Poland's Transition to a Market Economy: Prospects for Energy Efficiency and Conservation (1994)

Jan Kapala and Piotr A. Kaleta

Polish Academy of Sciences

Institute of Environmental Engineering,

Zabrze, Poland

Atmospheric pollution research in Poland indicates excess concentrations of sulfur dioxide, nitric oxides and suspended dust, and air quality standards for these pollutants are violated over 2.7%, 3.6%, and 5% of the nation's area, respectively. This condition results from high levels of pollutant emission from electric generation and district heating power plants contributing 88 % of total SO₂ emissions and 50% of total NO₂ emissions. Poland does not have domestically produced SO₂ and NO₂ removal technology, so we are interested in finding ways to solve air pollution problems partially by rationalization (conservation) of energy consumption. Many options for energy savings are available including: (1) increasing cogeneration of electricity and heat energy, (2) utilization of waste heat from industrial processes, particularly in the metallurgical industry, in heat distribution networks, (3) utilization of geothermal water for heating purposes, (4) elimination of irregularities in the operation of heating systems, (5) automation of the control of district heating systems, and (6) replacement of hard coal in house heating by natural gas or electricity.

Current annual primary energy consumption in Poland is about 4.95 × 10¹⁵ Btu. Per capita consumption of primary energy in Poland is lower, but not much lower, than that of highly developed countries. However, per capita consumption of electric energy in kWh per habitant per year is far lower than that of comparable countries and is lower than most countries in Europe. Comparing electric energy consumption to the primary energy consumption ratio in both Poland and Sweden, which is respectively 783 kWh/Btu and 2446 kWh/Btu we find Poland in a very disadvantageous situation [1].

Another disadvantage is the structure of energy demands in Poland, with 80% of demand being covered by hard and brown coal. To make matters worse, electric energy production is based almost 100% on coal. Consequently, power industry emissions are very hazardous for the environment. Official documents report the following pollutant emissions, in millions of tons per year: dust—2.8, sulfur dioxide —4.3, nitric oxides—1.5, and carbon monoxide—3.1. Total emissions of these pollutants are 11.7 million tons per year [4].

The main sources of nitric oxides in Poland are the electric power industry (27%), other branches of industry (27%), transportation (23%), industrial power and heat production (16%), house heating and agriculture (7%). Sulfur dioxide emissions come mainly from the electric power industry (45%), but significant amounts are also generated by house heating and agriculture (23%), industrial power and heat production (20%), other branches of industry (9.5%), and transportation (2.5%) [4].

After taking into account the sources, quantities, and emission procedures of several atmospheric pollutants, we determined the areas where permissible concentrations exceed the ambient air quality limits [Table 1]. The suspended particulate concentration exceeds the limits over 15,000 square kilometers, which amounts to 5% of the country's surface. For nitric oxides and sulfur dioxide, concentration limits are exceeded over 11,200 square kilometeres (3.6%) and 8,300 square kilometers (2.7%), respectively. The data in this table indicate the severity of the problem in Katowice province, where high concentrations of atmospheric pollutants for many years have caused the degradation of various elements of the natural environment. These data show that pollutant concentration limits are exceeded over the entire southwestern part of Poland.

By means of methods of air quality determination, supported by measurements of selected pollutant parameters [2], we can establish where the limits are exceeded for other pollutants. We estimate that limits are exceeded over 4% of the country's surface for benzo(a)pyrene, 5% for lead, 3.5% for aromatic hydrocarbons, and 3.5% for carbon monoxide. Also, a significant portion of the country is contaminated by phenol, formaldehyde, and oxidants. These pollutants exceed concentration limits locally around coking plants, chemical factories, etc. All these data are confirmed by National Statistical Office.

In 1988, The National Program for Environmental Improvement to the Year 2010 was established [4]. Regarding air quality protection, the following are acknowledged by this program to be principal goals:

• improvement of energetic fuel quality by depyrityfication of most sulfured grades of hard coal and deep desulphurization of medium-sulfured coals,

• providing power and thermal-electric power stations with desulfurization systems,

• modification of combustion processes by using fluidized bed furnaces,

• redesigning power boilers to provide them with low-emission burners,

• providing all industrial plants with dust collection plants,

• providing cars with catalytic converters and introducing lead-free gasoline onto the market, and

• redesigning dust collection devices manufactured in Poland.

