If the new nuclear powers are built there will have to be hundreds of miles of pylons built to carry the nuclear generated electricity across the countryside of England and Wales. This is because the new nuclear power stations will typically be 1.6GW, compared with around 1 GW of power that an existing typcial nuclear power station can produce.
Once you build more powerful power stations you have to make sure that the grid can carry the extra power generated. The grid will need to be adapted for this and that will mean more cables carrying current across the country.
You might be crossing some striking and glorious countryside, almost anywhere in the world, and then you spot the horrible steel masts carrying power cables that bring electricity. It would look neater and be better, environmentally, wouldn’t it, if we put those ugly cables underground? Well, no, actually!
If you were to put the pylons underground you would have to ensure that they are insulated. The cables need to be wrapped with something – usually oily paper, and over a number of years depending on the design and quality and the amount of electricity that the cables carry, the heat generated by the electricity flowing through the paper will cause an electrical arc, which destroys the insulation in part. That part of the cable that is not insulated becomes a device that leaks electricity.
When this happens you generate electricity which ends up useless in the ground. If you have used fossil fuel you have caused carbon dioxide and other emissions, needlessly. If you have generated the current by nuclear you would have created nuclear waste needlessly.
Now, when the underground power cable fails, (this may take up 40 years but fail one day it will), the electricity company will have to locate the fault and fix it. Under ground cable faults are notoriously hard to locate and plenty of roads are constantly dug up and re dug up in an effort to stop electricity leaking out of the cables. This causes direct environmental damage (digging up roads) and additional emissions (queues of vehicles running their engines at one way traffic lights while the roads are being dug up).
However, it is better in terms of saving electricity to send current through cables in pylons that are overhead. You do not need to insulate these cables, becasue air acts as an insulation and arcing only occurs if a pylon is damaged in a way that permits cables to get too close together.
You can pass lower voltages through the cables but you will lose a lot of energy by increased heat in the lower voltage cables. The lower the voltage that you run, the greater the energy loss. So, as strange as it may seem, if you want to reduce emissions from energy generation a good starting point is to cover the land with pylons carrying high voltage electricity.
They will inevitably be a blot on the landscape but that is the lesser of two evils, unless we can all reduce our electricity consumption but that is probably too much to expect.
Filed under: carbon emissions, climate change, electricity, energy | Tagged: arcing, digging up roads, high voltage, low voltage, pylons, underground cables
Robert , Thank you for an interesting article, From what I am reading and noting that the share price has increased new High Temperature Superconductor (HTS) [ http://www.zenergypower.com/ ] can improve performance and reduce loss from the cables, if you stand under these Pylons you may be able to sense the huge Electro-magnetic Field so this is energy being lost of course, so it may be feasible to replace the overhead cables to increase the energy that can be metered, as you know the amount of electricity generated is substantially less than that which is consumed for several reasons of loss in the distribution system.
http://www.independent.co.uk/news/business/analysis-and-features/small-talk-zenergy-tipped-to-power-ahead-in-836414bn-market-454601.html
http://www.lse.co.uk/ShareChart.asp?sharechart=ZEN&share=zenergy_pwr
Another interesting point I can add is that the top cable that can be seen in your photograph has at its core a Fiber optic communication cable, they use this to monitor all of the network and for communication between all the components of the power supply network, they sell the remaining capacity, so there is a good chance that this message is flying down that fiber optic as well.
It is easier of course to recycle (or weigh in as they say in the trade!) the cable that does not have the greasy insulating paper or PVC Insulation, and the price paid per kilo shows that clean metal is more valued than contaminated or difficult to extract metal.