Sky is to help customers reduce their household energy bills with the introduction of a new feature called "Auto Standby" that will automatically switch inactive Sky HD and Sky+ boxes into Standby mode overnight.

The new feature monitors whether people are using their Sky+ or Sky HD box overnight between 11.00pm and 4.00am. If the box has not been used for a period of two hours after 11.00pm, an "Auto Standby" warning will pop-up on screen for 3 minutes. If there is no further use the box will go into Standby mode automatically.

Although users won’t be able to switch off the unit due to the electronic programme guide needing power on all the time, the feature, which is the company’s latest step to reduce its own impact on the environment, will be introduced to more than 2 million customers' boxes in phases over the next few months.

It will be sent automatically to all Sky HD boxes from tomorrow and then to all Sky+ boxes, in stages, from mid-April and throughout the Summer.

Sky say that the new "Auto Standby" feature could save enough energy to light all the homes in Wolverhampton or power all the washing machines in Liverpool for a year.

It could also slash £7.5 million from customers' electricity bills and reduce the UK's carbon dioxide emissions by 32,000 tonnes a year.

Frances Galvanoni from the Energy Saving Trust said: "What's great about this is that the consumer doesn't have to worry about remembering to turn it off standby as Sky has built the functionality into the product. This is a welcome step and shows how seriously Sky takes it responsibility to the Environment. Energy efficient appliances use less power and are cheaper to run. And because they need less energy, they're responsible for fewer greenhouse gas emissions - this is good news for the environment and good news for Sky's customers".

However not all manufacturers are taking the Green route, Samsung’s latest range of televisions launched at CeBIT in Germany don’t come with an off switch, just Standby.