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Power - Photovoltaic - Community - 3.6 kW - Off-grid / Syrian Arab Republic
Case study assignment
The public electric utility in Syria has hired you to assess the financial feasibility of installing a centralized photovoltaic (PV) power plant for a village far from the nearest electric grid.
Site information
The project site is the village of Abou-Sorra, which consists of six households of settled Bedouins. The site is located at 33.3°N latitude and the nearest location for weather data is Aleppo. An existing 3 kW diesel genset has been meeting the energy needs of the village but it now needs to be replaced. This can be considered an "off-grid" system given the relatively small size. The estimated daily AC energy demand being supplied by the diesel genset is 8.4 kWh and the peak load is 2.4 kW. It is proposed that a "PV/battery" system be installed using 50 Wp modules from BP Solar. A 48 V battery bank is also proposed to provide 4 days of autonomy.
Financial information
The BP Solar modules are available to the project at a cost of US$6,500 per kWp. The total cost of the balance of equipment, including installation and transportation, is estimated at about US$17,000. The PV modules and electronic components are expected to have a lifetime of 20 years and 10 years, respectively. The batteries are expected to last 8 years.
A diesel generator like the one that is currently used at the site costs about US$1,000 and needs to be replaced every five years. The maintenance of the diesel generator costs about US$150/year and the price of diesel fuel is US$0.15/L with an annual escalation of 5%. The annual diesel consumption has been about 13,400 L.
The inflation rate in Syria is 6%. The discount rate can be taken as the prevailing commercial interest rates, which is 9.5%.
Prepare a RETScreen study, documenting any assumptions that you are required to make, and report on the significant conclusions from the analysis. Also, determine how much diesel fuel prices would have to be for the project to yield an Internal Rate of Return (IRR) of 15%.
Solution
The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.
Teacher's notes
Results
In March 1994, the Higher Institute of Applied Science & Technology (HIAST) in Syria established a solar village project in Abou-Sorra, 35 km south of Damascus. Technical support for the installation was provided by IT Power under a United Nations Development Program (UNDP) project. This was the first solar village project implemented in Syria. The photovoltaic (PV) project provides electric power to six households of settled Bedouins. The 3.6 kW PV system replaced a diesel generator that had previously provided electricity to the village.
The solar energy group at HIAST has been monitoring the system since 1996. Tests of the PV system have shown good performance under the local conditions.
System description
The PV system consists of a solar array of 72 modules of 50 Wp each. The modules were supplied by BP Solar. The array is divided into five sub-arrays: one sub-array of 24 modules, two sub-arrays of 16 modules each and two sub-arrays of 8 modules each. The total array area is 31.9 m². All the sub-arrays are positioned in a fixed direction facing south at a tilt angle of 45°.
The battery bank consists of 24 dry charged, deep cycle cells of 2 V each. The cells are connected in series to provide 48 V nominal storage voltage. The total capacity of the battery bank is 1,101 Ah. The battery bank was replaced after 8 years of service in 2001.
The system uses two inverters of 1.2 kW each. The electricity is conveyed to the village via a 700 m underground cable. Each house is equipped with a 2 A miniature circuit breaker to avoid overloading the system. The output from the PV arrays is fed to a control room consisting of two sections: one section contains a five-stage charge controller, data logger and 6 kWh meters, while the other section houses the battery bank. The site also has a solar water heating system used for providing hot water during winter months.
The small population and low load demand of the village does not justify an extension of the main electric grid.
Lessons learned
Stand-alone PV systems meeting the electricity needs of remote and rural communities offer an attractive alternative to diesel mini-grids when compared against lengthy grid extensions and in situations where diesel prices and/or genset maintenance costs are high.
When PV systems are designed and installed properly, they can provide a more reliable and environmentally benign community energy source than diesel generation. Distributed PV power systems have a significant potential globally in unelectrified and remote areas. The use of PV in such applications has been growing dramatically in recent years, especially for individual home systems.
Photo
Community - Photovoltaic - Off-grid, Abou-Sorra, Syria
References
Case study assignment
The public electric utility in Syria has hired you to assess the financial feasibility of installing a centralized photovoltaic (PV) power plant for a village far from the nearest electric grid.
Site information
The project site is the village of Abou-Sorra, which consists of six households of settled Bedouins. The site is located at 33.3°N latitude and the nearest location for weather data is Aleppo. An existing 3 kW diesel genset has been meeting the energy needs of the village but it now needs to be replaced. This can be considered an "off-grid" system given the relatively small size. The estimated daily AC energy demand being supplied by the diesel genset is 8.4 kWh and the peak load is 2.4 kW. It is proposed that a "PV/battery" system be installed using 50 Wp modules from BP Solar. A 48 V battery bank is also proposed to provide 4 days of autonomy.
