Do biomethane plants help reduce nitrate?
The Guadiana Hydrographic Confederation knows that I work on this issue and called me to give my opinion. Biomethane will increase nitrate pollution. In these plants, only 5% of the waste is transformed into gas and the rest is another waste, rich in nitrate, which is also generated in a territory already vulnerable to this pollution. Spain is already condemned by the European Justice for failing to comply with the Nitrates Directive. However, regions such as Castilla-La Mancha consider it a plus in favor of authorizing a project that is located in Zones Vulnerable to Nitrate Pollution, although in many of them, the origin of most of the pollution is not waste, but rather overfertilization. If Europe decides to restrict fertilization, it could be the last straw for small and medium-sized farmers and ranchers. Furthermore, if used as an organic amendment, pig manure contaminates groundwater almost four times less than digestate!
What about decarbonization then?
The assessments that biomethanization contributes to decarbonization and our energy sovereignty are false; In reality, it’s just the other way around. In Germany they already tried it a long time ago and they have a lot of plants. There it has a reason for being, because they are very dependent on Russian gas, but we have renewable production (in Castilla-La Mancha we produce twice as much energy as we consume). Biomethane has a problem, that we would only improve by 5%, and for that we should depend more on fossil gas, although it may seem paradoxical. And even if all the biomethanizable waste in Spain were biomethanized, the gas pipeline network would not achieve the necessary operating pressure to become independent from fossil fuels. We would still need 66% of the gas we use now.
Where is the problem?
The implementation model: large plants are planned following only the gas pipeline regardless of where the waste is, not small ones and where there is waste. The small ones even have a good perception, even homes at distances of six kilometers from small plants are revalued.
Castilla-La Mancha is one of the regions with the most demonstrations, why?
The region expects there to be between 70 and 100 plants. There are 15 projects in Ciudad Real alone and they have begun to appear like mushrooms in Cuenca, Toledo or Albacete. In Daimiel they want to set up a biomethane plant for 486,000 tons per year. And to get an idea, most of those they are putting in are between 100 and 200,000. With residue of what? In Daimiel they have 50,000 tons of wine waste, but the project plans to treat nine times as much. And now they already have odor problems every time the south wind blows. In Albacete, it is even proposed to use sewage sludge, which is the most likely to contain heavy metals. That cannot be put in the countryside, if somewhere they start producing foods that are accumulating heavy metals, we have a serious problem. Here, curiously, the mobilization is not environmentalist. Most of them are people from the towns. The Denominations of Origin have said no to biomethane plants.
Catalonia is the CC AA that has the most plants and the most meat production. Are there problems there?
In Catalonia they have another problem and that is that they do not have enough waste. An inflation in the price of waste has been detected: previously, the owners of macro pig farms had to pay €7/m3 to have their slurry removed. Now they get paid! €14/m3 for removing slurry. It is a perverse process, because before they optimized their production to minimize slurry.