To achieve this, the organizations have constructed a “hybrid microgrid” at the Klagenfurt highway maintenance depot. This microgrid supplies uninterrupted renewable energy to the entire site, even when the public grid experiences power outages. The Klagenfurt highway maintenance depot’s responsibilities include the monitoring and maintenance of various tunnels through the Alps as well as the well-traveled Tauern Autobahn highway.
The project’s role in the ASFINAG sustainability strategy
The highway maintenance depot in Klagenfurt is supplied with solar energy as part of ASFINAG’s plan to gradually switch all company’s locations over to green power. The integrated energy storage system ensures that solar energy generated by day can also be used at night or in the event of grid failure. Until now, such an uninterrupted power supply involved considerable additional technical overheads. Yet this power supply is responsible for making sure that tunnels and sections of highway can continue to be monitored even if the public power grid fails.
“The Klagenfurt highway maintenance depot’s microgrid goes to show that renewable energy and a reliable energy supply go hand in hand, assuming the right technological steps are taken. Thus, the new energy system is more than just a flagship project – it is a real bonus in terms of driver safety,” says Christoph Lang, Head of the Renewable Energy & E-Mobility Department at K.E.M. MONTAGE, the general contractor for the construction of the new power system.
Secure energy supply with the hybrid microgrid
Hybrid microgrids refer to small-scale, local power grids which are connected to the public electric grid. If necessary, they also function in island operation, being independent of the public grid, typically with the help of a battery storage system and specialized electronics.
The Klagenfurt highway maintenance depot’s hybrid microgrid combines a 220-kWp photovoltaic installation with a 522-kWh lithium-ion storage system. The Universal Power Platform (UPP) energy management system from DHYBRID controls and monitors all of the energy supply parameters. If the public grid fails, the battery storage system will seamlessly take over the supply to the microgrid with the support of the UPP.
Once the public grid is back in operation, the UPP measures the necessary parameters and ensures that the microgrid is seamlessly resynchronized to the grid for parallel generation. Under battery operation, the UPP also regulates the load management for three connected charging stations with up to 70 kW for electric vehicles belonging to ASFINAG. If the energy storage system’s capacity is completely exhausted due to a lasting power outage, the UPP will switch on a back-up diesel generator fully automatically.
DHYBRID originally developed its microgrid technology for use outside of Europe, for instance in remote areas which cannot reliably be supplied by a stable electricity connection. But the expansion of renewable energy and the increasing demand for customized energy storage solutions have paved the way for increased use of DHYBRID microgrids in Europe as well.