Miscanthus Giganteus – for the circular economy

Miscanthus Giganteus is a versatile crop being a hybrid cross of Saccloforus and Senensis originating from Asia in the early 80s.  Planted once, it is a sustainable, fast growing; non-invasive, true energy crop that will last for at least 25 plus years.  It has an energy balance of 1:33 mega joules per hectare, making Miscanthus one of the highest yielding Biomass Energy crops available today, requiring all the CO2 produced when burning as a fuel for re-growth the following year, whilst providing annual Carbon sequestration back into the soil.  Carbon sequestration is the process involved in carbon capture and the long-term storage of atmospheric carbon dioxide (CO 2).

Popularly known as Elephant Grass, Miscanthus has many uses in the alternative Bioenergy /Biofuels market. These range from ethanol, a refined second-generation biofuel, biomass, a sustainable renewable fuel for biomass boilers, available in  chip, pellet and heat log form, gasification, (the process that converts organic material into carbon monoxide, hydrogen and carbon dioxide resulting in a gas mixture known as syngas) and even in the replacement of plastics production.  It can also be used for Biomass Torrefaction, an advanced technology that provides an important green, renewable energy source utilising biomass and reducing emissions, and burnt to produce Biochar which is a charcoal used as an all-important soil improver (produced from biomass via pyrolysis, it is a thermochemical decomposition of organic material).

This bamboo-like crop can grow up to 4 metres during its growing season from March to October and yield 4-8 tonnes per acre, (moisture, soil and location dependant), with a net energy value of circa 18 gigajoules per tonne of Dry Matter.  This can equate to a cost as little as £0.01 per kWh when grown for own use, and unlike wood, it is dry and ready to burn when harvested.  Dry Miscanthus will provide circa 4000kWhs of heat when used on domestic or non-domestic Boilers with or without RHI (Renewable Heat Incentive).

Following the correct guidance enables Miscanthus to establish well.  Planted from a rhizome in the spring, with costs per acre equivalent to 1 year’s intensive wheat inputs, and subsequently incurring just one annual cost, (from year two after establishment), during early spring when the crop is harvested using standard farm machinery.

Miscanthus is a perennial crop on which land entitlements can be activated, it is resilient, versatile and economically viable, thus making it the ideal crop for the busy farmer or landowner and a sustainable alternative to cereal crops,  requiring just moisture, soil temperature and daylight hours to optimise yields of between 4t-8t per acre.  The crop is free of Pathogen so requires no fungicide and annual mulching controls most broad-leaved weeds as well as feeding the crop.

Nitrogen should not be required on most soils, however, this crop will benefit from organic manures and with no annual ploughing, reduces soil erosion.  It is tolerant to UK frosts when grown up to 1000 feet above sea level.

Growers with Blackgrass on more marginal land should consider planting Miscanthus to control the grassweed that appears to be coming resistant to chemicals.

Uses for Miscanthus

Energy:

Heat is considered to be responsible for 47% of all carbon emissions in the UK and the average UK household (AFCE) emits circa 8t carbon per annum, therefore by reducing our reliance on fossil fuels and turning to renewable alternatives to heat our homes, places of work, leisure and other buildings is the sustainable way forward.

For example: each 100kW (5 x 3 bedroom houses) of boiler output requires 35t of Miscanthus chips/pellets per annum which can be produced from 3 hectares (7.5 acres) annually.  1Kg of Miscanthus chip or pellets are circa 4 kWh of heat and are ideal for all sizes of sustainable local heat projects, especially when grown within 5 miles of a boiler.

Grown for own use, or close to the land it is grown on for Community Heat Projects, the chipped material equates to £0.01 per kWh. For long-term contracts, the crop cane is either baled for direct use at a cost of £0.03 per kWh or pelleted at a cost of £0.05 per kWh and sold to Power Stations and District Heating Projects (prices are linked to RPIX for security).

The current Carbon Intensity Limit is 34.8g CO2 / Mj (This is the amount of carbon by weight per unit of energy consumed, for example grams of carbon dioxide released per mega joule of energy produced, used to derive estimates of air pollutant of greenhouse gas emissions based on the amount of fuel combusted)

Miscanthus has the following levels of carbon intensity, according to the Solid and Gaseous Biomass Calculator, again proving that Miscanthus is the ideal sustainable fuel for the future.

Miscanthus Chip: Grown within 2km of the boiler c. <3g of CO2 per Mega Joule

Miscanthus Bales: Grown within 20km of the boiler c. <4.5g of CO2 per Mega Joule

Miscanthus Pellets: Grown within 160km of the boiler c. <7g of CO2 per Mega Joule

Animal Bedding:

Miscanthus bedding is available to purchase in 20 litre bags, de-dusted it is non-toxic, not poisonous with a very low pathogen count making it suitable for a variety of animals,  including cattle, horses, poultry and small pets.  The bedding requires an initial ‘dampening’ to work efficiently. The bedding is organic material grown without the use of Chemical or Chemical fertiliser.  Once used, ideally as deep litter bedding, Miscanthus breaks down very quickly into a peat type material ready for the garden.

Composites:

Miscanthus offers excellent opportunities for the production of fibre alternatives, both for the Biodegradable packaging products, and the new 5 times stronger and 3 times lighter than steel innovative materials made from Nano cellulose.  This will open up markets for any form of green building materials, homeware, car manufacturing, furnishing and many other uses.

Phytoremediation:

Using Miscanthus for clean-up of contaminated land, especially where the soil contains metals, enables a crop to be grown on otherwise useless ground.  The big advantages are that the crop can then be sold for other uses (depending on level of metals contained in the cane).

Game Cover:

Miscanthus offers excellent cover for small and large mammals making it the ideal Game Cover crop providing long-term winter cover.  The crop is benign and offers no feed value to its inhabitants. It is then harvested in the normal way.

For Gardeners:

There are many horticultural variations of Miscanthus varieties, but Miscanthus Giganteous probably offers the best plant for shade or as a windbreak when planted strategically in the Garden.

Biodiversity:

Miscanthus is very capable of breaking down heavy metals in the soil whilst increasing the Soil Carbon content. The Rhizomoius crop lends its self perfectly to an alternative for Reed beds.

Due to the mature plant having a 48% carbon content, this is a NON FOOD (although nanocellulose can be used as a carbohydrate replacement) crop and is excellent for Biodiversity; studies have shown an increase in small & large mammals and birds, by providing good winter cover.

Summary:

Renewable Energy is essential to replace and displace High Carbon fossil fuels worldwide. The UK currently grows circa 10,000 hectares of Miscanthus, The UK Biomass Strategy suggests that up to 350,000 ha could be grown in the UK, having no negative effect on food production, indeed when grown on marginal land it can actually compliment food production.  This amount of Miscanthus could reduce our current timber usage by circa 40% reducing our demand and allowing us to preserve our precious woodland.

Miscanthus provides actual carbon savings and is therefore an important component in reducing the effects of Climate change.

Note: This article was last updated Nov 6th 2015.  As science makes new discoveries, government makes changes and the market changes, the figures and statements made in this article are subject to change. Please ensure that you verify and check all figures and data before making any decision either commercial or personal with suitably qualified experts.