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THE RELEVANCE OF ENERGY SAVING CONTROL
IFAC WS ESC’06 ENERGY SAVING CONTROL IN PLANTS AND BUILDINGS, October 2-5, 2006 Bansko, Bulgaria
THE RELEVANCE OF ENERGY SAVING CONTROL Heinz-Hermann Erbe TU Berlin, Center for Human-Machine Systems Berlin, Germany [email protected]
Abstract: Energy providing and consumption regarding finite resources can cause conflicts between customers and between costumers and suppliers. Energy savings are necessary regarding finite resources. Effective use of available energy can be supported by automatic control of consumption in households, office buildings, plants, and transport. The energy intensity decreases in most developing countries. This is caused by changing habits of people but also by new control strategies. Copyright © 2006 IFAC Keywords: Energy saving control, energy efficiency, energy intensity, energy generation.
use of energy. It is defined as the ratio of energy consumption to a measure of the demands for services (e.g. number of buildings, total floor space, number of employees), more general: the energy required to generate $ 1000 of Gross Domestic Product (Fig. 1). High energy intensity indicates a high price or cost of converting energy into GDP, while low energy intensity indicates a lower price or cost of converting energy into GDP. Many factors influence an economy's overall energy intensity. It may reflect requirements for general standards of living and weather conditions in an economy. It is not untypical for particularly cold or hot climates to require greater energy consumption in homes and workplaces for heating or cooling. A country
1. GENERAL The aim of the workshop is to promote the reducing of energy consumption and the improvement of energy efficiency through automatic control. The use of energy in a country, in the residential sector, the commercial building sector, the transportation sector, and the industrial sector, influences the competitiveness of the economy, the environment, and the comfort of the inhabitants. While energy efficiency is a philosophical concept (energy inputs are reduced for a given level of service, or a relative thrift with which energy inputs are used to provide goods or services), energy intensity measures the efficient
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requiring heating and cooling, long commutes, and extensive use of generally poor fuel economy vehicles. The downward slope of energy intensity (Fig. 2) with time reflects increasing energy efficiency. While developed nations are increasingly efficient due to the introduction of new technologies in a wide variety of applications, there are still significant opportunities for efficiency gains in developing countries.
Fig. 1. Development of Gross Domestic Product (GDP), Energy Demand, and Energy intensity in the EU. (Source: Directorate general for Energy and Transport, European Commission, 2005). with an advanced standard of living is more likely to have a wider prevalence of such consumer goods and thereby be impacted in its energy intensity than one with a lower standard of living. Energy efficiency of appliances and buildings, fuel economy of vehicles, vehicular distances traveled, better methods and patterns of transportation, capacities and utility of mass transit, energy rationing or conservation efforts, 'off-grid' energy sources, and stochastic economic shocks such as disruptions of energy due to natural disasters, wars, massive power outages or unexpected new sources or efficient uses of energy may all impact the overall energy intensity of a nation. Thus, a nation with mild and temperate weather, demographic patterns of work places close to home, and uses fuel efficient vehicles, supports
Fig. 3. Estimated total energy consumption by fuel and energy intensity 1990 – 2020 of the 25 EU-member states.
Fig. 4. Energy intensity in 2003 (toe/million EUR of GDP at 1995 market prices) Figures 3 and 4 give some information on energy consumption and energy intensity in different countries. Figure 5 show energy consumption by sectors, and Fig. 6. estimates energy savings. Mtoe = Megatons of oil equivalent.
Fig. 2. Estimation of energy intensity world wide. (Source: www.Exxonmobile.com, 2005) carpools, mass transportation or walks or rides bicycles, will have a far lower energy intensity than a nation with extreme weather conditions
Fig. 5. Gross energy consumption (1725 Mtoe) by sector in 2005 of the 25 EU-states.
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3. RESIDENTIAL SECTOR Households consume 17 % of the estimated gross energy consumption of 1725 Mtoe in 2005 according Eurostat energy balances in the European Union. This amount can be reduced when 1) People could change their habits: Switch off when appliances are not in use, standby consumes energy! Select energy efficient domestic appliances, Use low energy light bulbs, Increase levels of recycling, Monitor energy consumption, Ensure systems correctly, Adjust central heating setpoint, correct distribution of sensors, Double glazing of windows against heat and cold, Insulation of walls, Etc.
