Natural gas is the cheapest fuel to run a generator on a per-kWh basis — approximately $0.10–$0.25/kWh delivered. Propane is next at $0.20–$0.40/kWh. Diesel runs $0.25–$0.45/kWh. Gasoline is the most expensive at $0.30–$0.60/kWh. Namun, the total cost of ownership depends on generator purchase price, maintenance intervals, engine life at that fuel, and how many hours per year you actually run.
Cost per kWh: The Full Formula
To calculate cost per kWh for any fuel, use this formula:
Cost per kWh = (konsumsi bahan bakar in gal/hr × Fuel price per gal) / (Generator output in kW × Load factor %)
For a 10kW generator at 50% memuat (5kW output):
- Bensin: (0.55 gal/hr × $3.25/gal) / 5kW = $0.358/kWh
- propana: (1.25 gal/hr × $2.50/gal) / 5kW = $0.625/kWh (note: propane burns more BTU/hr — 1 gal propane ≈ 0.7 gal gasoline equivalent, so consumption in gallons is higher)
- Gas Alam: (135 cu ft/hr × $0.01/cu ft) / 5kW = $0.27/kWh (at $1.00/therm; 1 therm = 100 cu ft)
- solar: (0.40 gal/hr × $3.75/gal) / 5kW = $0.30/kWh
But Wait — Correcting the Propane Paradox
Propane appears more expensive than diesel in the calculation above. That’s because propane has lower energy density (91,500 BTU/gal vs. diesel’s 138,000 BTU/gal), so you burn more volume for the same output. Namun, propana Generator typically cost less to maintain, run cleaner, and have longer engine life than gasoline. And in many regions, bulk propane prices are significantly lower than the national average. Always use your local fuel prices.
10-Year Total Cost of Ownership by Generator Type
| Cost Factor | Gasoline 7kW Portable | Propane 7kW Portable | Natural Gas 14kW Standby | Diesel 14kW Portable |
|---|---|---|---|---|
| Generator purchase | $800 | $1,000 | $3,500 | $4,500 |
| Instalasi (standby only) | $0 | $0 | $2,500 | $0 |
| Biaya bahan bakar (50 hrs/yr at 50% memuat) | $895 | $780 | $365 | $585 |
| Maintenance parts (minyak, filter, plugs) | $400 | $300 | $750 | $600 |
| Perombakan mesin (~2,000 hrs) | $0 (replaced before overhaul) | $0 | $0 | $1,200 (diesel lasts longer, minor rebuild) |
| 10-year total | $2,095 | $2,080 | $7,115 | $6,885 |
| Cost per hour run | $4.19/hr | $4.16/hr | $14.23/hr | $13.77/hr |
Catatan: Standby generators include installation costs that portable generators don’t. Diesel’s total is higher because of the initial purchase price premium, but operating cost is lower per hour. For heavy use (500+ hrs/yr), diesel becomes significantly cheaper.
When High Fuel Cost Is Worth It
Fuel cost is not the only factor. Gasoline generators cost the least upfront ($300–$800 for 5,000W) and are the easiest to find. If you run your generator only 10–20 hours per year during brief outages, the fuel cost difference between gasoline and natural gas is $5–$20 per year — negligible compared to the $3,000+ savings on initial purchase and installation.
Sebaliknya, if you run a generator 500+ jam per tahun (komersial, pertanian, or frequent-outage area), the fuel cost difference becomes substantial. A natural Pembangkit Gas berlari 500 jam di 50% load saves approximately $450/year in fuel vs. gasoline — and this covers the higher installation cost within a few years.
For high-hour applications where diesel fuel efficiency and long engine life drive total cost of ownership, Generator diesel Huaquan Power deliver the lowest cost per hour at high utilization rates.
Pertanyaan yang Sering Diajukan
Is natural gas always cheaper than diesel?
On a per-BTU basis, natural gas is typically 30-50% cheaper than diesel fuel. Namun, natural gas generators have a higher purchase price (20-30% more than equivalent diesel units) and require a permanent gas line connection. When factoring in the higher equipment cost, natural gas breaks even with diesel at approximately 1,500-2,000 jam operasional. Below that threshold, diesel’s lower equipment cost makes it more economical despite higher fuel prices.
