Energy Grasses vs. Woody Crops
Biomass to power has traditionally been fueled by waste streams from the paper and timber industries. This limited the size, location and scale of power generation, as well as efficiency, since operators could not necessarily dictate quality parameters.
As the industry grows and dedicated feedstocks are produced for combustion, operators can have much greater control over the availability and quality of biomass, especially with dedicated energy grasses.
A More Desirable Feedstock
The primary advantage of energy grasses is higher yield, which directly impacts costs, availability, scale and a project's footprint. Yield differences are especially apparent when calculated on an annual, dry-ton basis.
The lower moisture levels achievable in the field with grasses also mean you are transporting and handling more biomass and less water and not spending additional dollars on moisture, whether through drying costs for pelleting or lower efficiency from higher heat rates.
Energy Grasses |
Woody Crops |
|||
|---|---|---|---|---|
Yield Per Acre/Year¹ |
+ |
10-15 dry tons
|
− |
4-5 dry tons |
Moisture |
+ |
<20%² |
− |
40-60% |
Ash |
± |
2.5 to 7% |
+ |
1 to 3% |
Propagation |
+ |
Seeds |
− |
Vegetative |
Establishment Costs |
+ |
~ $250/ac³ |
− |
~ $1,000/ac |
Field Storage |
± |
Addressed via agronomic systems |
+ |
"Built in" |
¹ Average yields vary by location and management practices, among other factors.
² Can be dried in the field.
³ Applies to switchgrass and sorghum. (Miscanthus, though it is a grass, is currently vegetatively propagated and has establishment costs comparable to woody crops.)