ $96,000 — a gap of only $6,000. From Year 2 onward, solar costs nothing to run while the grid-tied system accumulates an electricity bill that grows every year.

Note: Year 5 solar cost reflects the battery replacement — 40 units × $470 each = $18,800. This is the only known future cost for solar, already fully priced into the 10-year total. The second battery cycle would fall around Year 10–11.

Why Solar Crosses Below Grid-Tied So Quickly

The reason is the Year 1 federal tax benefit stack. For a C-Corp — the typical structure for a commercial property owner or facility manager — two benefits apply simultaneously:

• ITC 30% Investment Tax Credit (IRA Section 48E): a dollar-for-dollar credit against federal tax liability. On a $195,000 system, this represents approximately $58,500 in Year 1 federal tax savings.
• Bonus Depreciation / MACRS: under current IRS rules, commercial solar property qualifies for accelerated cost recovery. The first-year depreciation benefit on this project is approximately $35,000 in tax savings.

Total Year 1 tax benefit: ≈ $93,000, applied against a $195,000 gross investment, bringing the effective net cost to ≈ $102,000. Grid-tied equipment also qualifies for depreciation, producing approximately $26,000 in Year 1 tax benefit and reducing its net cost to ≈ $96,000. From that point forward, solar accrues no electricity bill, while grid-tied runs at an average of approximately $13,000/year, escalating annually.

Disclaimer: tax benefit calculations assume C-corporation taxpayer and 2025–2026 IRS rules. Consult a qualified tax professional for your specific situation. This content is informational, not tax advice.

Electricity Cost Over 10 Years

The grid-tied model uses 40 fixtures at an average draw of approximately 164 watts each, operating 12 hours per night — approximately 26,280 kWh per year. At the SCE TOU-GS-1 Option E off-peak rate of $0.31/kWh effective January 2026, Year 1 electricity cost is approximately $8,147.

The 10% annual escalation used here is conservative: SCE raised commercial rates 12.9% in October 2025 alone, and SCE commercial rates have risen approximately 83% cumulatively over the past decade — a compound rate well above 10%/yr. The case for solar only strengthens as you increase the escalation assumption.

The Hidden Cost of “Just Connect to the Grid”

A common objection to solar is the higher upfront number: $195,000 versus $122,000. But this comparison is frequently incomplete — the $122,000 grid-tied figure assumes the property already has utility infrastructure readily available at the lot. For new construction, expanded lots, or facilities without existing outdoor electrical service, additional costs apply:

• Trenching: this project required approximately 1,800 linear feet of underground conduit — a major line item not included in the $122K equipment and fixture cost.
• Permits: grid-tied outdoor lighting in California requires a trenching permit and an SCE interconnection application, adding weeks to months to the deployment schedule.
• SCE interconnection: a new dedicated circuit requires SCE coordination — service upgrade fees, metering charges, and ongoing monthly customer charges can apply.
• Underground fault exposure: once conduit is in the ground, any future fault — ground movement, water intrusion, rodent damage, or copper theft — requires excavation to diagnose and repair.

Solar’s installation, by contrast, involves surface-mounted poles on portable bases — no digging, no permits for utility connection, no SCE coordination, and deployment measured in days rather than weeks.

Copper Theft Exposure

The 10-year financial model above does not include the cost of copper wire theft incidents, because solar eliminates that risk category entirely for this facility. For a grid-tied installation in Southern California, the exposure is real and documented:

• The Los Angeles Bureau of Street Lighting recorded 9,597 copper wire theft incidents in FY2022–23, up from 1,447 in FY2016–17 — a more than six-fold increase in six years (LA CAO Report, March 2025).
• Average response time for copper wire theft incidents in the LA street lighting system reached 110 days in FY2023–24, up from 12 days in FY2016–17 (Matrix Consulting Group / CAO Report).
• AT&T’s California operations alone suffered 7,300+ copper theft incidents in 2025, costing $54 million — for a single telecommunications provider, in a single state, in a single year (AT&T, 2026).

Source: CAO Independent Financial Analysis of the Revenue Requirements of the City Street Lighting System, March 14, 2025 (Matrix Consulting Group / City of Los Angeles).

Flexibility & Sustainability

The solar units in this project use portable bases — no concrete foundations, no permanent commitment to the current lot layout. If the property owner expands, reconfigures, or changes the lot, the lights relocate. Grid-tied conduit is permanent: every future layout change means excavation.

For commercial tenants or owner-operators with sustainability reporting obligations — including net-zero and Scope 2 emission reduction commitments — this installation eliminates approximately 26,280 kWh per year of grid electricity consumption, equivalent to removing approximately 3.7 passenger vehicles from the road annually, supporting ESG and RE100 procurement requirements.

10-Year Summary