Explanations:

Straw can be obtained from the production of the following cereals and oilseed plants: wheat and spelt, rye and winter cereal mixtures, barley, oats, spring cereal mixtures, grain maize and corn-cob-mix, triticale, other cereals and oilseeds – mainly rapeseed.

Calculation of theoretical straw potential

Y_S = Y_G · 0.9

where:

Y_S – theoretical straw yield (Mg/year)

Y_G – grain/seeds yield (Mg/year)

0.9 – coefficient of straw to grain ratio

Calculation of technical straw potential for energy purposes

Y_Se =  Y_G · 0.6 · 0.25

where:

Y_Se – technical straw potential for energy purposes (Mg/year)

Y_G – grain/seeds yield (Mg/year)

0.6 – coefficient of technical, practical possibilities to obtain straw from the production of cereals and oilseed plants

0.25 – coefficient of annual yield of straw which can be dedicated to energy purposes so as to avoid detrimental effects on animal production, to maintain the soil organic matter balance, and to supply straw for other alternative uses

Calculation of straw energy value

Q_S = Y_Se · LHV

where:

Q_S – energy potential of straw (GJ/year)

Y_Se – technical straw potential for energy purposes (Mg/year)

LHV – Lower Heating Value (14 GJ/Mg)