The Republic of Cameroon is located in mid-west Africa within the Gulf of Guinea. The country and its 24 million inhabitants are politically divided into ten regions, the North-west and South-west being English-speaking and the rest French-speaking (The Central Intelligence Agency, 2016). Each region is divided into divisions and sub-divisions. The country borders with Equatorial Guinea, Gabon and Congo in the south, Central African Republic and Chad in the east and Nigeria in the north-west.
With modest oil resources and favourable agricultural conditions, the country is being classed as a middle low income country with a GDP/capita at $2971 (The World Bank, 2016). However, the poverty rate in Cameroon is as much as 54%1 and has been showing an increase over the last 10 years (Bertelsmann Stiftung, 2016). Governmental mismanagement with poor social safety nets and ineffective financial management along with corruption and inadequate infrastructure has led to a situation where there is a shortage of jobs and declining incomes in many areas of the country. There is also a low public investment in health, less than 5% of GDP, resulting in limited access to modern health.
Like many other countries in the Sub-Saharan Africa region, Cameroon has many potential renewable energy sources that are not fully utilized. The majority of the population still use conventional solid fuels like wood or charcoal as their main energy source for heating, lighting and cooking. These household activities cover the largest proportion of energy consumption in the country. (Vernyuy Wirba & Abubakar Mas’ud, 2015).
Hydropower generated by three large hydroelectric stations provides as much as 75% of the country’s total electricity use. The remaining 25% is produced in diesel or natural gas driven thermal power plants. The national grid is facing large structural and technical difficulties and is mostly concentrated around the urbanized areas. This results in a general electrification rate of 22% and a mere 3,5% in the rural areas (Ayompe & Duffy, 2014). One of the major problems with relying on hydropower is the annually occurring dry seasons creating an unreliable water supply for months. The Cameroonian government is addressing this issue in their Vision 2035 development plan where the overall aim is to reduce poverty and to become an emerging-market economy (Bertelsmann Stiftung, 2016). The vision emphasises the importance of energy independence in the country and the government therefore intends to increase investments in both the delivery and the production of electricity (Vernyuy Wirba & Abubakar Mas’ud, 2015).
When it comes to solar power the country receives an average solar irradiation of approximately 2030 kWh/m2/year (Figure 3), and since the irradiation is most intense during the dry seasons, solar power has the potential to compensate the seasons’ low water levels and electricity rates. A number of large corporations, among them Chinese Huawei Technologies, has recognized this and carried out projects installing massive solar plants supplying thousands of villagers as well as simple street lights along the roads of the cities (REVE, 2015). The government has also just recently acknowledged solar energy as a viable source for electricity generation and has an ambition to increase investments in this sector as well (Ayompe & Duffy, 2014). However, the industry is facing a problem with maintenance after installations due to the lack of local technicians (Chi, 2017).
Despite decreasing prices within the PV industry, the cost for a SHS installation is still relatively high. As previously mentioned, in Cameroon 54% of the population is living on less than $3.10/day, resulting in an income of approximately $90/month. The price for a SHS in general varies between $6-15/Wp. The installed cost for a 150Wp SHS, big enough to cover basic lighting, phone charging and maybe a TV would be at least $900. (Urmee, et al., 2016). Up-front payment is evidentially not an option for any rural household.
Many of the households in the rural areas occupy themselves with agricultural activities, something that does not, in general, generate a regular income. Applying for and receiving a loan from a financial institution or commercial bank to install a system is therefore difficult. Even households with steady incomes from governmental or institutional work will have a problem with the short payback period that is usually demanded from these institutions (Urmee, et al., 2016). The monthly costs for a payback of the loan within any period that is shorter than the life expectancy of the first set of batteries will be too high for the general household. Another issue with obtaining a loan for a SHS is the fact that they are not what a financial institution would call a “productive use of credit”. Even though access to light is proven to increase well-being and quality of life, a SHS installation it is not considered to be income generating, which often is a requirement from loan givers (Baurzhan & P.Jenkins, 2016).
It should also be taken into consideration that in general, people of Cameroon do not use services of commercial banks to the same extent as the western world does (Ameh Akon, 2012). Salaries are often received in cash, which is also the most common payment method. The runner up to cash is a service called Telephone Mobile Money (TMM) where you through the service provider of your phone create an account that is connected to your number. You can then transfer and receive money by typing in certain codes on your phone and by going to certified service points you can also deposit and withdraw money from your account. TMM is in many ways similar to the Swedish service Swish, but the difference is that your account is not connected to any bank or credit card. In fact, credit cards are rarely used, especially not in the rural areas.
If not saving money in a bank, the people of Cameroon have the option of financial houses. Either through official credit unions3 with by-laws, facilities and employees or through something that in Lamnso is called a “Njangi”. A Njangi, which is mostly found in the rural areas, is a less official version of a credit union and consists of a group of friends, relatives or neighbours that save money together. The savings can be for a specific project such as all the group members buying a grating mill for their farming activities or it is simply general savings. By doing it together they can create a larger trust fund more rapidly than if doing it alone. Every month each member of the Njangi will contribute to the fund with a decided amount of money and the group then takes turns on who is entitled to the fund that specific month (Nyamnjoh & Fuh, 2015).
