**2.1 Energetic utilization**

In the recent decades among all *Salix* genotypes particularly *Salix viminalis* gained most attention as a agriculturally cultivated plant due to its application as a green fuel. Several positive and negative aspects of such an application are summarized in table 2.


Table 2. Selected positive and negative aspects of energetic willow (*Salix viminalis)* cultivation. Particular points in the table selected from the original content. Cited and translated after (Zabrocki & Ignacek, 2008).

Many of the above mentioned arguments result in fact from economic, social and political background. Thus, the cultivation of *Salix viminalis* may definitely find numerous supporters but also opponents. However, positive features of *Salix viminalis* cultivation must be kept in mind since they may help to solve some critical environmental and social issues. In some countries the cultivation and usage of Energetic Willow is at very limited level (Poland). Some sources claim (Bio-energia, 2008) that overall *Salix viminalis* cultivation area does not exceed 6000 hectares. The share of *Salix viminalis* wood burned as a fuel in the total mass of burnable fuels is only ca. 2% high. The situation has not changed significantly in the last period despite of competitive energetic (table 3) and economic (table 4) parameters of the fuel.

In the recent decades among all *Salix* genotypes particularly *Salix viminalis* gained most attention as a agriculturally cultivated plant due to its application as a green fuel. Several

Positive arguments Negative arguments

market

energy

fabrication

biomass

biomass

Table 2. Selected positive and negative aspects of energetic willow (*Salix viminalis)* cultivation. Particular points in the table selected from the original content. Cited and

Many of the above mentioned arguments result in fact from economic, social and political background. Thus, the cultivation of *Salix viminalis* may definitely find numerous supporters but also opponents. However, positive features of *Salix viminalis* cultivation must be kept in mind since they may help to solve some critical environmental and social issues. In some countries the cultivation and usage of Energetic Willow is at very limited level (Poland). Some sources claim (Bio-energia, 2008) that overall *Salix viminalis* cultivation area does not exceed 6000 hectares. The share of *Salix viminalis* wood burned as a fuel in the total mass of burnable fuels is only ca. 2% high. The situation has not changed significantly in the last period despite of competitive energetic (table 3) and economic (table 4) parameters of

Energy overproduction

High volume of biomass

High cost of biomass agglomerate

High cost of plantation lodging

Lost of financial fluency due to high cost of the preliminary stage of undertaking Difficult prediction of investment return Lack of integrated bio-energy consumer

High transportation cost from plantation Necessity of fast utilization after harvesting Better cost efficiency of coal originated

High nitrogen content in fresh harvested

High moisture content in fresh harvested

Threats resulting form monoculture cultivation on large agriculture areas Unexpected weather and climate changes Damages caused by diseases and pests

positive and negative aspects of such an application are summarized in table 2.

**2. Salix viminalis – Conventional applications** 

Low labor consumption and advantageous year schedule on labor demand during

Low capital consumption during vegetation

Reduced consumption of conventional fuels Environment friendly biomass utilization for

Efficient assimilation of heavy metals Possible cultivation on soils unusable for

Financial support from EU and local

Possible reclamation of deteriorated lands Constant price increase of fossil fuels Increase of ecological awareness of the

translated after (Zabrocki & Ignacek, 2008).

**2.1 Energetic utilization** 

High fertility and yield High environmental tolerance Long exploitation of plantations

Improvement of local economy Reduction of unemployment Diversification of energy resources

High energetic effectiveness

energetic purposes Exploitation of lie fallows

other crops

society

the fuel.

institutions

cultivation


 Table 3. Heat of combustion of selected fuels. The content of the table selected from the original material and translated (Iso-Tech, 2011).


\*Harvest frequency: 1 – each year, 2 - every 2 years, 3 – every 3 years

\*\*PLN – currency of Poland, 1 EUR = 4 PLN

Source: http://www.bio-energia.pl/

Table 4**.** Dry biomass prices in Poland. The content of the table selected from the original source and translated (Bio-energia, 2008).

Thus, 1000 kg of dry *Salix viminalis* wood offers amount of energy comparable to 700 kg of black coal of good quality. However, black coal mining is evidently associated with serious irreversible environmental damages what becomes more and more important issue nowadays. This is a next argument for increasing of biomass production and usage for energetic purposes. Energetic utilization of other plants from SRWC group like *Plantanus occidentalis, Liquidambar styraciflua, Pennisetum purpureum, Erianthus arundenaceum, Panicum virgatum, Ricinus communis, Hibiscus cannabinnis, Populus deltoids, Pinus elliottii, EucaIypytus amplifolis, Eucalyptus grandis,* or *Pinus taeda* is a much more rare case in the world scale and particularly in Europe where climate conditions are often the main limiting factor. In Europe, *Salix viminalis* wood seen as renewable source of "green fuel" has a one important competitor i. e. dry straw. Straw is a side product (ca. 20 billion kg per annum in Poland) of grains cultivation i. e. one of the most frequent agricultural activities (Gradziuk, 1999).
