Assessment of Energy Sources Using GIS

Our standard of life and our advanced technology are highly dependent on an adequate supply of energy. More and more energy is needed to supply our homes with electricity, to drive our transport, to power our communications, and to support our industry. Our living standards are dependent on energy consumption, which is strikingly illustrated by the connection to average life expectancy. People in rich well-developed countries like Japan and in continents like North America and Europe use considerably more energy per person and have longer average life expectancy. At the other end of the scale, people in poorer countries, such as in some parts of Africa and Asia, have significantly lower energy consumption and average life expectancy. Without energy, all the conveniences of modern life would be impossible on the scale needed, and our civilization would soon collapse into barbarism.

In this book, the concepts and procedures for assessment of energy systems are discussed in order to apply a number of spatial and temporal analyses with geographic information system (GIS). In addition to digital mapping, GIS can change the way of viewing our Earth’s resources in a more complex way by integrating data from remote sensing, GPS, and a wide range of databases. Many GIS packages are freely available as open software or as commercial software broadly used in industry, government, and academia. This chapter introduces some fundamental concepts that are dealt with in next chapters. After identifying certain open issues in spatial and temporal analysis, a case-oriented approach is proposed for assessment of energy sources including nonrenewable sources and renewable sources with their temporal dynamics and spatial patterns. Also presentation of new GIS technologies will discuss the strengths and weaknesses, along with the opportunities and limitations of using GIS methods for wide-ranging applications in assessment of energy sources.

Over the centuries, the energy has been extracted from nature in many ways. From ancient times to almost modern times, wood was the main fuel, which was often used more rapidly than was replaced by new growth, and therefore the forests of countries surrounding the Mediterranean were gradually destroyed, followed by the forests of central Europe and South America nowadays. The scarcity of wood stimulated utilization of other energy sources based on fossil fuels. Coal became the main energy source in many developed countries and provided the power for the industrial revolution, because it can be transported and has a higher caloric values than wood. During the twentieth century, coal is gradually displaced by oil and gas. In comparison with coal, these fossil fuels can be more easily transported over large distances by pipelines and tankers. Since the nineteenth century, the rapid development of the electrical industry has become a complex change of our civilization. The advantage of electricity being very easily transported displaced many local energy sources for heating, air-conditioning, suburban transport, and communication. It became a convenient power source for our factories and household articles. Electricity is mostly generated by turbines driven by steam produced by burning fossil fuels. It can be complemented by hydroelectric power and nuclear power. Nowadays the electrical industry makes possible to integrate a number of other sources, such as solar farms, wind and biofuel production, and small hydro energy plants.

At present fossil fuels are the most important sources of energy. In many countries most of the energy is still generated by nonrenewable sources, which are represented by a limited reserve coal, oil, and gas. They will become scarce and therefore prohibitively expensive after a few decades. The choice can be limited by other criteria such as air pollution and climate change. The pollution due to coal power stations depends on the quality of the coal. A coal power station can emit each year a few million tonnes of carbon dioxide, a million tonnes of ash, half a million tonnes of gypsum, and other pollutants such as nitrous oxide, sulfur dioxide, and smaller amounts of other toxic wastes. Besides that coal mining is dangerous, dirty and many miners contract debilitating diseases such as silicosis. Oil became one of the world’s leading energy sources. It has a higher caloric value than coal and is more easily transported. Transport and industry are more dependent on oil supply than on the availability of coal. Moreover oil is the basis of petrochemical industries such as plastics, drugs, and paints. Similarly to coal, main oil reserves last for a few decades, and then the production becomes increasingly expensive. The changes can be more rapid in individual countries, which do not have their own oilfields. Since a large fraction of the oil is used for transport, it is imperative to discover new ways of driving cars and ships. The energy supply of gas has risen rapidly. As the rate of consumption is rising, it is unlikely to last longer than oil. In comparison with other fossil fuels, gas is now the cheapest and convenient energy source, but its world’s reserve is severely limited.

Hydropower has been used for energy supply for many centuries. Now it accounts for about a few percent of world energy production. Hydropower is described as a renewable source, but it is slightly different, because it occupies large areas of land and can disrupt the local ecosystems. The dam prevents the upstream migration of aquatic animals, which can be overcome by building fish ladders. The areas below the dam are deprived of silt that causes lower yield in organic farming. Hydroelectric power is widely utilized by mountainous countries like Austria, Norway, and Switzerland. Nowadays, the expansion is limited in many developed countries, because most of the suitable sites have already been used. The hydroelectric potential can be increased by the concept of distributed generation from small hydro plants that are connected to conventional electrical distribution networks as a source of low-cost renewable energy. Also small hydro projects may be built in isolated areas, where there is no national electrical distribution network. Since small hydro projects generating capacity of 1–20 megawatts have minimal civil construction work, they are seen as having a relatively low environmental impact compared to large hydro plants.

