Bringing Light to Rural Communities in Senegal
Originally published in iC Communication magaizine, Edition 22/2018
In the West African country of Senegal, poverty is acute in remote rural areas, with little access to cooking fuel, electric lights and other basic amenities. Over the past two years CES clean energy solutions has been supporting the European Commission and the Senegal Rural Electrification Agency in providing off-grid renewable solar electricity to 76 remote communities in Senegal. This project will enable and catalyze education, safety, gender equality and economic development.
The challenges of rural life in Senegal
While many visitors only see Senegal’s capital city Dakar, one of West Africa’s key political and economic hubs, over half of the population of 15 million lives in remote rural villages deep in the Savannah. Rural life is challenging, with only seasonal road access and no access to electricity.
Senegal has a Human Development Index (HDI) ranking of 162 out of 188 countries. Over half of the population are “multidimensionally poor” while an additional 18 per cent are close to living in multidimensional poverty.¹ The Multidimensional Poverty Index identifies multiple overlapping deprivations suffered by households in three dimensions: education, health and living standards. Poverty rates are influenced by multiple complex factors. With a high number of children per female, it can be a struggle to feed a family. Stunting malnutrition identifies malnutrition in children 0–5 so severe that it has a permanent or long-lasting effect on health and performance. In Senegal, 20% of children experience stunting malnutrition.²
Energy poverty can be defined as the “inability to cook with modern cooking fuels and the lack of a bare minimum of electric lighting to read or for other household and productive activities at sunset” (UNDP 2005).³ Access to electricity is fundamental to fulfilling basic social needs, driving economic growth and fueling human development. Energy services have an effect on productivity, health, education, safe water and communication services.⁴
The Assignment
To support the objectives of the “National Programme of Rural Electrification”, the Senegalese agency for rural electrification (Agence Sénégalaise d’Electrification Rurale — ASER) aims to provide electricity to all rural communities by the end of 2025.⁵ The project is co-financed with 50% funding through the European Development Fund under the Africa-Caribbean-Pacific Energy Facility. The objectives of the grant are to alleviate poverty and fight against climate change. The project aims to provide electricity in the form of mini-grid photovoltaic plants to 76 remote villages in Senegal. This project should impact over 50,000 villagers in the regions of Matam — Bakel — Goudiry in Eastern Senegal.
CES clean energy solutions was awarded the role of consultant to ASER in the procurement, management and supervision of the construction of the photovoltaic systems. The project commenced in 2016 and is envisaged to continue to 2020. The tasks to date have included the selection of villages, the development of the technical concept and the successful launch of the call for proposals and selection of a contractor. The installation and commissioning of the plants is now underway. One of the challenges faced by the project team is the remoteness of the villages, which requires robust technical solutions and careful logistics planning.
Field visits to the rural communities
Upon the commencement of the contract, ASER presented their shortlist of 181 villages within the target regions, each inhabited by 30 to 5,000 people. In order to define the electricity demand of every village and to size the systems, a preliminary survey with representatives of every village was conducted and the GPS coordinates of important energy consumers (health care facilities, schools, mills, mosques, shops etc.) were recorded. During two field missions in 2016, two consultants from CES clean energy solutions visited a total of 22 villages to control the quality of the provided data, identify local partners and better understand the situation in the field.
Seeing a small piece of village life in Senegal was a life-changing experience, and provided a context to the project and its aims. The villages are all by definition “remote”, and some are only accessible by long off-road driving during the dry season. Even though the villages are sometimes 30 km from any planned roads or electrical grid, they all have good cell phone coverage, demonstrating how a new technology can leapfrog obsolete solutions in developing countries and providing evidence that solar energy could be the staple for developing countries instead of fossil fuel high voltage networks.
Each village has its own character, but one constant was evident: upon arriving at the village we were swarmed by young children, the girls wearing beautiful and colorful handmade dresses and the boys all wearing football shirts.
Life in rural Senegal proceeds within meager means. Typically, the women spend their days cooking and caring for the children. Agriculture and the herding of goats and sheep are the main occupation. We were once invited into a home where sleeping looked uncomfortable, on a mat on the bare earth, often without mosquito nets. In every village we would meet with the local Imam and the chief of the village to discuss the project and its impacts on the village and confirm the data gathered so far.
Electrical Demand Sizing
In order to size the solar photovoltaic system, an estimate of the village electrical load was made for selected villages on the basis of collected population data. This included numbers of households and commercial and industrial activities. The population growth rate projection over 15 years was considered in the sizing. Consumers are grouped as follows: households, public services (public lighting, schools, health care facilities etc.) and commercial and industrial activities.
Under households, a segmentation is made into four levels of service, from level one which represents the minimum level (LED lighting and cell phone charging) up to level four which represents more affluent households which can afford a television and would like their own refrigerator. All households are supplied (100% coverage). This segmentation of the population is an estimate based on local experience in Senegal and literature from similar international projects. Each household segment is assigned a number of devices, (radio, TV, LED lights) and each device has a consumption profile over 24 hours of the day.
The second class of consumers accounts for commercial and industrial activities and mainly includes shops, workshops (wood, metal) and common industrial consumers like water pumps or cereal mills.
