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An energy supply should be:
Sustainable
Affordable
Reliable
All over the world, existing power generation by large fossil fuel or nuclear plant fails to meet some or all of the above criteria. Because of this, more and more small scale power supplies based on renewable energy technology are being set up.
This is described as "micropower" or "personal power generation". A typical micropower installation might be a small power station fueled by sustainable biomass, a wind turbine park, or a single, small wind turbine. Ownership is by commercial organizations, communities or individuals. This page explains why the criteria of sustainability, affordability and reliability are important,
and why a wind energy system has all these essential characteristics. |
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Sustainable
Global warming and pollution
According to the Intergovernmental Panel on Climate Change, the concentration of greenhouse
gases (such as carbon dioxide, methane, nitrous oxide,
etc) in our atmosphere continues to increase. Analysis of meteorological data over decades has
provided evidence of climate change superimposed on natural variability. This shows up as an
increase in global average temperature, a rise in sea level, more extreme weather conditions and
unusually severe floods. The IPCC also lists a disturbingly large range of damaging effects on
health likely to be caused by climate change. There is still some debate over the extent to which global warming
and
climate change can be attributed to greenhouse gases, but the IPCC states that there is a discernible
influence. By the time everyone is finally convinced of this, it may be too
late.
Although modern coal burning power stations are a lot cleaner than they used to be, pollutants such
as oxides of sulphur and nitrogen are still
produced. These cause rises in diseases such as asthma. They also cause acid rain
which destroys woodland and fish stocks in lakes. There are still many
old and very dirty power plants in use throughout the world, usually in countries which cannot
afford to replace them.
Burning any fossil fuel produces carbon dioxide, with coal producing most. Oil produces 23% less carbon dioxide
than coal
and natural gas 44% less, per unit of energy.
Nuclear power is often hailed as a clean alternative to fossil fuel. But, as we have seen at Three Mile
Island in 1979 and Chernobyl in 1986, any accident is potentially devastating. In the Czech Republic and
Austria, there is widespread public opposition to the Chernobyl class reactor at Temelin, South Bohemia.
Since coming on line recently, Temelin has been plagued with technical problems.
It is true that the radioactive waste from nuclear power is in a confined, controlled space, but no one
has any workable ideas about where this confined, controlled space should be, because its contents remains dangerously
radioactive for thousands of years. This is also true of the nuclear plant itself. When its component
parts can no longer function safely, the plant is shut down and left for centuries until the radioactivity within
it decays. "Transmutation", a process which could greatly reduce the half-life of radioactive waste
products has barely made the transition from hypothesis to laboratory experiment.
Each kWh of energy generated by a coal fired plant sends about one 1 kg of carbon dioxide, 10g of sulphur oxides and
5g
of nitrogen oxides into the atmosphere. If that kWh is generated by a wind turbine instead, these gases are not
produced.
A wind turbine's emissions into the environment amount to a slight whiff of lubricating oil. At the end of a wind
turbine's life, it gets taken down and re-cycled.
Declining fossil fuel resources
Despite improvements in exploration technology, deposits of coal, oil and gas are going to
become increasingly harder to find in the next 100 or 200 years. The World Energy
Council's Survey of Energy Sources states that there are recoverable coal reserves of
984 billion tonnes. At the current rate of production, this should last the world 200
years. We have to decide whether we want to go on producing/using coal at this rate
and generating the carbon dioxide which goes with it.
Estimates of oil reserves are difficult because prospectors are getting better at finding
smaller deposits. According the WEC survey, recent discoveries have almost kept
pace with production. But it is possible to estimate that there were originally about
2.3 trillion barrels of oil in the Earth, of which we have now used about a third. If
consumption proceeds at the same rate, the oil should start running out towards the end
of the 21st century.
For years natural gas was treated as a useless, sometimes dangerous, byproduct of coal mines and oil wells; its potential
as a relatively clean, easily transportable fuel was ignored. Then
in Europe in the 1960s reserves of natural gas were discovered. It began to replace coal gas
because it was cheaper, but the real start of the boom in world gas use began in the mid-eighties. As
well as heating homes, it now fuels gas-turbine power stations, and liquified natural gas is increasingly used
for vehicle engines. Fuel cell technology based on natural gas is developing rapidly.