As a result of these actions, pollutants emissions should be decreased to the following levels:

• dust: 2.1 million tons in 1995 and 2.0-2.2 million tons in 2010,

• sulfur dioxide: 3.5 million tons in 1995 and 2.0-2.5 million tons in 2010,

• nitric oxides: 1.8 million tons in 1995 and 1.0-1.2 million tons in 2010,

• carbon monoxide: 2.7 million tons in 1995 and 1.5-2.0 million tons in 2010.

This program is ambitious but very hard to put into practice, particularly for the SO₂ emissions for which removal technologies are in an initial stage [4].

Limitations on Poland's ability to remove pollutants make it necessary to take other actions in addition to pollution control. Improvements to heating systems in the residential and commercial sectors are very important. House heating with coal in Poland is a source of pollutants such as dust, sulfur dioxide, nitric oxides, soot, aromatic hydrocarbons, and other pollutants formed in burners working under oxygen deficiency. Pollutants emitted from such heaters are elevated only five to ten meters above the home's chimney and are not well dispersed in the air. Thus, coal-fired home heaters are noxious and make a large contribution to air pollution.

Our research in the Upper Silesia Industrial Region indicates that the residential contribution to atmospheric pollutant concentration is significant: Benzo(a)pyrene—70%, tar products—50%, nitric oxides 31%, sulfur dioxide —73% and total suspended particulates— 34%. The quantities of pollutants generated by house heating are so large that pollutant concentration limits in the Katowice region would be exceeded even if industrial and other sources were eliminated. Thus, it is very important to modify the structure of energy consumption, and the most appropriate way to improve atmospheric air quality is rationalization of energy consumption. The rationalization of fuel and energy consumption depends on

• employing a very broad definition of an energy project to include any activity with the potential to reduce energy consumption,

• developing of the technical resources required to improve the efficiency of energy use, and

• finding sources of funds to finance energy rationalization projects with convenient terms of credit [5].

The Polish Government has set specific goals for decreasing energy consumption in the national economy [6]: structural changes in the national economy with up to 30 million Btu savings in the year 2000 and techno-economic rationalization giving near 40 million Btu savings. However, the Polish Academy of Sciences Committee on Energetic Problems concludes that these goals are not reachable because of

• the deficiency of effective rationalization of energy consumption,

• population growth accompanying the increase of energy demands,

• the necessity of making up delays in power supply, and

• the necessity of developing modern industry.

Furthermore, instead of savings, an increase in solid fuel consumption is predicted until the year 2000. This will cause increases in sulfur dioxide and nitric oxides emissions. This pessimistic assumption predicts the rise of SO₂ emissions in the year 2000 by about 25% compared to 1985 emissions and an even larger increase in emissions of NO_x[5].

The Polish Academy of Sciences Committee on Energetic Problems suggests the following ways to save energy in the electric power industry [7]:

• increasing the amount of cogeneration (combined electricity and heat production),

• utilizating waste heat, particularly in the metallurgical industry,

• utilizating low-temperature geothermal water for purposes,

• eliminating irregularities in the operation of district heating systems,

• complex automation of heating systems,

• replacing hard coal in residential heating by enriched energy carriers.

Also, increased amounts of active power can be obtained from existing power plants by reactive power management provided with electronically controlled capacitor banks into the national power network [3].

Undertaking programs for rationalizating energy utilization simultaneously in industry, electric power production, agriculture, and residential areas can meet the energy demands without new power stations or central district heating plants until the year 2000. Consequently, further deterioration of air quality in comparison with the data in Table 1 need not occur. Moreover, modifying residential and commercial heating systems by replacing hard coal with natural and/or coke-oven gas can significantly reduce the number of areas where atmospheric pollutant concentrations exceed limits. Thus, we can expect that energy and fuel rationalization programs will have an impact on the realization of pollutant emission limitation programs, particularly in the case of oxide emissions, and consequently, on air quality improvements in many areas of Poland.

1. Juda, Report for Polish Academy of Sciences Committee on Energetic Problems , Warsaw 1990.

2. Kapaga, Ochrona Powietrza, 3, 1986, pp. 57-63.

3. Mantorski, personal communication, Gliwice 1990.

4. “The National Program for Environmental Improvement to the Year 2010, ” published by MOSZNiL, Warsaw 1988.

