Energy crisis: we hear these words every day but what does it mean? Are we tired and worn out?
Not this time – this refers to something much bigger than us. In a nutshell we are not producing enough electricity from the various current fuel sources to produce the energy we need. But more importantly we are unable to extract sufficient fuel from mother earth to satisfy our increasing demand.
Presently most of our energy comes from fossil fuels, deposited underground more than 300 million years ago, namely oil, natural gas and coal. So we have started to look above ground, where the seas are constantly moving and the wind is constantly blowing. Wind is a resource that’s always in supply and doesn’t cause pollution, damage the environment or dump hazardous waste. And it’s not a new technology – windmills have been in use for hundreds of years, producing energy for one reason or another.
Plenty of good reasons
Why do we need to find alternative solutions to fossil fuels?
- The remaining supplies of oil are finite with roughly 40 years supplies left.
- Burning fossil fuels releases carbon dioxide which contributes significantly to global warming and therefore climate change.
- The cost of mining coal is rising rapidly and supplies in South Africa are expected to run out in about 25 years.
- In SA we use very dirty coal to generate energy, as we export all our cleanest coal, to the detriment of our local carbon footprint and human/environmental health
- It is also becoming increasingly expensive to afford the environmental damage and carbon emissions associated with coal mining.
- Burning fossil fuels adds particles to the air which contribute towards reducing the amount of sunlight allowed to enter the earth’s atmosphere, giving rise to another problem, global dimming (less sunlight reaching earth).
- Energy from coal needs too much water to generate (roughly 200 litres water/ ton of coal), another resource we can’t afford to waste
Feasible alternatives: sun, tides, hydro and wind
more important than ever
It’s now more important than ever to find renewable and clean sources of energy to replace those dirty, finite resources. Many alternative power sources are being tested but the most feasible at present include the following:
- Harnessing the sun’s energy is especially useful in sunny regions like southern Africa
- Tidal power, capturing the constant movement of the tides by means of turbines on the ocean floor
- Hydroelectricity uses dammed up rivers, which can have detrimental effects on humans and environment too, and more recently the natural run-of-the-river idea
- Wind creates waves at sea and offers us two options: wind turbines out at sea and on land, and the harnessing of the wave energy created by the wind.
These last two options are particularly useful for countries that have long coastlines like Australia, the UK and South Africa. The most consistent winds come from the west, so western coastlines are most suitable for wave energy harnessing. South Africa’s coastline is roughly 3000kms long and quarter or more of it is west facing.
Wind is one of the fastest growing clean energy sources and contributes to about 3 % of the global electricity demand. George Monbiot points out in his book Heat, that the UK, an island surrounded by wild seas with high winds, has not had one wind free hour in 33 years!
a slow start
Many countries have been slow in implementing wind farms. South Africa at present has only one Eskom-sponsored test farm in operation with two more planned for the west coast soon.
Some advantages of wind farms include
- Operation costs are amongst the lowest
- Social acceptance of wind power is generally high provided the communities affected are directly involved
- Can add new life to rural communities by providing a source of income, not to mention electricity
- Low transport costs involved; can be produced where needed
- Environmental plus points include maintaining clean air and water, reducing destructive mining for coal and the transportation involved, minimal generation of hazardous wastes.
- Quicker to erect than coal manufacturing plants or nuclear power stations
Negative aspects of wind farms:
- shadows and flickering are disturbing near residential areas
- the larger the turbine, the bigger the noise
- they are considered visually unattractive in natural areas
- can impact on natural environment such as killing migrating birds, and loss of natural habitat during heavy duty construction
harnessing the wind for years
Historically humans have been harnessing the wind for at least 1000 years, and the first written account of a wind turbine dates back to Alexandria around the 2nd century BC. Windmills soon became more common place together with the water wheel for providing much of our ancestors energy – think of the Dutch windmills. Their Karoo counterparts continue to pump water today over much of South Africa’s arid farming areas.
With the rise of the Industrial revolution, wind became less important or able to supply the increasing demands for electricity. But all over the world, inventive people continued to develop the windmill as a source of energy. In the 1970’s when the global need arose to search for alternative energy, wind turbines were already quite far advanced.
Today 86 countries use wind energy and many are seeking to replace fossil fuels in the future. The world’s top five producers are:
- Germany 22 250 MW
- USA 16 820 MW
- Spain 15 145 MW
- India 7850 MW
- China 5900 MW
10 000 GW by 2013
In South Africa the government is aiming for 10 000 GW of renewable energy production by 2013, 700 MW of which will come from wind, the rest from biomass, solar and hydro-electricity. The Department of Minerals and Energy has embarked on an Integrated Energy Plan (IEP) to develop the renewable energy resources.
We have 3 planned wind farms one of which is already operational:
- Three experimental turbines have been launched at Klipheuwel on the west coast with an ability to generate 3.2 MW.
- A 100 MW wind farm is proposed by Eskom at Kookenaap
- A 5.2 MW farm is proposed for Darling, also near the west coast
What are the chances that you and I will be able to install a mini-turbine for domestic use in our garden in the near future? This is another story, which we will share with you next month.
To find out more about the exciting future of wind energy visit the Windaba 2011 at the Cape Town Convention Centre from 27-29 September..
By Annabelle Venter