The Sarvisuo project began in May 2020 and was handed over to the Customer in the end of October 2020. The power plants to be installed are the second highest in Finland, 240 m, and they generate more than 5,000 GWh (0.5 TWh) of electricity per year. This corresponds to about 8% of all current Finnish wind power production.
The original plan for Sarvisuo was 8 gravity foundations and 19 rock anchor foundations. As the work progressed, 6 foundations were switched to rock anchor foundations after the bedrock was found to be higher than expected, in addition, 4 foundations were designed with an extension section as rock anchor foundations. Eventually, two gravity foundations were built in Sarvisuo. These changes reduced CO2 emissions by about 40,000 kg, while reducing construction materials by 4,800 cubic meters of concrete and 670,000 kg of reinforcing steel.
What is special about the project is that in all the foundations the upper surface has been built on the same level as the hardstand, which brought its own challenge to the design and implementation.
“The challenge for the project was to coordinate schedules with other site operations to ensure that foundation work progressed smoothly with civil engineering and cabling. In Sarvisuo, the changes in the quality of the rock, withing a small area, caused us quite a few surprises and extra work, but despite that we got the project completed before the end of 2020“, says Esko Erkkilä, the responsible site manager at Sarvisuo.