*2.4. PEST Analysis—Technological Environment*

In recent years, the RE sector has been developing rapidly in Poland and around the world. Moreover, numerous studies have been conducted to increase the durability and efficiency of RE installations. These studies, as well as the increasing demand, make it possible to reduce/maintain the prices of RE installations [55].

Table 4 presents the technological environment of RE in the Pomerania Voivodeship in the context of its development potential. It needs to be highlighted that Polish power blocks are obsolete. Due to their poor technical condition, shutdowns are anticipated in the future. On 1 January 2018, the "Adamów" power plant was shut down. The electricity transmission network is poorly developed. It should be emphasized also that the Pomerania Voivodeship has excellent conditions for the development of RE—so it is worth developing small, local RE installations that will transmit energy almost without grid losses [55].

In Poland, there is little cooperation between industry and science. This also applies to RE. This cooperation is necessary to develop modern and cheap RE technologies. An opportunity for the development of this sector is the creation of numerous cluster initiatives, based on the endogenous potential of a given region. The efficiency of RE installations is equal to and sometimes exceeds that of conventional energy installations. Hydroenergy power plants obtain energy with an efficiency of up to 90%, while agricultural biogas plants, cogenerating electricity and heat, achieve efficiency of up to 85% [55].


**Table 4.** The technological environment of RE in the Pomerania Voivodeship (author's own work).

The RE potential calculated in Section 3 in the Pomerania Voivodeship is high. The amount of electricity would cover the Voivodeship's electricity needs, and 53% of its heat needs. Membership in the EU is an opportunity for the further economic development of Poland, including the RE sector. Cooperation and knowledge exchange take place within the European Research Area. The information society is developing.

### **3. Evaluation of Renewable Energy in the Pomerania Voivodeship—Physical Aspects** *3.1. Use of Biomass in the Pomerania Voivodeship*

Two biomass power plants with a total capacity of 2350 MW are operating in the Pomerania Voivodeship [73]. The area of energy plantations in the Voivodeship currently amounts to nearly 1.7 thousand ha [74]. Four species of plants are cultivated: three woody species—willow, poplar, and birch—and one species of grass from the genus Miscanthus. The crop structure is dominated by fast-growing poplar, amounting to 68%, with willow constituting 20% and Miscanthus constituting 12%, while birch is grown in negligible amounts. There are 40 wood biomass boiler houses with a total capacity of nearly 105 MW in the Pomerania Voivodeship. These are mainly wood-fired boiler houses; there are a few with pellets, and the boiler house at IP Kwidzyn operates with waste from the pulp and paper industry [75]. The number of straw-fired boiler houses in the Pomerania Voivodeship ranges from 25 to 30. Previously, boilers based on various Danish technological solutions were used; after being depleted, they were then replaced with more effective boilers fired with wood chips and pellets [75].

In the CHP plant in L ˛ebork, waste generated in sawmills or furniture factories is the substrate used for the production of heat and electricity. The choice of biomass is not accidental. In the vicinity of L ˛ebork, there are many farms (which can supply plant waste or switch to high-energy crops) and wood processing plants (which also produce wood waste). The plant has three chippers for biomass homogenization (Figure 4) [76]. Thanks to these activities, the old heating plant has reduced the combustion of coal, which had a negative impact on the environment and the health of the inhabitants.

According to the data of the Agricultural Market Agency, in the Pomerania Voivodeship, in Malbork, there is a plant producing biodiesel in the amount of 159 million dm3, and in Goszyn, there is a plant producing bioethanol in the amount of 32 million dm3. In turn, Gda ´nsk produces:


**Figure 4.** Chipper for biomass homogenization in L ˛ebork (photo: B. Igli ´nski).

There are 22 biogas plants in operation in the Voivodeship, with a total capacity of 21,843 MW (data from the Energy Regulatory Office [78]; 20 biogas plants according to the Pomerania Spatial Planning Office [75]). According to the register of agricultural biogas producers, 10 agricultural biogas plants operate in the Pomerania Voivodeship (Table 5).

**Table 5.** Characteristics of agricultural biogas plants in the Pomerania Voivodeship (author's own study from: [75,78]).


### *3.2. Biomass Potential in the Pomerania Voivodeship*

### 3.2.1. Amount of Energy from Wood Harvested from Forests and Wood Industry

The technical potential of waste solid biomass and biogas from wastes in the Pomerania Voivodeship was calculated. The main source of energy is waste. In order to calculate the available energy, the following assumptions were made:


Formula (1) shows the annual amount of energy that can be obtained from wood harvested directly, i.e., logging in forests:

$$\mathbf{E\_{WW}} = \mathbf{0.8} \cdot \mathbf{0}.15 \cdot \mathbf{I\_W} \cdot \mathbf{W\_{W\_{\prime}}} \tag{1}$$

where: Eww—energy from wood generated in the process of logging (PJ/year), Iw—amount of wood harvested annually in forests (3.23 million m3/year), Ww—calorific value of biomass (7 GJ/m3).

