By Alex Misuko
In simple terms, wind can be defined as moving air. For centuries, mankind has leveraged on the wind to drive many things, making it, one of the most rapidly expanding renewable energy sources in the 21st century.
According to recent data from the International Renewable Energy Agency (IRENA), the installed capacity of onshore and offshore wind energy worldwide has expanded by a factor of about 75% over the previous two decades, moving from 7.5 gigawatts (GW) in 1997 to approximately 564 GW by 2018.
But with all this happening, where has wind power come from, and where are we headed to?
The first wind turbines surfaced more than a century ago following the invention of the electric generator in the 1830s. Thereafter, engineers began attempting to harness wind power to generate electricity. Although wind power was first produced in the United Kingdom and the United States in 1887 and 1888 respectively, modern wind power is thought to have originated in Denmark, where horizontal-axis wind turbines were erected in 1891, and a 22.8-meter wind turbine started operating in 1897.
Utilizing the kinetic energy provided by moving air, wind energy is used to generate electricity. Using wind turbines or other wind energy conversion technologies transform the kinetic energy into electric energy. Wind strikes a turbine's blades first, turning them and the turbine attached to them. By rotating a shaft that is attached to a generator, this converts kinetic energy into rotational energy, providing electrical energy through electromagnetism.
The turbine's size and the blades' length, will determine the quality and quantity of electricity generated. The output is inversely correlated with both the rotor's size and the wind speed cube. Theoretically, the potential for wind power doubles by eight when wind speed doubles.
The total capacity of wind turbines has developed over time. In 1985, average turbines had rotor diameters of 15 meters and rated capacities of 0.05 MW. New wind energy generators today feature offshore turbine capacity of 3-5 MW and onshore capacities of roughly 2 MW.
The average capacity of wind turbines grew from 1.6 MW in 2009 to 2 MW in 2014. With rotor diameters up to 164 meters, commercially available wind turbines now have a capacity of up to 8 MW
In Kenya, right at the northern tip of Kajiado County, about 25 kilometers from the capital city, Nairobi, is KenGen's Ngong Wind Farm, which was the first Wind Farm in Kenya and East Africa, sitting on 3,077.6 hectares of land. Its development dates back to 1993 when it had only two turbines.
In 2009, Phase I of Ngong wind farm was built. Phase 1 consisted of six turbines of 850 kW with a capacity of 5.1 MW which did very well; hence KenGen came up with Ngong Phase II, which was commissioned in 2014. Phase 11 had eight wind turbines from Vestas, a Danish model, and an additional 16 from Gamesa, which was a Spanish model generating 850Kw per turbine.
Currently, the farm has 30 wind turbines that readily convert the kinetic wind energy blowing from the windward end to the leeward side of the Great Rift Valley, generating 26 MW of clean power for the nation.
So next time you switch on the lights in your home, remember that it could be from the picturesque Ngong wind power plant.
By Tracy Chepkemoi
Energy is at the heart of climate change and is a key solution to what is considered one of the world’s most significant challenges in the 21st century. Research shows that a large chunk of the greenhouse gases that blanket the earth is generated through energy production by burning fossil fuels to generate electricity and heat.
Data from The Production Gap Report of 2019 by the United Nations Environment Programme (UNEP) indicates that fossil fuels, such as coal, oil and gas, are by far the most significant contributors to climate change globally accounting for over 75% of global greenhouse gas emissions and nearly 90% of all carbon dioxide emissions.
Alas, all is not gloomy for the Energy Sector as renewable energy sources, are available in abundance all around us. Through the sun, wind, water, waste, and heat from the Earth’s crust. Most renewable energy are replenishable by nature and emit little to no greenhouse gases or pollutants. This is why accelerating the transition to clean and renewable energy is the pathway to creating a sustainable future. And that is not all, here are more reasons;
1. Renewable energy sources are all around us
Provided by the sun, wind, water, waste, and heat from the Earth’s crust, renewable energy sources offer a way out of import dependency that cannot be depleted and are able to supply a continuous source of clean energy.This allows countries to diversify their economies and protect them from the unpredictable price swings of fossil fuels while driving inclusive economic growth, new jobs, and poverty alleviation.
2. Renewable energy is cheaper
According to the World Economic Report of 2020, Renewables are now significantly undercutting fossil fuels as the world’s cheapest energy sources; of the wind, solar and other renewables that came on stream in 2020, nearly two-thirds, 62%, were cheaper.
3. Renewable energy creates jobs
According to the World Resources Institute report, it is projected that $1 million in green energy investments would create more near-term jobs than the same amount invested in roads and fossil fuels. Increasing investments in the renewable energy sector has the potential to provide more jobs than any fossil fuel industry. This can be attributed to businesses realising that sustainable development is key to success, long-term positive performance, and secure investment. Aside from that, the prices of green energy products have dropped, over the last decade thus making them more affordable.
4. Renewable energy makes economic sense
Switching to renewables especially in existing power plants requires far less investment into the power sector than if you were to build new coal or nuclear power plants. This, in turn, means a lower electricity price, which impacts everything in the economy. Lower electricity price reduces production costs and increases business profit. Moreover, efficient, reliable renewable technologies can improve resilience and energy security by diversifying power supply options.
Recognising the urgency of mitigating climate change challenge, many countries and organisations have scaled up their efforts towards creating a sustainable and safer future. This was demonstrated at the recent COP 26, where 151 countries submitted new climate plans to cut their carbon emissions by 2030.
As a company, Kenya Electricity Generating Company PLC (KenGen) has been at the forefront in mitigating climate change in line with Kenya’s commitment to tackle climate change through reducing carbon emissions by 32% by the year 2030. The Company’s climate change policy has enhanced its commitment to reducing its carbon footprint and that of the country by investing in clean and low-carbon renewable energy sources.
Currently, KenGen is the leading electricity generating company in Eastern Africa with an installed capacity of 1,904MW, with 86 % from renewable and clean energy sources. Notably, KenGen supplies about 72% of electricity consumed in Kenya, which supports attainment of SDG 7 to ensure affordable, reliable, modern and sustainable energy for all.
The science is clear, to minimize the dire impact of climate change, we must invest in renewable energy sources, as they not only contribute to social and economic development, but also reduction of negative impacts of energy generation on the environment and human health.
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