An English village becomes self-sufficient thanks to biogas

Re-publication of an article by Mario A. Rosé on Agronotizie

Bureaucracy and Nimby at Italian levels, but perhaps with clearer regulations.

The political debate of the last month has focused on the consequences for the Italian economy of the international embargo on Russian gas. Despite the Guidelines contained in the communication of the Ce REPowerEU and the Spanish example of a quick and pragmatic reaction to the supply problem, the only answer that Italian politics was able to find was simply to replace dependence on Russia with dependence on other countries. Inter alia, not all democratic or politically stable.

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Biogas and independence from Russian gas: Spain will beat Italy on time?

According to the president of the Italian Biogas Consortium (Cib), Piero Gattoni, to increase by 20% the production of existing biogas plants would be enough only to reduce the bureaucratic burden. Moreover, says Gattoni, the delay in issuing clearer rules on the injection of biomethane into the network has slowed the construction of new plants, which today would be able to replace the 30% of natural gas imports. A delay what time the Government tries to compensate by desperately seeking alternatives abroad.

Meanwhile, the Parliament Italian perseveres in Byzantine discussions on the possibility of reintroducing nuclear power or install more solar panels on the roofs to solve the energy crisis, a small English village has reached the paradigm of’circular economy and l’energy self-sufficiency. South Molton is a rural village with 4.093 inhabitants located in Devon, about 300 miles west of London. L’Condate biogas plant (Opening photo of the article), placed at approx 1,5 kilometers from the town center, produces enough renewable electricity for 2.300 families, and gas for 4.600.

It is one of several plants belonging to the Ixora Energy Group. It is equipped with two cogenerators from 500 kW and an upgrading system with capacities up to 600 m3/h. It looks a lot like any of the over a thousand existing plants in Italy, except for two details: the design choice to install two cogenerators in parallel instead of the usual engine from 1 MW, and the simultaneous production of electricity and biomethane, still a rarity in our country due to unclear regulations.

Thanks to the general manager, Mr Darren Stockley, who kindly gave us his time to answer our questions, we offer our readers a summary on the general state of simultaneous electricity and biomethane production in the UK.

Years ago, in Italy it was allowed to feed the digesters with up to 100% of dedicated crops, and many old plants still operate on this diet. After the revision of the Red II, the limit for new plants has been set at 30% of the total weight in feed. Since the UK is no longer subject to the EU regulations, what are the percentages of dedicated crops and residues / by-products in your feed mixture?

“New plants in the UK must be powered with at least 50% of agricultural residues. Our plants are not subject to this rule, so we can operate with mixtures containing the 20-50% of agricultural residues. Condate works with the 20% of agricultural residues. We are constantly trying to identify new sources of agricultural residues to increase their percentage in the feed mix”.

In your web page it says that Ixora Energy pays local farmers for their manure and by-products. Calculate the price based on measurements of the Bmp of each lot? Or take the German approach, based on Bmp tables?

“We pay farmers based on the content of Ss, Dry substance, of their supplies. We have contracts for the entire life of the plant (15 years) and the price per ton of dry matter is updated every year by an independent expert who reviews their costs”.

Return the digestate to the farmers free of charge or make them pay for it as fertilizer?

“We give it to him for free backards, but we do not allow them to charge us with artificial fertilizer costs in the by-products we buy”.

How do you manage digestate?

“We separate the solid and liquid fractions. The solid is applied directly to the ground. The liquid fraction is currently used as a liquid fertilizer, but we are working with several British and European companies to extract and recycle water. This is an area for which we are very interested in finding a solution”.

Recover the residual heat from the cogenerator and / or the CO2 from the upgrading system for some use?

“The heat is recovered, but only to reduce the humidity of the digestate. We are evaluating several options to make the best use of heat for hydroponic and vertical farming. We are also modifying our plants to capture CO2 for its use in the food industry”.

You have designed the Condate plant from the beginning for the simultaneous production of electricity and biomethane? Or you started as an electrical system and then added biomethane production at a later time?

“It was designed from the outset for the production of electricity and gas. Gas production is limited only by the extent of the pipeline serving our community”.