Fig. 6. Examples of possible energy savings (Source: Directorate general for Energy and Transport, European Commission, 2005)
2. ENERGY GENERATION With energy ‘waste’ levels in the process of electricity generation running at 66 %, this sector possesses great potential. Using standard technology, only between 25 and 60 % of the fuel used is converted into electrical power. Combined-cycle gas turbines (‘CCGT’) are among the most efficient plant now available as compared with the old thermal solid fuel ones, some of which were commissioned in the 1950’s. The biggest waste in the electricity supply chain (generation – transmission, distribution – supply) is the unused heat which escapes in the form of steam, mostly by heating the water needed for cooling in the generation process. The supply chain is still largely characterized by central generation of electricity in large power plants, followed by costly transport of the electricity to final consumers via cables. This transport generates further losses, mainly in distribution. Thus, centralized generation has advantages in the shape of economies of scale, but also wastes energy. Decentralized generation of electricity and heat in regional or local units (including single buildings) could be of advantage. Such units are under development based on gas, or fuel cells in buildings. A combination of wind-, solar- energy, hydropower, energy from biomass, and fossil fuel in small units could provide electrical energy and heat in regions isolated from grids. These hybrid energy concepts are demanding advanced, but low cost controls.
2) People are lazy; automatic control can give support through managing the consumption of household appliances. The so called “intelligent home” could provide solutions, but anyway people have to be aware of unnecessary energy consumption. The table 1 below shows possible savings of electrical energy in households of the EU.
Table 1: Energy savings and consumption (Source: Directorate general for Energy and Transport, European Commission, 2005). 4. COMMERCIAL BUILDING SECTOR Energy and therefore costs can be saved with a suitable and intelligent automation. Energy management control systems (EMCS) are centralized computer control systems intended to operate a facility’s equipment efficiently. These
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transport management system. These problems of information control could be solved. Of course, achievements of automatic control in motor-management and electrical drives reducing the consumption of energy can be seen. Hybrid drives in cars with automatic control of the power management are favored. But more effort is necessary to find acceptable and costeffective solutions.
systems are still evolving rapidly, and they are controversial. Some applications are appropriate for computer control systems, and many are not. A range of simpler alternatives are available. Advantage of building automation systems includes monitoring, report generation, and remote control of equipment. Pitfalls, includes system cost, skilled staffing requirements, software limitations, vendor support, maintenance, rapid obsolescence, and lack of standardization. These systems are also known by a variety of other names, including “energy management systems” (EMS), “smart building controls,” “building automation system” (BAS), etc. A system typically has a central computer, distributed microprocessor controllers (called “local panels”, “slave panels”, “terminal equipment controllers”, and other names), and a digital communication system. The communication system may carry signals directly between the computer and the controlled equipment, or there may be tiers of communications. Building Automation can be a very effective way to reduce building operational costs and improve overall comfort and efficiency of a building. There are many definitions and examples of building automation. Simply put, building automation uses software to connect and control electrical functions in a building. Those functions usually include but are not limited to the HVAC (Heating, Ventilation, AirConditioning) and lighting systems.
6. INDUSTRIAL SECTOR An enterprise should always observe and improve its energy consumption at all levels - the energy improvement cycle. A pre-condition for entering the cycle is commitment at all levels of the enterprise. The table 2 below describes an uncommitted enterprise on the bottom row and an enterprise that is highly committed to the energy improvement on the top row. It is important that the enterprise demonstrates commitment to sustained energy improvement before the process of delivering that improvement can begin.
Table 2. Three levels of observing an improving energy consumption. (Source: M. Pattisson, ABB, 2006)
5. TRANSPORTATION SECTOR Transport consumes 20 % of the estimated gross energy consumption of 1725 Mtoe in 2005 according Eurostat energy balances in the European Union. To reduce the consumption is not only a technical problem, but mainly a political a hot potato. Road transport of goods gets direct or indirect subventions. The mostly state-owned railway-organizations in Europe are not able to install a common system to reduce inefficient road transport. Low cost air travel are rising polluting the air. Public transport offers not always an acceptable alternative to individual car using. To get persons or goods from A to B we have ways via the air, road, rails, and water. Today no interoperable information system is available. But this would be an assumption for an efficient
Fig. 7. Energy improvement strategy in an enterprise. (Source: M. Pattisson, ABB, 2006). The energy improvement strategy (Fig. 7) need not be long or complex but it is vitally important, as it will set the direction of all efforts to manage and improve energy consumption. The figure
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4
above shows that essentially there are two ways to cut energy bills: Pay less for energy or consume less energy. For to reducing the consumption of energy it is necessary to analyze all possible sources of wasted energy: buildings, machines and equipment, the production process of goods, recycling of wasted energy (heat, etc.), and transport of raw material, pre-manufactured parts, and the manufactured products. Developed automatic control concepts can help (less energy consuming drives), but control concepts for an enterprise as a whole may be of advantage regarding the reducing of energy consumption.
