Eustace NFAH - Academia.edu (original) (raw)
Papers by Eustace NFAH
Energy Conversion and Management, Jun 1, 2008
Wind/Diesel/battery hybrid power systems have been modelled for electrification of typical rural ... more Wind/Diesel/battery hybrid power systems have been modelled for electrification of typical rural households and schools in remote areas of the Far North Province of Cameroon. The wind resource of Maroua Salak for the period 1991-1995 was used in this modelling. The diurnal and monthly patterns of wind speeds at Maroua show that wind speeds in the range 3-6 m/s occur from 9:00 to 15:00 for eight months. The time duration of wind speeds in this interval was found to be 36.1%. The annual capacity factors computed for low start up wind turbines from China were found to be in the range 20-40%. Two wind turbines with rated powers 180 W and 290 W attained acceptable capacity factors of 38 and 40% and were used in sizing wind hybrid systems for typical rural households energy needs in the range 70-300 kWh per year. It was also found that a wind/Diesel hybrid power system based on a combination of two wind turbines rated 290 W and a 5 kW single phase generator operating at a load fraction of 70% required only 106 generator hours/yr to supply 2585 kWh/yr or 7 kWh/day to a typical secondary school. The renewable energy fractions attained in feasible systems were in the range 70-100%. These results show that there is a possibility to increase the access rate to electricity in the Far North without recourse to grid extension or more thermal plants in the northern grid or more independent Diesel plants supplying power to remote areas of the province.
Renewable Energy, Jun 1, 2009
Pico-hydro (pH) and photovoltaic (PV) hybrid systems incorporating a biogas generator have been s... more Pico-hydro (pH) and photovoltaic (PV) hybrid systems incorporating a biogas generator have been simulated for remote villages in Cameroon using a load of 73 kWh/day and 8.3 kWp. Renewable energy systems were simulated using HOMER, the load profile of a hostel in Cameroon, the solar insolation of Garoua and the flow of river Mungo. For a 40% increase in the cost of imported power system components, the cost of energy was found to be either 0.352 V/kWh for a 5 kW pico-hydro generator with 72 kWh storage or 0.396 V/kWh for a 3 kWp photovoltaic generator with 36 kWh storage. These energy costs were obtained with a biomass resource cost of 25 V/tonne. The pH and PV hybrid systems both required the parallel operation of a 3.3 kW battery inverter with a 10 kW biogas generator. The pH/ biogas/battery systems simulated for villages located in the south of Cameroon with a flow rate of at least 92 l/s produced lower energy costs than PV/biogas/battery systems simulated for villages in the north of Cameroon with an insolation level of at least 5.55 kWh/m 2 /day. For a single-wire grid extension cost of 5000 V/km, operation and maintenance costs of 125 V/yr/km and a grid power price of 0.1 V/kWh, the breakeven grid extension distances were found to be 12.9 km for pH/biogas/battery systems and 15.2 km for PV/biogas/battery systems respectively. Investments in biogas based renewable energy systems could thus be considered in the National Energy Action Plan of Cameroon for the supply of energy to key sectors involved in poverty alleviation.
International Journal of Photoenergy
This paper presents an enhanced perturb and observe (P&O) method for reconciling the trade-off pr... more This paper presents an enhanced perturb and observe (P&O) method for reconciling the trade-off problem between the dynamic response and steady-state oscillations in maximum power point tracking (MPPT). The constraint of having to sacrifice either the dynamic response or the steady-state oscillations has been solved. The method uses the relationship between the open-circuit voltage and maximum power voltage from the fractional open-circuit voltage (FOCV) MPPT method to establish a valid, reduced, and confined search space within which an enhanced P&O via dynamic adaptive step size terminates the search for the maximum power point. The feasibility of the proposed method has been validated by comparing its performance with the conventional P&O algorithm. It was noted that the proposed method increased the operational efficiency of the PV module to 99.89%, reduced the tracking time to 1.8 ms, and preserved the good steady-state response with a power attenuation of less than 0.10 W or re...
