Zyra's website //// Lighting //// Environment //// Saving Money //// Site Index

Economy Electric Lightbulbs


Although energy efficient light bulbs cost more initially to buy, they save much more than they cost! The amount of electricity used by a lightbulb per month is much more significant than the cost of buying the bulb.

To put some figures on that, a basic cut-price 60 watt lightbulb might cost 25p at the supermarket, but if it's switched on for 8 hours per day, then after three months it's used about 3 in electricity.

In contrast, it would be better to pay 2 and then you could afford to get a 100 watt economy bulb which only uses about 18 watts in real terms. When switched on for 8 hours per day, in three months it will use 90p in electricity.

So, in this example, you are clearly in profit on the deal at three months! It doesn't take a lot of doing to work out that over a period of years, the investment in economy energy efficient lamps is going to save a lot of money off your electricity bills.

I deliberately chose to compare a 100 watt energy efficient lamp, as I consider they are equivalent to about 80 watts of perceived light brightness. Less than a 100 watt filament bulb, but definitely more than a 60 watt lamp.

How to do the calculation yourself: Find out how much "per unit" your electricity is costing. uSwitch and Energylinx, and electricity companies in general, will tell you. Electricity costs so-many pence per "unit". A unit is a kWh (kilowatt hour) which is how much electricity a one kilowatt (1000 watts) electric fire bar uses in one hour. 1000 watts for one hour is one kWh or "unit". 100 watts for 1 hour is a tenth of a unit, and 20 watts for 100 hours is 2 units.

Total cost = cost per unit(pence) x power(kilowatts) x time(hours)

More about this in watts, volts, and amps where some more of this type of thing is explained in more detail.

Another thing about economy bulbs is that they last longer. It was traditional for a standard 100 watt bulb to last for 1000 hours. It was a piece of popular modern folklore that electric light bulb companies deliberately made the bulbs to be mortal so they could stay in business and continue to sell lightbulbs! There may be some truth in that, and I have some interesting ideas about it at the page titled "long life lamp", but meanwhile, on the economy bulbs, they have been rated at lasting 6000 hours or 8000 hours, or other periods much longer than 1000 hours. It may be possible to extend this much longer by using high frequency fluorescent lamp techniques in an energy efficient lightbulb fitting. Incidentally, 1000 hours is 40 days and 40 nights continuous, so in most uses a normal light bulb will last a few months as it's not on 24 hours a day.

Having a longer lasting lightbulb is desirable for more than just the cost of the bulb. Your time and effort to change the lightbulb is saved if you don't have to do this so often. It is sometimes amusing to think about how many people it takes to change a lightbulb, but in some places where there's a huge set of light fittings on a very high ceiling and you're having to pay someone to go up there and fix it, there are costs and insurance implications, so having bulbs that last longer helps!

Another point, which is often neglected to be mentioned, is that energy efficient lamps give off less heat. As well as being a consequence of the efficiency, it also means that it's safe to use a higher light intensity. If a light fitting has a safety label which says "maximum 60 watts", you'd be taking a fire risk putting a 100 watt conventional bulb in. However, a 100 watt economy bulb produces less heat as it's only using 18 watts. Safety is very much a matter of common sense.

To sum it up so far:

* Energy efficient lightbulbs save money as they use less electricity and this easily outweighs the higher cost of buying the bulb.

* Energy efficient lightbulbs last longer, which saves time and money.

* The waste heat produced is less.

However, there are some applications where it is not such a good idea to use economy bulbs. For example:

* Where there is a high risk of breakage. (replacing the bulb costs more)

* Where you've only got 2 weeks to go before the whole thing ends. (not enough time for the electricity saving to catch up with the bulb cost)

* Where the lamp is only lit for a very short time per day on average. (a quick calculation reveals the break-even point to be about 10 minutes per day, below which the saving is beaten by the interest on a bank savings account! This is one reason you don't see economy bulbs inside fridges).

* Where the supply is DC. see AC and DC

* Where thieves might steal your lightbulb! - see security

The other situation which at first appears to be one where you'd not want an energy efficient lightbulb is where you feel it's just not bright enough, not as bright as a traditional filament bulb, and you're wondering if you need to see an optician because you can't read the small print under the dim glow of a fluorescent economy bulb! The thing about this is that energy efficient economy lightbulbs are less bright, and considerably less bright for the first few seconds when they are switched on. The answer is to get one of those oldfashioned adaptors and put two economy bulbs in. It's still cheaper than using a traditional lamp.

This "when they are first switched on" thing reminds me of the idea that fluorescent lamps use a lot of electricity during the first few seconds, and it is true that economy lightbulbs are fluorescent lamps in disguise. You can see this if you look closely, as the glass tube is wrapped around and the rest of the fitment (including a neon starter and coil) is carefully packed into the unit which then has a standard light fitting connector on it. It's quite an achievement for the companies to have got all this equipment into something not much bigger than a lightbulb. It fits into most light fittings.

Economical electric lightbulbs are available from: Nigel's Eco Store, Asda, Maplin, Tesco, some component shops, electrical shops, and most supermarkets. Plus, a while ago, Powergen were giving away free bulbs! Now in 2011, even the Gas company British Gas is giving away economy electric lightbulbs.

Although compact fluorescent lamps are undoubtedly more efficient and cheaper to run, there are problems. They hurt people who have some health conditions such as LUPUS, and also they produce a light which appears to be dimmer. The whole issue has been swung violently against the economy lightbulb by a particularly nasty thing that Europe and a few other countries have done, where they have attempted a prohibition style BAN on 100 watt old-style lamps. Well, we protest!

Maybe things will improve when high-power LED lighting becomes the way.

Another thing: Has anyone considered if there are any ways of recycling economy lightbulbs?! We know that tungsten, steel, glass, and lead are recyclable, but what about the stuffs that economy bulbs are made of?