As the debate on the future role of gas in a decarbonised European energy system heats up, Navigant energy experts Daan Peters and Kees van der Leun explain why they see a large potential to scale up renewable gas sustainably.
Daan Peters is Associate Director at Ecofys, a leading energy consulting firm which is part of the Navigant group. Kees van der Leun is director at Ecofys.
In a study for the Gas for Climate consortium published earlier this year, Navigant concludes that biomethane and green hydrogen can be scaled up significantly, adding value in a decarbonised EU energy system.
We started our study from the perspective that Europe needs to fully decarbonise its energy system by 2050 to achieve the Paris Agreement target. This requires a large focus on energy efficiency and a transition towards renewable and low carbon energy.
Our study compares two ways to decarbonise the EU energy system: a ‘with gas’ versus a ‘without gas’ scenario. Our ‘with renewable gas’ scenario combines biomethane and green hydrogen with increasing quantities of renewable electricity, concluding that such combination would be the lowest cost way to fully decarbonise the EU energy system.
EU-produced renewable gas production could, by 2050, be scaled to at least 122 billion cubic metres (bcm) of natural gas equivalent, or about 1,200 TWh. This number consists of 98 bcm of biomethane plus 24 bcm of power-to-gas (green hydrogen) produced from otherwise curtailed electricity.
This is a rather conservative approach and much larger volumes could be feasible if more solar PV and (offshore) wind is constructed that is partly used to produce hydrogen. The biomethane potential is based on a bottom-up assessment of agricultural and forestry residues available in the EU, derived from Eurostat data and EU-wide biomass potential studies issued by the European Commission. We also see a potential for sequential crops produced as second crops on existing farmland. Our biomethane potential estimate is broken down as pictured below.
Our numbers are significantly higher than those in a briefing and working paper by the International Council on Clean Transportation (ICCT), which is referred to in a EURACTIV article. ICCT estimates a total potential of 36 billion cubic metres of biomethane and renewable power-to-methane produced in the EU by 2050.
It is difficult to draw detailed conclusions on the comparison between the renewable gas potential estimates by Navigant and ICCT because the ICCT briefing and working paper does not provide a breakdown of their biomethane potential over feedstocks, nor more public insight into the methodology followed.
Pilot projects required to generate sustainable low ILUC risk biomass from winter cover crops
Our study assumes that large quantities of agricultural and forestry waste can be used to produce biomethane in a sustainable way. Also, we think that agricultural crops as sequential crops or winter cover crops used to produce biomethane.
Sequential cropping is the concept of producing a second agricultural crop after the main crop on existing farmland within a year, requiring no additional farmland and therefore having a low risk of indirect land use change impacts. This concept is increasingly applied in Italy (Biogasdoneright) and France.
We see an important role for sequential cropping to provide abundant sustainable biomethane feedstock. Especially since it can sequester soil carbon below-ground, if low tillage is applied. In our study we note that today, winter cover crops are cultivated to produce biomethane only in Italy and France.
Pilot projects are required to assess where and how sequential cropping can best be implemented on farms close to biogas plants across Europe.
Delivering net cost benefits despite higher production costs
Using the renewable gas potential, we found in a smart combination with renewable electricity in a decarbonised EU 2050 energy system would save almost €140 billion per year compared to such a system without any gas.
While we think that biomethane and green hydrogen production costs will reduce, we expect large net societal cost savings resulting from avoiding the need for expensive electricity grid extensions and upgrades, installing hybrid heat pumps in older buildings rather than electric heat pumps in all buildings and using the existing gas grid for seasonal energy storage.
We also highlight that it will be difficult to fully decarbonise EU industry without renewable or low-carbon gases used as feedstock or to produce high-temperature heat. The Gas for Climate study thus has a broad aim and scope: estimating the future potential of renewable gas and analysing how this gas can be used in energy demand sectors in an optimal mix with renewable electricity to achieve a net zero emissions EU energy system in 2050 at lowest societal costs.
Action plan for scaling up renewable gas in Europe
Only a small quantity of biomethane is being produced in the EU today. Increasing this significantly in a sustainable way is feasible, as it is possible to scale up renewable hydrogen production.
Yet this requires efforts from companies, farmers and policymakers to improve production technologies, reduce costs, apply new agricultural concepts and reward renewable gas for the societal benefits it delivers in full decarbonisation of the energy system in a smart combination with renewable electricity.