International Journal of Dynamics and Control, 2016
In this paper, a new control strategy of a variable speed based SEIG wind energy conversion is pr... more In this paper, a new control strategy of a variable speed based SEIG wind energy conversion is presented. Nonlinear control strategy is proposed to extract maximum available energy from the wind turbine and regulate the rotor flux magnitude of SEIG and the DC-link voltage in the generator side as well as the load voltage magnitude in the inverter load side under wind speed, load and rotor/stator resistances variations. The proposed nonlinear adaptive controller is robust given its insensitivity to SEIG variation of the rotor and stator resistances. The global convergence and stability analysis taking into account the interconnections between the stator electrical angular position, the rotor flux and rotor resistance estimators and the nonlinear controller have been proved by using the separation principle. Another contribution of this paper is the robustness of the proposed method with respect to the variation of the driven speed and relatively low wind speed operation. Thus, the proposed B Godpromesse Kenne
Journal of Circuits, Systems and Computers, 2017
In this paper, an adaptive proportional-integral (API) control strategy is developed to extract t... more In this paper, an adaptive proportional-integral (API) control strategy is developed to extract the maximum power from a variable wind speed turbine and to regulate the DC-link voltage, rotor flux and AC load voltage in a three-phase grid-connected self-excited induction generator (SEIG) system. The resulting controller associated to the flux-oriented control technique can be easily implemented in practice since finite time estimators for the unknown time-varying rotor resistance, rotor flux (nonmeasurable signal) and stator electrical angular position required for the online implementation of the proposed algorithm are provided. Comparative results with a conventional nonadaptive proportional-integral regulator have shown the superiority of the proposed strategy in terms of robustness with respect to online variation of the rotor resistance (up to 100%) and large varying load condition. The computing results are obtained using relatively low wind speed profile. Thus, the generating...
Power and Energy Systems, 2010
A new generalised sizing method for photovoltaic hybrid system (PVHS) based on desired annual gen... more A new generalised sizing method for photovoltaic hybrid system (PVHS) based on desired annual generator hours has been proposed and tested with varying monthly energy demands (M1) and a constant daily profile of 72.6 kWh/d (M2). The PVHS options were determined using these load profiles and the monthly energy outputs of PV modules that have been computed for Garoua situated in north Cameroon. The results obtained showed that the PV array sizes computed with M1 were higher that those computed with M2 at renewable energy fractions greater than 84.6%. Power options with PV array sizes in the ranges 9.0 - 24.12 kWp and 9.0 - 21.96 kWp were found for M1 and M2 respectively and the renewable energy fractions were in the range 52 - 100%. The annual generator hours were in the ranges 0 - 1784 hours and 0 - 1787 hours for M1 and M2 respectively. The PV array sizes for a renewable energy fraction of about 60% was found to be 41.8% and 45.9% of the PV size required in standalone options for M1 and M2 respectively. This new method can be used for the sizing of PV hybrid systems irrespective of the monthly energy demand profiles
Solar Energy, 2012
Abstract Photovoltaic hybrid systems (PVHS) with 2 days of energy autonomy are shown to be optima... more Abstract Photovoltaic hybrid systems (PVHS) with 2 days of energy autonomy are shown to be optimal options for the supply of the daily energy demands of 33 base transceiver stations of MTN Cameroon. PVHS were computed for all sites using the technical data for a 150 Wp mono-crystalline module, the site specific hourly load data, the average monthly solar radiation and temperature. Hourly solar radiation data for all sites were downloaded using the solar resource module of HOMER and geographical coordinates of the selected sites. The 3-hourly temperature data available on a website maintained NASA was used to generate average monthly hourly temperatures needed in the calculation of the output of solar modules. The energy costs and breakeven grid distances for possible power options were computed using the Net Present Value Technique and financial data for selected power system components. The results with a PV module cost of 7.5 €/Wp, a remote diesel price of 1.12 €/l, a general inflation rate of 5% and a fuel escalation of 10% showed that the annual operational times of the diesel generator were in the range 3–356 h/year with renewable energy fractions in the range 0.89–1.00. However, only 22 PVHS had two parallel battery strings as stipulated in the request for proposal launched by MTN Cameroon in 2008. The PV array sizes evaluated for the 22 PVHS were found to be the range 2.4–10.8 kWp corresponding to daily energy demands in the range 7.31–31.79 kW h/d. The energy costs and breakeven grid distances determined were in the ranges 0.81–1.32 €/kW h and 10.75–32.00 km respectively.
Renewable Energy, 2007
... 180 W were selected on the basis of the availability of performance data for the modelling of... more ... 180 W were selected on the basis of the availability of performance data for the modelling ofsolar/diesel/battery hybrid power systems ... included three categories for household energy demand: low-energy households requiring less than 70 kWh/yr for lighting and radio ...
