The photovoltaic park, spirulina algae and a mega tower to study dark matter, or that 23 percent of the universe that is still unknown. The rebirth of Monte Sinni, the last Sardinian coal mine, passes through here. In 2022, with the Russian invasion of Ukraine, it seemed it would reopen because Moscow blocked the sale of gas to Italy. Then nothing more was done: restarting Monte Sinni, after five years of inactivity, would have cost too much. Thus the roadmap towards the farewell to coal continued without a hitch, with a whole series of deadlines between now and 31 December 2026. Objective: to restore a future to the Nuraxi Figus and Seruci sites .

The territory is that of Gonnesa, 68 kilometers from Cagliari, where Francesco Lippi travels every day, sole director of Carbosulcis, the regional spa which since 1996, after the exit of Eni, has managed Monte Sinni alone.

Lippi, appointed by the Solinas council in July 2019, outlines the horizon of the mine in this interview.

In the end Monte Sinni remained closed.

«Even in the contingency of the moment, with the risk that Italy would not have sufficient energy reserves in 2022, the expense of stopping the divestment would have been too high. Definitely out of proportion for public finances."

How much are we talking about?

«Of over 200 million euros, just to reorganize the infrastructures and put the plants that have been stopped since 31 December 2018 back into operation. All this in the face of poor quality production, given that the fossil fuel from Nuraxi Figus and Seruci is full of sulfur. Enel's own coal power plant, in nearby Portovesme, is preparing for conversion."

What does the divestment plan include in Monte Sinni?

«In agreement with Brussels, which in 2014 gave the OK to the timetable developed by the Region and Carbosulcis, the Nuraxi Figus and Seruci wells will have to be closed by the end of 2026. And all the structures made safe. The goods, if salable, will be sold on the market, otherwise they will be disposed of in authorized centres".

You arrived seven months after the mining activity stopped: what did you find?

«I found the planning of some specific interventions related to the closure, such as the recovery of materials, the segregation of parts of the subsoil and various reclamation actions».

What stage are the works at?

«After four years of mandate, activities continue in compliance with the so-called Phase out, the exit from coal. A roadmap for which, by will of the Region, the sole shareholder, we have foreseen support programs, of which one, called Aria, is already active".

Which region are you talking about, Pigliaru or Solinas?

«Pigliaru and Solinas, which are in continuity with a strategic and world-class partner such as the National Institute of Nuclear Physics».

Where will Aria's mega tower be built?

«It will be a cryogenic distillation tower for the production of argon and other noble gases. It will be built in Seruci well 1 and will be 350 meters high (higher than the Eiffel Tower, ed.). The investment is part of the international Dark Side project, for the study of dark matter. The value of Aria is double, if we imagine the intervention within a global project for the reconversion of Monte Sinni".

Why does he say "let's imagine": is there a risk that this won't happen?

«The Region can decide that the conditions are not met».

What are you rooting for?

«Obviously for reconversion, I am a supporter of the circular economy. It should be added that the Monte Sinni site, over the years, has cost the Sardinians and the coffers of the Region itself a fortune. We are in the order of hundreds of millions of euros. It should be added that since 1996, with Eni's exit from the management of the mine, around fifty billion old lire were spent per year. Between investments and losses to cover. But above all the mine is one of a kind, it has characteristics that make it the ideal site for many projects, including environmental ones. Monte Sinni can become an important attractor for the relaunch of Sulcis."

What stage is the work on the cryogenic tower at?

«The goal is to put it into operation in 2025. The well that will host it is now being prepared. Let us remember that isotopes are not only used for the study of dark matter, but their use also finds application in the field of medicine. Aria is a unique project in the world."

How much is it worth?

«We are around 25 million euros».

Who puts the money in?

«One part is the National Institute of Nuclear Physics, one is the Region and one is Carbosulcis».

How much revenue does the regional spa that you run have?

«We made money by disposing of the ashes arriving from the Enel power plant in Portovesme. An activity which, however, we finished at the end of 2020."

To return to the decommissioning plan to be concluded in 2026, where are you at with the reclamation?

«The Seruci embankments are completed, where the restoration of the places is completed. A similar intervention is nearing completion in Nuraxi Figus: the Province of Southern Sardinia has approved the green light for the works, we only have to activate the construction sites. Extra slowly, however, we are reclaiming the Nuraxi Figus landfill: the covering with clay will be completed within the year. The drainage will be placed on top and then a layer of topsoil. At that point the area will be ready to build the first photovoltaic system of Monte Sinni: work will begin on the first four megawatts out of the 10 authorized. We also fixed and closed the underground landfill, which was the only one authorized in Italy: there we stored the ashes from the Portovesme power plant."

How much are the interventions for the safety of the mine and its closure worth in total?

"Two hundred million."

How much do you still have to spend?

«About forty».

Difficulty?

«There are also those, as is natural, due to the fact that the more we progress with the plan, the less staff we have available. To facilitate the exit of employees, in view of 31 December 2026, incentives are also provided".

How many workers are left?

"One hundred".

How many were there when you arrived in 2019?

