Official Statistics

Section 2: Plant biomass: miscanthus, short rotation coppice and straw

Published 9 December 2021

Miscanthus and Short Rotation Coppice (SRC) are bioenergy crops grown primarily for use in the heat and electricity energy markets. They are burnt in power stations, combined heat and power units or heating systems.

2.1 Miscanthus areas

Table 2.1 Total area of miscanthus in England

Year	2015	2016	2017	2018	2019	2020
Area (ha)	6,905	7,057	7,366	7,149	8,171	8,286
95% confidence interval	+/- 514	+/- 526	+/- 1,097	+/- 1,290	+/- 1,275	+/- 2,046
Number of growers	409	361	787	767	731	708

Source: Defra June Survey of Agriculture and Horticulture. Defra analysis to produce numbers of growers.

Figures prior to 2008 are only available through subsidy scheme information (see below). The Defra experimental stats release published in 2009 gives further details of these historic areas. A regional breakdown for 2010, 2013, 2016, 2017, 2018 and 2019 is available in the report dataset. The regional breakdown for 2020 was not collected. Currently no data is available regarding UK-wide planting areas of miscanthus, however from 2008, official area estimates of miscanthus grown in England are available from the Defra June Survey of Agriculture.

The apparent decrease in area from 2009 should be treated with caution as this may be due to the sampling variation in the survey (indicated by the confidence intervals), rather than a genuine decreasing area.

Miscanthus is grown on around 0.1% of arable land in England.

Subsidy schemes provide a secondary source of area statistics. Under the Energy Crops Scheme (ECS) farmers could claim subsidies to assist with the establishment of miscanthus as part of the Rural Development Programme for England. The Energy Crops scheme closed in 2013 although planting for the scheme could be undertaken in 2013, 2014 and 2015 (more background can be found at Annex B).

The total area of new plantings claimed under the subsidies since 2000 was around 10,000 hectares. This includes miscanthus being grown at locations other than traditional farms (for example, country parks, and universities). These locations may not be covered by the June Agricultural Survey, which recorded 8,286 hectares of miscanthus in England in 2020.

2.2 Miscanthus yields/production

Although research has been done on miscanthus yields, as yet no official estimates of achieved yields are available. Yields vary greatly depending on a number of factors such as planting method, species, site conditions, as well as the standard variations of region and annual weather conditions. The first year’s growth is not suitable to harvest; annual harvesting takes place from the second year and can continue for 15-20 years. Some industry experts estimate that current miscanthus yields average between 12-15 oven-dried tonnes (odt) per hectare (equating to 15-18 fresh tonnes per hectare) although other industry bodies suggest a lower figure of 10 odt per hectare.

Table 2.2 Miscanths production based on upper and lower yield estimates (a)

	2015	2016	2017	2018	2019	2020
Lower estimate	69	71	74	71	82	83
Upper estimate	104	106	110	107	123	124

Source: Yield information taken from National Non-Food Crops Centre (NNFCC) miscanthus fact sheet and on direct conversations with growers and end users.

(a) Estimates based on areas from the June Survey of Agriculture and Horticulture and yields of 10 and 15 oven dried tonnes per hectare.

The estimated annual volume of miscanthus produced in England based on both the upper and lower yield estimates from industry sources should be treated as indicative estimates because of the yield uncertainties and the assumption that the whole of the area planted is productive, which will not be the case for recently planted crops^{[footnote 1]}.

Miscanthus production in England in 2020 was 83 thousand oven dried tonnes, based on the lower end assumption of yield.

2.3 Miscanthus usage

Usage data are collated by Ofgem as part of sustainability requirements under the Renewables Obligation. There are other outlets for using miscanthus including horse and livestock bedding, in small scale combined heat and power plants directly on farms for heating buildings and for domestic uses such as wood burners and open fires. Unfortunately, quantitative information on these end uses is not available.

Approximately 33 thousand tonnes of miscanthus were used in UK power stations for electricity in 2019/20 (Figure 2.1) which was less than half of all miscanthus produced in England in 2020, based on low end assumptions of yields. The 2019/20 volume was a 32% decrease on the previous year, with volumes returning to levels last seen in 2015/16. This decrease occurred despite a previous trend of increases since 2013/14, which reflected a general trend of existing power stations adapting infrastructure towards increased biomass capacity^{[footnote 2]}, and the opening of new biomass power stations^{[footnote 3]}.

Figure 2.1: Miscanthus usage in UK power stations (‘000 tonnes) (a)(b)

Year	Miscanthus (bales)	Miscanthus (pellets)	Miscanthus (other / unknown form)	Total
2014/15	1	31	0.4
2015/16	6	29	0
2016/17	29	26	0
2017/18	40	0	0
2018/19	49	0	0
2019/20	33	0	0

Source: Ofgem Renewables dataset

(a) Tonnages are reported directly by the generating stations so it is not known whether these are fresh weight or oven dried equivalents.

(b) Only categories where the proportion of miscanthus was greater than 90% are included.

See Annex B for more details on the Ofgem Renewables Obligations dataset.

