Why Commercial Solar Outperforms Residential on ROI
The fundamental advantage of commercial solar is consumption alignment. Residential households use most of their electricity in the evening — lights, cooking, entertainment — when solar generation has stopped. A purely grid-tied residential system therefore captures only a portion of potential savings through self-consumption. Hotels, offices, and most businesses, by contrast, run their heaviest loads during daytime: air conditioning, commercial refrigeration, kitchen equipment, and lighting. This means a well-designed commercial system can achieve 70-80% self-consumption rates versus 50-60% for residential, dramatically improving payback economics.
In Antigua's commercial context, the APUA rate of EC$0.45/kWh applies to commercial customers with additional demand charges based on peak kW drawn — charges that can add EC$0.05-0.10/kWh effective cost to the bill for larger consumers. Solar reduces both the consumption charge and, by smoothing out midday peaks, can reduce the demand charge component. This dual benefit makes the effective avoided cost of solar generation closer to EC$0.52-0.58/kWh for commercial customers, versus EC$0.45 for residential.
The 50kW Hotel System Case Study
Consider a mid-sized Antiguan hotel — say 40 rooms with central air conditioning, a pool, kitchen, and laundry — consuming roughly 62,000 kWh per year at an annual electricity cost of approximately XCD 27,900. A 50kW rooftop system installed on the hotel's flat concrete roof would generate approximately 70,080 kWh annually (50 × 4.8 × 365 × 0.80), exceeding total consumption. In practice, the system would be sized to maximize self-consumption without major export, landing at approximately 50kW for this load profile.
At current installed costs for commercial systems — approximately XCD 3,600 per kW installed, reflecting economies of scale over residential — a 50kW system costs XCD 180,000. With annual savings of approximately XCD 28,000 (accounting for the demand charge benefit), the simple payback is 6.4 years. Over 25 years, the net present value of savings at a 7% discount rate is approximately XCD 185,000 — meaning the investment more than doubles its money in present-value terms. Hotels that have made this transition report that the saving shows immediately on monthly operating statements and meaningfully improves property-level EBITDA.
Government Buildings: The Missed Opportunity
The single largest untapped commercial solar opportunity in Antigua may be government infrastructure. The Ministry of Works complex, hospital facilities, schools, and the V.C. Bird International Airport collectively represent an enormous daytime electricity load, all on buildings that are publicly owned, have ample roof area, and could benefit from reduced utility expenditure. The government currently spends an estimated XCD 8-12 million annually on electricity across its building portfolio — a figure that solar could cut by 40-50% over a 20-year horizon.
Several Caribbean governments have moved aggressively on public building solar: Barbados installed solar on its parliament building, schools, and health centers beginning in 2019. Dominica included public building solar in its post-Hurricane Maria reconstruction plan. Antigua has had feasibility studies commissioned but not yet acted at scale. The procurement challenge is real — government capital projects require tender processes and budget appropriations that slow deployment — but the economics are so strong that delayed action represents a genuine fiscal cost to the treasury.