There are large reserves of natural gas in Russia and more has been discovered in the North Sea, Argentina,
Mexico, Indonesia and North Africa. As with oil, exploration and extraction methods are improving
continually, so it is difficult to estimate when natural gas will become scarce. One estimate is
145 years at the current rate of production.
Fossil and nuclear fuels will probably never disappear entirely but there will come a time
when reserves will be so rare and difficult to extract that using them for energy generation
will no longer make commercial sense. Renewable energy however will always be there.
Sustainable development
The United Nations Development Program (UNDP) estimates that there are 2.5 billion people living in
remote rural villages throughout the developing world who do not have electricity. This prevents
rural people from harnessing their full potential.
It has been shown that access to even a small amount of electricity improves the health and prosperity of these communities.
But
there is little chance of the grid being extended to remote districts. Grid systems in undeveloped countries
are usually so overstretched as to be incapable of handling increased energy demand, especially over long distances.
Local solar, wind
and micro-hydro power are therefore the only practical alternatives, and already thousands of small wind turbines
are deployed in successful village power projects worldwide. These systems are
sustainable, cutting the community's dependence on expensive consumables which have to be brought long distances, such
as kerosene for lamps, dry batteries for radios or maybe diesel for a generator. Families don't have to breathe
kerosene smoke or diesel fumes so health improves. People no longer have to walk miles to fetch water or get a
car battery
recharged. A wind turbine can pump water or charge batteries. The electricity from small turbines
can enable small scale businesses to function and so prosperity increases. The country's dependence on imported
fuels is significantly reduced.
The largest successful deployment of small wind turbines outside pilot projects has been in China and Mongolia. The
Chinese wind turbine industry
began about 20 years ago with small machines that provided power for individual homes. Now there are more than
140000 of these operating with
7000 more installed annually. In the Inner Mongolian Autonomous Region, 600000 nomadic herdsmen depend on the electricity
produced by 100000 small wind turbines generating 1.2 billion kW/year.
Alongside other renewable energy technologies, small wind turbines can provide the world's poorest people with the electricity
they need
to improve health, education and expand opportunities for sustainable economic development.
Affordable
Despite the free fuel, wind power is only now after years of
development becoming economically competitive with fossil fired generation. This is because wind energy is much
less
concentrated than the energy in fossil fuel, so more wind generating equipment is needed per kW and capital cost is
therefore higher.
The cost of utility-scale wind turbines has dropped by about 80% in the last 20 years. The cost of
small wind turbines has been driven down less dramatically by economies of mass production, adoption of new
manufacturing techniques and improvements in energy capture. Good wind resource is critical for the
economic viability of any windpower project. For small wind systems, it has been stated that an average wind speed
greater than 5 metres/second is necessary, but this figure is being pushed downward. For a renewable energy system,
there
are two main costs: loan repayments and maintenance. These must be set against the cost of the electricity from
other sources, so that the turbine pays for itself after a number of
years. Cost also depends on application. For example, if the turbine is charging batteries, the cost of
changing them every five years or so must be taken into account. If the capital cost of a turbine is set against the
cost of
installing a grid connection in remote countryside then a small wind system is dramatically cheaper. A recent
quote for a mile long grid connection to a country home in the UK was over £150000!
UK electricity companies have been buying electricity from small grid connected turbines at very low rates compared with
sales at 6 to 7p per kW. But small turbine owners in the US are getting a fairer price for the electricity they sell
back to the grid because over 30 states now have net-metering or some arrangement approaching it. This is
where the electricity meter simply runs backward when power is supplied instead of consumed. In the UK, there are
rumours that some distribution companies are offering net-metering, but Iskra has so far been unable to get any of them
to admit it.
The energy generated by a large wind turbine equals that used to create it in a matter of months
according to three European studies. Small wind turbines achieve this balance in under a year.
An AT5-1 will cost as much as a new, medium price, family car. But the car gets junked after about eight years
while after
20 years, an AT5-1 will still be generating electricity.
Funding micropower for development
How can poor people in developing countries afford the equipment to generate their own electricity? There
are now organizations like the Grameen Bank in Bangladesh and ADESOL in Dominica, that give
credit to people wanting to buy renewable energy systems for their homes, to groups wanting to set up
a system to supply a whole village or to a small entrepreneur needing a power supply to start a
business. By this means, very small solar systems come within reach of many families, with larger solar systems
and wind turbines becoming feasible for communities and businesses.
