Heritage Giant Miscanthus
Miscanthus Giganteus - Commonly Know As:
- M. Floridulus
- Giant Miscanthus
- Giant Chinese Silver Grass
- Miscanthus 'Giganteus'
Miscanthus Giganteus is a large perennial grass (it can grow up to 13 feet in height) used for energy production. It is currently used commercially in the UK and Europe with a rapidly growing market demand. In addition to providing clean and affordable electricity and heat, Miscanthus is an environmentally friendly crop. Its large root system captures nutrients, and stems provide wildlife cover. As a high yielding, low input perennial, Miscanthus is also excellent for carbon sequestration and soil building. Miscanthus giganteus is a sterile plant established primarily through the planting of rhizomes (shoots) taken from the root ball. Once planted, Miscanthus giganteus requires 2 – 3 years to reach full production potential and has a stand life of about 15 years. Miscanthus giganteus is a C4 plant which has a high photosynthesis efficiency. The normal production cycle of Miscanthus giganteus is a single harvest late in the fall or early spring before new shoots emerge. This allows the nutrients to return to the root system and the plant material to dry to a moisture content of less than 15% prior to harvest. Miscanthus giganteus is harvested using readily available farm equipment.
| Biofuels | Algae fuel • Bagasse • Babassu oil • Biobutanol • Biodiesel • Biogas • Biogasoline • Cellulosic ethanol • Ethanol fuel • Vegetable oil | |
| Energy Crops | Jatropha curcas • Chinese tallow • Hemp • Maize • Rapeseed • Sorghum bicolor • Soybean • Stover • Straw • Sugarcane • Sunflower | |
| Non-food energy crops | Arundo • Big bluestem • Duckweed • Energy crop • Energy forestry • Jatropha curcas • Miscanthus Giganteus • Switchgrass • Pongamia pinnata • Wood fuel | |
| Technology | Bioconversion • Biomass heating systems • Biorefinery • Fischer-Tropsch process • Industrial biotechnology • Pellet mill • Pellet stove • Thermal depolymerization | |
| Concepts | Cellulosic ethanol commercialization • Energy content of biofuel • EROEI • Food vs. fuel • Sustainable biofuel | |
Use giant miscanthus as a stand-alone specimen or plant several in a line to form a screen - no, make that a barricade! Use it to anchor a mixed border, but you probably will want to keep it in the background. Giant miscanthus tolerates fairly wet soils and often is planted at waterside. The persistent stems and long-stalked flowers provide vertical structure and form through the winter. Giant miscanthus tolerates salty and coastal conditions, and can be used in seaside gardens, but withered, winter foliage is likely to be blown off in strong winds. Lower leaves tend to wither and drop off late in the season anyway, leaving a bare zone that may beg for something planted in front. The flowerheads are used in floral arrangements, both fresh and dried plumes persisting indefinitely.
Culture
Giant miscanthus flowers late in the season and may not bloom at all in northern latitudes. Cut dead stems back to 6 inches before new growth begins.
Light: Giant miscanthus does best in full sun. It is likely to stretch for the sun and wind up falling over if planted in too much shade.
Moisture: Giant miscanthus needs adequate of water during its first growing season, but likes it dry in the winter. It tolerates fairly moist soils, but does best in well-drained soils with average rainfall.
Hardiness: USDA Zones 5 - 9. Giant miscanthus flowers best following long, hot summers, and it may not flower at all above zone 5.
Propagation: Propagate giant miscanthus by dividing the root crown. This can be done with a back hoe or steam shovel if a standard garden spade seems inadequate.
Features
Definitely not for the small garden, giant miscanthus is an imposing and dominating plant, an imperial grass that plays second fiddle to no other. Use it where you want it to be seen! And, know that it will continue to enlarge (slowly) and be difficult to remove if you change your mind.
