TransBio:Biogas Versie 2.0:  Technological transition of the Flemish biogas sector towards innovative business models with increased profitability and reduced support dependence (TransBio)

The biogas sector in Flanders counts approx. 40 large scale installations, and 50 to 75 small scale (farm sized) installations. Biogas, as a renewable energy technology, produced 602 GWh of renewable electricity and 850 GWh of renewable heat in 2013. Yearly, 1.3 million tons of organic waste is converted to biogas, alongside hundreds of thousands of tons of manure. The biogas technology is therefore responsible for the valorisation of a large part of the organic residues produced in Flanders. The biogas sector enjoys an increasing appreciation because of the added value of this key technology apart from the renewable energy production. The biogas sector in Flanders saves approx. 625.000ton of CO₂ every year. It makes the biogas technology the most efficient renewable energy technology based on GHG reductions per installed capacity. Another advantage is the reliable and predictable production, compared to other, intermittent technologies as wind and solar power, resulting in a general reduction of the energy prices.

The biogas sector in Flanders has a yearly turnover of approx. € 50 million, alongside a total investment volume of over 70 million during the past seven years. The sector, including the suppliers, creates between 1.000 and 2.000 employment places. Each year it produces renewable energy for 300.000 IE’s.

Despite the strong economic added value, the biogas technology is confronted with high intrinsic investment and operational costs. Therefore, the technology strongly depends on financial support and subsidies. This aid dependency is a thorn in the eye of all actors: authorities and energy partners try to minimise the energy subsidies and plant operators strive for more independency from financial support schemes and more robust business models. TransBio wishes to engage innovations to increase the profitability of the business model of a biogas plant in Flanders, and lower the dependency on the subsidy schemes.

Biogas-E, together with the Ghent University, have researched the development and implementation of innovative business models. The project focussed on five promising scenarios:

1)      1) Mobilisation and valorisation of unexploited biomass

2)      2) Nutrient recovery from digestate products

3)      3) Innovative market models for electricity production and trading

4)      4) Upgrading and use of biomethane

5)      5) Utilisation of industrial waste heat for drying digestate

All project results can be consulted via www.transbio.be (Dutch only)

Unexploited biomass:

An important expense for biogas plants are the feedstock costs. Each operator is looking for the perfect deal: a high biogas potential at a low cost. Roadside clippings are such a feedstock type, and are abundantly available. We developed a tool, in particular for local municipalities, to assess the feasibility of a small scale monodigester on grass clippings. Based on our simulations, we could conclude that the cost for the disposal of the digestate and the self-consumption rate of the produced energy, are the primary factors influencing the feasibility of the project.

Nutrient recovery from digestate products

Digestate products have typically a high nutritional content, which makes them valuable organic fertilizers. Nevertheless, the distribution of digestate on agricultural land in Flanders proves to be difficult, because of the high nutrient surplus. Plant operators are forced to heavily invest in digestate treatment technologies. The upgrading of digestate products to mineral fertilizers equivalents would create a strong added value, but this is not always possible because of legislative and technical restrictions. In order to assess the potential of such upgrading technologies, we drafted a mass balance based on all nutrients arriving and leaving biogas plants in Flanders. Our results showed that 31% of all the nitrogen and 19% of all the phosphorus in the digestate was applied on agricultural land in Flanders. The remaining part was either exported or converted into nitrogen gas. The biogas sector is a net processor of nitrogen and phosphorus in Flanders and does not contribute to the nutrient surplus currently present in Flanders. The sector produces high quality digestate products with a strong market at home and abroad.

Innovative market models for electricity production and trading

Biogas is one of the few renewable energy technologies that can be easily stored for longer time periods. On top of that, the production of biogas is not depending on climate conditions like wind or solar power. Its production is predictable and reliable. At the start of the project, the first aggregators became active on the market and started to pool several biogas installations to participate on the balancing market (R1 down). The TransBio project went one step further and researched the potential of the day-ahead market for biogas installations. The Ghent University developed, together with Biogas-E, a model to assess the financial feasibility of flexible electricity production based on the day-ahead market. Positive results were obtained, based on a reference installation. By only producing electricity when the market prices were high, higher revenues were obtained, which could compensate for the lower total electricity production. Although, to make flexible electricity production really feasible, the subsidy scheme should be adapted. Today the support scheme focusses primarily on the constant production of electricity, without considering the market demand.

Upgrading and use of biomethane

The current subsidy scheme does not support the production of biomethane. The absence of an operational support scheme and a registration system for biomethane make that Flanders is failing to develop a biomethane sector, unlike our neighbouring countries. Because this technique is yet applied in our neighbouring countries, the challenge is more a legal question than a technical one. Therefore, we performed an analysis of the support schemes and registration systems of France, the Netherlands and the UK.

An important discussion questioned the most efficient way to valorise biogas compared to biomethane and the production potential of biomethane in Flanders. To assess the ecological impact of different valorisation methods of biogas and biomethane, we performed an consequential LCA. This type of LCA calculate the added CO₂ emissions of 1 m³ of biogas when valorised in a CHP, upgraded to biomethane and then used in a CHP or upgraded and used in an CCPP. Our results of the three scenarios suggested that the fraction of useful heat is primarily determining the carbon footprint.  

The assessment of the production potential of biomethane was meant to serve as background info to further develop a vision and roadmap for the biomethane sector. Based on the available organic waste streams in Flanders, it was calculated that 8.75% of the current natural gas consumption could be replaced by biomethane. Moreover, only 6% of the available potential was yet realised.

Utilisation of industrial waste heat for drying digestate

When a classic biogas plant is switching from a CHP to a biomethane upgrading installation, they lose their local heat source. The heat from the CHP is typically used to dry the solid fraction of the digestate and to regulate the temperature of the biogas reactor. Within the project, we studied the possibility to use industrial waste heat for drying the digestate. We looked actively to possible heat sources matching the heat requirements of the biogas installation. A first screening was performed for a small part of Flanders, because of limited data availability. For 4 out of 11 biogas plants a match was founded with an industrial heat source. In total, the exchange potential of heat was more than 50 GWh/yr.

Apart from techno-economic analyses of the five scenarios, we strongly focussed on the dissemination of the project results and project support. Different seminars, site visits, and demos were organised. On top, two different business workshops took place, bringing operators and technology suppliers together. 

During the project, different biogas installations invested in innovating technologies for digestate treatment, biogas upgrading, flexible electricity production and unexploited feedstock. Biogas-E supported several installation specific projects, focussing on the assessment of the economic impact of possible innovations.

The project TransBio contributed to the improvement of the financial stability of the biogas sector in Flanders. Nevertheless, some challenges remain. Research and innovations will play a key role the coming years resolving these issues.