The amount of energy that can be produced from waste wood from forests in the Pomerania Voivodeship is 2.71 PJ/year (283 GWh/year of electricity and 1.69 PJ/year of heat). In order to estimate the annual energy possible from waste wood from the wood industry, the same assumptions were made, but it was assumed that industrial and post-use waste wood constitutes 25% of that harvested [53].

Formula (2) shows the amount of energy that can be obtained from wood in the woodworking industry:

$$\mathbf{E}\_{\rm wi} = \mathbf{0}.8 \cdot \mathbf{0}.25 \cdot \mathbf{I}\_{\rm W} \cdot \mathbf{W}\_{\rm W} \tag{2}$$

where: Ewi—energy from wood generated in the wood industry (PJ/year), Iw—amount of wood harvested annually in forests (3.75 million m3/year), Ww—calorific value of biomass (7 GJ/m3).

The amount of energy that can be produced from waste wood from the wood industry in the Pomerania Voivodeship is 4.52 PJ/year (472 GWh/year of electricity and 2.92 PJ/year of heat).

A total of 40% of biomass from forests can be allocated to energy purposes (formula (3)):

$$\mathbf{E}\_{\rm W} = \mathbf{0}.8 \cdot \mathbf{0}.4 \cdot \mathbf{I}\_{\rm W} \cdot \mathbf{W}\_{\rm W} \tag{3}$$

where: Ew—energy from wood generated during logging and in the wood industry (PJ/year), Iw—amount of biomass harvested annually in the Voivodeship's forests (3.75 million m3/year), Ww—calorific value of biomass (7 GJ/m3).

The obtained amount of energy that can be produced every year from waste wood in the Pomerania Voivodeship is 7.23 PJ/year (755 GWh/year of electricity and 4.51 PJ/year of heat).

### 3.2.2. The Amount of Energy from Waste Biomass from Orchards

Orchard wood waste comes from both maintenance (e.g., cutting branches) and cleaning. The amount of wood produced annually during maintenance works varies depending on the age and species of trees—on average, it amounts to 7 Mg/(ha·year) [80]. As a result of the grubbing up of orchards, it is possible to obtain approx. 60 Mg/ha in the case of modern, low-growing plantations (15 years) and 80 Mg/ha of biomass in the case of older plantations (30 years) [80]; annually, this amounts to approximately 3.5 Mg/(ha·year). In order to calculate the available energy, the following assumptions were made:


Formula (4) shows the amount of energy that can be obtained from waste orchard wood:

$$\mathbf{E\_{o}} = \mathbf{0.8} \cdot \mathbf{0.3} \cdot (\mathbf{K\_{K}} + \mathbf{K\_{c}}) \cdot \mathbf{P\_{o}} \cdot \mathbf{W\_{o}} \tag{4}$$

where: Eo—energy from orchard wood waste (PJ/year), Kg—amount of wood harvested annually as a result of grubbing up one hectare of orchard (3.5 Mg/(ha·year)), Kc—the amount of wood harvested annually as a result of cultivation works per hectare of the orchard (7 Mg/(ha·year), Po—orchard area (2.0 thousand ha), Wo—calorific value of biomass from orchards (11.5 GJ/Mg).

The obtained amount of energy that can be produced every year from waste wood from orchards in the Pomerania Voivodeship is 0.058 PJ/year (6 GWh/year of electricity and 0.04 PJ/year of heat).

### 3.2.3. The Amount of Energy from Surplus Straw

In recent years, the agriculture of the Voivodeship has been dominated by the cultivation of cereals: rye, wheat, barley, oats, triticale, and cereal mixtures. According to the data of the Central Statistical Office, the annual weight of cereal grain harvested in the Pomerania Voivodeship is 874 thousand Mg/year of wheat, 181 thousand Mg/year of rye, 126 thousand Mg/year of barley, 66 thousand Mg/year of oats, and 222 thousand Mg/year of triticale [81,82].