In this section, we will cover the basics of PV technology. Commercial PV systems can be divided into two main technologies, cells made from crystalline silicon (c-Si) and thin-film cells. PV modules utilizing c-Si make up 94% of the market in the IEA PVPS4 countries (IEA, 2016), which is why we have chosen to focus on them.
How it works
Various PV technologies have one thing in common, they all utilize the unique properties of semiconducting materials to convert primary energy (solar irradiation) to secondary energy (electricity) (Mir-Artigues & del Río, 2016). When the sun shines on a PV cell, some of the irradiation is absorbed by the cell and the semiconducting material. As electrons are excited by the photoelectric effect, they flow through the material and a direct current is created. In smaller implementations, the DC is considered a final energy (Mir-Artigues & del Río, 2016), i.e. ready to charge a phone. An additional technical transformation, converting the DC to AC, is usually desired in larger implementations and Off-grid PV systems.
Off-grid PV systems
The off-grid PV system is autonomous and is directly connected to a series of loads. The off-grid PV system can be either a standalone energy system for a household, or be supported by another source, usually a grid connection. The off-grid system is common in the rural Sub-Saharan Africa context, as few households are connected to the main grid (Karekezi & Kithyoma, 2002). The key components of an off-grid system are the PV-modules, charge controllers and the batteries (IEA, 2016). During daytime hours, the PV-modules will provide electricity for the appliances and charging of the batteries. The charge controller will prevent the batteries from overcharging or exceeding the DoD limit. When the sun sets, the charged batteries will power the appliances. The off-grid PV system usually works in a 12V/24V/48V environment, although it is possible to connect an inverter. Adding an inverter to the system will convert the DC to AC, either 230V (single phase) or 400V (three phase) (IEA, 2016).
Picture 2: A typical off-grid installation. The charge controllers (green) can be seen to the left, the blue box is the inverter, the batteries are below and the modules on the roof, neither is visible in this picture. This SHS powers the Hilltop Breeze Resort and the ACOHOF community radio. Installation was done by the local technician Sylverius Bonjhajum
On-grid PV system
The on-grid PV system is connected to an electricity network. For on-grid systems adding an inverter is compulsory, whereas it is optional in the off-grid case. Consequently, system voltage is either 230V or 400V AC. Integrating the PV-system with the grid comes with a few incentives. For instance, adding an electricity meter allows the household to transfer excess electricity to the grid. Batteries and charge controllers are optional for the on-grid system, but they have gained in popularity. If a household for instance has opted for complementary batteries and charge controllers, the local grid can now also be used for charging of the PV system batteries. This is particularly useful days when the incident solar irradiation is poor and in areas where the grid connection is unreliable.
Efficiency and Cost
Historically, performance development of the cell has been paramount in making solar PV technology more affordable. As previously mentioned, one of the biggest obstacles for the spread of solar PV technology in the global south is the price per Wp. In this regard, PV technology has not been competitive in comparison to non-renewables (Energy&Innovation Policy and Technology LLC, 2015).
The efficiency of a PV cell is defined as the quotient between the useful energy being recovered and the total sunlight impacting the collector surface of the cell (Mir-Artigues & del Río, 2016). 𝜂=𝐸𝑜𝑢𝑡𝐸𝑖𝑛[𝑊𝑐𝑚2][𝑊𝑐𝑚2].
As can be seen in Figure 4, a couple of technological paradigms can be identified as leaps in development of efficiency performance under STC (Mir-Artigues & del Río, 2016). However, in the 21st century the performance of PV modules has seen some stagnation (Mir-Artigues & del Río, 2016).
Table of contents :
1.2 Engineers Without Borders and the Renewable Energy Program
4 PV technology
4.1 How it works
4.2 Efficiency and Cost
4.3 PV performance factors
5 Financial models for PV solutions
5.1 General models
5.2 Potential models for REP
6 Field study
7 Additional insights
7.1 The Solar Trap and the Pico PV system
7.2 The cultural aspect of long-term perspective
7.3 The focus of the REP – where is light really needed?
7.4 Local efforts for making PV systems less expensive
8 List of references
9.1 Appendix A – Afoni Children of Hope Foundation
9.2 Appendix B – Interview with Akem Lamisse Limnyuy
9.3 Appendix C – Interview with Christopher Olong
9.4 Appendix D – Interview with Mayor Suila Aruna
9.5 Appendix E – Interview with Charles Chi
9.6 Appendix F – Interview with Sylverius Bonjhajum
9.7 Appendix G – Questionnaire Households
9.8 Appendix H – Questionnaires Institutions
9.9 Appendix I – Result Questionnaires Households