Miscanthus Giganteus as Biofuel
Miscanthus Ginganteus is a c4 class crop, a hardy perennial woody grass which will grow for 20 years producing an annual harvest from year 2 onwards. It can be completely removed with herbicide if necessary, requires very low input with zero requirement for fertilizers or pesticides after establishment (end year 2). The crop is easy to grow, is virtually zero maintenance, and can therefore, dramatically reduce farming workload.
Importantly for Energy production, Miscanthus Giganteus is one of the fastest growing, highest yield per hectare agricultural biomass fuel feedstocks there is. Additionally it bales at 12-15% Moisture content in the field - compared with Woodchip, which is typically 50% moisture content, consider the huge savings in loads required to transport energy from field/forest to power station.
- A 5km square of Miscanthus crop will produce enough electricity to power 9,000 homes for 1 year
- 1 ton of Miscanthus contains the same energy content as 0.5t of coal
- 125kg of Miscanthus generated into electricity would light a 60W lightbulb for 8 hours per night for 1 year
Generally Miscanthus increases the wildlife biodiversity of insects and mammals and forms an excellent game cover. In a recent survey of 24 sites undertaken by Rural Economy & Land Use Program, compared to conventional crops, Miscanthus crops would have more butterflies of conservation interest and pest species were reduced. Research on the effects on bird populations are currently being researched but are generally understood to show an increase.
Effect on water resource
Measurements of water use at commercial field sites have shown that
- The rooting depth of Miscanthus is no deeper than deep rooting annual crops
- Water use of Miscanthus is slightly less than that of mature woodland
- Miscanthus requires far less Nitrogen & chemical application than conventional crops
Public’s Attitude toward the crops
Studies of public attitude have found that:
- Most members of the public were not concerned with the appearance of the crops and thought that they would fit in well with an agricultural landscape
- There were more concerns regarding trucking movements and with regard to locations of Biomass Power Generation plants (Miscanthus has an advantage here over wood fuels, in that it is baled at 12-15% Moisture compared with 50% for woodchip - requiring far fewer movements for the same amount of energy to be transported)
- Wider field margins with smaller scattered field (rather than large block planting) and local end use were favored.
‘Energy Crop’ qualified Biomass Fuel
Miscanthus fuels are well suited to co-firing alongside Coal, or alongside wood or straw fuels within dedicated Biomass plants and make an excellent consistent fuel for Gasification power generation.
The most flexible fuel format is pellets and Miscanthus fuel pellets can be produced for prices similar to other Biomass pellets. In the US ‘Energy Crop’ qualifying fuels attract the advantage of an additional 0.5ROC / MWh for power Generators. Lower processing costs are incurred for briquetted fuels and where baled fuels direct from farms are can be used, processing costs are lower still but at the penalty of a lower density for transport.
- Miscanthus Energy content- 16GJ/tonne (or 4.44MWh/t oven dried)
- Low Moisture Content, Pellets typical <8%, Briquettes circa 12% and bales 15%
- Ash- 1.5% to 2.5% typical, Melting temp 1,090degC, Sulphur 0.1%
Coal Co-firing
Miscanthus derived Biomass fuels are used increasingly widely by major power producers for co-firing alongside Coal. Typically 10 to 20% is co-fired in a format suited to the particular handling requirements of the Power Generation plant. Most flexible in terms of handling ease are Miscanthus pellets while lower fuel costs are achievable where a less processed product can be handled, say briquettes, chopped Miscanthus or even whole bales. Dependant on the plant, pellets are blown either into existing coal grinding equipment or hammer milled/ground and blown directly into the furnace.
Wood & Straw Biomass Co-firing
Similar to Coal co-firing, Miscanthus can straight forwardly be co-fired alongside wood or straw fuels within dedicated Biomass power generation. Dependant on furnace type/design, Miscanthus Fuels can typically be co-fired to 50%.
Gasification Power Generation
Miscanthus derived briquettes are an ideally consistent fuel to be used as part of the fuel mix for biomass gasification. They can easily and at low cost be produced in a standard uniform size round or rectangular ‘lump’ with a low degree of fines and low variability. Properties of the fuel are highly consistent and have low moisture content, typically 12%.