CT: Technology to utilise the forces of nature for doing work to supply human needs is as old as the first sailing ship. But attention swung away from renewable sources as the industrial revolution progressed on the basis of the concentrated energy locked up in fossil fuels. This was compounded by the increasing use of reticulated electricity based on fossil fuels and the importance of portable high-density energy sources for transport – the era of oil.
As electricity demand escalated, with supply depending largely on fossil fuels plus some hydro power and then nuclear energy, concerns arose about carbon dioxide emissions contributing to possible global warming. Attention again turned to the huge sources of energy surging around us in nature – sun, wind, and seas in particular. There was never any doubt about the magnitude of these, the challenge was always in harnessing them.
Today we are well advanced in meeting that challenge. Wind turbines have developed greatly in recent decades, solar photovoltaic technology is much more efficient, and there are improved prospects of harnessing tides and waves. Solar thermal technologies in particular (with some heat storage) have great potential in sunny climates. With government encouragement to utilise wind and solar technologies, their costs have come down and are now in the same league as the increased costs of fossil fuel technologies due to likely carbon emission charges on electricity generation from them.
S: WN – http://www.world-nuclear.org/info/energy-and-environment/renewable-energy-and-electricity/ (last access: 10.12.2015)
N: 1. First used in English by physician Sir Thomas Browne in 1640s. From Latin electrum, and from Greek ἤλεκτρον, which means ‘amber’.
2. Atoms are small particles and put simply, they are the basic building blocks of everything around us, whether it is our chairs, desks or even our own body. Atoms are made up of even smaller elements, called protons, electrons and neutrons. When electrical and magnetic forces move electrons from one atom to another, an electrical current is formed.
3. In physics, energy is the capacity for doing work. It may exist in potential, kinetic, thermal, electrical, chemical or other various forms.
Energy can be converted from one form to another in various ways. Usable mechanical or electrical energy is, for instance, generated by many kinds of devices, including fuel-burning heat engines, generators, batteries, fuel cells, and magnetohydrodynamic systems. Electricity, instead, deals with the nature and phenomena of electrical action.
4. Electricity supply can be generated from traditional fuels, such as coal and natural gas, and from renewable energy sources. Regardless of the chosen fuel, most generators operate on the same proven principle: turn a turbine so that it spins magnets surrounded by copper wire, to get the flow of electrons across atoms, which in turn generates electricity.
- Coal and gas work in similar ways; they are both burned to heat water, which creates steam and turns the turbine.
- Renewable energy sources such as hydropower and wind operate slightly differently, with either the water or the wind being used to turn the turbine, and generate the electricity.
- Solar photovoltaic panels take a different approach again: they generate electrical power by converting solar radiation into electricity using semi-conductors.
Power stations convert fuels into electricity:
- Coal and gas are burned to heat water and turn it into steam.
- The steam, at a very high pressure, is then used to spin a turbine.
- The spinning turbine causes large magnets to turn within copper wire coils, this is called the generator.
- The moving magnets cause electrons in the wires to move from one place to another, creating an electrical current and producing electricity.
S: 1. OED – http://www.etymonline.com/index.php?term=electric&allowed_in_frame=0 (last access: 10 December 2015). 2, 4. OE – https://www.originenergy.com.au/blog/about-energy.html (last access: 10 December 2015). 3. TERMIUMPLUS (last access: 10 December 2015).
CR: atom, bioelectricity, biomass, diode , electrical energy, linear accelerator, energy poverty, electric power station, Faraday’s law of electromagnetic induction, halogen, lepton , photovoltaic module, synchrotron, tungsten, [wind turbine], X-rays.