In order to calculate the available energy, the following assumptions were made:


Formula (5) shows the amount of energy that can be obtained from straw:

$$\mathbf{E\_s} = \mathbf{0.8} \cdot \mathbf{0.3} \cdot \left( \mathbf{Z\_W} / \mathbf{w\_W} + \mathbf{Z\_t} / \mathbf{w\_t} + \mathbf{Z\_b} / \mathbf{w\_b} + \mathbf{Z\_o} / \mathbf{w\_o} + \mathbf{Z\_t} / \mathbf{w\_t} \right) \cdot \mathbf{W\_s} \tag{5}$$

where: Es—energy from straw (PJ/year), Ws—the calorific value of straw (15 GJ/Mg) [4], Zw, Zr, Zb, Zo, Zt—annual crops of cereal grains (wheat, rye, barley, oats, triticale) (million Mg/year), ww, wr, wb, wo, wt—grain/straw ratio, respectively, 0.8, 1.4, 0.9, 1.05, 0.95 [53].

The obtained amount of energy that can be produced every year from surplus straw in the Pomerania Voivodeship is 5.97 PJ/year (622 GWh/year of electricity and 3.73 PJ/year of heat).

### 3.2.4. The Amount of Energy from Hay from Unused Pastures and Meadows

The Pomerania Voivodeship has a large area of pastures and meadows; according to the data of the Central Statistical Office, this amounts to 22 thousand ha and 106 thousand ha, respectively [83]. Due to the reduction in the number of livestock (mainly cattle), as well as the change in the animal nutrition system, most of the meadows and pastures are not used. In order to calculate the available energy, the following assumptions were made:


• the efficiency of obtaining energy is 80% (electricity from solid biomass will be obtained with an efficiency of 30%, and heat with an efficiency of 50%).

Formula (6) shows the amount of energy that can be obtained from hay from unused pastures and meadows (PJ/year):

$$\mathbf{E\_{h}} = \mathbf{0.8} \cdot \mathbf{0}.15 \cdot \left( \mathbf{z\_{P}} \cdot \mathbf{P\_{P}} + \mathbf{z\_{m}} \cdot \mathbf{P\_{m}} \right) \cdot \mathbf{W\_{h}} \tag{6}$$

where: Eh—energy from hay from pastures and meadows (PJ/year), zp, z m—weight of hay harvested annually per hectare from pastures and meadows (3.6 Mg/(ha·year) and 4.9 Mg/(ha·year), respectively), P m, Pp—area of pastures and meadows (million ha), Wh—hay's calorific value (14 GJ/Mg).

The obtained amount of energy that can be produced every year from hay from unused meadows and pastures in the Pomerania Voivodeship is 1.0 PJ/year (104 GWh/year of electricity and 0.63 PJ/year of heat).

3.2.5. The Amount of Energy from the Salix Viminalis Cultivated on Wasteland, Fallow Land, and 5% of the Cultivated Area

The Pomerania Voivodeship has a large area of wasteland (post-industrial and degraded areas) and fallow areas; according to the data of the Central Statistical Office, this amounts to 41.2 thousand ha and 12.6 thousand ha, respectively [83]. This land can be used for the production of energy crops: grasses (e.g., *Miscantus*), cereals (straw and bioethanol), trees (e.g., *Populus* L.), or shrubs (e.g., *Salix viminalis*). In this study, it was assumed that this would be *Salix viminalis*; it is a native species [86]. *Salix viminalis* tolerates the agroclimatic conditions practically all over Poland very well [82]. It was additionally assumed that 5% of the agricultural land area, i.e., 34.9 thousand ha, would be used for the production of bioenergy.

In order to calculate the available energy, the following assumptions were made:


Formula (7) shows the amount of energy that can be obtained from the *Salix viminalis* grown on unused fallow land and wasteland:

$$\mathbf{E\_{b}} = \mathbf{0.8} \cdot \left[ \mathbf{Q\_{f}} \cdot \left( \mathbf{0.2} \cdot \mathbf{P\_{w}} + \mathbf{0.5} \cdot \mathbf{P\_{f}} \right) + \mathbf{Q\_{a}} \cdot \mathbf{0.05} \cdot \mathbf{P\_{a}} \right] \cdot \mathbf{W\_{w}} \tag{7}$$

where: Eb—energy from basket willow grown on wasteland, fallow land, and agricultural land (TJ/year), Qf—annual yield of basket willow per hectare on fallow and barren fields (8 Mg/(ha·year)), Qa—annual yield of *Salix viminalis* per hectare on arable land (16 Mg/(ha·year)), Pf, P w, Pa—area of wasteland, fallow land, and arable land (thous. ha), W w—calorific value of biomass of *Salix viminalis* (19 GJ/Mg).

The obtained amount of energy that can be produced every year from basket willow grown on fallow land, wasteland, and agricultural land in the Pomerania Voivodeship is 10.3 PJ (1073 GWh/year of electricity and 6.44 PJ/year of heat).
