A LT E R N AT I V E F U E L S
Biomethane
Biomethane industry develops The UK’s first commercial-scale biomethane plant came onstream at the end of 2012. About 21 plants are planned to start-up in 2014 in the UK, following Germany’s initiative with 140 plants since 2007. John Baldwin, Managing Director of CNG Services, gives an overview of a new but expanding renewable energy business.
for each kWh of biomethane injected into the grid. The Renewable Energy Assurance GGC initiative (www.greengas.org.uk) is a not-forprofit scheme designed to allow tracking of biomethane from the anaerobic digestion (AD) plant to gas consumers. Each unit of green gas injected into the grid displaces a unit of fossil derived gas. The scheme tracks each unit of green gas through any number of trades to its sale to a consumer, monitoring the contractual rather than the physical flows to ensure the gas isn’t double counted. The gas is electronically labelled with a unique identifier – the Renewable Gas Guarantee of Origin – stating when, where and how the gas was generated. A new gas shipper, Barrow Shipping, trading as Barrow Green Gas, has been formed to provide gas shipping and GGC trading services to biomethane producers. The company has secured commitment from eight biomethane producers for the purchase and sale of their green gas. These contracts should supply at least 400mn kWh of certified gas in 2015, enough for the heating and cooking needs of nearly 30,000 homes. The first sales were made to The Duchy of Cornwall, Gas Bus Alliance and Brit European Transport. Brit European provides logistics services for JCB in a great example of a circular economy, given that JCBs are used to build most AD plants. Rainbarrow Farm produces biomethane which is taken out of the grid at the CNG Services’ station in Crewe and used to run a new fleet of 36 dual fuel tractors, using GGC as the link between production and utilisation.
Vale Green
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he 2011 Carbon Plan aims to reduce UK carbon emissions by a quarter from 1990 levels. Based on current energy policy, the country is on target to reduce emissions by over a third by 2020. With the introduction of new technologies this should increase to an 80% reduction by 2050. However, around half the UK’s carbon emissions result currently from heat related processes, and the latest analysis shows up to 52% of these heat-related emissions are from gas use. The greatest proportion is domestic gas use. UK Continental Shelf resources are in decline. The UK is becoming increasingly reliant on foreign imports of gas and is exposed to higher and more volatile fuel prices. Shale gas may mitigate supply issues but will not address the creation of an efficient and sustainable Arriva CNG bus at Crewe filling station
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The Rainbarrow Farm project has also helped to develop a market for the Green Gas Certificates (GGC) received
Barrow Shipping provides the same services to Springhill Farm’s Vale Green project, near Pershore in Evesham. Biomethane injection of around 400cm/h biomethane into the Wales and West Utilities (WWU) grid began in August 2013. The plant uses a new combined membrane and cryogenic technology developed by Dutch company Haffmans. This produces biomethane for injection into the gas grid and liquid carbon dioxide (CO2), which is then fed back into the greenhouses to aid tomato growth. The waste from tomato production feeds into the AD, providing another good circular economy example. Any AD operator within a reasonable distance of a large CO2 user is now able to utilise this technology to improve their overall carbon footprint and generate additional revenues. In addition,
Source: Arriva
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low carbon economy. Developing technologies to decarbonise the gas grid and heat production is key to achieving environmental goals. At the end of 2012, the UK’s first commercial-scale biomethane plant became operational, pumping renewable energy directly into the domestic gas grid network. HRH The Prince of Wales attended the official opening at Rainbarrow Farm, Poundbury, which represented the launch of a thriving new renewable industry in the UK, with the first commercial biomethane injected into the UK gas distribution network.
Green gas certification
PETROLEUM REVIEW
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2014
A LT E R N AT I V E F U E L S ... continued from p36 the gas grid owner WWU allowed Vale Green to procure all the equipment necessary, resulting in significant capital expenditure savings and reduction in project timescale and complexity. This model has been adopted by the National Grid and other grid operators to reduce cost and complexity. Both Rainbarrow Farm and Vale Green utilise some energy crops as part of the overall feedstock mix. Both farms also use waste and this co-digestion as a way to use waste in a balanced feedstock blend that produces a valuable digestate fertiliser. Barrow Shipping has also established a Biomethane Producers Club, with seven biomethane producers signed up currently. The purpose of the club is to share operational information to improve performance and lower costs, as well as working together to share spares and reduce the cost of buying such resources such as activated carbon and propane. This initiative gives the biomethane sector the opportunity to gain from the knowledge and experience of existing plant operations.
