Tenerga: sustainable energy from shallow geothermal energy

Posted on 16 Sep 2022

European and Belgian climate goals, stricter sustainability standards for buildings imposed by governments, investors resolutely opting for sustainable buildings, rising gas and electricity prices... The social framework for sustainability is growing daily. Sustainability is the future. Jan Laga, CEO and co-founder of Tenerga Group, is also convinced of this.

What is the core of Tenerga Group's business?

"We focus our activities on shallow geothermal energy as a cost-effective solution to cool and heat buildings. In this way, we can greatly reduce or even completely avoid fossil fuels, which are normally used for this purpose, and greatly reduce electricity consumption.

Tenerga Group guides projects from feasibility study to delivery, start-up, co-financing and 'full service' operation of the underground installations and the boiler room. Because operating such installations is more complicated than a conventional system. We want to use our expertise for this and offer energy 'as a service', in other words completely unburden the customer in that respect."

What is shallow geothermal energy?

"Shallow geothermal energy is energy from the shallow layers of the earth, usually between 50 and 150 metres deep. Terra Energy originated in late 2008 from VITO's 'underground energy storage' project group. Among other things, this project group conducted research into shallow geothermal energy. Despite the less favourable geological conditions in Belgium compared to the Netherlands, for example, it was quickly proven that shallow geothermal energy offers an economically viable solution for both heating and cooling.

Terra Energy thus demerged from VITO in 2008 to go its own way. Later, in 2018, Terra Energy, which focused mainly on research into solutions for the use of renewable energy, partnered with Tenerga for energy system implementation, operational operation, maintenance and financing."

Can you explain this geothermal solution?

"The principle works as follows: In summer, we will store heat in the ground by cooling the building. This can be done without using a heat pump. In winter, when it gets colder, we will recycle the same stored heat and use it to heat the building using a heat pump. So it is a season-spanning storage of heat. That is the essence of the system."

How does that work concretely?

"Via soil drilling, we are going to make a thermal interaction with the soil and in summer, for example, we will flush climate beams or floor loops with cool water of about 18 degrees. As a result, the water heats up a little, the building cools down and we are going to store that heat in the soil. That soil will then warm up slightly, from an average temperature of 12 to 13 degrees to 15 to 16 degrees by the end of summer.

In the winter, we take the heat out of the soil and use heat pumps to bring it up to a temperature of about 35 degrees and recirculate it in the building to heat it up and thus cool the soil again. Thus, this cycle can be repeated endlessly. Terra Energy was, by the way, the first to introduce the open system in the form of thermal energy storage (ATES) in a water-bearing layer (aquifer) and the closed BTES (Borehole Thermal Energy Storage) system to the Belgian market."

What are the advantages of energy solutions using shallow geothermal energy?

"In the context of the current scarcity of gas and electricity and extremely high energy prices, we see the market for applications using shallow geothermal energy growing as it is a renewable, sustainable source of energy. The immediate and permanent reduction in the cost of energy is certainly a very important additional benefit. During summer, you enjoy 'natural cooling', i.e. cooling without the use of a heat pump.

During the winter, shallow geothermal systems ensure fairly low energy consumption - and therefore lower energy costs - because we start from an average of 12 degrees from underground. Other systems start from water or outside air, which are much colder in winter and thus require more electricity to heat up. Moreover, through such heating, cooling and ventilation, we provide a pleasant indoor climate for the people working, staying, living in the building....

Finally, a geothermal system does not need blow-off installations on the roof of or next to the building."

The building itself also becomes more sustainable?

"Indeed, our systems significantly improve a building's EPB score and greatly reduce CO2 emissions, sometimes even to zero. This way, we enable building owners to build 'Nearly Zero Energy’ or even better."

Who are your customers?

"We focus exclusively on the B2B market: offices, hospitals, residential care centres, sports halls, collective living projects, utility and commercial buildings. For example, for the circular office building of Camp C, we provided an almost fully circular energy system. Camp C is an autonomous provincial company of the province of Antwerp and is a knowledge centre for sustainability and innovation in construction.

Other projects include the NATO offices in Brussels, the AZ Maria Middelares hospital in Ghent, various residential care centres in Lommel, Bruges, Beveren, etc. We are mainly active in Belgium and occasionally have projects in neighbouring countries. An overview can be found on our website: www.tenerga.com."

How do you see the future for Tenerga Group?

"Very positive! Cooling is no longer considered a luxury due to the changing climate. We see a continuous improvement of heat pump technologies that provide higher efficiency. The combination of cooling and heating with our systems dovetails nicely with this. Moreover, with rising energy prices, more companies and organisations are more likely to opt for circular energy.

But regulations are also evolving favourably. Stricter building standards offer many opportunities for Tenerga Group. Finally, public support for lower primary fossil energy consumption has also increased significantly. Shallow geothermal fits this perfectly: It is a highly sustainable but also almost always financially the most profitable solution to heat and cool larger buildings. So we believe in a future full of growth for Tenerga Group."

About Tenerga Group

In 2018, Terra Energy and Solutes joined forces and, together with the third pillar Tenerga Energy Services, they form Tenerga Group. Tenerga Group offers various turnkey solutions in the field of renewable thermal energy or ground energy. Each pillar focuses on a different aspect:

  • TerraEnergy researches solutions for the use of renewable energy. Terra Energy has its origins at VITO, from the underground energy storage project group. Terra Energy combines 20 years of national and international experience in energy generation and energy storage in the soil through various technologies.
  • Solutes focuses on the design, composition and integration of installations and management systems for renewable energy applications: construction, installation and start-up of energy systems.
  • Tenerga Energy Services focuses on the operational operation and maintenance of energy systems and financing: providing energy as a service.

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