Donnachadh McCarthy: The Home Ecologist

They may be fashionable, but traditional range cookers have huge carbon footprints

It has become the symbol of contented Middle England. You've done well in life, you've got the bells-and-whistles kitchen, and sitting in pride of place is an Aga. Even in more urbane kitchens away from the shires, Agas are the cooker of the moment – it's just that the ones in smart urban postcodes tend to be purple or turquoise, rather than cream or maroon.

But while these solid-iron range cookers provide a warm, cosy nest for decades on end, there is a problem: the ovens and hobs are hot 24 hours a day, in case one wants to bake a cake, roast a chicken or boil a kettle at 3am. This not only comes at a financial price, but can also have a massive environmental cost.

I first became aware of what a potential eco-monster these things could be when I learnt that a client's Aga had been on right through the summer. A four-oven, oil-powered Aga can consume over 3,000 litres of oil per year, which equates to a massive 8.5 tonnes of CO2 emissions. A gas-powered one with a back boiler can emit up to 7 tonnes. Even when you consider the potential carbon savings – not using an electric kettle or tumble drier or whatever – it still burns a huge amount of energy.

An average UK household produces 6 tonnes of emissions – for all heating, lighting and electricity use. Last year, despite cooking a hot meal for myself nearly every day, I calculated that my gas cooker emitted 0.15 tonnes of CO2. Aga's claim that the cookers are designed "to consume the minimum of fuel" should clearly be taken with a pinch of salt.

Having such ovens burning right through the summer, though, is even more irresponsibly profligate. Aga does seem to be aware of the environmental challenge now facing them. Their website declares, rather prosaically, that they are "at the forefront of green issues." An Aga spokesperson told me: "We have spent £7m ensuring the emissions from our plant are as clean as the air you breathe and continue to invest heavily in improving the energy efficiency of this iconic cooker." As society urgently moves to a carbon-negative economy, such companies will either have to adapt or die.

I am, however, happy to say that the firm's sister company, Rayburn, has made a pure wood-burning model. This is exciting in a number of ways, in that it not only cooks but also provides hot water and central heating.

To environmentalists, this is the Holy Grail: a renewable energy technology that cuts up to 70 per cent of a home's carbon emissions. The cookers compare favourably with solar electric panel installations, which reduce about 20 per cent of a home's carbon emissions. Unlike wood room-heaters, they can also qualify for the Low Carbon Building grant of £1,500, and their installation in the home can also qualify for the reduced 5 per cent VAT rate.

The Rayburn models cost from £3,400, plus installation – so, happily, the moral is that Middle England can continue to have its contented warm nest while being eco-responsible.

Donnachadh McCarthy is author of 'Saving the Planet Without Costing the Earth' and works as an eco-auditor. www.3acorns.co.uk

d.mccarthy@independent.co.uk