Renewable Energy, 2008
Off-grid generation options have been simulated for remote villages in Cameroon using a load of 1... more Off-grid generation options have been simulated for remote villages in Cameroon using a load of 110 kWh/day and 12 kWp. The energy costs of proposed options were simulated using HOMER, a typical village load profile, the solar resource of Garoua and the flow of river Mungo. For a 40% increase in the cost of imported power system components, the cost of energy was found to be 0.296 h/kWh for a micro-hydro hybrid system comprising a 14 kW micro-hydro generator, a 15 kW LPG generator and 36 kWh of battery storage. The cost of energy for photovoltaic (PV) hybrid systems made up of an 18 kWp PV generator, a 15 kW LPG generator and 72 kWh of battery storage was also found to be 0.576 h/kWh for remote petrol price of 1 h/l and LPG price of 0.70 h/m 3. The micro-hydro hybrid system proved to be the cheapest option for villages located in the southern parts of Cameroon with a flow rate of at least 200l/s, while the PV hybrid system was the cheapest option for villages in the northern parts of Cameroon with an insolation level of at least 5.55 kWh/m 2 /day. For a single-wire grid extension cost of 5000 h/km, operation and maintenance costs of 125 h/yr/km and a local grid power price of 0.1 h/kWh, the breakeven grid extension distances were found to be 15.4 km for micro-hydro/LPG generator systems and 37.4 km for PV/LPG generator systems respectively. These results could be used in Cameroon's National Energy Action Plan for the provision of energy services in the key sectors involved in the fight against poverty.
Renewable and Sustainable Energy Reviews, 2012
This paper examined the initiation, funding, realisation and the current state of some renewable ... more This paper examined the initiation, funding, realisation and the current state of some renewable energy applications in the West Region of Cameroon. The findings from the study conducted showed that all of the renewable energy applications were initiated by indigenes living outside the beneficiary communities. The lack of fee-for-service tariffs was partly responsible for the failure of a wind electric installation for potable water pumping. Conflicts in a local management committee resulted in the inoperative state of a pico-hydro installation, while the lack of finances accounted for the failure of a PV system of rural Health Centre. Although, some successful results were noted in the activities of African Center for Renewable and Sustainable Technologies (ACREST) involving foreign technical expertise in small scale renewable energy applications, ACREST had difficulties with the implementation of 100 kW micro hydro project. The stakeholders identified for successful renewable energy applications in Cameroon included local management committees, microfinance institutions, Non-Governmental Organisations (NGOs), Renewable Energy Enterprises (REEs) and universities. Local management committees must be in charge of the supervision, operation and maintenance of installed systems as well as revenue collection based on fee-for-service tariffs. Microfinance institutions should grant loans for the acquisition of financially and economically viable off-grid renewable energy systems to communities with monthly installments based on established monthly energy expenditures. NGOs are expected to provide technical assistance for the conception of community projects, the procurement of funding from cooperation partners and for the realisation of projects. REEs should have competence for sizing, installation and post-installation maintenance of renewable energy equipment. Universities must train the technicians and engineers that will be used by NGOs and REEs. This important role has been recognised by the government of Cameroon through the creation of the first Department of Renewable Energy at the University of Maroua in 2008.
Revue Africaine de la Recherche en Informatique et Mathématiques Appliquées, 2019
International audience Electricity access in remote areas of Sub-Saharan Africa is limited due to... more International audience Electricity access in remote areas of Sub-Saharan Africa is limited due to high costs of grid extension to areas characterised by low population and low energy densities. Photovoltaic hybrid systems can be computed using an energy balance equation involving one unknown. For hypothetical village with an average daily energy demand of 153.6 kWh/d, the monthly energy output of photovoltaic modules at Garoua, Cameroon, enabled the evaluation of feasible photovoltaic hybrid (PVHS) options. An option with a renewable energy fraction of 0.557 having lower initial investments is suggested for electrification of more remote villages in Sub-Saharan African countries which have high solar radiation levels. This option comprises a 23.56 kWp PV array, a 15 kWp PV inverter, a 25 kW bi-directional inverter, a battery bank of capacity 324.48 kWh and a 25 kW diesel generator with an operating time of 1309 h/yr or 3.59h/d. The size of the PV array determined is smaller compared...
