Which? report highlights money-saving eco products 'you should avoid'

Consumer group identifies 10 products, including a voltage optimisation device and an eco shower head, that it thinks might not be the best ways to save money, by Rebecca Smithers (the Guardian, Wednesday 20th July 2011). With energy prices on the rise consumers may well be tempted by dozens of so-called eco products which claim to slash their energy, heating or water bills.

But an investigation by Which? magazine has identified 10 products which the consumer group claims might not offer worthwhile savings, including one they say could actually increase your energy use.

Some of the products went to the Which? laboratory for testing, while others went to a user panel for assessment. During the tests researchers found that one product actually did the opposite of what it claimed to do.

The investigation, 10 Eco Products You Don't Need, is published in the August issue of Which? later this week. By avoiding the products, it says, consumers will avoid wasting up to £535.

The most expensive product is a £300 VPhase voltage optimisation device, which claims to cut about 10% from your annual electricity bill by dropping the voltage in your home to 220V. Which? said it was "pricey and will take a long time to pay for itself".

Another voltage optimisation device, the Ecotek Energy Wizard, plugs into any socket in the home and also claims to cut up to 10% off your electricity bill (a saving of £60 on average). Which? said it was not worth spending £25 on it as: "Our lab test showed it didn't reduce the power used, and actually increased it when it was linked to a plasma TV, a hi-fi or an energy-saving light bulb."

The Mira Eco Shower Head, which costs £35, was another product highlighted by Which?. One user who didn't have high water pressure found that the water-saving shower head only provided a disappointing trickle of water. Which? said there were cheaper ways to save water, including spending less time in the shower and manually reducing the flow of the shower by not using it at the maximum setting.

An £8 window insulation kit from Stormguard, which claims to help reduce heat loss and provide "an economical alternative to double glazing" in the form of a transparent film was also on the list.

It said: "Our lab test found that the film made minimal difference … The film may need to be re-stretched periodically (with a hairdryer) which can be inconvenient. It can easily tear and you would have to buy a new pack if it did."

Which? also offered some alternatives. For example, it said the most cost-effective way to save heat was to stop it escaping in the first place by installing effective loft and wall insulation, which can even be installed free if you are in a priority group.

Vphase disputed the findings and defended its green claims. Head of marketing Matthew Cody said: "We can fully substantiate all our claims. The technology itself is proven to work and commercial versions are in use throughout the UK, used by companies such as Tesco, Asda, the NHS and DECC. The VPhase device is a domestic version of this technology, based on exactly the same principles."

Which? energy expert Syvia Baron said: "For the product to truly make a difference in terms of carbon savings, it will need to save more carbon when in use than it consumes during its production and disposal. And this is quite complicated to work out.

"As a general rule, if you buy an eco product and don't use it much, it is likely that you will have contributed to more carbon being burned than saved."

The 10 Eco Products Which? says consumers don't need

1. Freeloader Classic £40

2. Vphase Voltage Optimisation Device £300

3 + 4. Disposable Battery Chargers – Battery Wizard Deluxe and Battery Charger for Alkaline Disposable Batteries £30-£35

5. Ecotek Energy Wizard £25

6. Treegreen Energyegg £40

7. Standby Saver £17

8. Mira Eco Shower Head £35

9. Nordic Galant Shower Head £40

10. Window Insulation Kit £8