Interview: Alessandro Piubelli of Turboden on the new Soultz-sous-Forets plant

Soultz-sous-Forets geothermal plant in 2014 before installation of new plant (source: ThinkGeoEnergy)

Alexander Richter 21 Sep 2016

The European geothermal energy industry is meeting these days at the European Geothermal Congress in Strasbourg/ France. Organized by the European Geothermal Energy Council (EGEC), the event brings together representatives from all angles of the industry, from research, to consultants, technology providers and academics.

Naturally the French industry is strongly represented, but so are international suppliers, such as Turboden and others. Italian Turboden as a supplier of ORC power plants for the geothermal, waste heat and biomass market was chosen to rebuild the Soultz-sous-Forets geothermal plant here in the Alsace/ France.

As one of the key EGS research sites, Turboden was chosen among a group of contenders to rebuild a power plant on the research site. The plant is already operating, but will be officially inaugurated during a field trip on site on Friday this week. ThinkGeoEnergy will be attending the event and report from the site. Pictures of it you will be able to find on ThinkGeoEnergy’s Flickr page soon thereafter.

During the EGC event currently going on, I was able to talk to Alessandro Piubelli, Commissioning, Service & Aftersales Manager of Turboden. Here a short interview we took.

The Soultz-sous-Forets geothermal project has been a very international research project on EGS technology. So seeing a power plant restarting power generation is a significant step. The new plant built by Turboden replaces an old pilot plant, how does the project compare to other projects you have developed so far?

The project is similar to others so we have been able to leverage many teams inside the company that have been working together on the development and execution of such projects for a long time. Of course every project also has its own peculiarity to manage particularly related to specific technical characteristics, like the type and quality of the thermal source, type of turbine and working fluid used to maximize the produced energy, type of cooling system (ACC, cooling towers, dry coolers), specific customer requirements for the project or specific local standards applicable.

In the case of the Soultz project, the main difference is coming from the type of the reservoir and thus the type and quality of the brine.

What is the temperature of the resource being utilised for power generation?

The temperature of the resource is 155°C and we receive a flow of 32 kg/s.

What have been some of the challenges for the development of the project and how did you overcome them?

As indicated earlier, the main specific feature of this project is the type of the reservoir and the brine. It was really important to maximize the performance of the ORC plant with the target to re-inject the source at a specific range of temperature of 60-75°C. This was possible thanks to the specific design of the system and of the control software, completely developed and prepared internally by our process and automation team leveraging of course the experience done with the pilot plant of 2008.

With 1.7 MW of power generation capacity, the plant is of smaller-scale, what standard size options does Turboden offer for geothermal projects?

In geothermal there is no standard size. Each resource is different, and can be intelligently developed by means of a modular approach. Currently, Turboden largest frame is 20 MW per single turbine. Therefore we can realize projects with a size of 40 MW, which features two turbines and a single generator. Average size (worldwide) of binary plants is about 7 MW, but we see a trend of increasing size in with projects of 10 – 20 MW for the last two years .

The Soultz plant is now the only geothermal power plant operating in France itself (There is an operating geothermal plant in the French territory of Guadeloupe in the Caribbean), how do you see the opportunities for Turboden in further development of geothermal power plants in the country?

We consider France as one of the next leading European geothermal markets. There are good geothermal resources in the Rhine valley as demonstrated by other plants installed across the border in Germany. The regulatory framework is also well developed to sustain the growth of the market.

Where do you see key growth markets for Turboden in the geothermal industry for ORC solutions today?

We are globally present with our binary plants in 35 countries. Therefore we are targeting almost all the advanced projects. Turboden is the European leader of binary technology, we therefore see France and Germany as key markets for us. The Middle East and South East Asia are also target areas of our company. The Caribbean and Africa will follow soon.

ORC solutions are being applied in a lot of industrial applications, utilising waste-heat, biomass etc., how important is the geothermal market for Turboden’s business?

We plan to continuously gain market shares and and grow our business, geothermal will count for at least 50% of the revenues.

In comparison to your industry peers, what makes the offering of Turboden competitive in the market?

We have developed by far the largest number of binary solutions in the market. Therefore flexibility and reliability are the key. We deliver top quality equipment and most of our customers are repetitive, which is a sign of dependability of our technology and superior after sales services. At present, we are the only company in the binary marketplace with O&M capability.

Being part of the Mitsubishi Heavy Industries group of companies, do you offer joint products, e.g. a combined flash-condensing and ORC solution for the geothermal sector?

Yes, this is one of the other advantages of Turboden, which is the possibility to offer fully integrated solutions within the same group.

ThinkGeoEnergy thanks Alessandro for taking the time to talk to us, and we are looking forward reporting from the site of the plant on Friday.