Renewable Energy, 2013
Optimal photovoltaic hybrid systems (PVHS) have been evaluated for remote villages in Far North C... more Optimal photovoltaic hybrid systems (PVHS) have been evaluated for remote villages in Far North Cameroon using a recent iterative optimisation method based on desired annual number of generator hours and the Net Present Value technique. PVHS configurations with the same PV array size were computed for varying energy demand (D1) and constant daily energy demand (D2) when the minimum desired renewable energy fraction was set to 20%. However, the annual diesel generator operating times in PVHS configurations were found to be higher for D1 at renewable energy fractions greater than 71.9%. The results of economic analysis using a PV module cost of a remote fuel price of 1.12 V/l, inflation rate of 5%, discount rate of 6%, 2 days autonomy, PV module costs in the range 7.5 V/Wpe0.75 V/Wp, and fuel escalation rate in the range 5%e20%, showed that PVHS were the optimal options for D2 for all combinations of sensitivity variables. PVHS were also found to be the optimal option for D1 at a fuel escalation rate of at most 10%. SPVS were found to be optimal option for D1 at a fuel escalation is at least 15% and PV module costs are in the range 2.25 V/Wp À0.75 V/Wp. The renewable energy fractions evaluated for optimal PVHS options were found to be in the ranges 88.7%e97.0% and 89.4%e99.9 % for D1 and D2 respectively. Consequently, PVHS are the optimal power option for the electrification of villages in Far North Cameroon, with annual solar insolation of at least 5.5 kWh/m 2 /d and annual energy demand of 72.6 kWh/d if the fuel escalation rate is at most 10%.
Renewable Energy, 2010
A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standal... more A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standalone diesel generator options is performed using the net present value (NPV) technique. A typical village mini-grid energy demand of 7.08 kWh/day is considered in the computation of energy costs and breakeven grid distances. A first sensitivity analysis is conducted using remote diesel prices of 0.8 V/l, 0.98 V/l, 1.12 V/l, 1.28 V/l with a PV module cost of 7.5 V/Wp. A second sensitivity analysis is also done using PV module costs of 5.25 V/Wp, 6 V/Wp, 6.75 V/Wp, 7.5 V/Wp with a diesel price of 1.12 V/l. The energy cost for the diesel option was found to be 0.812 V/kWh at a diesel fuel price of 1.12 V/l. The sensitivity analyses showed that minimum energy costs were attained in PVHS at renewable energy fractions in the range 82.6e95.3%. In the second sensitivity analysis the energy costs and breakeven grid distances were found to be in the ranges 0.692e0.785 V/kWh and 5.1e5.9 km respectively. For a PV module cost of 5.25 V/Wp, the lowest energy cost for the PVHS option was 0.692 V/kWh at a final renewable energy fraction of 95.3% with the diesel generator hours being 37 h compared to 2075 h in the standalone diesel generator option. Consequently, a 30% reduction in custom duties and taxes on imported PV modules and subsystems would increase the use of small-scale and climate friendly PV mini-grids in remote areas of far north Cameroon that have an annual insolation of at least 5.55 kWh/m 2 /day.
Renewable Energy, 2010
A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standal... more A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standalone diesel generator options is performed using the net present value (NPV) technique. A typical village mini-grid energy demand of 7.08 kWh/day is considered in the computation of energy costs and breakeven grid distances. A first sensitivity analysis is conducted using remote diesel prices of 0.8 V/l, 0.98 V/l, 1.12 V/l, 1.28 V/l with a PV module cost of 7.5 V/Wp. A second sensitivity analysis is also done using PV module costs of 5.25 V/Wp, 6 V/Wp, 6.75 V/Wp, 7.5 V/Wp with a diesel price of 1.12 V/l. The energy cost for the diesel option was found to be 0.812 V/kWh at a diesel fuel price of 1.12 V/l. The sensitivity analyses showed that minimum energy costs were attained in PVHS at renewable energy fractions in the range 82.6e95.3%. In the second sensitivity analysis the energy costs and breakeven grid distances were found to be in the ranges 0.692e0.785 V/kWh and 5.1e5.9 km respectively. For a PV module cost of 5.25 V/Wp, the lowest energy cost for the PVHS option was 0.692 V/kWh at a final renewable energy fraction of 95.3% with the diesel generator hours being 37 h compared to 2075 h in the standalone diesel generator option. Consequently, a 30% reduction in custom duties and taxes on imported PV modules and sub-systems would increase the use of small-scale and climate friendly PV mini-grids in remote areas of far north Cameroon that have an annual insolation of at least 5.55 kWh/m 2 /day.
