A green battery increasing the annual net energy production of the power plant complex by 260 GWh
The Kühtai storage power plant project, another storage lake and a pumped storage power plant are being built as the second upper stage of the existing Sellrain-Silz power plant group. With this upper stage the overall efficiency of the power plant group in electricity generation can be sustainably increased. The additional storage volume increases the flexibility and functionality of the overall system. More available water enables electricity to be produced over a longer period of time. In phases with a lot of generation from solar and wind power, more energy potential is therefore stored in the large lakes at high altitude.
The planned Kühtai storage facility will not only store water for pump circulation. By capturing water in the rear of the Stubai Valley and in the Sulz and Winnebach valleys, an additional 260 million kWh of electricity can be generated from natural inflow alone.
Key figures of the Kühtai storage power plant:
- Kühtai storage capacity: around 31 million m3.
- Kühtai 2 power plant: average capacity of 130 MW in turbine mode and 140 MW in pump mode
- Length of the bypass system: around 25 km from the rear Stubai Valley to Kühtai
- Catchment area: around 68 km2
- Electricity generation from nat. Inflow: 260 GWh / year
The Kühtai 2 power plant, including the headrace, connects the Finstertal and Kühtai reservoirs. The cavern excavated for this purpose is located at a depth of 174 m below the surface. The power plant is designed for combined turbine and pump operation. Up to 90 m3 of water per second will flow through the two machine sets.
The cavern has connections to the outside via an access tunnel and a drainage tunnel. Only the portals of these two tunnels are visible in the area.
AFRY's assignment covers the execution design of the main caverns including structural calculations, coordination with electro-mechanical (EM) parts, preparation of formwork and reinforcement drawings and a 3-D coordination model of the main structures of the pumped storage power plant (PSPP). The 3-D Model forms the basis for the incorporation of the system in Building Information Modeling (BIM).
The overall schedule for AFRY's services is about 66 months.
This is a continuation of AFRY's outstanding experience in the development and design of PSPP globally.
“We are very pleased to continue our good cooperation with TIWAG in executing this important project. This award further strengthens our leading position in the development of pumped storage power plants worldwide with the goal to become No 1 in Design of PSPP,” says Ernst Zeller, Regional Director of AFRY Austria GmbH.
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