What are the electrical and biomethane rated powers?

“The flow rate of biomethane to the pipeline is approx 500 m3/h, and the electric power is 1 MW (of which 400 kW represent the self-consumption of the system)”.

The production of electricity and gas are simultaneous, or the electric generator is switched off when biomethane is produced?

“Before, enough electricity is produced to power the plant, then gas production is maximized, then the electric one. Therefore, the production is simultaneous.

How much time did you waste for the bureaucratic procedures before getting permission to start construction and operation?

“They have passed 12-18 months to obtain the building and environmental permits needed to start construction. Lately this problem has gotten worse in the UK, despite the need to become energy self-sufficient”.

There were local protest committees, or spreading fake news on biogas in an attempt to block your project? How did you solve the problem?

“Condate was not a problem, but we have other plants that suffer from the protests of the neighbors. This situation has worsened with the use of social networks. To overcome this problem, we try to invite as many people as possible to visit the site and show them that the rumors about biogas plants are incorrect. We also try to dialogue with local politicians to show the benefits that the plant provides to the environment”.

How the sale of electricity and gas is organized in England? Sell ​​gas and electricity directly to the municipality or to a distributor that owns a local network? Or inject them into the national grid?

“We directly inject gas and electricity into national networks. We sell the production to private energy companies such as BP / Total / EDF, which they resell to the final consumer”.

British regulations recognize a rewarded rate compared to market prices, or subsidize the construction of the plant, or recognize only a fixed proportional to the nominal power of the system?

“We receive a subsidized payment based on actual gas and electricity production. Payment is made monthly by the Government and we must demonstrate our environmental performance by providing detailed information. Everything is regularly checked”.

summing up: the situation in England does not seem so different from the Italian one. Over-regulation seems to be a recurring problem both inside and outside the EU.

England benefits from greater flexibility in the use of dedicated crops to feed the digesters and slightly shorter administrative times, though 12-18 months is not a very short time if we consider the urgency of global climate change. The anaerobic digestion technology of the Condate plant is Central European, as in the majority of Italian plants. The logic of state incentives on biomethane and electricity products, as well as the way these incentives are administered, they look similar in both countries.

Comparing the statistics of energy production from biogas on a national scale, we observe some interesting additional differences on the evolution of both markets (Photo 1).

Graphic: Energy production

Photo 1: Official data on English production. Official data on Italian production. Conversion factors to be able to compare data from different sources: 1 TJ = 23,8846 TEP e 1 GWh = 85,9845 TEP

(Click on the image to enlarge)

The reason for which the biogas industry is growing faster in the UK than in Italy it seems to be legislation.

In Italy, the biogas boom began years earlier than in England, but Italian policies have remained static and at times alternately contradictory, therefore the Italian anaerobic digestion market is still strong globally, but stagnant. In the United Kingdom, the sector expanded between 2009 and the 2017 under the legislation known as Renewables Obligation (RO), main incentive mechanism for large renewable energy projects. In March 2017 RO is over and most of the significant growth in energy produced by anaerobic digestion is attributed to various mechanisms, specially designed to provide sufficient financial incentives to reduce the cost gap between conventional and renewable energy sources.

A example of these is the non-domestic Renewable Heat Incentive (Rhi, incentive for the production of heat for non-domestic use), which provides payments to encourage the production of renewable heat, both through direct production (combustion of biogas on site) and injection of biomethane into the network. In Italy, there is no direct combustion support policy for the production of heat from biogas. Incentives for heat recovery from cogenerators are not attractive to investors and plants capable of producing electricity and biomethane are just a handful.

Then, we deduce that the culprits of the stagnation of the biogas industry in Italy are bureaucracy and short-sighted policies. Elementary, Watson!

The role of bioenergy in soil protection

republication of an article by Mario A. Rosé on Agronotizie

In data 24 February 2021 it was held, in webinar format, the conference “Caring for soil is caring for life”, as part of the European Mission for Soil and Food Health.
The event was organized by the Ministry for University and Research, Opens, Agency for the Promotion of European Research, Resoil foundation e Santa Chiara Lab (University of Siena). The Minister for University and Research has opened the meeting, Cristina Messa, and Dr. Antonio Parenti, head of the European Commission Representation in Italy.
The video recording was made available to the public on the Open YouTube channel. The presentations of the various speakers can be downloaded from this page.