Energy Conversion and Management, Jun 1, 2008
Wind/Diesel/battery hybrid power systems have been modelled for electrification of typical rural ... more Wind/Diesel/battery hybrid power systems have been modelled for electrification of typical rural households and schools in remote areas of the Far North Province of Cameroon. The wind resource of Maroua Salak for the period 1991-1995 was used in this modelling. The diurnal and monthly patterns of wind speeds at Maroua show that wind speeds in the range 3-6 m/s occur from 9:00 to 15:00 for eight months. The time duration of wind speeds in this interval was found to be 36.1%. The annual capacity factors computed for low start up wind turbines from China were found to be in the range 20-40%. Two wind turbines with rated powers 180 W and 290 W attained acceptable capacity factors of 38 and 40% and were used in sizing wind hybrid systems for typical rural households energy needs in the range 70-300 kWh per year. It was also found that a wind/Diesel hybrid power system based on a combination of two wind turbines rated 290 W and a 5 kW single phase generator operating at a load fraction of 70% required only 106 generator hours/yr to supply 2585 kWh/yr or 7 kWh/day to a typical secondary school. The renewable energy fractions attained in feasible systems were in the range 70-100%. These results show that there is a possibility to increase the access rate to electricity in the Far North without recourse to grid extension or more thermal plants in the northern grid or more independent Diesel plants supplying power to remote areas of the province.
Renewable Energy, Jun 1, 2009
Pico-hydro (pH) and photovoltaic (PV) hybrid systems incorporating a biogas generator have been s... more Pico-hydro (pH) and photovoltaic (PV) hybrid systems incorporating a biogas generator have been simulated for remote villages in Cameroon using a load of 73 kWh/day and 8.3 kWp. Renewable energy systems were simulated using HOMER, the load profile of a hostel in Cameroon, the solar insolation of Garoua and the flow of river Mungo. For a 40% increase in the cost of imported power system components, the cost of energy was found to be either 0.352 V/kWh for a 5 kW pico-hydro generator with 72 kWh storage or 0.396 V/kWh for a 3 kWp photovoltaic generator with 36 kWh storage. These energy costs were obtained with a biomass resource cost of 25 V/tonne. The pH and PV hybrid systems both required the parallel operation of a 3.3 kW battery inverter with a 10 kW biogas generator. The pH/ biogas/battery systems simulated for villages located in the south of Cameroon with a flow rate of at least 92 l/s produced lower energy costs than PV/biogas/battery systems simulated for villages in the north of Cameroon with an insolation level of at least 5.55 kWh/m 2 /day. For a single-wire grid extension cost of 5000 V/km, operation and maintenance costs of 125 V/yr/km and a grid power price of 0.1 V/kWh, the breakeven grid extension distances were found to be 12.9 km for pH/biogas/battery systems and 15.2 km for PV/biogas/battery systems respectively. Investments in biogas based renewable energy systems could thus be considered in the National Energy Action Plan of Cameroon for the supply of energy to key sectors involved in poverty alleviation.
International Journal of Photoenergy
This paper presents an enhanced perturb and observe (P&O) method for reconciling the trade-off pr... more This paper presents an enhanced perturb and observe (P&O) method for reconciling the trade-off problem between the dynamic response and steady-state oscillations in maximum power point tracking (MPPT). The constraint of having to sacrifice either the dynamic response or the steady-state oscillations has been solved. The method uses the relationship between the open-circuit voltage and maximum power voltage from the fractional open-circuit voltage (FOCV) MPPT method to establish a valid, reduced, and confined search space within which an enhanced P&O via dynamic adaptive step size terminates the search for the maximum power point. The feasibility of the proposed method has been validated by comparing its performance with the conventional P&O algorithm. It was noted that the proposed method increased the operational efficiency of the PV module to 99.89%, reduced the tracking time to 1.8 ms, and preserved the good steady-state response with a power attenuation of less than 0.10 W or re...