"Twice. Of the 50 percent who still work, some are workers and some are administrative. The former are employed on the construction sites of above-ground and underground landfills and also take care of the ordinary and extraordinary maintenance of the mine. The bulk of decommissioning activities are concentrated in shafts and tunnels. The administrators take care of the bureaucratic part linked to the interventions and the presentation of the projects on environmental reclamation and recovery".

How many wells are there in Monte Sinni?

«Both Nuraxi Figus and Seruci have a main and a secondary well. There are also others of lesser importance for which we are starting the tombing procedures."

What depth are we talking about?

«Minus 500 meters».

How big is the entire mining area?

«Two hundred hectares».

What will happen after December 31, 2026?

«The plan ratified by the European Commission provides that from 1 January 2027 Carbosulcis will no longer have the mining concession. The workers, at least that residual portion that will not be included in the incentives, will have until June 2027 to complete the specific training provided for in the resignation plan".

Will Carbosulcis be put into liquidation?

«In theory yes. It is one of the possible scenarios. Or the Region can decide to merge the company with another subsidiary."

For example?

«To Igea, which is already involved in land reclamation. Certainly the staff will be absorbed by other bodies in the Region."

What is scenario two?

«Like Carbosulcis, at the request of the sole shareholder, in December 2022 we presented a pre-feasibility plan for the ecological reconversion of the site. We have proposed a series of interventions compatible with the Aria project. The papers are for the attention of the Region which could give Carbosulcis the task of presenting a new industrial plan".

What does the pre-feasibility plan include?

«Transforming Monte Sinni into an energy hub».

That is to say?

«Start production from renewable sources for a total of 22 megawatts. In addition to the aforementioned 10 megawatt project, to be built in the reclaimed landfill in Nuraxi Figus, the construction of a second 12 megawatt photovoltaic plant is planned, this time in Seruci. The positive fact is that the creation of this park is a request expressed by the European Commission to offset Co2 emissions in the era of coal."

Who should manage photovoltaic systems?

«We are waiting for the Region to make a decision. Next Monday, in the Department of Industry, a meeting is scheduled in which the political party, Carbosulcis and workers' organizations will participate. It will be an opportunity to find out the Region's intentions on the continuation of the possible reconversion. The photovoltaic park would allow Carbosulcis itself to reduce the costs of its bills: today we pay between 1.7 and 1.8 million euros a year".

Do you see the uphill road?

"At all. I believe that the Region has every interest in supporting the construction of the photovoltaic park, which would become public property."

A push towards energy easements, given that on renewables, with wind power in the lead, there is a real assault against Sardinia.

«By thinking big and following the examples of other regional public companies, such as that of Valle d'Aosta, the Region could play a key role in the energy field. The Sardinian electricity company has written a piece of history on our island. And nothing prevents private operators from participating."

How much does a 10 megawatt wind farm cost?

«Around 600-700 thousand euros per megawatt. Plus some collateral works. We, like Carbosulcis, believe that Monte Sinni can also host a renewable energy deposit with the gravitational storage system".

How would it work?

«Through the lifting and falling of weights, which, in the absence of sun, would descend to produce energy».

Weights constructed how?

«Made through coal processing waste, waste left aside in Monte Sinni. This system would be totally mechanical, therefore very long lasting, unlike battery storage. As we know, lithium deteriorates after eight to ten years, and also generates problems in disposal."

Has any partner come forward for the gravity storage depot?

«Yes, we are in contact with a Swiss-American company, Energy Volt, which designs and sells storage systems all over the world. The partner is interested in sharing with us the analysis for the use of the three kilometers of the mine's descent: there are three ramps of a thousand meters each, with a 15 percent slope that takes you down to minus 400 meters. The goal is to create a prototype. Not only that: in Monte Sinni there are aquifers, from which water is sucked every day to prevent the tunnels from flooding. A working hypothesis is to produce energy by also creating a hydroelectric pumping system. By the end of the year we should have costs and feasibility."

You are also putting your nose into bio-agronomy through the desulphurisation of coal. What's new?

«Technically we also talk about leaching. Using a special acid, the coal waste from Monte Sinni would be treated again to produce a fertilizer. We have already filed a patent on the process. Quality would even increase by enriching the product with compost obtained from the humid fraction in the Tecnocasic plant, in Macchiareddu, where the garbage from the vast area of Cagliari arrives. The project is carried out together with the University of Cagliari. Monte Sinni could become the first center of excellence on industrial policies linked to the ecological and environmental transition. Crea, the National Council for Agricultural Research, is also collaborating."

What do you want to do with spirulina?

«Always together with the University of Cagliari, it has been ascertained that the miracle algae, capable of reducing cholesterol, triglycerides and blood pressure, improves its beneficial effects if cultivated using the hot waters of the mine».

Is there a private partner?

«It's the goal. I am optimistic, about everything: Monte Sinni has enormous potential, also in terms of synergy with Sotocarbo, another regional spa that is working on energy production, exploiting hydrogen. Renewables must be a side of public commitment, in the interest of the environment and of all Sardinians."

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