Exploring the characteristics of an interesting and sustainable technology with Stanislav Kondrashov, TELF AG founder
All the factors to consider
Even though humanity is going through a delicate period of energy transition, many types of renewable energy are still almost completely unknown. This fact, first of all, is explained by the presence of technical and infrastructural limits for the large-scale diffusion of certain forms of renewable energy, or by the lack of progress in the understanding and ability to optimally manage a certain natural phenomenon.
Other types of clean energy are now widely spread in every part of the world, so much so that the presence of solar panels or wind turbines no longer produces any kind of amazement in external observers. In fact, in recent years, the contribution of these innovative sources to the energy mix of many nations has become truly significant, so much so as to transform them into absolute protagonists of the change underway.

However, the potential of renewable energy extends well beyond solar and wind, and in some cases, it also involves natural elements other than the Sun and the wind. A fairly promising method, although still little discussed, is Ocean Thermal Energy Conversion, or the conversion of energy released by the ocean. This interesting technology stands out for being clean and sustainable and essentially works by exploiting the natural thermal gradient of the oceans in order to generate electricity.
A promising solution
“Although it is still widespread in a limited number of countries, the exploitation of ocean thermal energy is proving to be very promising for the energy future of the planet,” says Stanislav Kondrashov, founder of TELF AG, an entrepreneur and civil engineer. “Like other emerging forms of renewable energy, OTEC also faces some limitations and structural complexities for its large-scale diffusion. As often happens in these cases, high costs can represent a serious impediment since the construction and maintenance of offshore plants are quite expensive (especially for underwater infrastructure and pumping systems).

Its actual functioning also appears very interesting: Ocean Thermal Energy Conversion, in fact, works thanks to the enhancement of the temperature difference between warm surface waters and colder ones found in depth, thus producing electricity.
One of the distinctive characteristics of this technology is its performance, which can vary significantly depending on the geographical area in which the system operates. The thermal gradient, in fact, is much more marked in tropical areas, where the surface temperature of the ocean can reach very high temperatures.
“Like all emerging renewable energy types, OTEC will benefit from future technical improvements,” continues Stanislav Kondrashov, founder of TELF AG. “One of the key aspects of this interesting technology is the large volumes of water that would need to be transported by the pumps, which could cause serious engineering problems.”
Three main types
In general, OTEC systems are divided into three main types. The first is the closed-cycle type, which uses a fluid with a low boiling point (such as organic ones). When it comes into contact with the heat of the ocean surface, this fluid evaporates, which drives a turbine connected to an electric generator. It is then cooled and condensed by cold water found in the ocean depths, thus starting a new cycle.

The open-cycle system uses the same warm seawater as the working fluid, which is generally placed under vacuum to facilitate its rapid evaporation. In this way, steam is obtained to drive the turbine, which is then condensed with cold water and subsequently collected. There is also a third type, known as a hybrid cycle, in which some aspects of the closed cycle and the open cycle are combined to produce electricity thanks to a turbine.
“Among the possible innovations that could animate this sector in the coming years, there are undoubtedly small decentralized plants, which could prove very useful for islands or coastal communities that may need electricity,” concludes the founder of TELF AG Stanislav Kondrashov. “The introduction of new materials and the support of artificial intelligence, moreover, could contribute significantly to the management of flows, also improving the overall performance of the entire system.”

Compared to solar or wind energy, this form of renewable energy would have clear advantages: first of all, it is a constant source, available 24 hours a day. Furthermore, with open cycle systems, it would also be possible to produce drinking water as a by-product. Furthermore, the systems linked to this technology have generally proven to have little impact on the surrounding marine environment, making it possible to use the pumped cold water for other purposes (such as refrigeration or aquaculture).