photovoltaic systems
Up to 70% higher annual yields
In alpine areas the sun shines more often and the sunlight is more intense than in the lowlands. Reflection of the sunlight, e.g. on adjacent reservoirs or in the snow, makes it possible to benefit from the so-called albedo effect. The solar panels also work more efficiently at low temperatures. On average, up to 70% more energy can be produced on a yearly basis in a high alpine location than in the Swiss Plateau.
Winter electricity share of 45%
High-alpine PV systems therefore provide valuable winter electricity. This enables the threat of a winter power gap to be reduced and security of supply to be increased.
The Swiss 'Federal Act on Emergency Measures for the Short-Term Provision of Secure Electricity Supply in Winter' (amendment to the Energy Act) has paved the way for the rapid expansion of PV systems in open areas with high winter production levels.
Large-scale alpine PV systems produce a lot of electricity, especially in winter when conditions in the Swiss plateau are unfavourable and the probability of a power shortage is at its greatest in Switzerland. At the beginning of spring, the reservoirs for hydropower plants and the gas storage tanks show the lowest water levels. But that is precisely when the days are much longer, the temperatures are still relatively low and there is snow – perfect conditions for alpine solar panel installations.
ewz is equally committed to expansion on roof spaces, infrastructure facilities and high-alpine systems in open spaces.
All potential for electricity production from solar energy needs to be exploited in order to achieve the ambitious expansion targets. The roof spaces that are available are often small and are a slower way to expand in comparison to adding large-scale systems.
An alpine PV system consists of individual tables, each with 8 modules, which are anchored to the ground using a substructure of steel columns. The modules are mounted at a height of about 2.5 metres above the ground and are directed as far as possible towards the south. The panels are set at a very steep angle of at least 60 degrees. This makes use of the low winter sun and also prevents snow from settling on them. The individual rows of modules are positioned several metres apart.
The specific substructure is still under development. The intention is for farm animals to be able to move safely beneath the facility. Grazing may also be safeguarded by having small livestock, such as sheep. ewz is in active contact with farmers and specialists in this regard.
In the short to medium term, it is important to avoid an imminent power shortage. ewz is committed to the creation of additional renewable capacity in order to secure supplies. At present, the best way to do this is with hydro, wind and solar energy. ewz invests in renewable energies where the natural resources for the respective technology are most available.
This project enables the municipality to show that sustainable energy production in Switzerland can be expanded to ensure a secure energy supply. The municipality can invest in the joint stock company (Aktiengesellschaft) and draw energy from the PV system. If the municipality owns the land, it will benefit from an annual ground rent as well as from tax revenue from the joint stock company, which will be based in the municipality where it is located. The construction and operation of the plant also adds value to the local region.
There is no doubt that there are also disadvantages associated with energy production. This is also the case for wind, solar and fossil power plants. The main disadvantages of alpine solar systems are the impact on the landscape and the construction site activities. ewz strives to make these impacts as environmentally friendly as possible.
In addition to the good conditions for high-alpine PV systems, the strong local connection is an important prerequisite for successful projects. ewz and the Grisons have worked in partnership for almost 120 years. 111 employees work for ewz in the Grisons. From there, they control and monitor the power plants in Mittelbünden and Bregaglia, as well as the Limmat power plants in Zurich. Sils im Domleschg also runs the Mittelbünden regional grid. ewz also supplies various municipalities in the Grisons with energy and heat.