Environmental problems, social and economic degradation of agricultural soils, overbuilding and other phenomena induced by human activity, they are extremely complex and go beyond the main topic of this column. We offer our readers a report to Professor Giuseppe Corti, president of Sipe, Italian Society of Pedology, who kindly gave us a deepening of his presentation, focused on the potential of agro-energy for soil recovery.

Why is the health of European soils a concern??
“The concern is great and has been denounced for several years by the scientific societies that deal with soil. My company (Sipe), eg, in 2013 has presented a bill to uniquely define the soil and safeguard it; the proposal received a number (the 1181) after some years, but it was never scheduled. After a few more years, during a meeting, a government official told us (verbatim): 'Your proposal will never find acceptance for adverse crystallized interests!’. Then, evidently, we are not compatible with the general interests of the country. And we instead thought we were working for the good of the country, because the soil is the basis of a healthy and lively economic and social policy without which we can hardly hope for a brighter future than the past.

In any case, the most urgent threats facing soil across Europe are ten:

Reduction of organic matter. The problem of problems. In fifty-seventy years of intensive agriculture not harmonized with the pedoclimatic conditions, it has also produced 3% (absolute) of organic matter from agricultural soils. We have soils with less than 1% of organic matter, whose management becomes more and more difficult. (1)
Erosion. Unsustainable! In many areas of the country, erosion also takes away 1 centimeter of soil per year, in some cases even 2. Consider that 1 centimeter of soil per hectare per year means 100 tons of land per hectare removed every year, that sooner or later will end up in the sea, creating eutrophication problems. Then, double damage: the most fertile part of soil leaves and becomes a pollutant of the seas. (2)
Pollution. Italy is among the countries with the largest amount of areas polluted by organic pollutants (Petroleum, oil…) and minerals (especially heavy metals). If we start right away, we may be able to successfully recover the less polluted soils in a few decades, for others it will take centuries. And all this time, those soils will prevent the production of food and will not help purify the water. (3)
Soil consumption and sealing. Even in the midst of the economic crisis following the collapse of the so-called construction bubble, in Italy we continued to consume land at a rate of 10 thousand hectares per year (Ispra data). To do what? To sell to whom? We have tens of thousands of empty buildings, skeletal, abandoned, unsold that fall on themselves. Useless to the economy and the country, where, however, it is no longer possible to produce anything. We have areas covered with useless concrete or asphalt, where we could have grown chickpeas, tomatoes, eggplant .... Nothing, we'll never do anything about it again. (4)
Salinization. Problem on the rise throughout Italy. The soils are becoming rich in salt, of marine origin in the vast majority of cases. We also blame climate change, but we begin to check the concessions of the wells and swoop down the illegal ones. Then we also talk about climate. (5)
Loss of biodiversity. The reduction of organic matter and erosion have already caused a great loss of biodiversity at the level of higher organisms (snakes, amphibians, insects, spiders, …), but also in soil microorganisms. And to think that in many cases, at least the cleansing of organic pollutants could be easily canceled by the soil's trophic chain. (6)
Vertisolization. Soils with a significant amount of clay (greater than 30%), if in a climate that foresees a strong alternation between the rainy season and the dry season they tend to become dizzy, that is, to form fractures that deepen even further 1 metro. The cause of the transformation is partly to be found in the extreme rainy events, but it is largely caused by erosion, which prevents more and more water from penetrating the soil. Once the process has begun, difficult to go back, with the impossibility of continuing to produce tree and shrub crops. (7)
Entisolizzione. With erosion accelerated at a rate of 1-2 centimeters per year, soils become Entisols. This is how soil scientists define soils that have now become not very fertile terrigenous mattresses, without an optimal differentiation in horizons, reduced production capacity. Commonly defined as “soil-not-soil”, they represent the step before the disappearance of the soil itself. (8)
Acidification. This is a problem that does not interest Italy too much but, Rather, the countries of Northern Europe, dell’Africa, of South America and China. As acidification proceeds, the ability to retain nutrients is reduced and food production drops inexorably.
Fires. Another huge problem affecting forest and natural soils. It must be said that, absolutely, fire is also an evolutionary agent of vegetation, but if it is repeated with excessive frequencies (due to mismanagement or vandalism) then it involves a degradation of vegetation and soil”.

