Electric vs Wood-Fired Steam Boiler: Cost Comparison for a 500 kg/hr Plant in Nepal
At quoted prices, a 500 kg/hr wood-fired steam boiler costs far less to buy and run than an electric one, saving NPR 6.5-9 million a year in fuel. Electric still wins on cleanliness, space and control, and this guide shows when it makes sense.
Which is cheaper: an electric or a wood-fired 500 kg/hr steam boiler?
At the prices in this comparison (electricity NPR 10.50/kWh, wood NPR 10-15/kg) and a 10-hour operating day, a 500 kg/hr wood-fired steam boiler is cheaper than an electric one on both quoted purchase cost and daily fuel cost. Electric energy costs NPR 42,000 per day, while wood costs NPR 12,000 to NPR 20,250 per day. Electric boilers are cleaner, more compact and easier to automate, so the right choice depends on your priorities as well as cost.
This article compares the two options for a 500 kg/hr plant running 10 hours a day, 300 days a year. The cost reference date is 11 July 2025, using prices supplied for this comparison.
How we calculated the running cost
**Electric boiler.** The boiler needs about 375 kW of useful energy. With pumps and other losses, total electrical demand is 400 kW.
Actual wood use depends strongly on moisture content, so confirm it with a supplier guarantee and a fuel test.
Initial capital cost
The electric package is NPR 7,663,000 higher on quoted prices. The wood option will cost more once you add the boiler house, fuel yard, chimney and other site works. Those extra works would need to exceed the whole NPR 7,663,000 gap before electric becomes cheaper at installation.
**Transformer note.** A 400 kVA transformer is marginal for a continuous 400 kW load. At 0.95 power factor, 400 kW needs about 421 kVA. With a 20% design margin, that rises to about 505 kVA. Ask a qualified electrical engineer and the utility whether 500 kVA or 630 kVA is required, especially if other factory loads share the transformer.
Annual and five-year cost
Annual figures assume 300 operating days (3,000 hours per year) and include energy or fuel cost only.
These totals exclude wood-only costs such as operator labour, maintenance, ash disposal and fan power. They also exclude electric-only costs such as utility demand charges and power-factor penalties. For electric to be cheaper within five years, those wood-only costs would have to exceed NPR 40,288,000 to NPR 52,663,000.
When does an electric boiler become the cheaper choice?
Under the base inputs, an electric boiler has no financial payback against wood. It only breaks even if one or more inputs change a lot:
If you add an illustrative NPR 200 per operating hour for wood-only operator, maintenance, ash and auxiliary costs, the break-even tariff rises to NPR 3.50-5.56/kWh. The wood-price threshold falls to NPR 29.63-33.33/kg. Replace this allowance with your own actual records.
**Factors that can strengthen the electric case:**
- A negotiated off-peak, captive-hydropower or other low effective electricity tariff.
- Short, intermittent production, where instant start-stop avoids warm-up and standby losses.
- High value on floor space otherwise used by a boiler house, chimney and wood yard.
- High labour, transport, fire-control, ash-disposal, downtime or emissions-compliance costs for wood.
- Processes where smoke, dust or fuel handling creates hygiene or product-quality risk.
- High condensate return and hot feedwater, which reduce the kWh needed per kg of steam.
Safety, space and environment compared
An electric boiler is simpler and cleaner at the point of use, but it is not hazard-free. Both types are pressure equipment and need certified protection devices, water-level controls, safe blowdown, planned inspection and trained operators. Electric systems also need correct short-circuit protection, interlocks, earthing and arc-flash controls. Water treatment is critical for both, because scale reduces heat transfer and can damage pressure parts or overheat elements.
Our recommendation
| Your priority | Best choice | Condition |
|---|---|---|
| Lowest direct cost at 10 hours per day | Wood-fired | Enough space, compliant emissions control, reliable dry wood supply, trained labour and maintenance capability |
| Cleanest and simplest plant | Electric | Compact installation, clean production, quick response and automation matter, and you accept the energy-cost premium or can secure cheaper electricity |
| Balanced option | Wood for base load plus a smaller electric unit | For start-up, low-load production or standby. Needs a separate hybrid design and capital review |
What to confirm before you buy
1. Steam pressure, feedwater temperature, condensate return percentage and hourly load profile.
2. Guaranteed electric consumption in kWh per tonne of steam, and guaranteed wood consumption at a stated moisture content.
3. A utility quotation for transformer size, connection, demand charge, fixed charge, tariff category and outage history.
4. Prices for the wood boiler house, foundation, chimney, fuel store, fire protection, electrical auxiliaries and ash area.
5. Your actual operator salary, maintenance records, cleaning frequency, consumables and ash-disposal cost.
6. A supplier performance test, comparing total cost per tonne of steam under the same feedwater and steam-pressure conditions.
For help sizing and costing a steam boiler for your plant, contact ME Engineering (contact details: confirm with owner).