Introduction to the Bulbs
incadesent bulbs are currently the most commonly used bulb in households today howver many people are changing to energy saving. It has been used for many years because it is easy to produce and does not need many expensive materials. It works incredibly simply: electricity flows through the filiment on thr pins in the bulb causing the filament to heat up. The filement will then heat up until light is produced. The galss incasing is filled with an inert gas so that the very hot metal filement wil not oxidize as it would do in normal air and the bulb would be useless from the second you turned it, on this is why when u crack the actual glass encasing of the bulb it blows when you turn it on.All different parts of the bulb can be seen easily in figure 2
Energy saving bulbs or filmament bulbs are more compicated than the filement bulbs in that they are filled with a gas that produces light when a electrical cu rrent is passed through it: the inside of the tube is filled with a combination of argon and mercury vapour, and a phosphor coating on the outside of the tube. When electrons are passed through the filling of the tube it cause the mercury to gain energy and become excited. They cannot stay like this forever however and they release this energy they have gained in the form of photons, these photons however are around the frequency of Ultraviolet and subsequently we can not see this and it needs to be converted into visable light. The photons then hit the phosphor coating and change the frequency of the photons to that of visable light and conserquently allowing us to see them for light. The energy differace between the ultra violet and the visable light is converted usually into heat or vibrations within the phospur.
Life Cycle Assesments Of Both Bulbs
I will be looking at both life cycles of either bulb and looking at the enviromental impacts each bulb has in its lifetime.
Production And Raw Materials Used
The production of the incadesent light bulb is simplier and esier than the energy saving light bulb and does not include as any components, for instnce all that is used for the bulb is the pins, the base, the screw top, glass dome, the gas inside and the tungsten used for the actual filiment.
Also the actual mecurt content in each energy saving bulb will also need to be put into consideration (5 mg tpical) as this can have a devastating effect on the enviropment if exposed to it. However usually this is not the case and most times if not all energy saving bulbs are produced in a way not likely to result in damage to the enviroment by spillage if the mecury vapour so this I think is a minor aspect to consider and should not weigh
the argument too severly.
As you can see from the table the amount of energy and materials needed to produce the energy saving bulb is far higher than than that of the incadesent as well as some extra materials used in the energy saving than in the incadenent. However this angle of view is one that of the energy required bulb against bulb and if we were to look say at the energy requied to produce one a luman hour ( measure of light produced over time) the production cost would be less for energy saving than incadesent. This is a very important point because it shows that although the energy saving bulb costs more to produce innitly the actual cost to produce one over time is significantly less.
Usage and Lifespan
N.B We are assuming that both the packaging for both bulbs are the sma eas usually both bulbs are placed in the same packaging and transported the same distence in the same way.
The floresent tube consumes much less energy when being used than the filament incedesent bulb as you can see in table 2. This is the main reason why people are so attracted to using floresent bulbs.
As you can see in table 2 incadesnt bulbs use roughly 5 times the amount of electricity than the flouresnt energy saving bulbs, and of course the fact also that the floursent bulbs last 8 times the amount of hours that the incedesnt bulbs also times the production cost and impacts of the incedesnt bulb.
We are looking at each bulb haing the same usage pattern in their lifetime when sometimes this is not the case because people think that continuos turning on and off of the bulb will shortern its lifespan and also that the apparent warm up period of the bulb (spike of enegy sed when the bulb is first turned on) is significant enough to mean that they should not turn the light off when leaving the room for only a short period of time. This apparent warm up time for flouresent bulbs has been proven to be so small that you would have to be back into the room in a split second for it to be any more energy saving than turning the bulb off and on. Also the link that continous turning off and on of the bulb is also incorrect.
Disposal of the Bulbs
The actual energy required to dispose the bulbs in negliagable compared to the amount of energy needed to power the bulbs in their lifetime however there are some environmental effects that should be noted: Ina t traditional waste disposal plant the waste is incinerated and if the floresent lamps were to be incinerated this would release the mercury vapour into the atmosphere and pollute, however normaly this is not the case and they are usually collected and the mecury vapour is stored or collected so that it is not reeased into the atmosphere however as per this assessment we are assuming that the mercury is not collected and is released into the enviroment.
Total Emmisons And Energy Used
Here we can see the actual energy used in each stage of the bulbs lives not just per bulb but also over a set amount of luman hours. As you can see in the first set of data in the table flouresesnt bulbs do take maore energy to produce and scrap as well as use if we are looking on a bulb for bulb basis, however all this becomes irrelevant if we look that the actual light given off per bulb is significantly larger for the floresnt bulb than the incedesent. This equates to having to replace the incedesnt bulb 8 times over the same period of usage for just one of the flouresent bulbs!
The actual energy comsumsion per luman hour can be seen in the second part and this gives a better view of the amount of enegy used to give a set amount of light again the flouresent is the better. It is worth noting also that the incesent bulb loses a lot more energy as heat than the flouresent bulb.
The emmisions can be seen in table 4 as the different amount of gases given off as a direct resultof the bulbs being made used or disposed and the indirect emmisions used through these ( the emmision that are given off by coal being burnt to power the different stages). You can see in the reduction colum that the flourent bulb beats the incadesent in emmisions of every gas exept mecury, however an interesting point is that the actual extra energy used by the incadesent bulb means that more coal has to be burnt and this extra amount of coal would mean an extra amount of heavy metals released into the atmosphere including mecury so again the flouresnt bulb actual wins over this.
Conclusion
In conclusio I think that in every apect of life cycl assesmnt the flouresnt bulb is supoior to the incadesant because not only does it use less electricity to produce the same amount of light it also has a life time 8 times that of the incadesent meaning that the production cost and impacts of the flouresnt bulb is far less than that of the incadesnt bulbs that are equivelent.
People I think should change to the bulbs based on this information as it would be the best thing for the enviroment however the bulb may prodiuce undesirable effects for the consumer such as light colour and apparent strobbing effects however I have not put these into consideration in lght that this is a life cycle assessment n impacts of the bulb on the enviroment and not anything else.
