Sustainable Energy Supply: Photovoltaic Systems

The visit to Mwanza by Mayor Christian Schuchardt and his delegation in November 2016 marked the halfway point of the most important of the many projects of the Mwanza–Würzburg climate partnership. The two sides entered into this climate partnership in 2011. Two of the four photovoltaic systems planned in Mwanza – a city located on the shores of Lake Victoria – have now been installed. The rooftop plant at Nyamagana Hospital and the solar panels at a radio station in the city are providing around half the total module capacity of around 110 kWp. This was made possible by the generous support of the German Federal Ministry for Economic Cooperation and Development (BMZ). In 2013 the ministry already approved just under 400,000 Euros; Würzburg will have to meet only around ten per cent of these costs.

At the ceremonial opening of the plant on the hospital roof Dr. Jakob Frommer, Head of the Department for Environmental and Climate Protection, put this global cooperation in the right context:‘We are the first generation of which it is said that we are already feeling the impacts of climate change ourselves. Networks across national boundaries are absolutely crucial for dealing successfully with this huge challenge. The many individual measures here are part of a coherent overall strategy.’ Climate-related phenomena are indeed already palpable in both cities, and these can only be dealt with effectively by adapting to climate change. In Würzburg the city is already groaning under hot tropical summer nights, and anticipates a mean annual temperature increase of up to five degrees by the end of the century. In Mwanza the impacts of continued unfettered climate change might be a drop in sea level, or a continued increase in extreme weather events such as torrential rainfall leading to flooding, or long phases of drought.

As one of nine pairs of German-African pilot municipalities in the BMZ programme, Würzburg and Mwanza have joined forces to do something about these negative forecasts. Solar technology is playing a key role in this. Projected figures for annual power generation are already available for both the systems already installed. According to the Belectric company, the two plants in Tanzania will ‘harvest’ around 80 per cent more power than a comparable system in Germany. Close to the equator, the modules are aligned almost vertically towards the heavens. Whereas here in Germany roofs pointing south promise an optimal yield at the right angle of inclination, in Tanzania any flat roof receives on average between 7 and 9.5 hours of sunshine a day. In Germany, the range in monthly averages of between 1.5 and 7.5 hours of sunshine means the seasons are felt more keenly. Furthermore, a photovoltaic plant in Würzburg may be covered in snow for several days a year, and therefore receive no sunshine at all.

In Tanzania, the general public are as yet by no means aware of this huge potential offered by photovoltaic systems. The four plants (one is in the process of being installed near the town hall, another on the roof of a school) are therefore designed as pilot projects to raise public awareness and inspire as many people as possible to emulate them. In the presence of Heike Jope from the German Embassy in Dar es Salaam, the local project manager Amin Allbright reported that he had already presented the system in the hospital compound to the first groups of interested citizens. The distinctive feature of this system is that it is not a stand-alone solution. It is the first photovoltaic system in Tanzania that can also feed electricity into the power grid. No one can say that Tanzania is not open to renewable energy – some 57 per cent of the energy generated by the parastatal organisation TANESCO comes from hydropower. Overall energy production in Tanzania could be increased, however – the energy import rate is currently 46 per cent. This dependency on foreign markets plus increased domestic demand continue to cause bottlenecks and power cuts, which in turn are likely to deter investors.

Together with a fisherman's light project, the photovoltaic systems currently form the two pillars of the climate partnership between Mwanza and Würzburg. In Wolfgang Kleiner's environmental and municipal affairs department in particular, supporting ‘help towards self-help’ has a long tradition in this partnership. To this day, two refuse collection vehicles that used to serve Würzburg's city cleansing department now remain in service in Mwanza – the greenest city in Tanzania. Right now an emergency vehicle is also on its way – this time to support the fire department. Reciprocal visits between the partner municipalities also always provide opportunities for face-to-face interim project reporting, expert exchange or even special training for staff.