International Journal of Dynamics and Control, 2016
In this paper, a new control strategy of a variable speed based SEIG wind energy conversion is pr... more In this paper, a new control strategy of a variable speed based SEIG wind energy conversion is presented. Nonlinear control strategy is proposed to extract maximum available energy from the wind turbine and regulate the rotor flux magnitude of SEIG and the DC-link voltage in the generator side as well as the load voltage magnitude in the inverter load side under wind speed, load and rotor/stator resistances variations. The proposed nonlinear adaptive controller is robust given its insensitivity to SEIG variation of the rotor and stator resistances. The global convergence and stability analysis taking into account the interconnections between the stator electrical angular position, the rotor flux and rotor resistance estimators and the nonlinear controller have been proved by using the separation principle. Another contribution of this paper is the robustness of the proposed method with respect to the variation of the driven speed and relatively low wind speed operation. Thus, the proposed B Godpromesse Kenne
Journal of Circuits, Systems and Computers, 2017
In this paper, an adaptive proportional-integral (API) control strategy is developed to extract t... more In this paper, an adaptive proportional-integral (API) control strategy is developed to extract the maximum power from a variable wind speed turbine and to regulate the DC-link voltage, rotor flux and AC load voltage in a three-phase grid-connected self-excited induction generator (SEIG) system. The resulting controller associated to the flux-oriented control technique can be easily implemented in practice since finite time estimators for the unknown time-varying rotor resistance, rotor flux (nonmeasurable signal) and stator electrical angular position required for the online implementation of the proposed algorithm are provided. Comparative results with a conventional nonadaptive proportional-integral regulator have shown the superiority of the proposed strategy in terms of robustness with respect to online variation of the rotor resistance (up to 100%) and large varying load condition. The computing results are obtained using relatively low wind speed profile. Thus, the generating...
Power and Energy Systems, 2010
A new generalised sizing method for photovoltaic hybrid system (PVHS) based on desired annual gen... more A new generalised sizing method for photovoltaic hybrid system (PVHS) based on desired annual generator hours has been proposed and tested with varying monthly energy demands (M1) and a constant daily profile of 72.6 kWh/d (M2). The PVHS options were determined using these load profiles and the monthly energy outputs of PV modules that have been computed for Garoua situated in north Cameroon. The results obtained showed that the PV array sizes computed with M1 were higher that those computed with M2 at renewable energy fractions greater than 84.6%. Power options with PV array sizes in the ranges 9.0 - 24.12 kWp and 9.0 - 21.96 kWp were found for M1 and M2 respectively and the renewable energy fractions were in the range 52 - 100%. The annual generator hours were in the ranges 0 - 1784 hours and 0 - 1787 hours for M1 and M2 respectively. The PV array sizes for a renewable energy fraction of about 60% was found to be 41.8% and 45.9% of the PV size required in standalone options for M1 and M2 respectively. This new method can be used for the sizing of PV hybrid systems irrespective of the monthly energy demand profiles
Solar Energy, 2012
Abstract Photovoltaic hybrid systems (PVHS) with 2 days of energy autonomy are shown to be optima... more Abstract Photovoltaic hybrid systems (PVHS) with 2 days of energy autonomy are shown to be optimal options for the supply of the daily energy demands of 33 base transceiver stations of MTN Cameroon. PVHS were computed for all sites using the technical data for a 150 Wp mono-crystalline module, the site specific hourly load data, the average monthly solar radiation and temperature. Hourly solar radiation data for all sites were downloaded using the solar resource module of HOMER and geographical coordinates of the selected sites. The 3-hourly temperature data available on a website maintained NASA was used to generate average monthly hourly temperatures needed in the calculation of the output of solar modules. The energy costs and breakeven grid distances for possible power options were computed using the Net Present Value Technique and financial data for selected power system components. The results with a PV module cost of 7.5 €/Wp, a remote diesel price of 1.12 €/l, a general inflation rate of 5% and a fuel escalation of 10% showed that the annual operational times of the diesel generator were in the range 3–356 h/year with renewable energy fractions in the range 0.89–1.00. However, only 22 PVHS had two parallel battery strings as stipulated in the request for proposal launched by MTN Cameroon in 2008. The PV array sizes evaluated for the 22 PVHS were found to be the range 2.4–10.8 kWp corresponding to daily energy demands in the range 7.31–31.79 kW h/d. The energy costs and breakeven grid distances determined were in the ranges 0.81–1.32 €/kW h and 10.75–32.00 km respectively.
Renewable Energy, 2007
... 180 W were selected on the basis of the availability of performance data for the modelling of... more ... 180 W were selected on the basis of the availability of performance data for the modelling ofsolar/diesel/battery hybrid power systems ... included three categories for household energy demand: low-energy households requiring less than 70 kWh/yr for lighting and radio ...
