Niall’s virtual diary archives – Monday 20th January 2014

Monday 20th January 2014: 10.08am. Someone asked about my last post's assertion about coal being so cheap relative to other fuels here in Ireland, thinking surely gas beats it? So I figured why not supply some numbers which are my calculations for various home heating sources here in Dromahane, Mallow in € cent per kWh including VAT and carbon taxes:

Premium Polish Coal: 4.82
Natural gas (from pipe, not bottle): 5.1 (not including standing charge)
Peat Briquettes: 5.93
Heating oil: 8.48
Electricity: 18 (not including standing charge)

Of course, getting the fuel converted into heat in your house is another matter, so assuming 30% efficiency for an open fire with standard back radiator and 70% efficiency for oil and gas furnaces plus central heating system and pumps (remember these use electricity too), this is the cost to get an actual kWh of heat into your house:

Natural gas (from pipe, not bottle): 7.29 (not including standing charge)
Heating oil: 12.11
Premium Polish Coal: 16.06
Peat Briquettes: 19.75
Electricity: 18 (not including standing charge)

We have an old oil furnace here (certainly not a condensing boiler model), so I certainly think one can add 10% to the heating oil cost for us personally taking that cost up to 13.32 euro cent per kWh. Of course natural gas is much cheaper than oil, but we have no gas here in Dromahane, and bottled gas is much more expensive. Heating oil remains popular in rural Ireland for good reason - it's the only game in town!

However there still remains one more important difference: a fire heats a room, while a heating system heats a house. If you only care about heating a single room to warmth, you can divide the cost of a coal fire by 2.5 as it is very unlikely you'll turn off every radiator in your house but that for a single room. Natural gas is now about the same cost as a coal fire with a coal fire handily beating all other sources of heat, which is why those with natural gas heating may not light a fire each evening while those without will certainly do so if they're on a budget.

Let me put it another way: we might consume 3kg of coal per evening. That is equal to about 7.5 kWh of heat being pushed into a single room which is about the same as running a 1.5 kWh electric heater for five hours. With electricity, that would cost us €1.35 per night, whereas with coal that costs us €1.20 per night, an 11.1% saving. Which sounds about exactly right, thinking about it.