2.4 Short Rotation Coppice (SRC) - willow or poplar areas

Table 2.3 total area of short rotation coppice grown in England

	2015	2016	2017	2018	2019	2020
England total	2,885	2,926	2,966	2,826	2,233	2,032
95% confidence interval	+/- 656	+/-665	+/- 593	+/- 1,045	+/- 1,019	+/- 227
Number of growers	361	437	379	305	271	306

Source: Defra June Survey of Agriculture and Horticulture Defra analysis to produce regional figures and numbers of growers.

Currently no data is available regarding UK-wide planting areas of SRC, however from 2008, official area estimates of SRC grown in England are available from the Defra June Survey of Agriculture. A regional breakdown for 2010, 2013, 2016, 2017, 2018 and 2019 is available in the report dataset. The regional breakdown for 2020 was not collected.

SRC (since 2009) represents less than 0.1% of the total arable area in England.

Subsidy schemes can provide a secondary source of area statistics. The Energy Crops Scheme closed in 2013 although planting for the scheme could be undertaken in 2013, 2014 and 2015. More background can be found at Annex B.

The total area of SRC in 2020 was 2,032 ha, a decrease of 9% from the 2019 figure.

2.5 Short rotation coppice yields/production

Much research has been done on SRC yields but as yet, no official estimates of achieved yields are available. SRC is harvested every 2-3 years and yields vary greatly according to the number of years since planting, site conditions, type of planting method, crop type (willow or poplar) as well as the standard variations of region, annual weather conditions etc.

Table 2.4 Short rotation coppice production based on upper and lower yield estimates (a)

	2015	2016	2017	2018	2019	2020
Lower estimate	23	23	24	23	18	16
Upper estimate	43	44	44	42	33	30

Source: National non-food crops centre SRC factsheet, M.J. Tallis, E.Casella et al, GCB Bioenergy, 2013, 5;1, 53-66.

Estimates based on areas from the June Survey of Agriculture and yields of 8 to 15 oven dried tonnes per hectare.

Industry experts at the National Non Food Crops Centre (NNFCC) estimate an average SRC yield of 8-17.5 oven dried tonnes (odt)/ha/yr (taking into account the 2-3 year harvesting period) while the Forestry Commission ForestGrowth-SRC model predicts average yearly yields at 9.0 odt/ha/yr and 10.3 odt/ha/yr for willow and poplar respectively.

Table 2.4 shows the estimated volume of SRC produced in England each year based on both the upper and lower yield estimates of 15 odt/ha and 8 odt/ha. These figures should be treated as broad estimates rather than definitive figures as there is much uncertainty behind the estimates.

Total SRC production in England was around 16 thousand tonnes in 2020, based on low end assumptions of yields.

2.6 Short rotation coppice usage

An estimate of the volume of UK produced SRC Willow used in power stations is collated by Ofgem, as part of sustainability requirements under the Renewables Obligation. SRC is suited to a range of heat and power generation systems down to domestic level (not captured here). There are few other end uses.

Figure 2.2: Short Rotation Coppice usage in UK power stations (‘000tonnes)(a)

Year	Willow (dust)	Willow (pellets)	SRC (wood chips)	Total
2014/15	0.4	6.6	8.4
2015/16	0.0	7.9	1.5
2016/17	0.0	0.0	9.3
2017/18	0.0	0.0	25.9
2018/19	0.0	0.0	28.2
2019/20	0	0	7.3

Source: Ofgem Renewables dataset

(a) Tonnages are reported directly by the generating stations so it is not known whether these are fresh weight or oven dried equivalents.

Approximately 7 thousand tonnes of SRC were used in UK power stations for electricity in 2019/20, which was a 74% decrease on the volume used in the previous year (Figure 2.2). This decrease saw a return to more typical volumes of SRC following two years of higher-than-normal usage. 2014/15 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 in previous years. ^{[footnote 4]}

2.7 Straw availability and usage

Unlike SRC and miscanthus, straw is not grown specifically as a bioenergy crop, and is instead a by-product of the cereals industry. It is used for animal bedding, as animal feed and, to a small extent, as an energy crop to be burnt for heating and electricity in power stations and combined heat and power units. The Defra June survey records UK cereal areas for wheat, barley and oats on a yearly basis (Figure 2.3). As straw is a by-product of these cereals, these areas give a good indication of hectares of straw produced.

Figure 2.3: Areas of selected UK cereals at June each year

The decrease in 2013 wheat area was the result of prolonged wet weather leading to very difficult planting conditions.

From 2014 to 2020, Defra’s Cereal and Oilseed Production Survey has collected data on straw yield, production and area for England only. Results for 2020 are shown in Table 2.5. In 2020 data was only collected for production, with questions on yield and area removed from the survey. Historic yield and area data can be found in the dataset.

Table 2.5: Estimates of cereal and oilseed rape straw production in 2020, England

	Wheat	Oats	Barley	Oilseed rape
Production (‘000 tonnes)	1,864	1,610	281	59
% change from 2019	-40%	-16%	+8%	-34%

Source: Defra Cereal & Oilseed Production Survey

In 2020 the area of wheat planted was the smallest recorded since the 1970’s whereas the area of barley was the highest recorded since 1990, driven by the switch to plant spring barely following the failure of the winter cereal crops.

