After half a year of operation, the electricity company of the city of Zurich (EWZ) draws a positive interim conclusion regarding the operation of the solar plant on the Albigna dam wall. The planners expected a high yield from the generator on the wall of the reservoir in Bergell, high up in the Alps, especially in winter. This has been confirmed. From mid-September 2020 to mid-March 2021, the plant generated a whopping 223 megawatt hours of clean solar electricity.
Advantages in winter
With a plant output of 410 kilowatts, which the EWZ installers built on the 670-metre-long dam wall, that is a yield of more than 1,000 kilowatt hours per kilowatt of output, even in winter. The advantage of the system is that about 1,200 modules are installed almost vertically on the wall. On the one hand, this means that no snow remains on them in winter. On the other hand, they are better aligned to the lower sun and can use the light reflection of the snow. In this way, the system can deliver about half of its yield in winter alone.
Monthly record: almost 49 megawatt hours
This was almost achieved in the first six months of operation. In the months of October, November and February, the generator reached peak values of up to almost 49 megawatt hours per month. In the first half of March, it also reached its highest daily value to date with 2,792 kilowatt hours. The EWZ assumes that these peak values will actually be exceeded in the cool but sunnier month of April.
25 per cent more electricity than on the Central Plateau
This is because while the orientation and type of installation are the main advantages in winter, the cold mountain air provides sufficient cooling for the modules. In addition, the solar radiation at an altitude of about 2,100 metres above sea level is higher than in the Swiss midlands, which should provide plenty of solar power in summer. The planners therefore expect the generator to produce 25 per cent more electricity overall than a comparably sized plant in the Central Plateau.
Citizen participation still possible
Citizens can participate in the plant and benefit from the high yield. For 20 years, they will be credited with 180 kilowatt hours for every square metre they invest in financing the generator. One square metre costs 560 francs. This means that the investment would pay off for the citizens within a good ten years. Further information can be found on the EWZ website. (mfo)
