The Insider: You don't have to go flat out to find the green choice

Buying a new TV can seem like a minefield at the best of times with the number of brands, screen sizes and choice of plasma, LCD and new LED models available. Add trying to be environmentally friendly into the mix and it can seem like an impossible task.

"There are great choices for people looking for an energy efficient TV, and, in general, the power consumption of TVs has dropped rapidly this year across all formats and screen sizes", says Martyn Hocking, editor of Which?. "It is possible to enjoy your favourite programmes without worrying about your green credentials".

The latest models come with a range of energy efficient tools and functions, such as power-saving modes that can cut power consumption by more than half. Some models feature "hard" off switches to ensure they don't drain any power, and screen-blanking options that darken the screen when you're listening to a radio station.

There are several other "green" features to look for, including sensors that switch the picture off when the TV is left on standby mode for too long, or when there is nobody in the room. Avoid quick-start standby modes, which save a few seconds when you turn the TV on – a couple of extra seconds of viewing time doesn't offset the extra expense of power used.

Plasma screens are the worst offenders if you want a green model, as they use far more energy than LCD screens and conventional widescreens. LED models are the latest technology to hit the high street. It's early days yet, but the models Which? has tested tend to use even less power than LCDs.

Also, as a general rule, the smaller the screen, the less power it uses, so you may need to sacrifice screen-size for energy efficiency. On the flip-side, this normally means you'll save money too.

The 42-inch LH2000 from LG (£900) and the Sony WE5 Eco TV are both rated highly by Which? for their energy use and energy-saving features.

Where to buy

Plasma, LED and LCD TVs can be bought from supermarkets, electrical stores, department stores or online. Be aware that display models in TV showrooms often show high-definition pictures on screen, so it's not representative of the picture quality you will get if you're watching a standard broadcast signal or DVD.

A better way to judge the picture quality is to take DVDs with you that have fast-moving action scenes and dark sequences (such as The Matrix), or a football match.

Five questions to ask

Which screens are the most energy efficient?

Generally, plasma TVs use the most amount of energy. New technology TVs, such as LCD and LED models, use more power than traditional "big box" CRT models. However, the developments in power-saving and light-sensor technology is beginning to close the gap.

What "green" features are available?

The most energy-efficient settings involve ambient light sensors, which can slash a typical 100 watt reading for a 32-inch TV screen in half in dark conditions.

Big screen or small?

There's no way of getting around it, the smaller the screen, the less energy it typically uses. On average, a 32-inch LCD TV uses 109 watts compared to 168 watts for a 40-inch screen.

Is standby so bad?

Standby wastes a lot of energy so stay clear of it. If your TV has a power-hungry quick-start standby mode, disable it. Switch it off at the socket or unplug it when not in use.

How can I be greener with my TV once I get it home?

Toning down the brightness on your TV can make a big difference. The ideal settings for viewing at home are often very different to the manufacturer's settings.

The Insider is written by Which?, the independent consumer champion. To get three issues of Which? magazine for a special price of £3, call 01992 822800 and quote INADVICE. For more energy saving tips and to find out how to save money on your energy bills, go to www.which.co.uk/switch. If you switch energy suppliers during August, you could be in line to win your quoted annual energy savings

theinsider@independent.co.uk