Wind power plants have been indicated great progress for last decades. They consist of large propeller blades driving turbines mounted on high towers. Hundreds of wind power plants are approximately needed to equal the output of one coal power station. The energy output of wind turbines is highly variable, because it is proportional to the cube of the wind velocity. The wind power plants are mostly grouped into the wind farms that occupy large areas of land, so many of them are often being built offshore. It results in the highly variable output power that can oscillate during an hour. In many countries, the subsidies for wind power are on the low level, which causes stopping further the development. Wind power is useful on remote windy sites where the electricity demand is insufficient for the development of large power stations and the transport of electrical power is uneconomical.

The Sun energy falling on the Earth at the rate of about 100 PW/year is enough to support our energy needs about a few thousand times. If new technology could find a practical way of transformation and accumulation, we would have supply by energy our industry and personal consumption without any energy crisis. Although the heat of the Sun stirs up the atmosphere and causes wind and water circulations on the surface of the Earth, a considerable part can be used to generate electricity or used directly. The currently used photovoltaic cells are inefficient and expensive to substitute traditional fossil energy sources. Also the territorial claims are high and output power variable due to meteorological conditions. Despite the Sun giving approximately 1.4 kW per square meter to the Earth, we can use a small part such as about 100–200 W per square meter at the Earth’s surface, with higher values at the equator. Although current technology for electricity generation is still too costly for general use, there are many applications for relatively small amounts of electricity needed in remote sites such as navigation lights, road signs, computer networks, power supply, or recharging of consumer electronics. Another way is to use solar energy for domestic water heating. Many houses are equipped with solar panels that can substitute a part of heating energy produced by traditional heating systems on sunny days.

Biomass is generally represented by an organic material that can be used to produce heat or allowed to decay and emit natural gas. In the form of wood, this has been done for centuries. It is still widely used as a predominant heating source in poorer countries. The uncontrolled use can lead to desertification. It is an environment-friendly source that does not add to global warming since the carbon dioxide produced when it is burned equals the amount absorbed by the photosynthesis that originally produced it. But carbon savings are decreased by additional services that are necessary for its agricultural production, such as transportation and needed agricultural operations. Unsuitable agricultural practices can rise to erosion. An expansion of biofuel production affects water availability and pesticide use. The growth of industrial crops for biofuels requires large areas of land, which can lead on a large scale of exploitation to disaster. Also the massive switch from food production to growing industrial crops will lead to the growing shortage of food, especially in developing countries.

Heat generated by the fission represents higher order amounts of energy in comparison with other energy sources such as fossil or renewable. Nuclear reactors can transform 60TJ of energy from 1 kg of uranium 235, which can give, assuming 30% efficiency of conversion, 3 GWh of electricity. For example, a small 1 cm reactor fuel pellet produces the same amount of energy as 1.5 tonnes of coal. Actually, energy from nuclear reactors ranks among major sources of energy such as coal, oil, and gas. For example, France producing 80% of its electricity by nuclear power and exports this energy to surrounding countries. Due to the limited resources of fossil fuels, hundreds of fossil-fuel power stations must be replaced. It cannot be mainly done by renewable sources of energy, but the renewable source can complement these high-performance sources of energy. Up-to-date nuclear reactors are reliable and operate over 90% of the time, and the remainder of the time is mostly covered by essential maintenance that is scheduled in advance. The number of unplanned shutdowns has fallen to about one in 7000 per day. The main disadvantage of nuclear reactors during their operation is the long period to come up to full power than other power stations. But temporary electricity failures by nuclear reactors can be quickly replaced by alternative sources such as gas power stations that can be rapidly activated in case of a sudden need. The concern about nuclear radiation has diverted attention from other hazardous to our health, but the nuclear industry is responsible for less than 0.01%.

Over short periods of time, the amount of generated electricity is relatively fixed, but demand for electricity fluctuates throughout the day. Thus, technology for storing electrical energy is needed to manage the amount of power required to supply customers at times when need is greatest, during peak load. Also it can help to make renewable energy, whose power output cannot be controlled by grid operators, without interruptions of power supply and smooth. Suitable local energy storage can balance microgrids to achieve a good match between generation and load. Storage devices can achieve a more reliable power supply for industrial facilities, and hold considerable promise for transforming the electric power industry. Energy storage technology is applied to a wide range of areas that differ in power and energy requirements. It includes batteries, electrochemical capacitors, superconducting magnetic storage, pumped-storage hydroelectricity, and flywheels. Also new technology seeks to improve energy storage density in electrolytes and nano-structured electrodes.

Spatial and temporal modeling can be extended by other computer tools focused on optimization of fuel and power supply. Multi-criteria analysis is used for regional energy planning and development because the optimization of energy systems requires physical, economic, environmental, and social considerations. The more complex energy supply models can be used for predicting the feature. They deal with technological innovations and efficiency improvements, which can provide better optimization on the local and global scale. Many of the assessment tools are used to support decision-making. Renewable energy sources can be included in the models as a component that helps to reduce the environmental impacts of energy consumption. In order to develop an efficient power grid, it is important to know the exact capacity of various renewable energy sources because each renewable energy source has a different energy generation capacity. Optimized deployment of innovated existing power sources and renewable energy sources will reduce the operational and maintenance costs of the energy generated units. In general, cost minimization and power maximization under defined environmental restrictions are the two main objectives in the described assessment tools.