5. Filipowicz, Archiwum Energetyki 2 1988, pp. 119-160.

6. Polish Government report nr 34/84, Warsaw 1984.

7. Polish Academy of Sciences Committee on Energetic Problems Report , Warsaw 1986.

Antoni Goszcz and Marian Chaber

Central Mining Institute

Katowice, Poland

The main source of energy in Poland is hard coal. However, the natural conditions in Polish coal deposits are very complicated, and exploitation of those deposits is causing serious ecological problems. The most important of these problems are

• disposal and utilization of mining wastes,

• treatment and disposal of saline water from deep mines, and

• coal desulfurization.

Each of these problems requires special technical solutions that involve the technologies of clean coal utilization. These problems are discussed in this paper. Some projects which have been undertaken for the solution of these problems are also described.

The exploitation of useful minerals always interferes with the natural environment, causing changes that are mostly irreversible. Mining of coal causes some of the most severe environmental problems, considering problems directly and indirectly connected with it. Polish coal deposits have complicated tectonics. Some coal seams have a lot of ash and sulfur, and the underground waters which must be removed during mining have a high degree of mineralization.

Development of clean coal technology in Poland requires the solution of problems in three areas, namely: reduction of mining wastes, the limitation of discharges of saline waters into surface waters, and desulfurization of coal.

The main problem in abating the environmental problems caused by coal mining is the reduction of mining wastes. Polish coal deposits have a very complicated geological structure,

and the exploited coal seams have many impurities and disturbances. In many cases roofs and floors have inconvenient geomechanical parameters.

The quantity of wastes generated is large and is the result of both difficult natural conditions and inappropriate mining practices. The problems caused by natural conditions are

• complicated tectonics which require many shafts, chambers and cross-headings,

• many thin coal seams that can be reached only by first removing great quantities of waste rocks, and

• frequent occurrence of interlayers and geological disturbances in the coal seams.

Mining practices that contribute to excess creation of wastes include

• inappropriate selection of coal deposits for mining which generate excessive amounts of waste rocks,

• inappropriate mining technology, especially the use of ill-suited machinery,

• frequent occurrence of rooffalls and bottom raising, which could be limited, for example by bolting,

• inappropriate roof control, especially at the beginning of the exploitation of the first slice of a thick seam by caving, and

• leaving waste rocks behind in heaps.

The mining wastes consist of sandstones, mudstones, and shales generated at the mines and at coal processing plants. The wastes vary in size from dusts to lump rocks. The storage of wastes causes problems such as spontaneous combustion on the spoil bank, emission of carbon and sulfur oxides to the atmosphere, dustiness, and other environmental damages.

In 1990, coal mines generated 64.7 million tons of wastes:

22% of the wastes were utilized economically as follows:

The remaining 51.7 million tons of wastes were stored at disposal sites.

The reduction of the amount of wastes is a key problem of the industry. Without deep structural changes in the mining industry, no less than 55 million tons would be generated annually with coal output on the level of about 145 million tons per year. This is a great amount, and its reduction requires a systematic solution, considering that available storage sites are practically exhausted. Moreover, the amount of wastes may increase in the future if fine coal is to be enriched.

In the future, the amount of wastes used as backfilling material will increase. Also, more wastes will be utilized in materials for forming road and railway embankments and in ceramics. However, these are partial solutions. Storage of 30-35 million tons will still be necessary.

Environmental laws in Poland will have to become more stringent. First, regarding changes in mining practices, exploitation of coal seams that generate extraordinary quantities of wastes should be discontinued. Improved planning procedures are also necessary.

Mining equipment should be appropriate for local conditions because inappropriate equipment can lead to excessive generation of wastes. If proper mining technology is used, the total amount of wastes will decrease to the level of about 30 million tons, and this amount could be utilized for backfilling, building material, etc.

Polish coal deposits are typically low in sulfur. The average is about 1.1%. The youngest seams of Westphalian age have higher sulfur content, up to 2.5%. These seams are mined in the Eastern part of the Upper Silesian Coal Basin. The mines having coal with high sulfur content are in Siersza, Jaworzno, Komuna Paryska, and Janina.

In the Lower Silesian Coal Basin, the coal seams contain about 1.1% and in the Lublinian Coal Basin, 1.3% sulfur. The sulfur in coal occurs in both organic and inorganic forms.