Renewable Energy, 2008
Off-grid generation options have been simulated for remote villages in Cameroon using a load of 1... more Off-grid generation options have been simulated for remote villages in Cameroon using a load of 110 kWh/day and 12 kWp. The energy costs of proposed options were simulated using HOMER, a typical village load profile, the solar resource of Garoua and the flow of river Mungo. For a 40% increase in the cost of imported power system components, the cost of energy was found to be 0.296 h/kWh for a micro-hydro hybrid system comprising a 14 kW micro-hydro generator, a 15 kW LPG generator and 36 kWh of battery storage. The cost of energy for photovoltaic (PV) hybrid systems made up of an 18 kWp PV generator, a 15 kW LPG generator and 72 kWh of battery storage was also found to be 0.576 h/kWh for remote petrol price of 1 h/l and LPG price of 0.70 h/m 3. The micro-hydro hybrid system proved to be the cheapest option for villages located in the southern parts of Cameroon with a flow rate of at least 200l/s, while the PV hybrid system was the cheapest option for villages in the northern parts of Cameroon with an insolation level of at least 5.55 kWh/m 2 /day. For a single-wire grid extension cost of 5000 h/km, operation and maintenance costs of 125 h/yr/km and a local grid power price of 0.1 h/kWh, the breakeven grid extension distances were found to be 15.4 km for micro-hydro/LPG generator systems and 37.4 km for PV/LPG generator systems respectively. These results could be used in Cameroon's National Energy Action Plan for the provision of energy services in the key sectors involved in the fight against poverty.
Renewable and Sustainable Energy Reviews, 2012
This paper examined the initiation, funding, realisation and the current state of some renewable ... more This paper examined the initiation, funding, realisation and the current state of some renewable energy applications in the West Region of Cameroon. The findings from the study conducted showed that all of the renewable energy applications were initiated by indigenes living outside the beneficiary communities. The lack of fee-for-service tariffs was partly responsible for the failure of a wind electric installation for potable water pumping. Conflicts in a local management committee resulted in the inoperative state of a pico-hydro installation, while the lack of finances accounted for the failure of a PV system of rural Health Centre. Although, some successful results were noted in the activities of African Center for Renewable and Sustainable Technologies (ACREST) involving foreign technical expertise in small scale renewable energy applications, ACREST had difficulties with the implementation of 100 kW micro hydro project. The stakeholders identified for successful renewable energy applications in Cameroon included local management committees, microfinance institutions, Non-Governmental Organisations (NGOs), Renewable Energy Enterprises (REEs) and universities. Local management committees must be in charge of the supervision, operation and maintenance of installed systems as well as revenue collection based on fee-for-service tariffs. Microfinance institutions should grant loans for the acquisition of financially and economically viable off-grid renewable energy systems to communities with monthly installments based on established monthly energy expenditures. NGOs are expected to provide technical assistance for the conception of community projects, the procurement of funding from cooperation partners and for the realisation of projects. REEs should have competence for sizing, installation and post-installation maintenance of renewable energy equipment. Universities must train the technicians and engineers that will be used by NGOs and REEs. This important role has been recognised by the government of Cameroon through the creation of the first Department of Renewable Energy at the University of Maroua in 2008.
Revue Africaine de la Recherche en Informatique et Mathématiques Appliquées, 2019
International audience Electricity access in remote areas of Sub-Saharan Africa is limited due to... more International audience Electricity access in remote areas of Sub-Saharan Africa is limited due to high costs of grid extension to areas characterised by low population and low energy densities. Photovoltaic hybrid systems can be computed using an energy balance equation involving one unknown. For hypothetical village with an average daily energy demand of 153.6 kWh/d, the monthly energy output of photovoltaic modules at Garoua, Cameroon, enabled the evaluation of feasible photovoltaic hybrid (PVHS) options. An option with a renewable energy fraction of 0.557 having lower initial investments is suggested for electrification of more remote villages in Sub-Saharan African countries which have high solar radiation levels. This option comprises a 23.56 kWp PV array, a 15 kWp PV inverter, a 25 kW bi-directional inverter, a battery bank of capacity 324.48 kWh and a 25 kW diesel generator with an operating time of 1309 h/yr or 3.59h/d. The size of the PV array determined is smaller compared...
