Biomethane to Grid

Biomethane injection into the gas grid.

This is the first project of its kind here in the UK and represents an important milestone in the development of UK renewable energy, showcasing technologies previously only available in countries such as Sweden and Germany.

The Didcot project proved that biomethane injection into the gas grid is possible and has identified significant opportunities to reduce the capital and operating costs, making it easier for future biomethane injection projects to go ahead. SGN provided `Innovation Funds' designed to facilitate research and development in the UK gas industry, which enabled the project to be built ahead of the introduction of the Renewable Heat Incentive (RHI) from Q3 2011.

CSL have always championed renewable sources of gas as the key to reducing the UK's dependency on fossil fuels. CSL wanted to introduce a truly sustainable fuel source to the UK that could replace fossil fuels.

At sewage treatment facilities, such as at the Thames Water site in Didcot, anaerobic digestion (AD) of the organic matter is used as a method of removing pathogens from the waste before water can be reintroduced to rivers. A by-product of AD is the production of biogas, which is a mixture of methane and CO2 with some other materials including siloxanes, H2S and nitrates. The biogas at these sites is flared to the atmosphere, contributing to greenhouse gas emissions.

CSL developed a concept and design to capture the flared biogas, clean and upgrade this and inject into the gas grid.

Similar techniques have been used for a number of years in other European countries, such as Sweden and the Netherlands, and have been very successful but until now the UK has lagged behind in this field.

In April 2009, CSL made a proposal to Scotia Gas Networks and Thames Water for a biomethane injection project at Didcot sewage works where biogas was being flared, and was then appointed Project Manager for Scotia Gas Networks/Thames Water & Centrica in this collaborated project. The Didcot project was approved at the end of 2009 and the first biomethane was injected into the UK gas grid on 3rd October 2010.

Achievements:

  1. The Didcot BtG project was the first BtG plant in the UK and has proved to be a major success. CSL proved that it is possible to take biogas derived from sewage, clean and upgrade it to make biomethane and inject it into the UK gas grid. The success of the project demonstrated that the technology available (previously only seen in Germany and Sweden) can work in the UK, which has eliminated much of the scepticism which surrounded it. As a direct result this has generated a massive increase in interest in BtG, with potential for as many as 40 more projects of its kind to be initiated by the end of 2011.
  2. The Biomethane being injected into the gas grid is being used to fuel the homes in the town of Didcot, so as long as Didcot continues to create sewage and waste water, the Didcot BtG plant can continue to create biomethane to inject back into the grid and fuel homes. The Didcot project proves that using biogas from waste in this way is a truly sustainable option and is applicable to many more similar sites across the UK.
  3. The Didcot project represents an important milestone for the UK and the start of a new energy market and barriers such as oxygen content and capital costs being overcome.