In Italian soils we have lost the 2-3% of organic matter in the last fifty-seventy years. It is not enough to add compost and / or digestate? Because in Italy it is “virtually prohibited” use the sludge deriving from sewage treatment? If they are dangerous, as i claim “local committees”, environmental groups and some politicians, why in countries like Sweden they are even used in organic farming?
“For the first question, unfortunately it may not be enough to add organic substance to the soil to see it increase. It can happen in cold environments, we say from us above at least one thousand-1,200 meters of altitude, but not elsewhere. And the reason is the activation of the microflora, the more active the more easily degradable is the organic substance. For the second question I answer that unfortunately in this country things are banned because we do not trust who could go to manage them., perhaps because we imagine that others behave as I would behave in their place ...”.

What can you tell us about biochar? Better to apply it alone, or mixed with compost, or to digestate?
“We must get rid of the fact that biochar is the panacea for all evil. For biochar to have an effect on crops, a soil thickness of at least 20 centimeters contains at least 1% of biochar. If we plan to improve the conditions of degraded soils by adding biochar, the forests of two planets like the Earth would not be enough! Biochar is an excellent solution for small surfaces, where it does its best to increase and improve production (also reducing the availability of heavy metals) when combined with other fertilizers”. (9, 10)

Since the area more “biodiverse” of the soil are i 30 superficial centimeters: we must deduce that it is better to use herbaceous energy crops to decontaminate soils? There is a criterion for choosing between herbaceous and woody?
“The greatest biodiversity of the soil is in the former 30 centimeters because that is the thickness of the soil richest in organic matter (which is the substrate on which microorganisms live) and oxygen. This does not mean that there are important microorganisms even at greater depths. To decontaminate soils, probably the best solution is to use both types of plants, arboreal and herbaceous, so as to affect a wider thickness of soil from which to extract (in the case of heavy metals) or in which to degrade (in the case of organic materials) pollutants. But we must be aware that, In many cases, it will take decades or centuries to bring the pollutant values ​​back to the current legal parameters, also using varieties of plants with high absorbing or degrading power of pollutants”.

What an energy crop it is, in his opinion, the most suitable for containing erosion? Why do you say there is still a need for field research rather than desk research?
“There is probably no crop more suitable for reducing erosion, rather a productive system (choice of crop / crops, type of processing, development of hydraulic arrangements) that aims to reduce runoff formation, that is, the surface flowing water.
It takes field research why, also guilty of ridiculous funding to cope with field and long-term research, more and more research is being done based on pedofunctions and models, sometimes without even trying again in the field the veracity of the model developed, but based on values ​​published by other authors on soils similar to those considered in the desk research. If we want to acquire seriousness and authority in this field of study, in a country that badly needs it, research needs to be funded in the field, where you go to test the validity of a production system for years. The variability of weather events is such that based on one year's data we could conclude that there is no erosion, except the year after they found themselves with hundreds of tons of soil removed. We need targeted research, functional in order to reduce erosion, multi-year e, then, adequate funding”.

How should the different agro-energy chains be integrated with soil protection policies?
“In a very simple way: polluted soils must be cultivated to eliminate pollutants with the biomass produced (obviously no food or fibers can be produced). Which means moving the problem from soil to biomass, with which we would not know what to do. Furthermore, at high costs and continued for decades, at least! How is it possible that the community can absorb such expenses? One possibility is to create biomass processing chains that can be economically sustainable, so that there is convenience in cultivating those soils, moving towards a progressive de-pollution. One possibility is therefore to assess the level and type of pollution and proceed with one type of supply chain rather than another.

