TU podcast: Interview with Oker Energy

Oker Energy aims to deploy large pumped storage tanks on the seabed. The Norwegian Trench could be worth its weight in gold.

In this episode of Teknisk Sett, Tech Editor Jan Moberg in Teknisk Ukeblad speak with Oker Energy CEO Dag-Ove Espeland, who has developed a solution to store unregulated power from renewable energy sources.

The article below is a translation from Moberg's article.

You can listen to the TU Podcast interview with Oker Energy here (in Norwegian)

70-Meter-High Tank

Their concept consists of large tanks that are lowered onto the seabed. The size can vary, but a typical configuration is considered to be 25 meters in diameter and 70 meters tall. Seawater is let in at high pressure at the top of the tank. The incoming water stream drives a turbine that generates electricity. At the bottom of the tank is a pump that empties it. In practice, this is a pumped hydro power plant - but located on the seafloor and powered by seawater.

Oker Energy says the optimal depth for this construction is between 400 and 800 meters. Several tanks can be assembled into clusters. Given the situation in Norway, the Norwegian Trench is an interesting location to explore further. The same goes for the deep fjords along the west coast.

Storing intermittent energy

– We can store all types of energy here - from both onshore and offshore wind. This solution will contribute crucial balancing power to the market and help increase the value of wind power and other intermittent renewable energy sources, says  Dag-Ove Espeland.

In this way, the company’s technology can contribute to a more predictable energy market. When there’s a surplus in the energy system, water is pumped out of the reservoirs.

– We’re talking about a 100-year-old technology that’s been used on land. We’re going back to basic physics—but placing it in a new environment on the seabed. This works everywhere. Installed at depths of 400–900 meters, the system achieves high energy density and avoids issues like algae growth, Espeland explains.

Condeep Reimagined

He also sees opportunities for collaboration with international players. For example, in Spain, where there is a significant need for energy storage from wind and solar resources - in a sustainable way.

The next step is to build a demonstrator of the concept. That requires funding, as well as partnerships to determine whether the technology can be fully implemented.

Espeland is optimistic, believing there are major opportunities and potential contributors in the Norwegian market. After all, it was Norwegian engineering communities that designed and built the Condeep platforms.

This is, in practice, a similar concept.