Organic sulfur occurs in bituminous compounds in coal. Inorganic sulfur occurs as sulphides and sulphates: pyrite, marcasite, and gypsum. The inorganic sulfur creates 69% of the total amount of sulfur in typical Polish coal and the organic sulfur 31%. These data refer to the contents of sulfur in raw coal.

In processed coal the amount of sulfur is smaller and depends on the enrichment technology. More than 20 mines employ enrichment of coal. With graining below 20 or 30 mm, the coal is unenriched and is delivered as unenriched fines. Because the main part of delivered coal is fines, the amount of sulfur in final production creates problems. The gas coal is enriched when the graining is above 0.5 mm and coking coal is completely enriched.

Pyrite is the main source of sulfur in coal and occurs as scattering particles, impregnations, and in fillings of fractures. Because the size of pyrite grains in coal is small, the effectiveness of enrichment is greater for fine-grained material. If the raw coal is broken up to a size of 3 mm, 80% of sulfur could be removed. Presently, Polish coal-processing plants remove about 30% of the sulfur. The product is used mainly by power plants and district heat-generating plants, and high emissions of SO_xand NO_xinto the atmosphere result.

Plans are under way to reduce air pollution emissions by reconstruction of the existing coal preparation plants. The program includes coal washing, and at present, four washing facilities in four mines have been built.

The improvement of coal desulfurization creates another environmental problem: the storage of pyrite wastes. Storage yards must be secured to avoid spontaneous combustion, infiltration of acid wastes into groundwater, and generation of dust.

The protection of storage yards requires a special landfill technology. The most efficient method of fire protection is the proper compacting of wastes. The slopes and bottoms of the storage yards should be covered by an insulating material such as soil and ash from power plants.

In order to protect underground waters from acidification, the bottom of the landfill should be covered by a special impermeable layer. Additionally, wastes can be mixed with alkaline substances to neutralize the acid.

The salinity of underground waters varies from several milligrams per liter to more than 200 g/l. Usually, the salinity increases with the depth of the coal mines. The chemistry of waters changes also. As a result three hydrochemical zones can be distinguished:

• the infiltration zone—fresh water having salinity below 1.6 g/l,

• the mixed waters zone—with moderate salinity, to 35g/l, and

• the fossil water zone—with high salinity, to 230 g/l, including chlorides and sulphates.

The occurrence of these zones and their depths depend on the local geological conditions and hydrology of the rock massif.

Groundwater is also classified in four groups depending specifically on salinity:

• Group I—fresh waters with salinity below 0.6 g/l,

• Group II—industrial-use waters having salinity from 0.6 to 1.8 g/l,

• Group III—low-salinity waters having salinity from 1.8 to 42 g/l, and

• Group IV—saline waters having salinity above 42 g/l.

The total outflow from Polish coal mines is 952,000 cubic meters per day. These waters flow into the main Polish rivers: the Vistula and the Oder. The discharges from coal mines into these rivers (in thousands of cubic meters per day) are given below.

The amount and salinity of underground waters depends on local conditions. The quality of discharged mine water is determined by the depth of mining works and by hydrological properties of the overburden. In regions where the overburden is thin, the waters have lower salinity. In regions with greater overburdens, discharges from mines are rather high in salinity.

The amount of salts introduced into the rivers are as follows.

We do not expect the amount of flow to increase in the future, but unfortunately the salinity of the water will continue to be high.

The high salinity of discharged underground waters creates a very serious problem for the Polish economy, and it is necessary to find methods to control the discharges. Presently, four ways of desalination are being tested.

The first way is “Debiensko” technology. This technology is based on an evaporative system and allows the treatment of about 2500 m³/d of saline water. The “Debiensko” Desalination Plant has been working for about ten years. From the residual salts are extracted NaCl, KCl, MgCl₂, iodine and bromium. Gypsum is a waste material. The steam created by the process is used by the mine for heating.

The “Debiensko” technology is expensive, energy-consuming, and inefficient. Considering the large amounts of saline waters that must be treated, experiments with other methods have also begun. In the “Debiensko” mine the RCC technology is also being tested. A special plant based on this technology is now under construction. In the next year, the construction will be completed and the plant will begin operation.

