How much heat is in a 15kg bag of pellets?

A standard 15kg bag of wood pellets contains roughly 75 kWh of energy. After factoring in stove efficiency (around 85%), you get about 64 kWh of useful heat.

How long does a 15kg bag of pellets last?

Depending on how high you set the stove and outside temperatures, a bag typically lasts between 1 to 2 days of moderate use.

Are pellets cheaper than electricity in Spain?

Pellets are cheaper than standard electric resistance heaters, but they are generally more expensive than running an efficient air conditioning unit (heat pump).

Are pellet stoves cheaper than air conditioning?

No. Because air conditioning uses a heat pump (COP 3-4), it is significantly cheaper per kWh of heat than burning pellets at current market prices.

Are Pellet Stoves Worth It in Spain? Cost vs Air Conditioning

Are Pellet Stoves Worth It in Spain?

Pellet stoves can be comfortable and convenient, but at typical current prices they are often more expensive to run than a modern air conditioning unit in heating mode.

Pellet Cost Calculation

Let's look at the real maths based on typical 2026 prices in Spain:

Pellet bag price: €8 per 15kg
Energy content: ~75 kWh per bag
Stove efficiency: ~85–90%
Usable heat: ~64–68 kWh
Effective Cost: roughly €0.118–€0.125 per kWh of heat

Pellet Stove vs Air Conditioning

Compared to the cost above, an air conditioning unit running on a good electricity tariff (around €0.10/kWh) with a COP of 3.5 provides heat for roughly €0.028 per kWh. That makes the pellet stove over 4 times more expensive to run.

Heating Cost Comparison

Based on electricity tariff: €0.098/kWh (Updated 2026-04-27)

Show Monthly Cost (300 kWh heat)

Heating Method	Efficiency	Cost per kWh (Heat)	Est. Monthly Cost	Notes
Air Conditioning (Heat Pump)Lowest Cost	300% - 400% (COP 3-4)	€0.033 - €0.025	€8.58	Most efficient option.
Olive Wood Stove	75%	€0.052	€15.56	Cheap but requires storage & cleaning.
Pellet Stove	87%	€0.123	€36.78	Convenient but prices have risen.
Butane Gas Bottle	90%	€0.115	€34.41	Good for spot heating, adds moisture.
Electric Heater	100%	€0.098	€29.40	Very expensive to run constantly.

Pellet Stove vs Olive Wood

Olive wood is much cheaper per kWh (around €0.05 per kWh of heat), but requires significant physical labor to move, chop, and store. Pellets offer convenience, but you pay a premium for it.

Convenience, Cleaning, and Storage

Beyond running costs, pellet stoves require:

Dry storage space for dozens of heavy 15kg bags.
Daily or weekly cleaning of the burn pot and ash pan.
Annual professional servicing.
A proper flue/chimney installation.

When Pellets Still Make Sense

If you love the feeling of a real fire, want to heat a specific large room quickly, or live in a very cold inland region where heat pumps struggle, a pellet stove can still be a cozy, if premium, choice.

Heating with electricity? Your tariff matters.

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