New Internationalist

New Internationalist Issue 284

Issue 284

SIMPLY - Energy

No single energy system is perfect. But some are a good deal better than others. Future energy use is likely to consist of a mix-and-match approach - ideally, phasing out conventional sources and bringing in a range of non-polluting renewable options.

MICRO-HYDRO
Small-scale systems tap the energy of flowing water. These are not to be confused with big dam projects which totally transform ecosystems, wreaking environmental havoc. [image, unknown]

[image, unknown] Upside
[image, unknown] Very simple, cheap technology
[image, unknown] Clean, non-polluting
[image, unknown] Suitable for remote and hilly regions
[image, unknown] Produces cheap electricity
[image, unknown] Safe

[image, unknown] Downside
[image, unknown] Needs a sharp drop and regular, flowing water
[image, unknown] Needs to be small scale not to damage the environment

WINDPOWER
An ancient source undergoing a revival with modern turbine technology. [image, unknown]

[image, unknown] Upside
[image, unknown] Clean, non-polluting
[image, unknown] Plentiful, renewable supply
[image, unknown] Suitable for less sunny regions
[image, unknown] Dovetails well with other systems
[image, unknown] Simple technology
[image, unknown] Produces cheap electricity
[image, unknown] Safe if properly maintained

[image, unknown] Downside
[image, unknown] Aesthetically intrusive
[image, unknown] Windfarms make noise in quiet places

BIOMASS
Biomass is vegetal or organic material - including dung and plants - and biofuels are the solid or liquid or gaseous fuels that derive from it. Wood, methane and alcohol are all biofuels. [image, unknown]

[image, unknown] Upside
[image, unknown] Cheap, renewable
[image, unknown] Ideal for rural communities
[image, unknown] Recycles waste, including sewage
[image, unknown] Fertilizer as by-product
[image, unknown] Biofuels are less polluting fossil fuel alternatives

[image, unknown] Downside
[image, unknown] Specially-grown agricultural biomass could compete for land with other crops
[image, unknown] Reliance on woodfuel contributes to deforestation
[image, unknown] Some pollution from burning biofuels but no more carbon dioxide than would have been produced anyway by natural processes

GEOTHERMAL
This energy comes from the heat stored in rock below the earth's surface. The heat is 'mined' by drilling a bore hole and used to generate electricity or to heat water. [image, unknown]

[image, unknown] Upside
[image, unknown] Relatively clean, non-polluting
[image, unknown] Safe and inexhaustible
[image, unknown] Cost effective and growing fast
[image, unknown] Suitable sites exist in many parts of the world

[image, unknown] Downside
[image, unknown] Drilling is noisy and disposal of drilling fluids requires large lagoons
[image, unknown] Produces small amounts of carbonate, chloride and sulphide pollution



SOLAR
The sun's power can be harnessed in various ways: by using photovoltaic cells to generate electricity directly; by using thermal collectors to make steam to generate electricity; by using passive solar materials that maximize or retain the sun's heat. [image, unknown]

[image, unknown] Upside
[image, unknown] Clean, non-polluting
[image, unknown] Renewable, endless supply that belongs to no-one
[image, unknown] Operates best in the sunniest - often the poorest - parts
of the world
[image, unknown] Dovetails with other clean systems, eg windpower, hydrogen
[image, unknown] Flexible and modular - means systems can be any size
[image, unknown] Safe

[image, unknown] Downside
[image, unknown] Research and development underfunded
[image, unknown] Electricity produced is more expensive
[image, unknown] Cannot be used as the only system in cloudy places
[image, unknown] Energy has to be stored in batteries, hydrogen, water or other matter

NUCLEAR ENERGY
Currently produced by 'fission'. An atom is split - using uranium - and the heat produced drives steam turbines to generate electricity. [image, unknown]

[image, unknown] Upside
[image, unknown] Massive investment already committed
[image, unknown] Does not cause global warming or air pollution

[image, unknown] Downside
[image, unknown] Nuclear accidents and radiation leaks cause cancers and other fatal disorders.
[image, unknown] Legacy of radioactive waste that remains 'live' for
50-100 years
[image, unknown] Decommissioning old power stations very costly
[image, unknown] Expensive way of generating electricity

TIDAL POWER
Tidal energy is harnessed by building a barrage across an estuary. At high tide the barrage traps a head of water which is released at low tide to drive turbine electricity generators. [image, unknown]

[image, unknown] Upside
[image, unknown] Produces cheap power
[image, unknown] Clean, renewable, safe
[image, unknown] Low running costs
[image, unknown] Water behind a barrage is clear and more biologically productive
[image, unknown] Barrages protect against floods and storms
[image, unknown] Lots of potential worldwide

[image, unknown] Downside
[image, unknown] Set-up costs are high
[image, unknown] Tidal power comes, usually, in two daily bursts
[image, unknown] Tidal barrages have to be carefully situated to be efficient
[image, unknown] Large barrages affect estuary ecosystem


FOSSIL FUELS
Derived from long-dead organic and animal matter. Oil, coal, natural gas are all fossil fuels. [image, unknown]

[image, unknown] Upside
[image, unknown] World economy geared to fossil fuels
[image, unknown] They are practical

[image, unknown] Downside
[image, unknown] All produce greenhouse gases that cause global warming
[image, unknown] Oil produces toxic fumes causing air pollution, asthma and
brain damage
[image, unknown] Coal produces acid rain, air pollution and acute respiratory diseases


Sources: The Future of Energy Use by Robett Hill et al, Earthscan, London 1996. Renewable Energy: Power for a Sustainable Future ed. Godfrey Boyle, OUP/Open University 1996.
Illustrations by EARL DUKE

[image, unknown] NI Home Page[image, unknown] Issue 284 Contents


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