Recently, revised mining and hydrological methods have been tested which limit the flow of saline waters into the mines. The simplest method is to abandon coal seams in the region with a high inflow of saline waters. Limitation of the saline water inflow may be obtained by the use of mining methods which increase the rock fractures. The general principle is the protection of insulated layers in the rock massif. The hydrogeological methods for the limitation of saline water inflow to rivers are the recirculation method and the method of deep crowd. The main difference between these methods is that in the recirculation method, the waters are pumped to rocks above a mined level, and in the deep-crowd method the waters are pumped into rocks below mined level. The recirculation method is being tested at the present time. Experiments with the second method will start next year. Recently, the interest in hydrological methods for limiting inflows has been increasing, because these methods may be the least expensive and very effective.

Franciszek Krawczynski

Central Planning Board

Warsaw, Poland

The electric power industry can make significant contributions towards reducing future environmental impacts. Progress in impact reduction will require sustained capital investment in the electricity sector, particularly in Eastern Europe and in developing countries. All fuel cycles within the electricity-generating system involve some environmental impacts such as air pollution, acidification of forests and lakes, and climate changes. This paper classifies energy technologies in Poland according to their environmental impacts into three broad groups -fuels, renewable resources, and the nuclear fuel cycle. Incorporation of this analysis into policy, planning, and decision making is also discussed.

The global demand for electricity will continue to increase. Electrical services are essential to the quality of life, especially in developing countries. The electricity sector can make significant contributions towards a reduction in environmental impacts. Efficiency improvements, demand-side management, and the use of non-fossil fuel energy systems are options that are available for substantial reductions in emissions.

Different energy systems for electricity generation have a variety of negative regional or global environmental impacts . Coal-fired electricity generation presents a number of particular concerns. Its combustion byproducts include more carbon emissions than other energy sources, more sulfur dioxide, NO_x, and far more solid wastes (shown in Table 1).

The energy resources of Poland are considerable, but these are mainly solid fuels: hard coal and brown coal. Reserves of natural gas are small and those of crude oil are insignificant. The hydroelectric energy resources of our rivers are limited. The potential capacity of hydroelectric energy generation is 12-13 TWh per year. Only about 15% of potential hydroelectric capacity is presently utilized. We have no nuclear power plants.

In 1990, as a consequence of the recession and economic restructuring, the production of primary energy and of electric energy declined.

The most important characteristics of Polish energy sector are as follows:

• The structure of primary energy production and consumption is very disadvantageous with regard to efficiency and environmental effects. Liquid fuel consumption per capita is 3 times lower than in EC countries.

• The Polish economy has a high energy intensity of domestic product compared to the West European countries, with low electric energy consumption per capita.

• High consumption of solid fuels is the main cause of environment degradation.

• The shortage of investment capital has almost stopped the increase in capacities of basic energy subsystems (for example electrical energy) and the construction of the first nuclear power station has been halted (Soviet type PWR ).

Poland's total installed electric generating capacity in 1990 was 31,952 MW (32 GW); 2,005 MW is installed in hydroelectric plants and the remainder in thermal plants. (Table 2). About 20,800 MW is fired by hard coal and 9,060 MW by brown coal. The largest thermal plant has a capacity of 4,320 MW (12 units × 360 MW) and is fired by brown coal. The largest industrial power station is 275 MW. The capacity of the largest hydroelectric plant (pumped storage) is 680 MW. More than 50% of total electric power generation is in plants with over 1,000 MW capacity. The public centralized district heating industry produces 235 PJ of heat energy, which is distributed by centralized heating networks. In terms of electrical energy produced, recently about 96% was generated from solid fuels: 60% from hard coal and 36% from brown coal. The average age of thermal electric generating stations is about 16 years, and over 7 GW capacity has been in operation for over 20 years.

Between 1980 and 1988, Poland's electric energy production increased at an annual rate of 2%. Since 1988, however, annual decreases in the range of 1%-7% have occurred. We attribute the decline to the economic recession and weather conditions that reduced energy demands. Most of the increase in electricity demand that occurred during the decade of the 1980s is attributed to growth in electricity use by households, farms, and public services. Overall consumption by industry decreased.