Just under half of all straw grown in England in 2020 was wheat straw, with 1.9 million tonnes produced. This is a decrease of 40% from the figure in 2019. As a whole, straw production is significantly lower than in 2019 (Table 2.5). A combination of factors have led to this drop in production, with the primary driving force being the unfavourable weather in autumn 2019/spring 2020 that made establishment of winter crops difficult. Farmers switched to spring crop plantings and there was a somewhat mixed growth pattern in the spring, thus affecting both planted area and yields.

UK production of straw is estimated by applying the yield for England to the total UK area.

Figure 2.3: End use of cereal and oilseed rape straw England 2020 (a)

End usage % of straw production	Home use bedding / feed	Sold / exchanged for feed / bedding	Sold for other purposes	Sold for biomass	Home use for other purposes	Home use biomass	Total
2020	41%	35%	14%	8%	1.2%	0.7%	100%

Source: Defra Cereal and Oilseed Production Survey

(a) End usage includes a small number of holdings with rye straw tonnage.

Since 2014, Defra’s Cereal and Oilseed Production Survey has collected data on the end use of straw. Figure 2.3 shows the proportion of straw by end use for 2020. Whilst these figures cover England only, they are broadly in line with the UK estimates in Table 2.5.

As for the UK estimates, by far the largest end use of straw is in animal bedding and feed. It is also worthy of note there is a small but growing percentage of straw used in on-farm biomass purposes, which will not be captured in other estimates of energy production from biomass.

2.8 Power station usage of straw

Figure 2.4: Straw usage in UK power stations (volume in ‘000 tonnes)(a)

Biomass type and form	Pellets or dust	Cereal straw	Total
2014/15	92	312
2015/16	53	508
2016/17	52	676
2017/18	2	735
2018/19	0	625
2019/20	0	888

Source: Ofgem Renewables Obligation dataset

(a) Tonnages are reported directly by the generating stations so it is not known whether these are fresh weight or oven dried equivalents.

Data collated by Ofgem as part of sustainability requirements in the Renewables Obligation indicate that in 2019/20, 888 thousand tonnes of straw were used by power stations (these were all in England). This was an increase when compared to 2018/19 when the figure was at 625 thousand tonnes.

This trend of increasing straw use in power plants since 2013/14 has been influenced by a number of 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 total installed capacity (TIC) of 1MW or greater had to submit a sustainability audit. ^{[footnote 4]}

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 reportedly been put on hold as a result ^{[footnote 5]}. In addition, challenging weather conditions during 2017 and 2018 had led to severe shortages in supply and extremely high prices for straw during this time, which may have limited its long-term appeal for energy purposes in comparison to other bioenergy crops. ^{[footnote 6]} During the spring of 2018 there was also a significant increase in demand for straw due to cold weather conditions caused by the ‘Beast from the East.’ ^{[footnote 7]}

For more details of the Ofgem Annual Sustainability dataset and report see Annex B.

2.9 Volumes of biomass used in the UK for energy

Data from the Department for Business, Energy and Industrial Strategy (BEIS) in the Digest of UK Energy Statistics (DUKES) publication show the volumes of plant biomass used in the UK for energy, with the figures representing the energy content of the fuel used. These figures cover all plant biomass, which includes, but is not restricted to, miscanthus, SRC and straw.

As plant biomass comprises a variety of materials, it is not possible to convert these DUKES values from tonnes of oil equivalent to volumes or raw materials in tonnes. Nevertheless, these data are useful for showing trends in plant biomass usage over time.

Figure 2.5: Volume of plant biomass used for electricity: 2000 to 2020

Source: Digest of UK Energy Statistics

(a) Increases in capacity reflect conversions from previous coal-fired capacity to biomass.

In 2020 around 7.2 million tonnes of oil equivalent of plant biomass was used to produce electricity and heat in the UK, a 7% increase on the 2019 figure.

79% of plant biomass (5.6 million tonnes oil equivalent) is used for generating electricity. This percentage has remained largely similar since 2015, with volumes used to generate heat increasing at a more rapid rate.

There was a 5% increase in the volume of plant biomass used to generate electricity in 2020 when compared to 2019, (Figure 2.5). This continues a general slow upward trend in both plant biomass and total bioenergy volumes, and follows more rapid increases between 2011-2015, which reflected significant conversions from previously coal-fired capacity to biomass.

No biomass was used for co-firing with fossil fuels in 2020, following a long term downward trend.

Go to Summary

Go to Section 1 - Biofuels

Go to Section 3 - Anaerobic digestion

Go to Annex A, B and C

1. The first year’s growth is not suitable to harvest; annual harvesting takes place from the second year and can continue for 15-20 years. ↩

2. Press release – Drax given green light to complete biomass update ↩

3. Snetterton renewable energy plant ↩

4. Section 4, Renewables Obligation Annual Report 2013/14. ↩ ↩²

5. Policy changes dampen new straw power potential ↩

6. National Pig Association- Straw burning plants contributing to ‘severe straw shortages’ ↩

7. AHDB - Farm costs at a glance ↩