The third class of consumers accounts for public services like public lighting or health facilities. All of these loads are considered a priority and therefore need to have some autonomy from the remaining consumers. In order to assure a constant supply of electricity they have a dedicated independent cable and an inverter to feed it. Moreover, at a defined level of discharge of the batteries the electricity will be cut off from regular consumers, to assure its supply to the priority consumer.
This detailed demand sizing was performed on several representative village sizes in order to arrive at a demand curve based on village population. The hourly profiles of each device for each sub-class of consumer were added together to provide the overall demand curve for a village, as presented in the village hourly load profile. In this figure, the average 24-hour power consumption profile is shown, with each consumption category identified. Generally, peak demand occurs in the evening and is primarily driven by household consumption.
Supply Sizing
With the estimated hourly electric load determined, a systems model was created in order to select an optimal system design to meet the village requirements. The primary cost vs. performance factors of a mini-grid PV system are the total battery bank capacity in ampere-hours or kilowatt-hours and the area of photovoltaic panels in m² or kilowatts-peak. The battery bank is necessary to meet the diurnal phase mismatch of supply (peak solar power at noon) and demand (evening), and also to cover load during cloudy days.
A dynamic model of the system was created with these parameters and component efficiencies. The model was simulated over a period of a “design week”, including a number of sunny days, average days and cloudy days, as defined by an analysis of the local historical weather conditions.
System design sizing tool presents the dynamic simulation tool which is typically sized over a week but shortened to three days for this article. In this figure, the demand curve, as described above, is presented in the solid black line. The meeting of demand is the key objective of the design exercise. Demand can be met with stored energy in the battery bank (dark blue area), or by direct consumption from the photovoltaic panels (yellow area). Excess solar energy is used to recharge the battery bank (light blue area). The hourly state of charge is represented by the dashed blue line and measured on the right axis. As can be seen in this illustrative example, demand is not met on a cloudy day. Both increasing the battery capacity or the photovoltaic panel area could increase the energy output of the system, but in this case the panel area would need to be increased as the battery is not fully charged.
Using this tool, several village PV plants were designed by optimising the key parameters for autonomy and cost. Using these as typical designs, the resulting capacity of the battery bank in kWh and the design power output of the plant in kW were calculated for all 76 villages in order to calculate quantities for plant components. These parameters are used by the contractors in preparation of their bids and designs.
An electrical network plan was designed for villages taking into consideration all the consumers and their geographic layout. The location and total amount of utility poles has been defined, as have the type and length of each of four types of transmission cables. Figure X — Network outline of a sample village. The total envisaged capacity over the whole project is 1.27 MW of photovoltaic panels and 195.8 kAh of battery capacity. Moreover, 268 km of cables and 3,420 wooden poles will be installed.
TECHNOLOGY SELECTION
As discussed, the main components of the system are the photovoltaic panels and the battery bank. Further elements of the plant include the inverters, electronics and a structure for housing the components. The low voltage grid and household components (lights, power sockets) are also in the scope of the project.
One technological innovation which benefits such an off-grid application is the AC bus system, which places PV production parallel to the storage system. This means that the photovoltaic energy is converted directly to 3-phase AC on the grid. The energy can then be consumed directly by the village and/or used to recharge the battery bank. This can be contrasted with a DC system, where the PV array is placed behind the battery which means that if the battery is fully charged the solar energy is wasted. A further advantage of the AC-bus is that other energy sources can be easily integrated into the mini-grid, for example further PV plants or a bio-diesel generator.
Conclusion
On the publication date of this article, the tender process has officially finished and the supplier of the systems has been chosen. Construction work commenced in 2018 and will last approximately 16 months. CES will then step in to fulfill the next parts of the assignment i.e. construction supervision. Very important to overall project success is the informed handover of the plant and network to the final operator.
It is clear that the project will have a real impact in of the lives of these remote Senegalese villagers. With electricity available, potential new commercial and industrial activities will be enabled, education and healthcare will be improved and a better future will be made possible. The contractor has been selected, and construction has commenced.
For more information, visit CES Clean Energy Solutions in Vienna, Austria
And the Agence Sénégalaise d’Electrification Rurale in Dakar, Senegal
The authors
Marcus Jones studied physics and mechanical engineering at Queen’s University. He joined CES clean energy solutions in 2013 as a consultant and project manager and simulation expert. More recently, he started working at oceanprotocol in Berlin as a Data Scientist and software engineer.
Szymon Zwoniarkiewicz studied building science and technology at Vienna University of Technology as well as architecture and urban planning at Poznan University of Technology. He has been with CES clean energy solutions since 2016 as an expert in green building certification.
Citations
1 — WHO/World Bank Group Joint Child Malnutrition Estimates (2017).
2 — Ibid.
3 — UN, Development Programme, Energy Services for the Millennium Development Goals, in pursuance of UN Millennium Development Goals (2005).
4 — Amie Gaye, Human Development Report 2007/2008 Fighting climate change: Human solidarity in a divided world, Access to Energy and Human Development(2007).
5 — Agence Sénégalaise d’Electrification Rurale, http://www.aser.sn.
