One of the most rewarding aspects of being a 100% green energy supplier is knowing that we are supporting independent businesses around the UK. Many of our generators have an inspirational story to tell and we are proud to be part of it.
We visited dairy farmer Stephen at his farm in Norfolk to find out what inspired him to invest in an anaerobic digester (AD) and why his zero-waste approach to farming is so important.
Watch our little film and then read on to discover how natural waste across the UK is being turned into green gas and renewable electricity.
What is biogas?
Biogas is a green and renewable energy source. It can be used to generate electricity, fuel vehicles and also injected into the gas grid in the same way as fossil-fuel generated gas.
How is biogas made?
Biogas is made from natural, organic matter such as plants, food scraps, manure and other agricultural waste. So much of the natural waste that humans and animals create can be used to create biogas.
The first stage of producing biogas is for the waste to be broken down into a slushy mix called ‘feedstock’.
Anaerobic digestion is a process similar to what happens inside the stomach of a cow when digesting food. The biowaste is heated to a similar natural body temperature of 37 °C. In the case of Stephen’s AD, he uses the waste heat from his electricity generator to maintain the correct temperature.
An anaerobic digester is a sealed tank that starves the feedstock of oxygen. This allows the right bacteria to exist and breakdown the waste into simple chemicals and carbon dioxide, which another type of microbe, the Archaea, then turn into methane. This happens over the course of around 8 weeks.
Biogas is produced from renewable, natural organic material, which creates a mixture of methane and carbon dioxide. This gas is prevented from being released into the atmosphere so even the process of creating it is environmentally friendly.
How do you make electricity from biogas?
Much of the UK’s electricity comes from burning fossil fuel gas. Which is why electricity prices can be effected by gas prices.
In the same way, biogas can be burnt to create renewable electricity. The biogas is fed into an engine where it is burnt - this process drives a generator which produces electricity. This does produce some CO2 but because it has been captured from the atmosphere recently, it is just being recycled, unlike fossil fuel CO2 which adds to the load in the atmosphere. This means that it is far kinder to our planet than fossil-fuel generated electricity.
Can biogas be put into the gas grid?
Biogas can be upgraded to become biomethane which can be used to heat our homes in the same way that natural gas can be. The process of upgrading biogas involves removing the carbon dioxide, hydrogen sulphide and any moisture.
At 100Green we only supply gas created in this way. We do not supply fossil fuel generated gas. All of our green gas is certified by the green gas certification scheme.
What are the environmental benefits of biogas?
Biogas comes from natural waste that was created recently and will be replaced – after all humans and animals will always create waste. The whole process of anaerobic digestion takes approximately 3 weeks. Whereas using fossil fuel generated energy causes damage to our planet because we are extracting material and gas made millions of years ago – which can’t be replaced.
Not only is the source of energy green and renewable, the actual process of generating the energy has environmental benefits. Organic matter will always de-compose naturally whether that is cow poo in an open food or natural waste throw into landfill. When the process happens naturally, the methane created is released into the atmosphere.
Methane is one of the biggest greenhouse gasses. Essentially when this gas escapes, it traps heat – so during the day, the sun shines on the earth and warms our planet far more than it should – creating the effect we all know as global warming.
There are other circular-economy benefits of anaerobic digestion that help farms and business adopt zero-waste policies, just like our dairy farmer Stephen explains in our film. On Stephen’s farm, the excess heat created by the electricity generator is piped around his farm to heat water, farm buildings and help make his cheese!
Similarly, we have worked with a generator in the past who used the excess carbon dioxide from his anaerobic digester to carbonate the beer at his local brewery.
Are there any challenges or controversies surrounding the process of Anaerobic Digestion?
Yes, there are challenges when creating biogas – if the process was perfect, we wouldn’t be reliant on fossil fuels anymore!
At 100Green we are pragmatists not idealists. But creating energy from anaerobic digestion is without a doubt far kinder to our planet than fossil fuels. Which is why we are committed to only supplying our customers with gas generated in this way – and some of our electricity too.
One area of controversy however is what is appropriate organic matter to be used as feedstock for the anaerobic digester. At 100green we support the principle of using waste that is naturally created and would have gone to landfill or decomposed naturally if it wasn’t fed into the digester. This would mean releasing harmful gasses into our atmosphere.
Our biogas usually comprises of a cocktail of animal waste (manure), food waste and poorer quality crops. This means that our energy is not vegan because it may contain manure from Stephen’s dairy cows, for example.
However, the alternative is for large amounts of land to be bought exclusively to be used to grow grass for example, to feed the anaerobic digester. The challenge is whether that land could be better used to grow food for an increasing world population.
It is true that a proportion of Stephen’s crops are fed to the digester – however as he quite rightly points out in our film, the generations before him who farmed his land always used a proportion of land to grow crops for energy. But in those days, the crops were fed to horses who ploughed the fields! As with every circular economy, there are decisions to be made at every level – but if the ultimate aim is to adopt a zero-waste approach to business then we are fully committed to supporting those who are on the journey.
Because we take the verification of our energy seriously, we offer a tariff that requires additional certification over and above anything that our industry regulator currently requires. The energy is our EKO tariff must come from sources that make use of naturally created waste. So if you are looking to buy energy that is guaranteed to not come from energy crops then do take a look at our EKO tariff.
Is biogas a fuel for the future?
Using naturally produced waste to create energy is a sustainable and environmentally friendly process and is helping to reduce the UK’s reliance on fossil fuels. It can be used to create electricity which is the fuel of the future.
But around 74% of UK households still use gas. And until the entire infrastructure in the UK is upgraded allowing homes to be powered and heated via other forms of energy, 100Green are proud to be supplying our customers with 100% green gas sourced and produced in the greenest and most sustainable way possible.