Renewable Energy, 2013
Optimal photovoltaic hybrid systems (PVHS) have been evaluated for remote villages in Far North C... more Optimal photovoltaic hybrid systems (PVHS) have been evaluated for remote villages in Far North Cameroon using a recent iterative optimisation method based on desired annual number of generator hours and the Net Present Value technique. PVHS configurations with the same PV array size were computed for varying energy demand (D1) and constant daily energy demand (D2) when the minimum desired renewable energy fraction was set to 20%. However, the annual diesel generator operating times in PVHS configurations were found to be higher for D1 at renewable energy fractions greater than 71.9%. The results of economic analysis using a PV module cost of a remote fuel price of 1.12 V/l, inflation rate of 5%, discount rate of 6%, 2 days autonomy, PV module costs in the range 7.5 V/Wpe0.75 V/Wp, and fuel escalation rate in the range 5%e20%, showed that PVHS were the optimal options for D2 for all combinations of sensitivity variables. PVHS were also found to be the optimal option for D1 at a fuel escalation rate of at most 10%. SPVS were found to be optimal option for D1 at a fuel escalation is at least 15% and PV module costs are in the range 2.25 V/Wp À0.75 V/Wp. The renewable energy fractions evaluated for optimal PVHS options were found to be in the ranges 88.7%e97.0% and 89.4%e99.9 % for D1 and D2 respectively. Consequently, PVHS are the optimal power option for the electrification of villages in Far North Cameroon, with annual solar insolation of at least 5.5 kWh/m 2 /d and annual energy demand of 72.6 kWh/d if the fuel escalation rate is at most 10%.
Renewable Energy, 2010
A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standal... more A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standalone diesel generator options is performed using the net present value (NPV) technique. A typical village mini-grid energy demand of 7.08 kWh/day is considered in the computation of energy costs and breakeven grid distances. A first sensitivity analysis is conducted using remote diesel prices of 0.8 V/l, 0.98 V/l, 1.12 V/l, 1.28 V/l with a PV module cost of 7.5 V/Wp. A second sensitivity analysis is also done using PV module costs of 5.25 V/Wp, 6 V/Wp, 6.75 V/Wp, 7.5 V/Wp with a diesel price of 1.12 V/l. The energy cost for the diesel option was found to be 0.812 V/kWh at a diesel fuel price of 1.12 V/l. The sensitivity analyses showed that minimum energy costs were attained in PVHS at renewable energy fractions in the range 82.6e95.3%. In the second sensitivity analysis the energy costs and breakeven grid distances were found to be in the ranges 0.692e0.785 V/kWh and 5.1e5.9 km respectively. For a PV module cost of 5.25 V/Wp, the lowest energy cost for the PVHS option was 0.692 V/kWh at a final renewable energy fraction of 95.3% with the diesel generator hours being 37 h compared to 2075 h in the standalone diesel generator option. Consequently, a 30% reduction in custom duties and taxes on imported PV modules and subsystems would increase the use of small-scale and climate friendly PV mini-grids in remote areas of far north Cameroon that have an annual insolation of at least 5.55 kWh/m 2 /day.
Renewable Energy, 2010
A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standal... more A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standalone diesel generator options is performed using the net present value (NPV) technique. A typical village mini-grid energy demand of 7.08 kWh/day is considered in the computation of energy costs and breakeven grid distances. A first sensitivity analysis is conducted using remote diesel prices of 0.8 V/l, 0.98 V/l, 1.12 V/l, 1.28 V/l with a PV module cost of 7.5 V/Wp. A second sensitivity analysis is also done using PV module costs of 5.25 V/Wp, 6 V/Wp, 6.75 V/Wp, 7.5 V/Wp with a diesel price of 1.12 V/l. The energy cost for the diesel option was found to be 0.812 V/kWh at a diesel fuel price of 1.12 V/l. The sensitivity analyses showed that minimum energy costs were attained in PVHS at renewable energy fractions in the range 82.6e95.3%. In the second sensitivity analysis the energy costs and breakeven grid distances were found to be in the ranges 0.692e0.785 V/kWh and 5.1e5.9 km respectively. For a PV module cost of 5.25 V/Wp, the lowest energy cost for the PVHS option was 0.692 V/kWh at a final renewable energy fraction of 95.3% with the diesel generator hours being 37 h compared to 2075 h in the standalone diesel generator option. Consequently, a 30% reduction in custom duties and taxes on imported PV modules and sub-systems would increase the use of small-scale and climate friendly PV mini-grids in remote areas of far north Cameroon that have an annual insolation of at least 5.55 kWh/m 2 /day.