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Electric lights & appliances

Under European Union law, all incandescent bulbs will cease being sold by 2016 and be replaced by energy efficient compact fluorescent lamps (cfl). The Building Regulations part L1A (of the Approved Documents) already require a percentage of new light fittings to be low energy only – see Internal lighting. This will save an enormous amount of energy and pollution. Handled correctly, low energy lighting can be superior to incandescent lighting in a number of ways. However there are several issues, real and perceived, around low energy lights which need addressing. Some of these are to do with general acceptance, others with technical issues.

  • Lower levels of light output is sometimes a criticism with low energy bulbs. This typically comes from silly people who have tried to replace an incandescent 100W lamp with an 11W cfl. It needs to be at least 20W, maybe up to 30.
  • Colour rendering has been something of a problem with cfls although that problem has now been fairly well fixed. Some of the worst makes used to give a strange slightly sickly colour of light with a tinge of green but these are getting fewer. Cfls may never give the full frequency lighting spectrum that incandescent lighting does but it may give healthier lighting if the results coming from research into 17,000ºK  fluorescent lighting by Philips is anything to go by.
  • run up speed is being rapidly improved
  • dimming is now possible with some cfls
  • problems with bulbs breaking loose from their bayonet plugs within the light fitting have ceased with cfls. This was linked to the heat problem which often caused the plastic sockets to go brittle.

Conventional fluorescent lighting is particularly good when high frequency gear is used.


LEDs are rapidly becoming more energy efficient than cfls. See energy comparisons. LEDs also last longer and there is the possibility of colour balancing by the mixing of different coloured LEDs into a single lamp.


Appliances are rated according to the EU energy rating system. However there are other factors to take into consideration.

Are the appliances intrinsically efficient? For instance induction hobs and microwave ovens are more efficient than conventional ones because there is little residual heat after use. This can also be an issue around cooling as well as energy usage. A superinsulated house will have to contend with removing excess heat from ovens. If this goes out through a MVHRPassivhaus standard)  system then it will reappear again in other rooms.

Dishwashers can be considerably more efficient than poor hand washing (both in water and probably energy consumption) although the studies so far don’t seem to have taken into account the embodied energy of the machines themselves

Voltage Optimisation

In theory the mains voltage has been harmonised across Europe at 230 volts. What happened in practise was a bit of a fudge. Instead of the UK voltage being changed to 230V it was allowed to be 230 V +10% -6%. This effectively allowed it to stay at 240V. and it can therefore rise to 256V. Manufacturers of electrical equipment work to 230V to best cover the European market and so when equipment is fed the much higher voltage of up to 256V it is not working to its optimum efficiency. Enter the Voltage optimiser which is a gadget fitted near the electric meter to regulate the incoming voltage down to 230. There are claims that this could save up to 10% of your electricity costs.

2 comments to Electric lights & appliances

  • Jas

    and to add insult to injury all the so called energy efficient light bulbs only save heat when the heating is turned off!. in a house I built to modern insulation standards + a bit,,, as i was finishing it off and was living in it, and before heating was installed, my bedroom was heated by the 3x 100w traditional bulbs,,, these were phased out,,, and I fitted low energy bulbs sent FOC in a pack from my energy provider,,,,,, then i went out and bought a fan heater!!! if the light bulbs dont chuck out heat the boiler has to !!!!! what a con!!!

  • Tony

    I would also comment that the range of low-energy lighting (now required to be 75% of all lights in new-build properties) is very poor and unimaginative. There is an enormous restriction going on in terms of what lighting fixtures one is allowed to put in new-build properties – deeply depressing for anyone trying to add some personality to new houses.

    Also, consumers are being forced into a steady reduction in the light volumes they can practically achieve in their houses from pendants. Try buying a 100W equivalent replacement low-energy lightbulb in a standard DIY shed like Homebase or B&Q, and you’ll see what I mean. They are extraordinarily difficult to come by!

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