For example, in case of minor pollution, herbaceous crops can be grown from which to produce methane (via digestore), ethanol (via fermentation), automotive oil (via extraction) and with residues (and other organic matter) produce soil improvers by composting that could re-enter the soil as fertilizer. Or, in the case of major pollution, produce firewood, from whose ashes to extract metals by electrochemical way. Consider that the extraction of metals such as gold, silver, platinum, chromium and others is cost effective starting from the ashes. A metal extraction plant could therefore be fed with ash from biomass power plants produced in polluted sites, without producing air pollution, helping to reduce our dependence on fossil fuels and creating jobs. (10)
in conclusion, bad to say so as not to stimulate its increase, but we can transform a problem such as that of polluting soils into an economic opportunity that acts as a driving force for their de-pollution”.

Photo 1: Possible agro-energy production chains for soil decontamination. (Photo Source: presentation by Professor Giuseppe Corti during the conference “Caring for soil is caring for life”)


The health of European and Italian soils is threatened by many anthropogenic causes e, to a much lesser extent, from climate change. We must therefore stop using climate change as a mitigating factor for the impossibility of improving the condition of our soils. Research has shown, for years, that land management has much more responsibility than climate change in degradation. This means that we no longer have time available and that we can start work without waiting for the climate to normalize or return to the levels of the second half of the century.. XX. We have to channel all our energies, technical and economic, in the undertaking of recovering degraded soils, with the commitment not to detract from those who are not yet.
At the European and national level, the conservation and recovery or improvement of the health of agricultural soils is also a duty to debase the drive to occupy forest soils, problem that is occurring in many parts of the world. We owe it to our children and grandchildren more than to us either, If we want, to our consciences.

Bibliographical references

(1) Short G., Cocco S., Brecciaroli G., Agnelli A., Seddaiu G.. (2013). Italian soil management from Antiquity to Nowadays. Chapter 9, pp. 247-293. In: Costantini, E.A.C., and Dazzi, C. (Eds.) The soils of Italy. World soils book series. Springer Science+Business Media, Dordrecht.
(2) Short G., Horse E., Cocco S., Biddoccu M., Brecciaroli G., Lambs A. (2011). Evaluation of erosion intensity and some of its consequences in Vineyards from two Hilly Environments Under a Mediterranean Type of Climate, Italy. In: Godone D., Tired S. (Eds.) Soil erosion in agriculture. Chapter 6. InTech Open Access Publisher, Rijeka, Croatia. ISBN 978-953-307-435-1.
(3) Visit this page.
(4) Visit this page.
(5) Dazzi C., The Pope G., 2013. Soil threats. Chapter 6, pp. 205-245. In: Costantini, E.A.C., and Dazzi, C. (Eds.) The Soils of Italy. World soils book series. Springer Science+Business Media, Dordrecht.
(6) Visit this page.
(7) Visit this page.
(8) Dazzi C., Monteleone S. (2002) – Soil emergency and anthropization of the territory: an example of loss of pedodiversity due to entisolization. Proceedings of the conference of the Cinquantenaire Siss “The soil emergency” Boll. SISS vol. 51, n° 1-2, pp. 557-570.
(9) Visit this and this page.
(10) Visit this page.

The opportunities of the new European Fertilizer Regulation for the agricultural and waste sectors

The theme of the future of agricultural biogas plants is closely linked to the enhancement of by-products and waste of agri-food origin. The biogas plants built in the last 10 years and partly financed with public money, to encourage the progressive replacement of fossil sources, they are a technological asset and an important source of economic sustainability for farms, that, without substantial changes, they would be able to be fed with the organic fraction of municipal solid waste (FORSU), reducing the management costs of separate waste collection.

On the other side, the recovery of organic waste and the return of nutrients to the soil is a very important issue for the Circular Economy.

The new European Regulation on Fertilizers was moved precisely by the objective of limiting or, in perspective eliminate, the use of non-renewable fertilizers.

In the webinar of Thursday 14 January we will talk about the important changes introduced by the new regulation, which will be operational by half 2022 and the opportunities that open up for both the agricultural sector, than for that of waste.