Financial information
The BP Solar modules are available to the project at a cost of US$6,500 per kWp. The total cost of the balance of equipment, including installation and transportation, is estimated at about US$17,000. The PV modules and electronic components are expected to have a lifetime of 20 years and 10 years, respectively. The batteries are expected to last 8 years.
A diesel generator like the one that is currently used at the site costs about US$1,000 and needs to be replaced every five years. The maintenance of the diesel generator costs about US$150/year and the price of diesel fuel is US$0.15/L with an annual escalation of 5%. The annual diesel consumption has been about 13,400 L.
The inflation rate in Syria is 6%. The discount rate can be taken as the prevailing commercial interest rates, which is 9.5%.
Prepare a RETScreen study, documenting any assumptions that you are required to make, and report on the significant conclusions from the analysis. Also, determine how much diesel fuel prices would have to be for the project to yield an Internal Rate of Return (IRR) of 15%.
Solution
The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.
Teacher's notes
- The system was financed by a United Nations Development Programme (UNDP) grant and was considered to be a pioneering effort in the region.
- This heat rate is very high since the generator was mostly run at very low load, resulting in low fuel efficiency.
- All costs are in US dollars and reflect prices in 1994, when the system was installed.
- The transportation cost shown under "Balance of Equipment" combines transportation for all components, including the photovoltaic (PV) modules, from Damascus to the village site. Where relevant, the component costs include shipping to Damascus.
- Using the "Goal Seek" function on the RETScreen Toolbar, the cost of diesel fuel would have to rise from US$0.15/L to approximately US$0.40/L for the project to yield an Internal Rate of Return (IRR) of 15%.
Results
In March 1994, the Higher Institute of Applied Science & Technology (HIAST) in Syria established a solar village project in Abou-Sorra, 35 km south of Damascus. Technical support for the installation was provided by IT Power under a United Nations Development Program (UNDP) project. This was the first solar village project implemented in Syria. The photovoltaic (PV) project provides electric power to six households of settled Bedouins. The 3.6 kW PV system replaced a diesel generator that had previously provided electricity to the village.
The solar energy group at HIAST has been monitoring the system since 1996. Tests of the PV system have shown good performance under the local conditions.
System description
The PV system consists of a solar array of 72 modules of 50 Wp each. The modules were supplied by BP Solar. The array is divided into five sub-arrays: one sub-array of 24 modules, two sub-arrays of 16 modules each and two sub-arrays of 8 modules each. The total array area is 31.9 m². All the sub-arrays are positioned in a fixed direction facing south at a tilt angle of 45°.
The battery bank consists of 24 dry charged, deep cycle cells of 2 V each. The cells are connected in series to provide 48 V nominal storage voltage. The total capacity of the battery bank is 1,101 Ah. The battery bank was replaced after 8 years of service in 2001.
The system uses two inverters of 1.2 kW each. The electricity is conveyed to the village via a 700 m underground cable. Each house is equipped with a 2 A miniature circuit breaker to avoid overloading the system. The output from the PV arrays is fed to a control room consisting of two sections: one section contains a five-stage charge controller, data logger and 6 kWh meters, while the other section houses the battery bank. The site also has a solar water heating system used for providing hot water during winter months.
The small population and low load demand of the village does not justify an extension of the main electric grid.
Lessons learned
- The PV power plant has proven to be a success in providing a reliable supply of electricity to the village.
- The battery bank provided 8 years of service.
- The low cost of diesel fuel in Syria makes it difficult to justify the PV system on financial grounds alone. However, the environmental, noise, reliability and power availability benefits of the PV system make it an attractive option compared to a diesel genset.
- The reliability and availability of the electricity supply is an important consideration in comparing alternative power sources. The Abou-Sorra example demonstrated that the PV system (with battery storage), which provides power 24 h/day, is preferable to the diesel generator system that typically operated 8 h/day.
- The successful implementation of this system holds strong promise for its replication in other rural electrification applications elsewhere in Syria and other Middle Eastern countries.
Stand-alone PV systems meeting the electricity needs of remote and rural communities offer an attractive alternative to diesel mini-grids when compared against lengthy grid extensions and in situations where diesel prices and/or genset maintenance costs are high.
When PV systems are designed and installed properly, they can provide a more reliable and environmentally benign community energy source than diesel generation. Distributed PV power systems have a significant potential globally in unelectrified and remote areas. The use of PV in such applications has been growing dramatically in recent years, especially for individual home systems.
Photo
Community - Photovoltaic - Off-grid, Abou-Sorra, Syria
References
- Abed-El-Hadi Zein & Wala'A Sarsar, Analysis of Solar Photovoltaic-Powered Village Electrification at Abou-Sorra in Damascus Region, HIAST, Syria, 1998.
- Parthan, Binu K., "Personal communication," IT Power India, 2002.
