Kondopozhskaya HPP is a derivation hydroelectric power plant with an open-flow intake system in the form of a channel, using the height difference between the Sandal water-storage basin and Lake Onega. The plant uses the runoff of Lake Sandal (turned into a regulating water-storage basin), as well as most of the runoff of the Suna River, which is transferred to Palyeozero and further to Lake Sandal through the Palyeozerskaya HPP. The Kondopozhskaya HPP consists of dams Navda and Sopokha (forming the Palyeozerskoye and Sandalskoye water-storage basins respectively), a derivation channel with head and appurtenant structures.

The dam Navda is an earth dike made of sand and has clay as its blanket. The dam is 1,500 m long, the maximum height is 5.4 m. It forms the transit Palyeozerskoye water-storage basin with the flood-control storage level of 72.5 m, an area of 109 km2 and a useful capacity of 158.5 million m³. The dam Sopokha is an earth dike, made of sand and sand soils, is 1,427 m long and maximum height of 5.2 m. It blocks the Sandalka River and forms the Sandalskoye water-storage basin. Originally, the dam had a wastewater outlet into the river Sopokha Sandalka, but now it is buried.

The derivation channel has a length of 1,950 m, a top width of 34 m, a maximum output of 200 m³/s. In the beginning part of the channel there is a head structure, which is a surface water intake with one opening which is 11 m wide. There is a railway on the abutments of the head structure.

The appurtenant structures include a head pond with a water intake house, delivery pipelines, wastewater outlet, the HPP building and an outlet channel. The head pond (intake chamber) is located at the end of the derivation channel and accumulates water supplied to hydroelectric generating units of the HPP. At the end of the head pond there is a low-level water intake house. To the left of the water intake house there is a wastewater outlet with a capacity of 72 m³/s.

The water is supplied to the hydroelectric generating units through the delivery pipeline system. Pipelines of the first HPP stage are made of reinforced concrete, with a length of 83.3 m. One of them has an inside diameter of 3.2 m and is in operation, the second one has an inside diameter of 2 m and is not in operation (shut with a concrete plug). Pipelines of the second HPP stage are metal, have a length of 92 m and a diameter of 4.5 m.

There are three hydroelectric generating units in the HPP building equipped with radial-axial turbines operating at a rated head of 28 m. Two of them are vertical, with a capacity of 10.7 MW, and one is horizontal, with a capacity of 4.2 MW. Wastewater from the turbines is discharged into Lake Onega through the outlet channel which is 113 m long.

Electricity from the Kondopozhskaya HPP is supplied to the power system from a 110 kV outdoor switchgear. Annual average electricity output amounts to 131 million kWh.

Construction parameters