58 research outputs found
Performance evaluation of wind turbines for energy generation in Niger Delta, Nigeria
This paper evaluates wind energy potentials of seven selected locations spreading across Niger-Delta
region of Nigeria using wind speed data that extend over 9 to 37 years and subjected to 2-parameter
Weibull distribution functions. The performance of four wind turbine models ranging from 35 to
500 kW was simulated in all the locations considered. The results show that the performance of all the
wind energy conversion systems gave the least energy output values at Ikom. In addition, annual energy
output ranged from 4.07 MWh at Ikom to 145.57 MWh at Ogoja with Polaris America (100 kW) and Zeus
Energy (500 kW) wind turbines respectively. It was also observed that, irrespective of the site, G-3120
(35 kW) wind turbine has the highest capacity factor among the models considered. Therefore, for wind
energy development, G-3120 model or wind turbine with similar rated wind speed would be most suitable
in all the locations. The number of inhabitants that can be served by the energy produced using
G-3120 turbine in each location was estimated
Solar energy applications and development in Nigeria: Drivers and barriers
In this study,current perspectives of solar energy utilization as a renewable energy option in Nigeria are
examined and discussed from the stand point of sustainable development.The country being a world
crude oil and natural gas producer,is over-dependent on the seenergy sourcesforelectricitygeneration
and otherenergyapplications.Thishascurrentlyputthecountryatariskofimpendingenergycrisesin
view ofthefastdiminishingfossilreserves,inadequaterefining capacitytomeetdomesticconsumption
and seriouscasesofenergyinsecurityinrestiveregionswhereexploitationsexist.Inspiteofthevast
fossil basedenergyreserves,ameagerelectricityproductioncapacitythatisputat4517.6MWasat
December 2012isgeneratedtosupporttheeconomyofateemingpopulationofapproximately170
million people.Nigeriaisnaturallyendowedwithabundantdepositofrenewableenergyresourcesof
which solarenergyfromtheSun(beingtheworld0s mostabundantandpermanentenergysource)has
for decadesbeenenjoyingveryhighlevelutilizationbyruraldwellersforagriculturalprocessingsinthe
country.Itisvastlydepositedwithanestimated17,459,215.2millionMJ/day of solar energy falling on the
country0s 923,768km2 land area(approximaterangeof12.6MJ/m2/day in the coastal region to about
25.2 MJ/m2/day in the far north). The different applications to which solar resources have been put and
the extent of utilization(including details of existing projects)in the country were thoroughly
investigated and discussed.The possible motivations for extensive development of solar energy
conversion systems in Nigeria area l so discussed and some of the barriers and challenges are presented.
Step sand policy measures to over come the barriers and facilitates the utilization of this resource are
suggeste
A Typical Meteorological Year Generation Based on NASA Satellite Imagery (GEOS-I) for Sokoto, Nigeria
Energy remains the convergence point of most critical economic, environmental,
and developmental issues confronting the wodd at the moment.
Clean, efficient, stable, and sustainable energy seiVices are ideal for global
prospe1ity. Energy is paramoru!l to achievi11g Nige1ia's Vision 20:2020
needed by the coruttly to be among the top 20 industiialized nations of
the world. Lack of energy or its insufficiency in an economy is a potential
source of social and economic pove1ty [I]. In general, a larger prop01tion
of energy is found to be consumed in buildings in Nigeria as is the case in
many countries. There is thus a growing concern about energy consrunp
The effect of climate change on solar radiation in Nigeria
In this study, global solar radiation over Nigeria was simulated under an enhanced atmospheric CO2 level using the International
Centre for Theoretical Physics (ICTP) Regional Climate Model version 3 (RegCM3) for the period 1981 to 2100 with ECHAM5
GCM as the lateral boundary conditions. The simulated seasonal global solar radiation bias for the RegCM3 with NIMET and
NASA observed datasets in the control period are of similar magnitudes and showed a mixture of persistent positive and negative biases
ranging between �10% and 30%. The model generally underestimates solar radiation (biases �10% to �30%) across the whole country in
most of the months. In addition, it overestimates radiation (biases +2–30%) over the northern region of the country. Alongside the present
climate (1981–2010), three future periods were considered viz: period 1 (2011–2040), period 2 (2041–2070) and period 3 (2071–2100)
for the potential future changes. The seasonal potential future changes in period 1 (i.e. potential future changes with respect to 2040)
showed a reduction in the range of 0% (North) to 3.27% (South) whereas more reduction in global solar radiation is observed in period
2 (i.e. 2041–2070 minus present climate) having general decrease ranging from 0.11% to 3.39% with the least value in April (Middle-belt)
and the largest in the South zone (March). Potential future changes in period 3 (i.e. 2071–2100 minus present climate) is generally
characterized with mixed increase and decrease in global solar radiation across the country than the previous two periods (1 and 2).
For the annual potential future changes, RegCM3 model predicted a decrease in solar radiation towards the end of the century with
more reduction found in the South zone and the least in the North region. Furthermore, future changes in global solar radiation across
the zones in all the periods are however found to be insignificant at p 6 0.01
A Typical Meteorological Year Generation Based on NASA Satellite Imagery (GEOS-I) for Sokoto, Nigeria
Computer simulation of buildings and solar energy systems are being used increasingly in energy assessments and design. This paper evaluates the typical meteorological year (TMY) for Sokoto, northwest region, Nigeria, using 23-year hourly weather data including global solar radiation, dew point temperature, mean temperature, maximum temperature, minimum temperature, relative humidity, and wind speed. Filkenstein-Schafer statistical method was utilized for the creation of a TMY for the site. The persistence of mean dry bulb temperature and daily global horizontal radiation on the five candidate months were evaluated. TMY predictions were compared with the 23-year long-term average values and are found to have close agreement and can be used in building energy simulation for comparative energy efficiency study
Blind test comparison on the wake behind a yawed wind turbine
This article summarizes the results of the Blind test 5
workshop, which was held in
Visby, Sweden, in May 2017. This study compares the numerical predictions of
the wake flow behind a model wind turbine operated in yaw to experimental
wind tunnel results. Prior to the workshop, research groups were invited to
predict the turbine performance and wake flow properties using computational
fluid dynamics (CFD) methods. For this purpose, the power, thrust, and yaw
moments for a 30° yawed model turbine, as well as the wake's mean and
turbulent streamwise and vertical flow components, were measured in the wind
tunnel at the Norwegian University of Science and Technology (NTNU). In order
to increase the complexity, a non-yawed downstream turbine was added in a
second test case, while a third test case challenged the modelers with a new
rotor and turbine geometry.Four participants submitted predictions using different flow solvers, three
of which were based on large eddy simulations (LES) while another one used an
improved delayed detached eddy simulation (IDDES) model. The performance of a
single yawed turbine was fairly well predicted by all simulations, both in
the first and third test cases. The scatter in the downstream turbine
performance predictions in the second test case, however, was found to be
significantly larger. The complex asymmetric shape of the mean streamwise and
vertical velocities was generally well predicted by all the simulations for
all test cases. The largest improvement with respect to previous blind tests
is the good prediction of the levels of TKE in the wake, even for the complex
case of yaw misalignment. These very promising results confirm the mature
development stage of LES/DES simulations for wind turbine wake modeling,
while competitive advantages might be obtained by faster computational
methods.</p
Impact of the Foreign Exchange Rates Fluctuations on Returns and Volatility of the Bucharest Stock Exchange
- …