As power crisis continue to haunt the Southern Region, Zimbabwe has joined other member states in an effort to generate electricity using wind by establishing a pilot project in Mamina (Mashonaland West).
Harare – The pilot project is meant to study the viability of generating electricity using wind in the country to avert power crisis.
Wind energy, which involves using air to turn turbines and generate electricity, is regarded as one of the most reliable, cheap, renewable and clean form of power that does not pollute the environment as compare to other types such as thermal. Energy and Power Development Minister Samuel Undenge said government was doing all it can to produce adequate power.
“We want to explore all avenues to produce adequate power for the country, wind energy included. We are already running a wind energy pilot project in Mamina to see how feasible it is if implemented in the country,” Undenge said. Experts contend that wind energy potential exist in most parts of Zimbabwe for wind pumping and other mechanical conversion systems, with utilizable wind speeds ranging from 2,6 metres per second(m/s) to about 4 m/s.
Generally most parts of the country have a good wind energy resource averaging 3, 2 m/s all year round, good enough for wind pumping except areas around Kariba (Mashonaland Central). Areas around Bulawayo and some selected areas in the Eastern Highlands (Manicaland) have potential for power generation application since the most prevalent wind speeds range from 4 to 6 m/s.
These wind speed ranges have a high frequency and time distributions to give satisfactory power generation resumes.
The Southern African Development Community (SADC) has set itself a target of generating 20 percent of the region’s energy needs from renewable sources by 2025. Other SADC member states currently leading the quest on how to harness the vast wind potential that lies unexploited in the region are Mozambique, Tanzania, South Africa Madagascar and Namibia.
According to the African Development Bank, Sub-Saharan Africa has the potential to provide more than 170 gigawatts (GW) of additional power using wind far more than the sub-region’s current installations
provided other forms, apart from thermal and hydro are exploited.
These are solar and wind. Wind farms are also relatively easier to construct – as it takes about twelve months to build one with a capacity to generate 100 MW.
Zimbabwe Power Company managing director Noah Gwariro said generating energy using wind was pollution free. “Wind energy is really something which SADC can turn to, South Africa and other regional countries are already doing it.
Of course in the earlier days it may distort the skyline, but people will get used to it,” Gwariro said.
Some of the current wind farms in Southern Africa include two facilities in South Africa’s Western Cape Province (Klipheuwel and Darling); various 21 kilowatts wind/solar hybrids in Malawi. A 10 MW pilot project in Chicumbane in Mozambique is also under development.
In addition, Belgian green electricity company, Electrawinds, has begun the construction of a wind turbine in the harbor of Coega, near Port Elizabeth, South Africa.
The development is the first phase of a large wind farm that, in time, will comprise 25 wind turbines.
The first large scale wind farm in South Africa became operational in 2014, and others are in planning and construction stages.
Most of these are earmarked for locations along the Eastern Cape coastline. Eskom has constructed one small scale prototype windfarm at Klipheuwel in the Western Cape and another demonstrator site is near Darling with phase 1 completed.
In terms of future capacity building, wind power is expected to play a marginally bigger role in providing energy. Of the total new generation projects that came on board in Southern Africa in 2011, wind energy comprised 1, 5 percent.
This came entirely from a 25 MW project in the Lesotho highlands. In 2012 alone, 3,6 percent of new generation projects was wind power.
These included a 100 MW project from an Independent Power Producer (IPP) in South Africa and a 40 MW IPP project in Luderitz, Namibia. In 2013, a 40 MW wind project from an IPP in South Africa’s Eastern Cape made up one percent of the entire new generation capacity that came on stream during that year.
Despite the projects that have already been announced, South Africa was promoting 2,500 MW of wind power by end of last year. According to Global Wind Energy Council (GWEC), compared to other parts of the world, wind energy generation in Southern Africa still has a long way to go.
The world’s top five wind energy producers are currently the United States (installed capacity of 35,064 MW), China (25,805 MW), Germany (25,777 MW), Spain (19,149 MW) and India (10,926MW).
Apart from generating electricity, wind energy can also be used to pump water for agricultural purposes among other uses.
Wind turbines use the wind’s kinetic energy to generate electrical energy that can be used in homes and businesses. Individual wind turbines can be used to generate electricity on a small scale – to power a single home, for example.
A large number of wind turbines grouped together, sometimes known as a wind farm or wind park, can generate electricity on a much larger scale.
A wind turbine works like a high-tech version of an old-fashioned windmill.
The wind blows on the angled blades of the rotor, causing it to spin, converting some of the wind’s kinetic energy into mechanical energy. Sensors in the turbine detect how strongly the wind is blowing and from which direction.
The rotor automatically turns to face the wind, and automatically brakes in dangerously high winds to protect the turbine from damage. A shaft and gearbox connect the rotor to a generator (, so when the rotor spins, so does the generator.
The generator uses an electromagnetic field to convert this mechanical energy into electrical energy.
The electrical energy from the generator is transmitted along cables to a substation.
Here, the electrical energy generated by all the turbines in the wind farm is combined and converted to a high voltage. The national grid uses high voltages to transmit electricity efficiently through the power lines to the homes and businesses that need it.
Here, other transformers reduce the voltage back down to a usable level. Wind power converts the kinetic energy in wind to generate electricity or mechanical power.
The International Renewable Energy Agency (IRENA) said achieving a 36 per cent share of renewable energy in the global energy mix by 2030 has the potential to increase global gross domestic product (GDP) by up to 1.1 per cent, roughly USD 1.3 trillion.
“This analysis provides compelling evidence that achieving the needed energy transition would not only mitigate climate change, but also stimulate the economy, improve human welfare and boost employment worldwide,” the agency said recently.
The improvements in human welfare, IRENA noted, would go well beyond gains in GDP thanks to a range of social and environmental benefits.
The impact of renewable energy deployment on welfare is estimated to be three to four times larger than its impact on GDP, with global welfare increasing as much as 3, 7 per cent.
Employment in the renewable energy sector would also increase from 9, 2 million global jobs today, to more than 24 million by 2030.