The representatives of G-Solar visited Munich Fair solar roof as a successful example of commercial solar roof implementation. The roofs of Munich Trade Fair Center were at the time of its construction in 1997, the world’s largest roof-mounted photovoltaic system. The available roof surface of 66.000 m2, out of which only 38.100 m2 were covered with solar modules to keep the requirement of not being visible from the ground. The construction itself lasted only 40 working days.
Frameless solar modules consist of 84 mono-crystalline silicon cells and an output of 130 watts. The efficiency of solar cells is up to 15%. The electrical energy from the 12 PV generators is fed into a centrally located,air-conditioned inverter room. The inverter unit consists of three devices, each with an output of 394 kVA which are alternately used in accordance with the amount of electricity being generated. Today the Fair’s PV system still belongs to one of the 50 largest roof-mounted systems in the world with a total installed capacity of 2.1 MW. After almost 20 years, the modules still show minimum power output loss. Only 44 modules out of 7.800 had to be replaced during that period. Electrical components were renewed through retrofit program enabling to meet modern technology standards with a minimum replacement of components. In addition, the savings in carbon dioxide emissions amount more than 600 tons/year.
The funding and the organization of this project were strongly supported by regional Bavarian government. The project amounted 7 million euros and was designed to promote the use of renewable energy sources in Bavaria. E.ON Energie contributed 50% of the costs for installing the solar roof, Bavarian Government contributed 20% and Siemens, Stadtwerke München and German Federal Government contributed 10% each.
There is enormous possibility of growth in this segment. Photovoltaic panels installed on commercial buildings can increase property value, reduce running costs and generate additional incomes. Companies operating shopping centers, factories, warehouses, parking lots are increasingly seeing PV panels as a source of revenues, taking advantage of large and unused roof surface. Sainsbury’s , the UK supermarket chain with 1.200 stores is the largest multi-roof solar panel operator in Europe. They have installed or are in the process of construction of altogether 170.000 panels generating 40 MW. Paul Crew, one of the managers at Sainsbury’s says that “supermarkets have the equivalent of football fields on their roofs, many of them underutilized, so it is ideal for turning that space into something positive”
Another example of state regulatory involvement is France that has just passed a new law requiring all new buildings in commercial zones to be covered with green roofs or solar panels. This simple decision brought by the state authorities can lead to stronger solar development.
