• Question: how long is it when all electricity is wasted?

    Asked by sodiumpolyacrylate to David, James, Mike, Suze, Will on 21 Jun 2011. This question was also asked by drfc.
    • Photo: James Marrow

      James Marrow answered on 20 Jun 2011:

      Sodiumpolyacrylate: I’m not quite sure what you mean. Could you try to explain what you want to know, please?

      We generate electricity by converting other forms of energy (e.g. chemical energy or wind energy or nuclear energy) into electrical energy. All of these forms of energy originally derive from the sun (or in the case of nuclear energy, previous suns!).

    • Photo: Suze Kundu

      Suze Kundu answered on 20 Jun 2011:

      I don’t think that we can ever run out of electricity. Electricity is energy, and energy is never used up, but changed into another form of energy. Like with our screaming jelly babies. The energy in the jelly baby is changed to noise, heat and light. Theoretically, we wo’t run out of it. We might need new ways of converting it from one form to another, especially as fossil fuels are running out, but the electricity hopefully won’t run out.

    • Photo: David Ingram

      David Ingram answered on 21 Jun 2011:

      I’m not quite sure what you mean, but some electricity is “wasted” during transmission. We send power in the grid down wires and Ohm’s law says because of the resistance in the wires energy is lost to heat. We keep the voltage as high as possible to reduce these losses but we are still heating the wire.

      One of my colleagues says that when he worked in Sri Lanka they found that the coal fired power station on the island was just generating enough electricity to warm up the network and so making no contribution to peoples electricity demands! This was a very bad situation and fixed by modernising the network.

      In the UK most of our marine energy resources are in the North of Scotland and the South West of England and if we are to maximise their use and minimise losses we will need to increase the size of the wires used in the network in these areas and increase the network voltage. This will be expensive (transmission lines cost more than motorways to build) and is needed because our current network was designed to take power from coal mining areas to London, Birmingham and other big cities in the UK.