Overcoming barriers The most significant barrier to biomethane injection into the UK grid was the level of oxygen allowed in the gas. Until summer 2013, the oxygen specification was set to 0.2% in the final gas, which was problematic for many potential projects, particularly if oxygen or air dosing was required to reduce the level of hydrogen sulphide in the gas. However, the Health & Safety Executive (HSE) issued a class exemption to Gas Safety Regulations (GS(M)R) to allow network conveyance of gas with an oxygen content of up to 1% (molar) at pressures up to 38 barg, and this has been important in creating an acceptable regulatory framework for the biomethane market. At present, biomethane has to meet the flow weighted average calorific value (FWACV) of the gas grid, which, in most cases, requires the addition of around 10% propane energy. A typical FWACV is 39.2 MJ/cm (100% methane has a CV of 37.8 MJ/cm) and hence propane is added to enrich the CV and ensure that customers who receive biomethane are not disadvantaged. Around 10% of projects have an option to blend the biomethane into the existing gas stream, which reduces the propane required. Work is underway to establish the viability of a change to the gas industry CV regime which may reduce the need to add propane in the future. A remaining issue relates to capacity in the gas grid, with estimates of
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approximately 40% of potential projects constrained by lack of network capacity. Northern Gas Networks and National Grid have carried out an Innovation Funding Initiative (IFI) to prove the viability of using a small compressor to reverse flow within the grid, creating capacity for biomethane. Following a successful pilot study, a number of projects are now under development that will utilise this option and enable more projects to go ahead. As solar farms and wind generators account for increasing electricity grid capacity, the use of the gas grid to get energy from AD plants to the customer is also seen as highly attractive and efficient.
CNG trucks and buses Another driver for the biomethane market is the market for CNG trucks and buses. In 2013, four new CNG filling stations were built (at Reading, Darlington, Beccles and Runcorn) by the Gas Bus Alliance to supply CNG to Scania and MAN buses. These represent the first new CNG buses to come to the UK since the 1990s and are a result of the push to improve air quality and reduce CO2 emissions. The buses are given additional financial support if they use biomethane via the GGC scheme. Three companies are now working closely with truck manufacturers to convert a new diesel tractor into a dual fuel CNG-diesel version. Clean Air Power is working with Volvo, Hardstaff with Mercedes Benz, and Prins with DAF. Whilst grid CNG is the fuel of choice with biomethane via the GGC scheme, the potential abundance of UK shale gas means it could be possible for most trucks and buses to shift to natural gas by 2030. This could result in around 25% CO2 reduction compared to diesel as well as major benefits in terms of balance of payments, given that gas only costs 40% of the cost of oil. In June 2014, Scania launched a Euro 6 standard 350 bhp dedicated CNG tractor in the UK. This is the first such vehicle
Springhill Farms’ Vale Green project produces biomethane for grid and greenhouses nearby Source: John Baldwin
Biomethane made by a major manufacturer and is expected to appeal to the supermarket sector, with focus on lower costs and lower emissions. The CO2 saving from the Scania is estimated to be 20% compared to diesel.
European market The first biomethane project in Germany was in 2007, and there have now been 140 such projects. In 2013, new rules were introduced to link support for biogas electricity generation to require high utilisation of waste heat, which has led to growth in biomethane. The logic is to take renewable gas to where it can be used efficiently, whether in CHP in Berlin or to run cars. Of the 900 CNG filling stations in Germany, around 50% sell gas with a GGC. Sweden has a buoyant biomethane market. The main market for utilisation is compressed biomethane (CBM) for cars, because Sweden has a limited gas grid but significant low carbon electricity from nuclear and Norwegian hydro. There are over 50,000 carbon neutral CBM cars in Sweden. The Dutch and French biomethane markets are also very buoyant, with significant support from their gas grid owners. A number of Intelligent Energy Europe projects, Green Gas Grids, BioMaster and Biogas Regions have also made significant progress in relation to biomethane market development.
UK market forecast The Renewable Heat Incentive (RHI), a renewable premium for biomethane injected into the grid, is set at 7.3 p/kWh. There could be some reduction in this tariff in 2014 under the degression rules. The DECC is reviewing the tariff for large projects, which has helped to create a new renewable market that is driving down costs through competition and the establishment of UK supply chains. There are 21 biomethane projects under development which are due for completion by the end of 2014, including Crouchlands Farm – Chichester, Northumbrian Water – Howdon, Wessex Water – Avonmouth, Euston Estates – Bury St Edmunds, Greener for Life – Fraddon, Wyke Farms – Somerset, Apsley Farms – Andover and Coupar Angus – Perthshire, Severn Trent Water – Minworth, and ReFoods – Widnes. The long-term commitment by the UK government to reward biomethane production has made it attractive to many AD operators for electricity generation. The Energy Networks Association (ENA) is also supportive and is working with the industry to reduce the costs and complexity associated with biomethane injection projects. ●
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2014