Most new appliances are energy efficient. They have circuitry in them that means that their energy consumption is kept to a minimum and they also have higher levels of insulation (for fridges, freezers and cookers) where appropriate. So buying new appliances is a good way of reducing your energy consumption when needing to replace old, broken white goods.
However there are instances where buying new is a costly and unnecessary expense. Large freezers can go on for years and replacing them can be very expensive, so what to do with the energy consumption?
Thankfully there are a couple of ways of doing this. The main inefficiencies (apart from lack of insulation – and this is more difficult to tackle) are due to the lack of control circuitry that reduces the power drawn down to start up the pumps and then smooths out the current to provide a more efficient power flow into the motors. However, if you have these technologies already installed then you will not benefit.
The most well known product is called Savaplug and it fits onto fridges and freezers. A list is available here of the makes and models that will not work with Savaplug.
Another system is hard wired into your electrical mains. This is made by V-Phase and claims up to 10% savings. These systems are being trialled by some housing associations and so some meaningful data should be available soon, but the company claims lots of independent testing and successes. This system works by reducing the voltage in the house down from around 250V to 220V, as most appliances will work at this lower level. Their product has been designed for the domestic market, so it will be interesting to see if they get anywhere near the saving that has been accrued by the commercial sector.
Other systems claim that they can ‘treat’ whole ring mains, so everything plugged into a circuit. So for example if you have an old fridge and freezer in the kitchen / garage etc then you can just plug in Power Factor correcting device, however the claims of savings are not independently verified in the UK. These systems are based on industrial energy saving devices where saving are certainly available, however their effectiveness in the domestic market seems to be under a great deal of scrutiny.