What is the cost per kWh for each fuel type?
Berdasarkan 2026 fuel prices: Gas alam: $0.08-0.15/kWh. propana: $0.15-0.30/kWh. solar: $0.20-0.35/kWh. Bensin: $0.25-0.50/kWh. Natural gas is consistently the cheapest fuel per kWh delivered, but the gap narrows when equipment costs and installation are included in the total cost of ownership.
Which fuel has the best energy density?
Diesel has the highest energy density of all common generator fuels at approximately 45.5 MJ/kg. Gasoline follows at 44.4 MJ/kg, propane at 46.4 MJ/kg (but lower volumetric density), and natural gas at 38.7 MJ/m3. Higher energy density means less fuel storage space is needed for the same runtime. Diesel requires approximately 40% less storage volume than propane for the same energy output.
What is the cheapest fuel for a standby generator running 100 jam per tahun?
For low-hour standby applications (di bawah 200 jam/tahun), the equipment purchase price dominates the total cost equation. A gasoline Generator Portabel biaya $500-1,500, while a natural gas standby unit costs $3,000-8,000 installed. Pada 100 hours/year of operation, gasoline is the cheapest option despite having the highest per-kWh fuel cost, because the equipment investment is so much lower.
How does fuel availability affect the cost decision?
Diesel is available at virtually every fuel station in the world and can be stored on-site for months without degradation. Natural gas is delivered by pipeline and stops flowing when the grid fails (though many gas utilities have backup generators for their pumps). Propane has excellent shelf life (indefinite in sealed tanks) but requires delivery. Gasoline degrades in 3-6 months and is the least practical for long-term storage. Itu “cheapest” fuel is useless if it isn’t available when you need it.
What is the 10-year total cost of ownership comparison?
For a 20kW generator running 500 jam/tahun: Gas alam: $22,000-28,000 (peralatan $8,000 + instalasi $3,000 + bahan bakar $7,000 + pemeliharaan $4,000-10,000). solar: $24,000-30,000 (peralatan $6,000 + instalasi $2,000 + bahan bakar $10,000 + pemeliharaan $6,000-12,000). propana: $26,000-34,000 (peralatan $7,000 + instalasi $2,500 + bahan bakar $10,000 + pemeliharaan $6,500-14,500). Bensin: $20,000-26,000 (peralatan $1,500 + instalasi $500 + bahan bakar $12,000 + pemeliharaan $6,000-12,000). Natural gas has the lowest 10-year total cost when a gas line is available.
Does the generator fuel cost vary by region?
Ya, significantly. Di Amerika Serikat, natural gas costs $0.08-0.12/kWh in gas-producing states (Texas, Oklahoma, Pennsylvania) versus $0.15-0.25/kWh in New England. Diesel costs $0.20-0.25/kWh in the Gulf Coast versus $0.30-0.40/kWh in California and the Northeast. In Europe, diesel is $0.35-0.55/kWh and natural gas $0.12-0.20/kWh. Always calculate based on your local fuel prices, not national averages.
Which fuel type requires the most maintenance?
Diesel generators require the most comprehensive maintenance: oil changes every 250-500 jam, fuel filter changes every 500 jam, injector service every 2,000 jam, and fuel polishing for stored diesel. Natural gas generators have simpler maintenance (no fuel degradation, clean combustion, longer oil life) with intervals typically 50-100% longer than diesel. This partially offsets natural gas’s higher equipment cost.
Can I switch fuel types later?
Dual-fuel and tri-fuel generators can switch between gasoline, propana, and natural gas with a simple valve change or carburetor kit. Dedicated diesel generators cannot be converted to gas without a complete engine replacement. If fuel price uncertainty is a concern, choose a propane/gasoline dual-fuel generator for maximum flexibility.
What is the most cost-effective fuel for off-grid living?
For off-grid systems running 4,000-8,000 jam/tahun, a hybrid approach is most cost-effective: solar panels for daytime loads, battery storage for nighttime, and a diesel generator for backup. Diesel is the preferred backup fuel because it can be stored in bulk (500-2,000 gallon tanks) dengan a 12-24 month shelf life when properly treated, and diesel engines have the longest service life (20,000-30,000 hours before major overhaul).
