Diesel (AGO) Generator Cost Calculator
See your true monthly and annual diesel spend — including fuel, delivery, and maintenance. Then compare what solar would cost instead.
Generator Details
Based on 0.22L/kWh diesel gen efficiency
Fuel & Delivery
Lagos average Sep 2026: ₦1,300/L
Maintenance Costs
Cost Breakdown
A diesel generator at ₦/kWh is among the most expensive electricity in the world. Solar costs ₦0/kWh after installation — and most systems pay back in 3–5 years.
AGO Pump Prices — Sep 2026 (Estimates)
| City | Price/L | Trend |
|---|---|---|
| Lagos | ₦1,280–₦1,350 | ↑ |
| Abuja (FCT) | ₦1,300–₦1,400 | ↑ |
| Port Harcourt | ₦1,200–₦1,280 | → |
| Ibadan | ₦1,280–₦1,350 | ↑ |
| Kano | ₦1,350–₦1,450 | ↑ |
| Enugu | ₦1,300–₦1,380 | → |
Indicative only. Prices vary by station and availability. Source: community reports Sep 2026.
Diesel vs Petrol Generators: Which Is Right for Your Situation?
Nigeria's generator market is split between petrol and diesel machines, and the choice between them has significant financial implications over the life of the equipment. Understanding the true economics of diesel (AGO) generators — not just the fuel price per litre, but efficiency, lifespan, maintenance cost, and total cost of ownership — is essential for any home or business making a long-term energy backup decision.
Fuel Energy Density and Efficiency
Diesel has a higher energy density than petrol: approximately 35.8 MJ/litre versus 34.2 MJ/litre for petrol. More importantly, diesel engines convert that energy to mechanical power more efficiently. A well-maintained diesel generator typically achieves 0.3 to 0.35 litres per kWh of electricity generated. A comparable petrol generator uses 0.4 to 0.5 litres per kWh. At the same fuel price per litre, diesel therefore delivers 20 to 40 percent more electricity for every naira spent on fuel.
Diesel generators become cost-competitive vs petrol above 5 KVA. Below that threshold, petrol generators have lower capital cost despite higher fuel consumption per kWh — making petrol the practical choice for small household backup units.
Upfront Cost vs Long-Term Economics
A diesel generator of equivalent power capacity costs 30 to 50 percent more than a petrol unit at the point of purchase. A 10 KVA petrol generator might cost ₦800,000 to ₦1,200,000, while a comparable diesel unit costs ₦1,200,000 to ₦1,800,000. For small residential users running the generator two to four hours per day, the fuel savings may not justify the higher upfront cost.
For commercial users, businesses, and households running generators six or more hours per day, the calculation changes dramatically. At 10 hours per day on a 10 KVA unit, the fuel cost difference between petrol and diesel easily reaches ₦80,000 to ₦150,000 per month. The capital cost premium pays back within six to eighteen months, and the diesel unit continues to save money for another decade or more.
Lifespan and Maintenance Advantages of Diesel
Diesel engines are fundamentally more durable than petrol engines for heavy-duty continuous operation. While a quality petrol generator might last 2,000 to 3,000 hours before requiring a major overhaul, a well-maintained diesel generator typically delivers 10,000 to 20,000 hours of service life. Diesel engines are compression-ignition and do not require spark plugs, distributors, or carburettors — reducing the frequency and cost of consumable parts replacement.
For a generator running 10 hours per day, 2,000 hours translates to roughly 200 days of operation — less than seven months. A diesel machine at 15,000 hours represents over four years of continuous daily operation. On a per-kWh basis over the machine's life, diesel maintenance costs are significantly lower than petrol.
When Petrol Still Makes Sense
Despite diesel's efficiency advantages, petrol generators remain the right choice in certain situations:
- Low usage (under 4 hours per day): The fuel savings do not offset the higher capital cost within a realistic ownership period
- Small loads (under 3.5 KVA): Diesel engines under 3 KVA are rare, expensive, and often noisy; petrol units dominate this segment
- Portability requirements: Petrol generators are lighter and more portable, which matters for construction sites or occasional rural use
- AGO availability concerns: In some areas of Nigeria, diesel delivery is inconsistent or requires bulk purchase; petrol is more universally available by the jerry can
The True Cost Calculation
This calculator uses 0.22 litres per kWh as the diesel consumption factor — a conservative figure for a well-sized diesel generator running at 70 to 80 percent load. Lightly loaded generators (running at 30 to 40 percent of rated capacity) consume proportionally more fuel per kWh due to engine inefficiency at low load. Always size your generator appropriately for your actual load, and consider a smaller unit for the NEPA-off period rather than running an oversized unit at low efficiency.
Delivery costs add up fast: Four deliveries per month at ₦2,000 each is ₦96,000 per year in delivery fees alone — money that could be eliminated by transitioning to solar-plus-battery. Factor delivery into your total cost calculation before comparing energy options.
Planning the Transition to Solar
The five-year cost figure in this calculator is often the most striking number for diesel generator users. A 10 KVA diesel generator running 10 hours per day commonly accumulates ₦6 million to ₦12 million in total five-year costs when fuel, delivery, maintenance, and oil changes are properly accounted for. A solar-plus-battery system capable of replacing that generation typically costs ₦3 million to ₦8 million and requires minimal ongoing expenditure for 20 to 25 years. Use the Solar ROI calculator to model your specific payback period and determine whether the transition makes financial sense for your situation.