Government statistics released on 10 December show the area of non-food crops grown in the UK and their usage in bioenergy applications.
The figures show 20% of land used for bioenergy was for biofuel (biodiesel and bioethanol) in the UK road transport market, with the remainder mostly used for heat and power production. Just over 6.7 million tonnes of oil equivalent of plant biomass were used to produce electricity and heat in the UK.
Of the 96,000 ha of agricultural land used for bioenergy crops, 67,000 ha of maize was used for anaerobic digestion; 8,000 ha of Miscanthus and 2,000 ha of short rotation coppice (SRC) was used in biomass.
In 2019, arable land used for bioenergy crops in the UK equated to 1.6% of the total arable area, the same figure as in 2018.
Approximately 49,000 tonnes of Miscanthus were used in UK power stations for electricity in 2018/2019, which was just under half of all Miscanthus produced in England in 2019, based on low-end assumptions of yields.
The 2018/2019 volume was a 22% increase on the previous year – a return to trend of increases since 2013/2014, which is reflective of a general trend of existing power stations adapting infrastructure to accommodate increased biomass capacity and the opening of new biomass stations. The 2018/2019 volume is an increase of 122% since 2013/2014.
The decrease in 2013/2014 reflected the Renewables Obligation Amendment Order which came into force in April 2013 and introduced several changes that reduced the incentive for power stations to use energy crops.
Approximately 28,000 tonnes of SRC were used in UK power stations for electricity in 2018/2019, a slight increase from the volume used in the previous year. The figures show 2014/2015 was the first year when solid biomass and biogas stations with a total installed capacity (TIC) of 1MW or greater had to submit a sustainability audit, which may have influenced the increase seen at that time.
Data collated by Ofgem indicate 625,000 tonnes of straw were used by power stations in 2018/2019, a drop compared to 2017/2018 when the figure was 735,000.
The trend of increasing straw use in power plants since 2013/2014 has been influenced by several factors including new power plants, conversion of previously coal-fired capacity to biomass, and the new requirement that solid biomass and biogas stations with a TIC of 1MW or greater had to submit a sustainability audit.
The government report suggests changes to the renewable heat incentive (RHI) tariffs have already been blamed for a decline in interest across the industry, and several plans to build straw-pelleting plants have been put on hold as a result.
Challenging weather conditions in 2017 and 2018 also led to severe shortages in supply and high prices for straw during this time, which may have limited its long-term appeal for energy purposes in comparison to other energy crops.
In spring 2018 there was a ‘significant increase’ in demand for straw due to cold weather conditions caused by the ‘Beast from the East’ - a severe cold weather spell.
In 2019, the total energy produced from anaerobic digestion (AD) was 1.018 million tonnes of oil equivalent – a 4% increase from 979,000 tonnes in 2018. Energy production from AD followed a growing trend from 2009-2016, a result of rapidly expanding capacity for AD in the UK over this period.
Electricity produced by AD made the most significant contribution to total energy production in 2019 at 950,000 tonnes of oil equivalent – a 4% increase on 2018 (914,000). At 69,000 tonnes of oil equivalent, the heat produced by AD makes up approximately 6.7% of the total energy contribution in 2019, similar to 2018.
By the end of 2019, there were 94 registered biomethane producers in the non-domestic RHI, producing over 9,800 GWh of heat from AD between 2011 and 2019.
Biomethane generated from AD is generally fed into the mains gas grid rather than being burned directly to produce heat, and as a result, is given as equivalent heat generated when this gas is burned.
As in 2014-2018, this contribution makes up the most significant proportion of heat generated by AD, totalling 3,202 GWh in 2019, comprising 26% of the total heat produced under the non-domestic RHI for 2019, and is an increase in the quantity produced in 2018 (2,324 GWh).
Heat produced directly by biogas combustion, typically through a combined heat and power (CHP) system or a biogas boiler, makes up a much smaller proportion of the heat generated from AD for all years recorded, totalling 973 GWh in 2019. This is 8% of the total heat produced under the non-domestic RHI for 2019 and an increase of 10% from 2018.
The report showed changes to the tariffs available under the RHI scheme introduced in 2017 will likely have impacts on heat-energy production from AD, and on feedstocks used. One of the key changes is that from May 2018, all AD plants producing biomethane or biogas were subject to feedstock restrictions, with payments limited where more than 50% of feedstocks come from crops or other non-waste sources. This could lead to declining production of biogas from crops and increased use of waste feedstocks in the future.
In 2018/2019, there were 486 operational AD plants, with a cumulative installed capacity of 429 MWe. Of these, 338 were farm-fed, and the remainder being waste fed.
A further 343 AD projects were under development in this time, with a proposed total installed capacity of 225 MWe. Of these, 239 were farm-fed, with the remainder being waste fed.
Of the feedstocks used in operational plants in 2018/2019, 35% were crop-derived. The vast majority of this was crops purpose-grown for AD, while crop waste made up 460,000 tonnes (4% of total). The remaining 65% of feedstocks tonnage comprised non-crop wastes.
- For further analysis and insights, look out for our January/February edition