Experience with rural renewable energy projects shows that it is essential for long term success that
the people who need the power should be involved in running the project. Long term support is needed until they
are able to organize the collection of payments, the maintenance of the system etc. Where the infrastructure
that we take for granted in affluent nations does not exist, the provision of a secure supply of electricity is not
only a matter of demonstrating that some technology works. Several projects have run
into difficulties or failed completely because local institutions to look after the system(s) have not been established.
But where this has been carefully done, projects achieve financial and technical sustainability and have
been running successfully for years.
It is becoming possible for poor people in under developed countries to purchase and control there own environmentally
benign power systems.
Reliable
Centralized power supplies
We have already seen that remote communities in poor countries are unlikely to get power from a national
grid.
But how reliable are the grid systems to which many people are connected, especially those systems struggling to cope
with
ever increasing demand and under-funded maintenance? A search of any news web site produces a long list of
power black outs and brown outs which have happened all over the world. In Vladivostock, the main roads were
recently blocked by people protesting at the deaths of children because of winter power cuts in temperatures below
-30oC. At the end of 2000, much of Serbia was blacked out as the state power company introduced
rationing.
India and Bangladesh both suffer from chronic shortage of electricity. The greater part
North India was blacked out early in 2001, when a fault in one power station set off a domino collapse
of all the stations supplying the grid. Then backup systems also failed. In Bangladesh, the whole country
was plunged into darkness the night everyone wanted to watch the World Cup.
In the west, we depend increasingly on electricity to run the computer based systems which have become - for good or
ill -
so necessary to our daily lives.
We might expect countries with struggling economies to have problems with their electricity distribution. But
even in the affluent west it seems that electricity supply can no longer be taken for granted. In the summer of
1999,
Washington, New York and Chicago were each hit by blackouts. In December of the same year, France's national grid was
damaged by severe storms so extensively that three million people were left without electricity. In Washington
DC, freak
storms and flooding in August, 2001, caused elderly power cables to overheat, resulting not only in blackouts but also
explosions which blew manhole covers high in the air.
Probably the most dramatic recent event to affect the market for small wind energy systems has been the sudden
instability of power supplies from conventional utilities in California caused not by extreme weather but by problems
with the US's newly
deregulated market for energy. Around half a million Californian homes and businesses were subjected to black-outs
repeatedly during the winter and spring of 2001. This, coupled with steep rises in electricity prices
throughout America, has resulted in an increase in demand for small wind turbines with which US manufacturers say they
are struggling to keep up.
A robust electricity distribution system receives its power from many sources, diverse in fuel and size. The failure
of one or a few of these does not bring down the whole system. Also the burden on distribution equipment is reduced
if it contains a large number of small generators. A centralized system is only supplied by a few very large power
stations, so the consequences of a failure at one station or in part of the grid can be catastrophic.
A large population of diverse micropower sources, including even small windturbines like the AT5-1, makes for a reliable
electricity supply system.
Security
Many countries do not have their own fossil fuel resources and so have to rely on imports.
A rise in
the cost of imported fuel does heavy economic damage to developing countries, slowing down economic growth and
increasing their burden of debt. In the early 1980s, some developing
countries spent around half their export earnings on importing oil.
Fuel imports can be threatened in times of political dispute. In 1989, India imposed an embargo
on the sale of kerosene to Nepal, causing massive
economic disruption. Countries like Nepal not only have to be careful not to upset fuel exporters but also
have to find more and more money to pay them, .
Rich countries are also seriously affected. In 1973, the Arab nations imposed an oil embargo
on the US because of its support for Israel in the Yom Kippur war. This was the last straw at a time of
increasing oil demand and diminishing supplies. Not only did this mean queues at petrol stations but the
end of an era of economic growth fuelled by cheap, abundant oil. Oil prices took another leap in 1979 with the
downfall of the Shah of Iran, as the ensuing political turmoil disrupted Iranian oil production. At the
beginning of another century, about two thirds of the world's remaining oil reserves are still concentrated in a small
area of the Middle East, which, thanks to the best efforts of politicians, is still dangerously unstable. The pressure
on the region will only worsen as supplies diminish, production costs rise and world demand increases.
No one has yet found a way of turning off the wind.
Iskra Wind Turbine Manufacturers
Email Iskra
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