Currently the Polish electric transmission network is interconnected with networks in the Czech Republic of Slovakia, the former USSR, and Germany (Eastern Germany) at voltages of 750 kV, 400 kV, and 220 kV. There are 114 kilometers of 750 kV lines, 4,000 kilometers of 400 kV, and 8,000 kilometers of 220 kV. The main transmission system and the local distribution systems have suffered from under investment. Losses in transmission are high, about 11%.

Poland is one of the world's most intensive users of district heating. Of the 7 million dwellings in urban areas, 70% are supplied from central heating stations. Some 35% of the heat is supplied from large plants operated by the public power industry.

Presently, Poland has ample electric generating capacity. We expect this situation to continue in the near future, assuming the low growth of industrial activity and continuation of relatively easy winters. However, after 1995 we expect growing shortages of power and energy that will probably constrain the country's economic growth. Therefore, plans should be made to adjust the power system to accommodate expected economic growth and corresponding growth in electricity demand. The most difficult period will be between 1995 and 2,000, when new peak-load capacity, such as gas turbines, will be needed to cover the expected deficiency while new base-load power stations are constructed.

Polish authorities plan to modernize more than 5 GW of old capacity. Efforts are being made to interest foreign investors in new power plants, including the 2,160 MW plant under construction at Opole.

We are seeking to diversify the pattern of primary energy supply in electricity generation, although coal will continue to provide the dominant contribution. The medium scenario projections for 2010 are that coal will provide just under 70% of this primary energy (1989 - 95%), gas 10%, and nuclear power 14%. This would require a decision to proceed with construction of a nuclear power station. The decision will depend on careful public examination of the role of nuclear power in Poland.

Natural gas, which is a universal, highly efficient, and non-polluting primary fuel, should be used mainly in households. Simultaneously, the supply of natural gas is planned for CHP plants and district heating, peak and combined (dual) cycle gas turbogenerators, and in power plants during the summer season. The supply of 3-4 billion m³ of natural gas for electric energy generation till 2000 should be feasible.

The maximum feasible increase in hydroelectric generation is estimated at 13 Twh, which is 5% of the forecasted electric energy demand in 2010.

The public power industry produces about 240 PJ of energy for district heating per year, which amounts to 45% of space heating and hot water demands. Substantial increases in cogenerating capacity are planned: 1,500-2,500 MW of electric power during the 1990s. These developments would permit an increase in the share of cogenerated heat to about 80% in 2000 and even more in the long term. The advantages of increased cogeneration will be

• efficiency increases for electric and heat energy generation;

• reduction of capital expenditure for new generating capacity;

• improvement of environmental conditions in the towns; and

• fuel savings estimated at 2-3 million tons coal equivalent in the year 2000.

In order to utilize maximally the existing electric energy generating capacity, intensification of modernization and reconstruction programs is required, including reconstruction of old plants to improve efficiency and reliability and to reduce environmental pollution.

The main problem facing Polish energy policy planners is the future role of coal, especially in generating electrical energy. Coal is the most abundant fossil energy resource for the long term and it is an economically attractive option, aside from the environmental impacts. Displacing coal with other supply sources will be limited by economics and national advantage. The options available to reduce the environmental impacts of coal use are

• increased use of “clean coal” technologies such as fluidized-bed combustion and gasification with combined-cycle generation, and

• improved efficiency in power supply systems which provide more electricity services per unit of coal consumed.

Our priorities for environmental protection policy are the following:

• SO₂ annual emissions decrease from the current 4.2 million tons to 2.9 million tons in 2000 and further decrease to 2.0 million tons in 2010;

• NO_x annual emissions decrease from the current 1.5 million tons to 1.4 million tons by 2000 and further decrease to 0.8 million tons by 2010;

• decrease of emissions of CO₂, particulates, hydrocarbons, heavy metals, etc. to the air;

• reduction in discharges of saline mine waters to river basins;

• 20% decrease in solid industrial wastes by 2000 and by 50% as of 2010; also, substantial increases in waste utilization; and

• reclamation by 1995 of all natural areas degraded by the fuel and energy sector.

Roman Ney

Polish Academy of Sciences

Minerals and Energy Economy Research Center

Krakow, Poland

During the 1970s, after the world crude oil crisis, more rational use of fossil energy resources was observed, and there was more interest in finding new technologies of energy generation from renewables. In the 1980s, growth of ecological consciousness occurred, mainly in the highly-developed countries, caused by the recognition that some areas were showing signs of ecological disaster. In Europe there is such a zone located in the northern part of the Czech Republic, southeastern Germany, and in the Polish regions of Upper Silesia and Krakow and around the Karkonosze Mountains. region. Degradation of the natural environment has been caused by air, soil, and water pollution mainly due to energy production and conversion utilizing high sulfur coal and lignite and also due to iron and nonferrous metal industries.

