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BIOGAS - A WIDELY UNDERESTIMATED ENERGY SOURCE


One issue that does not get enough public attention when it comes to future national energy security in the UK is biogas. This is because biogas can be produced domestically, ensuring independence from international suppliers, which, as Russia has recently shown, can fall away, threatening the energy supply of the entire western world.


Characteristics of biogas

Biogas is produced from domestic energy crops and residues. It can be converted into biomethane of natural gas quality or used as fuel to generate electricity and heat. Whether biowaste, liquid manure, catch crops, maize, or other energy crops - they can all be degraded by microorganisms. In the absence of air, i.e. in an anaerobic process, biogas is produced. As an energy-rich gas mixture, it is ideal for generating electricity and heat. Processed into biomethane, it can also be fed into the public gas grid or used as fuel. The remaining fermentation residue is used to produce high-quality fertiliser.


Advantages and supposed disadvantages

Anyone who operates a biogas plant produces almost climate-neutral energy. This is because biogas production is environmentally and climate-friendly. The conversion of biomass into biogas releases hardly any CO2. As a further benefit, biogas can be used for a wide range of purposes. In addition, biogas can be stored very well. It can be produced and made available flexibly, on-demand, and in a decentralised manner. Biogas plants can make a decisive contribution to national energy independence.


But there are also objections. The production of biogas is criticised as technically demanding and expensive. The use of maize as an energy crop is also viewed critically by many.


Concerning the supposedly complicated plant technology, a lot has been done in recent years, so that the technical side of biogas production can now be described as easily manageable.


The question of the price of biogas can also be put to rest. The price of biomethane compared to natural gas is quite competitive due to recent developments in Russia. Since biogas is produced domestically with long-term supply contracts, the price of biogas is stable and reliable in the long term.


A large proportion of biogas plants in the UK use maize as an energy crop in addition to residues. Criticism of maize in the UK is mainly directed against the soil degradation that maize cause because maize crops leave soil exposed during the winter and cause surface water runoff. It should be noted that maize is grown on about 200,000 ha in the UK while the total cropable area in the UK is around 4,900,000 ha. So, we are talking about less than 5% of the arable area. Apart from that, there are now perennial energy crops like Miscanthus or the cup plant which can compensate for the supposed negative impact if they would be planted on 20% of the maize area, i.e. on the areas threatened by leaching when maize is cultivated. Here too, development has outstripped the critics.


A statement for more biogas plants in the UK

The loss of Russia as a supplier of gas and oil has shown how dependent and therefore blackmailable those western countries are that do not have their own oil and gas reserves. Even a country like the United Kingdom, which covers 50% of its gas demand from its resources, is not unaffected by the negative effects of the current energy crisis.


At the moment, substitute suppliers of LNG are stepping in to replace the lost capacity from Russia, but the question is how sustainable the supply of LNG produced by fracking in the USA will actually be. The LNG supplies from Qatar may also not be considered 100% secure by some.


This makes the hesitant attitude of western governments regarding the further expansion of biogas capacities all the more surprising. Only Denmark recognised the signs of the times early on and began to intensively build up biogas capacities years ago. Here, the focus has increasingly been on replacing natural gas with biomethane. According to the Danish Energy Agency's forecast, biogas will account for 72 % of the gas flowing in the natural gas grid by 2030.


In creating energy security for the future, there is certainly no one ideal way, as all energy resources, be they renewable, fossil, or nuclear, have their advantages and disadvantages. Even biogas could never guarantee the entire energy supply. That is why an energy mix is certainly advisable. However, biogas is a renewable energy source that needs to be significantly expanded in the UK and should play an important role on the way to national independence in energy supply.



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