The state of biomethane plants in Italy: some considerations in view of a new decree

This article aims to examine the state of development of biomethane in Italy, object of 3 seminari on line, between October and November 2020, taking up some arguments made with Snam and Federmetano, on this occasion. More than two years after the second decree came into force and seven years after the first, the effects of which had been virtually nil.

Of course, all this time, the market has become fully aware of the reality of biomethane as an important and sustainable energy source, and there are many new economic entities that have entered this sector, whose importance has been fully enhanced by Snam, the largest national operator of the gas network.

With the second decree on biomethane, the legislator has treasured the lessons learned with the former, starting from the method. The decree was in fact born after six months of consultation with the operators concerned and has a coherent and well-articulated approach, concentrated, according to a shared logic, on the priority to the transport destination, in light of the delay in this sector, compared to other renewable energy sectors, and without forgetting the strength of the national industrial chain in natural gas transportation.

Continue reading “The state of biomethane plants in Italy: some considerations in view of a new decree”

The selection of the inoculum for the biogas plant – III Part

Easy Methane Lab

For each by-product its digestate!

Re-publication of an article by Mario A. Rosé on Agronotizie

In Part I of this article we have explained how an anaerobic digestion system works by comparing it with a “breeding of bacteria”. For the proper functioning of a biogas plant, its manager must know how to choose the inoculum according to the by-products with which the digester will be fed, just as a breeder chooses the breed to breed according to the business purpose, for example dairy or beef cattle. On the sidelines of the verification of methanogenic activity (SMA) – explained in Part II of this article – it is important to verify the ability of the inoculum to degrade complex organic matrices, such as cellulose, proteins and fats.

Continue reading “The selection of the inoculum for the biogas plant – III Part”

How to select the inoculum for the biogas plant – Part II

BRS bioprocess control

The specific methanogenic activity (High school): realization and interpretation of the test results.

Re-publication of an article by Mario A. Rosé on Agronotizie

In Part I of this article we have illustrated how the biological activity of an inoculum is measured by introducing a certain amount of reference substrate into a test reactor and verifying that for each gram of COD (Chemical oxygen demand) are produced at least 350 Ncm3 of methane.

Let's analyze in this Part II of article le peculiarities of the test of Specific Methanogenic Activity (High school).

Continue reading “How to select the inoculum for the biogas plant – Part II”

How to select the inoculum for the biogas plant – Part I


The specific methanogenic activity (High school): a very useful test but still to be normalized. Re-publication of an article by Mario A. Rosé on Agronotizie

“I often say that when you canto measure what you are talking about, and express it in numbers, thensai something of it; but if you can'tmeasure it, if you can't express it in numbers, your knowledge is meager and unsatisfactory; it can be the beginning of knowledge, but he will not have allowed you, in your mind, to advance in the progress ofscience, whatever the discipline”.
  William Thomson, The Barons of Kelvin (Lesson on “Electrical units of measurement”, 3 May 1883)

Continue reading “How to select the inoculum for the biogas plant – Part I”

The biological self-management of the biogas plant


Re-publication of an article by Mario A. Rosé on Agronotizie

Optimally manage a biogas plant it means becoming a "breeder of bacteria".
Like farm animals, i battery they do their best if they are kept in conditions that are optimal for them, it is therefore essential to monitor the various aspects that affect the functioning of the entire anaerobic system. It is known to all that the different manufacturers and some independent workshops, offer biological care service.
Typically all of these services have a weakness: the results are not provided in real time. Moreover, the analyzes provided, generally they only concern the dynamics of the anaerobic degradation process, but not the verification of the biomass quality – silage or by-products that are – with which the system is powered.

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FORSU and agricultural biomethane plants

In most European countries, there has always been a clear and strong separation in biogas / biomethane plants between those fueled by agricultural biomass and those fueled by waste, although, from the chemical point of view, the composition of the digestate in the fermenter has little difference between the two.  Agricultural biogas is produced, as well as a share of cultivated biomass (being phased out, in homage to the guidelines of the ILUC directive, concerning raw materials to be used for biofuels, and is concerned about the potential competition of energy crops against food crops), especially from agricultural by-products and waste .  

Continue reading “FORSU and agricultural biomethane plants”