Power of the Nigerian WindBy Ayoola Brimmo
Published on 14 July 2015
In May 2015, the Federal Government of Nigeria disclosed that the construction of a 10MW wind farm in Katsina State had reached 98 percent completion. This being the country's introduction into large scale renewables deserves some accolades --especially as the kidnapping of a staff of the wind turbine installation company in 2012 did not significantly delay the original commissioning date.
However, we shouldn’t get overwhelmed with this accomplishment to the extent that the fundamental principles of wind power are neglected. As Steve Wyne warned: “if you neglect the basics, you're at risk, and the people with you are at risk”.
The first law of thermodynamics suggests that energy can never be created nor destroyed – it can only be transformed from one form to the other. Echoing this principle, wind energy conversion in itself is the transformation of the prevailing wind’s kinetic energy into more readily accessible forms of energy such as electricity. Simply put, in the absence of wind, generating electricity with wind turbines would be impossible.
Large scale wind turbines are usually designed to generate their rated power at wind speeds between 10-15 m/s. However, even in regions where the wind speeds are predominately above 10m/s, wind farms generate only about 50% of their rated capacity all year long. This is due to inevitable losses and variation in wind speed with seasons.
Putting Katsina State into perspective, the state government estimated the average annual wind speed, at the hub height of the installed wind turbines, as 6.044 m/s. It is vital to note that other calculations and satellite captured data corroborate this value. Based on this wind speed, the average capacity factor of the Katsina wind farm would be about 5 -15% — on an annual average, the wind farm would supply only about 0.5 - 1.5 MW. Using Irena’s data for the cost of wind power facilities in developed countries, the Levelized Cost of Energy (LCOE) of the power plant is estimated as $0.20 per kWh. Hence, it is anticipated that in the case of Katsina – located in a developing country like Nigeria – the LCOE may be as high as $0.30 per kWh. This is about twice the average electrical energy cost from the national grid and only about 20% lower than the cost of using a diesel generator.
In Nigeria, Katsina is one of the windiest regions– only Jos and Kano are windier. Based on the wind resource available, the country’s wind is classified as poor in the south and moderate in the north— no region within the country is classified as being ideal for large scale wind energy conversion. Considering that wind energy now sells at $0.025 per kWh, an LCOE of $0.30 per kWh is truly a far cry from ideal.
The wind energy option might pose a better alternative for the Nigerian manufacturers who solely rely on diesel generators or the 60% of Nigerians who have no connection to the national grid. Despite that, it is still questionable if this is intuitively their best option. Further contemplations arise when one considers that Katsina has about the same amount of solar irradiation as the United Arab Emirates where solar energy is planned to be sold at an unsubsidized rate of $0.054 per kWh – less than the $0.09 per kWh LCOE for natural gas fired power plants.
Globally, on-shore wind power is considered as one of the cheapest renewable energy option but this does not necessarily apply to Nigeria due to its wind power density– or lack thereof. The country can avail itself of its many renewable energy options but in doing so, it must not neglect the fact that financial sustainability is equally as important as environmental sustainability. Perhaps, solar PV is more appropriate for the region or maybe even natural gas fired power plants with CO2 capture would suffice.