Consumers concerned with their environmental impact should buy energy saving lightbulbs rather than switching to "green" power tariffs.

This is the view of the Telegraph's energy columnist Rowena Mason, who stated that the so-called green tariffs offered by suppliers are often more expensive than regular deals, but provide little in the way of eco-friendly benefits.

Under Ofgem's regulations, she explained that for a tariff to be classed as green, providers must only agree to 50 kg of carbon dioxide out of the atmosphere per year.

Citing analysts at electricity firm Ecotricity, she pointed out that this could be achieved by replacing one regular light source with an energy saving lightbulb for far less than the average annual £25-30 hike in costs which is faced by moving to a green tariff.

Energy saving is a major issue at present with many consumers, with Moneysupermarket announcing earlier this month that householders have been hit with their highest-ever winter fuel bills this year.