The kettle debate

Gerry1

wild666 said:

Gerry1 said:

Daily Mail columnist Emilia Shovelin simply hasn't a clue.

"On average, electric ovens have a power rating of 2.0-2.2 kWh, whereas slow cookers use 0.64 kWh of electricity on low settings and 1.65 kWh on high settings."

She's confusing power with energy (those units should be kW, not kWh), and the low settings are typically 100W - 200W, not 640W.  It's true that some slow cookers do have high power settings of over 1kW, but she's failed to realise that they can't be used at this power for long periods.  1.65kW is almost the power level of an electric kettle, so after eight hours the contents would have been boiled dry and frazzled to cinders !

Her next howler is saying "For those worried about how much energy their slow cooker is using, experts suggest they get a smart meter and monitor their energy use to work our whether it is saving or costing them money."  The smart meter can only monitor the electricity usage of the whole house, so it will be virtually impossible to see whether the slow cooker costs more than the oven.  You'd have to use the slow cooker one day and the oven for the same meal another day, but all the other electricity usage would have to be exactly the same, which is unlikely.  The comparison could be completely skewed just by using another appliance such as the tumble dryer, hotplate, hair dryer etc.

It would be necessary to use a plug-in energy monitor, but most ovens don't plug in to a 13A socket.

There are only two ways to test how much energy a slow cooker, or any electrical appliance, is actually using one is turn everything off at the wall socket and read the usage at the start and finish and the other is buy a plug adaptor that reads how much energy is consumed by the device, These plugs are available on Amazon or eBay  

Agreed, a plug-in energy monitor with a 13A outlet socket would be fine for measuring the slow cooker's energy usage, but it's a lot harder for the oven if it's not powered by a 13A socket.

• Her article fails to explain that you'd need to do two lengthy 'everything else off' tests to compare the oven / slow cooker energy usage.
• She's fallen for the smart meter hype, believing that one is needed and that it can magically do the comparison, but that's nonsense.  Any traditional meter will do as long as it doesn't show only whole kWhs, but the procedure won't be simple.
  
• Slow cookers are often left switched on for long periods e.g. the working day.  Even if they managed to identify all the relevant circuits and appliances, many people might find it impractical to switch absolutely everything else off including the central heating, washing machine, tumble dryer, immersion heater, fridge, freezer, lighting, TV, telephones/answering machines etc.