Environmental problems have created growing interest in renewable energy. Energy obtained from renewable sources is usually ecologically pure and only affects the environment to some limited degree, but always on a local scale. Some technologies of energy production from renewables, such as biogas production, make use of communal, agricultural, and animal waste which otherwise would cause contamination of the environment. This type of technology then plays a double role: production of energy and elimination of waste. The majority of technologies used for the use of the renewables such as water power, solar energy, wind power, geothermal energy, and biomass have been known for a long time. Some of these are characterized by rather low efficiency of conversion. Except for electric energy generation at hydropower plants and from high-temperature geothermal sources, the majority of known renewable sources of energy technologies can be used only locally.

Another reason for the relatively limited use of renewables is high cost. Of considerable importance is the relatively low price of crude oil, which to a high degree dictates the prices of other conventional energy carriers. Presently, hydropower in rivers and small streams is economical, especially in the mountainous regions. Other forms of renewables compete successfully only on a small scale in remote locations far from the industrial electric energy network, gas network, and other energy carriers. The high costs of energy transport from remote energy resources to individual users such as farms or rural and urban settlements can make some renewable energy installations non-competitive. Moreover, in cold climates some forms of renewable energy can not meet the entire energy demand. However, the necessity of environmental protection makes economically justified to use renewable energy in

combination with traditional energy. Examples include thermal solar collectors combined with electric energy use and geothermal energy in district heating combined with natural gas or oil.

In Poland, renewable energy use is very low. In the structure of primary energy use, it amounts only to 0.5% and combined with waste energy, the total is 1.9%. Except for the countries that utilize hydroelectricity on a large scale, such as Sweden, Canada, Japan, Austria, the U.S., and the former Soviet Union, the contribution of renewables in the structure of the primary energy balance amounts barely to 3-6%, but it is increasing. In the first half of the 21st century, participation of renewable energy in the total world use of energy could amount to 15%. It will be totally environmentally benign energy, and therefore new technologies connected with its utilization should get special preferences.

Poland has limited hydroelectric energy resources. Presently, seventeen hydropower stations with a total capacity of 1860.8 MW are in operation contributing 8.25% of the total electric power system of the country. Also, during the last few years, about 350 small individual power plants with a capacity of several kW have been established by individual users. Some 18% of Poland's hydropower resource is presently in use.

Utilization of water energy resources has limited environmental impact that occurs only on a local scale and only in case of large water reservoirs. Water reservoirs affect local climate, especially when they are situated in lowlands. Arable land for cultivation and forests are lost in connection with their construction. During construction of reservoirs, significant devastation of landscape occurs that often eliminates many settlements. About ten to fifteen years after construction of a water reservoir, a new ecological balance is attained. In mountainous areas, the combination of morphological conditions with unfavorable geological structure can lead to dam failure causing a catastrophe in the river basin and sudden flooding of the neighboring areas with water and rock waste. Some examples of such catastrophes have already been observed in our century. At the same time, it should be stressed that properly used energy reservoirs play an important role in flood control and can be used as a source of water supply for urban and industrial complexes and also for agriculture.

Technologies for energy production from wind power plants are on the whole environmentally friendly, although in larger installations of 30-60 kW, electric power should be placed at a distance of 200-300 meters from residences because they produce harmful noise levels. Climate conditions in Poland are not favorable for constructing wind power plants except for the Baltic seaside and some regions of central Poland. Only one third of Poland's area fulfills conditions for wind power plants with turbines up to 40 kW.

Thermal solar collectors, which are usually installed on the roofs of buildings, can receive in our climate on sunny days energy at the rate of 0.9 to 1.3 MJ/day/m². The energy obtained in this way can be utilized for hot water production in single family houses. Presently, some experiments are being conducted on utilizing solar collectors for space heating in single-family homes and greenhouse heating. If thermal solar collectors are installed on the roofs of houses, they must be situated properly in relation to the sun. Generating heat power in solar collectors is ecologically pure, because the heating medium, i.e. water or some other liquid, circulates in a closed system. Thermal solar installations can be used for hot water production during the winter in combination with electric power. In this way, in the Polish climate, about 40% of traditional energy in one-family houses and in greenhouses can be supplied by solar collectors.

