Solar Energy is one of the main sectors of renewable energy and has enjoyed extensive development in the world. The sun is the very basis of the existence of life on our planet. It is the driving force behind other sources of energy such as: wind, biomass or hydro. On industrial level solar energy systems have been developed in recent decades for thermal and electric applications. Through solar collectors hot water can be generated or agricultural products can be dried. But sunlight can also be transformed into electrical energy through solar photocell systems.

Unfortunately, until now the solar technology is still very capital intensive, that way remaining prohibitively costly for massive use. That way therefore, solar systems still remain attractive to limited applications including; electrification of rural households through lighting, providing light to schools and health centers as well as running the computers. It might also be used for pumping water or for telecommunication purposes.
 
Since Rwanda, along with most other countries worldwide is currently eager to increase the share of renewable energy in general and electricity from renewable sources in particular towards the total national energy balance, solar energy becomes increasingly important to achieve our objectives.

While solar photovoltaics remain relatively expensive, the solar thermal systems that are mainly used for water heating are to some extent affordable.
What is a Solar Water Heater?

Each square meter of Rwanda receives sufficient solar energy each day to heat about 50 liters of water from the normal room temperature (20ºC) up to 60ºC!

This can be achieved with a Solar Water Heater (SWH), an appliance which is converting solar radiation into heat energy, by using solar collectors. These are available as flat plate collectors, evacuated tube collectors or concentrating collectors. They use both direct beam and diffuse solar radiation. The Solar Water Heater can be mounted on a roof, on a balcony or in a yard and its installation requires no special technology.

The Solar Water Heater is able to substitute other sources of energy currently used to heat water, like electric energy, gas or fuel, by solar radiation. Considering that solar energy is abundant, available and for free, Solar Water Heaters contribute substantially to saving energy as well as financial resources.   

Solar water heaters are most widely used in households, hotels, hospitals or other public buildings. We know that 1 square meter of solar collectors can produce about 700 to 900 kilowatt-hours per year and thus avoid an equivalent of 3 tons of Carbon Dioxide otherwise emitted into the atmosphere through the use of other fuels for heating the water.

This is why it would be beneficial to the country to grant subsidies for the acquisition of solar water heaters or to oblige property developers and constructors to include solar water heaters in all new buildings.

Through incentives and obligations 180 million square meters of solar collectors have been installed world wide since 2007 that are producing 128 million kilowatt-thermal per year. A thriving solar industry has thus come into being in a lot of countries.

Solar Water Heating Potential in Rwanda

The Rwandan climate is very favorable for solar energy exploitation, even during the months of the rainy seasons there is daily and sufficient sunshine: 4 - 6 kWh per square meter and day can be produced which makes solar energy exploitation in Rwanda economically viable.

Going by our Economic Development and Poverty Reduction Strategy (EDPRS) target, it is expected that by 2012, electricity connections shall have moved from the current 92,000 to 350.000. Estimating that at least 20% of them use warm water in their showers or bathrooms, solar water heating could be installed in at least 70.000 households and some hotels, health centers, schools, hospitals, etc.

This is equivalent to a total sensor surface of 200.000 square meters which will potentially save 20.000 tons of oil equivalent per year or about 2000 Megawatt-hours per year. Taking into account the current price of oil, Rwanda could save fuel expenses equivalent to US$ 294 million (120$/barrel). On top of that, the country would profit from the employment created in a developing solar market.

Photovoltaic Solar Energy for electricity

As mentioned above solar energy can also be converted into electric energy and is a means of electrifying rural populations far from the national grid. This transformation is achieved through so called Photovoltaic Panels that can be installed on rooftops. The produced electricity is then transported to a battery where it is stored until usage. That means the energy that is generated by day can be used at any time of the day and thus for lighting purposes mostly at night.

In 2007 there were more than 2,5 million rural homes worldwide enjoying electricity access derived from Solar Photovoltaic panels on their roofs. 20% of those are located in Africa so far. The total global capacity generated exceeded 12.000 MW.

The status of solar energy in Rwanda

In Rwanda, solar energy has been exploited in recent decades by local and international organizations for the electrification of churches, schools and households in rural areas. However the relatively high cost of solar systems has been a barrier to widespread dissemination until now. With the Government new outlook in regard to investments in the energy sector, and following the target we gave ourselves to have achieved within our vision 2020 – whereby the electricity access must have reached at least 35% - 40% of the population, then solar energy as one of the optimum options come strongly into play.

Solar energy shall particularly be used to serve the areas that are not grid connected and those that can not be served by micro-hydro isolated grids. First priority shall be focused on to schools, clinics and other health centers as well as all administrative centers.

To achieve the vision 2020, we are moving in steps! Our fist step, which is target oriented and time bound is the 5 year EDPRS. To be precise, we have only about 55 months remaining. And going by numbers and timeframe we have targeted by 2012 to have solar-electrified all health centers, more than 50% of all schools, and all administrative centers.

In the process, some households shall as well benefit, but this is open also to individual interventions.
In this rigorous process, the Government has been able to attract good partners who strongly support this initiative.

The major partners that have prescribed to this effort include the European Commission, the Belgian Technical Cooperation and the Global Environmental Fund and the USAID.

It is important also to note that the private sector that has been dormant for almost the entire past is eventually emerging. A number of players in both thermal and photo-voltaic are setting themselves up and some have already started to offer these services in isolated cases.

The private sector is very key in addressing the household requirements. The Government through the Ministry of Infrastructure is keen to assist such private initiatives in the capacity building of their staff and other promotional logistics.

In the process of laying out clearly the areas with the possible specific energy supply option, the Ministry has been working on Electricity Master Plan which is nearing completion. This will provide concretely the areas that are electrified by the national grid.

Those that are not, those that are close to the grid in which case extension becomes an optimal option, and those for which it might take long and more investment in terms of grid electricity extension in which case then solar systems become justifiably a solution. Under this extensive undertaking, a so called "Roll Out Programme”.

The programme will come up with least cost options for the electrification of all public institutions and all residential settlements will be identified. To ensure a no-miss approach, an inter-ministerial task force has been formed and is getting formalized.

This group that includes representatives from MINEDUC and MINISANTE and MININFRA shall ensure coordinated efforts in order to avoid duplication and observe rational use of resources.

MININFRA, in collaboration with the Development partners is also working on establishing standards for all components of solar equipment to ensure the supply of high level quality products.

Beyond rural electrification, solar photovoltaic systems can also be used to generate power for our national grid. The Ministry of Infrastructure with the support of the "Stadtwerke Mainz” the power utility in Rhineland-Palatinate, a federal state of Germany, was able to inaugurate the first phase of a solar power generation project in June last year. Kigali Solaire is located on Mount Jali at the outskirts of the city and is currently feeding 250 KW into the grid. It is so far the largest one solar power plant so far known in Africa.

Stadtwerke Mainz in cooperation with MININFRA are looking into expanding the plant to a capacity of 1 MW eventually. Technicians from Electrogaz have already been trained to take care of the maintenance of this system.
 
In the process of encouraging more players in the subsector and particularly focusing on the private sector, the Ministry of Infrastructure has been seriously working on establishing the clear regulatory and institutional frameworks.

The new laws governing electricity and gas sectors of Rwanda have already been passed in cabinet. They cover all aspects regarding the development of the sector: technical, institutional, financial and legal.

It is necessary that we start using the sunshine that we get in Rwanda beyond the daylight hours and store it in form of hot water or in electricity form through battery storage so that we can be able to use it even after the sun sets.

This will result into not only achieving wider rural electrification in very isolated areas, but also substantial energy saving in urban areas.

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