The technological watchword of our times is ‘eco’. Ever since the Toyota Prius made it big in Hollywood, gadget-heads and geeks have placed a renewed focus on tech that makes a smaller impact on the environment.

The ideal is pretty straightforward for some gear: cars should use no petrol, houses should generate their own power, and everything should be built from recycled or at least renewable material.

But there’s one device in your house that’s big-ticket not only in terms of price, but also its ecological footprint. And that’s your fabulous flat panel TV.

It makes sense: the TV of today is so much bigger than the TV of the 1980s or even 1990s. Exactly how much power your TV uses depends on the technology behind the panel. Plasma is the worst offender, not only because of the nature of the tech, but also because plasmas boast bigger sizes at each price point.

As a result, the average plasma from the last few years can consume more than 300 watts of juice at full load. The average LCD, on the other hand, consumes a more modest but still alarming 200-plus watts.

Remember, that’s like having two or three 100 watt lightbulbs running, for the whole time you’re watching TV – up to six hours a day, depending on your household habits.

What’s worse, the TV has become the centre of a veritable octopus of electrical consumption. Each device you plug in has its own power requirements, with games consoles such as the Xbox 360 and PlayStation 3 at the top of the heap, sucking down the best part of 200 watts each.

No wonder that in some parts of the world, studies have determined that nearly ten percent of household power use is somehow related to TV.
Does this mean we should all go back to 50 cm CRTs? Should we bin the plasma and instead buy four 22 inch LCDs and bolt each one to the arm of a recliner, for a sort of airliner business class cabin look?

No – though that would be cool. While green activists decry technological solutions to environmental problems as naive, when it comes to consumer electronics it’s reasonable to expect clever companies to come up with less power-hungry TVs. And they have.

LED backlit LCD TVs use less electricity than an old-school cold-cathode fluorescent (CCFL) backlit TV. The equation really is as simple as that. Depending on what you watch, an LED TV will use as much as 40 percent less power.

Companies such as Samsung, Sharp and Sony make a big deal of LED LCDs, and go further than the backlighting in explaining how their TVs save the environment. Most CE uses pretty toxic stuff to complete the product, and getting rid of a tube full of toxic gas in favour of a grid of solid-state LEDs that are unlikely to fail and thus need discarding is a good thing.

TVs that have eco-aspirations also tend to eliminate things such as painted casing (paint is toxic, and the painting process produces copious waste) and they’ll point out that by getting rid of CCFL backlights, the TVs no longer contain mercury. And everyone knows mercury is bad.

Okay, so would you ever choose between two TVs based on eco-credentials over actual performance? Any saving in power consumption is a good thing, but let’s not pretend the new generation of TVs are without eco-sin – they still use a lot of non-renewable resources such as tantalum and columbium (the bane of electronics) and complex devices of all kinds have relatively inefficient manufacturing processes, with quite a bit of waste.

What’s more, companies pushing low-power TVs will make it seem like 300 watts is a totally outrageous power-draw, but let’s put it in context. The electric blow heater you might be using to warm up the TV room will draw as much as 2800 watts. The air conditioner, 1500 watts or more. And that’s before we get to the fridge. When it comes to a top ten of your big power eaters, the TV is pretty low on the list.

Yes, it’s like running three lights. But forget compact fluorescent bulbs that last three years – the backlight in your TV will last 15 years, or longer.
The manufacturers of eco TVs have their heads in the right place though. And for us it’s the changes in the manufacturing process that are more interesting, ecologically. Factories that output less carbon dioxide and comply with reduction of hazard substance (ROHS) standards are much more important than saving a fraction of a kilowatt hour when you’re actually watching Today Tonight.

It’s also important to remember that you’ll do more damage to the environment by throwing away your old plasma than you can hope to make up by buying an eco-TV. That said, we love LED backlighting as a technology and if your flat panel monster is more than four or five years old, you’ll see the difference from a performance perspective – that’s why you should buy.

At the moment, the eco-credentials of a new TV should be considered a happy bonus. You’re not going to make that much of a difference, yet. When a TV uses ten percent of the power of its forebears, and your back wall is painted with photovoltaic cells that catch light from the display and put it back into the grid, that’s when we’ll admit it really is easy, being green.