Another form of utilizing solar energy involves photovoltaic cells, where electromotive power is generated as a result of irradiation of a semiconductor. It is achieved in photovoltaic cell assemblies in series connection in order to provide an adequate voltage and in parallel connection to provide an adequate power. In Poland research in this field is being conducted which has resulted in small installations that feed 12 V batteries. The energy they produce may be utilized at camping sites, for lighting summer cottages, and in agriculture. Photovoltaic cells may make use of scattered radiation, i.e. they can generate electric energy also on cloudy days. The efficiency of the photovoltaic cells constructed of silicon plates amounts to 11%. If doped quartz grown in a form of band crystal is used to construct the photovoltaic cells, then this efficiency can be raised to 16%.

Recently, a new cell has been made in the United States which consists of three layers of gallium arsenide of various thickness. Those cells can reach 20% efficiency. This efficiency can still be raised to 25% when in those cells strong optical concentration with simultaneous cooling of the cell is applied. At present in the newest cells with plates made of alluminogallium arsenide or arsenogallium phosphide, the efficiency of energy conversion into electricity amounts to 30%. In order to increase energetic systems' efficiency and improve the economy of their exploitation, the photovoltaic cells are combined with heat collectors. In this case photovoltaic cells become the surface layer of a heat collector. Such systems permit the use of 60% of the solar radiation. The greatest number of photovoltaic power plants are in the United States, and their total power in the world amounts to 65 MW.

It should be expected that on introduction of further efficiency improvements, the use of solar energy will be much wider. It is obvious that to a high degree the insolation conditions will play the decisive role. The technologies of generating energy from solar radiation are ecologically pure, and for this reason they should be developed. However, during construction of the solar power plants of several tens kW efficiency, or still larger based upon photovoltaic technology, the local natural landscape can be disrupted.

An important technology of energy generation is fermentation of biomass to produce biogas. One of the advantages of this technologies is utilization of the municipal and agricultural waste that provides valuable fertilizer with simultaneous production of biogas with a net caloric value from 21 to 23 MJ/m³. Analyses in Poland indicate that after the introduction of world prices for natural gas, the production of biogas will be fully profitable. Biogas production potential in Poland is estimated at 5-6 billion m³/year.

During recent years, a rather rapid development of installations utilizing geothermal energy for generating electric energy and heat energy in particular has occurred. The thermal energy of geothermal waters and also that of dry rocks originates from the energy of the heat stream of the earth, which constitutes the heat coming from the depth of the earth and the heat that is generated in the lithosphere. The earth is also heated by solar radiation. For geothermal purposes the zones of the earth with anomalously high temperatures are used. Traditionally, they are volcanic zones with superheated steam or with very hot water, which are used for electric energy generation. However, recently lower temperature sources in the range of 50-100 C have been developed for heating purposes in Italy, France, Hungary, the former Soviet Union, Japan, the U.S., the Philippines, New Zealand, and China.

As the geothermal waters are usually mineralized, the modern technologies of their use require forcing the cooled waters back into the rock mass after the heat has been extracted by heat exchangers. Geothermal energy is of local character but it can cover whole regions where numerous installations can operate. It is ecologically pure energy and can be utilized in a very wide range of areas—from district heating to recreation and agriculture. Geothermal energy resources are estimated in Poland to be significant, especially in the southern part of the country. Geothermal waters with a temperature below 70 C can be utilized in winter for heating when combined with electric energy or natural gas in ways that might substantially improve the natural environment by reducing air pollution from coal burning.

At present in Poland, a pilot 1.5 MW geothermal installation is being built in the sub-Carpathian region. The method of intrinsic flow to the rock mass of cooled water without the use of pumps has been worked out. The power of this installation can be raised to 11.8 MW by means of utilizing pumps and extracting heat from the water by cooling from the temperature of 86 C to 35 C.

This paper has reviewed the potential for renewable energy development in Poland. Development and utilization of renewable energy will proceed with the improvement of technological processes in which this energy is generated and with the growth of ecological consciousness of the people.