Table 4. Final energy demand. (Source: Directorate general for Energy and Transport, European Commission, 2005). REFERENCES
7. CONCLUSIONS
Directorate-General for Energy and Transport, European Commission (2005). Doing more with less. Green paper on energy efficiency, http://europa.eu.int/comm/energy/effici ency/index_en.htm Pattisson, M. (2006). Energy prices are rising and will continue to rise. Conference paper, Quito, Ecuador.
Energy saving strategies and also individual solutions for reducing energy consumption are challenging politicians, the public, and the researchers. The conference on Energy Saving Control presents surveys of the situation in the different sectors mentioned above, the state of the art of solutions with automatic control and the challenges in the future. The cost aspect is very important. Components of controllers like sensors and actuators could be expensive, but one has to calculate the savings on energy costs of a certain period or a life cycle of a building or plant. The following tables 3 and 4 show potential savings of energy, and the estimated final energy demand respecting the available energy resources.
Table 3. Potential energy savings. (Source: Green paper on energy efficiency (Directorate-general for Energy and Transport, European Commission, 2005))
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THE RELEVANCE OF ENERGY SAVING CONTROL Heinz-Hermann Erbe TU Berlin, Center for Human-Machine Systems Berlin, Germany [email protected]
Abstract: Energy providing and consumption regarding finite resources can cause conflicts between customers and between costumers and suppliers. Energy savings are necessary regarding finite resources. Effective use of available energy can be supported by automatic control of consumption in households, office buildings, plants, and transport. The energy intensity decreases in most developing countries. This is caused by changing habits of people but also by new control strategies. Copyright © 2006 IFAC Keywords: Energy saving control, energy efficiency, energy intensity, energy generation.
use of energy. It is defined as the ratio of energy consumption to a measure of the demands for services (e.g. number of buildings, total floor space, number of employees), more general: the energy required to generate $ 1000 of Gross Domestic Product (Fig. 1). High energy intensity indicates a high price or cost of converting energy into GDP, while low energy intensity indicates a lower price or cost of converting energy into GDP. Many factors influence an economy's overall energy intensity. It may reflect requirements for general standards of living and weather conditions in an economy. It is not untypical for particularly cold or hot climates to require greater energy consumption in homes and workplaces for heating or cooling. A country
1. GENERAL The aim of the workshop is to promote the reducing of energy consumption and the improvement of energy efficiency through automatic control. The use of energy in a country, in the residential sector, the commercial building sector, the transportation sector, and the industrial sector, influences the competitiveness of the economy, the environment, and the comfort of the inhabitants. While energy efficiency is a philosophical concept (energy inputs are reduced for a given level of service, or a relative thrift with which energy inputs are used to provide goods or services), energy intensity measures the efficient
1
1
requiring heating and cooling, long commutes, and extensive use of generally poor fuel economy vehicles. The downward slope of energy intensity (Fig. 2) with time reflects increasing energy efficiency. While developed nations are increasingly efficient due to the introduction of new technologies in a wide variety of applications, there are still significant opportunities for efficiency gains in developing countries.
Fig. 1. Development of Gross Domestic Product (GDP), Energy Demand, and Energy intensity in the EU. (Source: Directorate general for Energy and Transport, European Commission, 2005). with an advanced standard of living is more likely to have a wider prevalence of such consumer goods and thereby be impacted in its energy intensity than one with a lower standard of living. Energy efficiency of appliances and buildings, fuel economy of vehicles, vehicular distances traveled, better methods and patterns of transportation, capacities and utility of mass transit, energy rationing or conservation efforts, 'off-grid' energy sources, and stochastic economic shocks such as disruptions of energy due to natural disasters, wars, massive power outages or unexpected new sources or efficient uses of energy may all impact the overall energy intensity of a nation. Thus, a nation with mild and temperate weather, demographic patterns of work places close to home, and uses fuel efficient vehicles, supports
Fig. 3. Estimated total energy consumption by fuel and energy intensity 1990 – 2020 of the 25 EU-member states.
Fig. 4. Energy intensity in 2003 (toe/million EUR of GDP at 1995 market prices) Figures 3 and 4 give some information on energy consumption and energy intensity in different countries. Figure 5 show energy consumption by sectors, and Fig. 6. estimates energy savings. Mtoe = Megatons of oil equivalent.
Fig. 2. Estimation of energy intensity world wide. (Source: www.Exxonmobile.com, 2005) carpools, mass transportation or walks or rides bicycles, will have a far lower energy intensity than a nation with extreme weather conditions
Fig. 5. Gross energy consumption (1725 Mtoe) by sector in 2005 of the 25 EU-states.
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2
3. RESIDENTIAL SECTOR Households consume 17 % of the estimated gross energy consumption of 1725 Mtoe in 2005 according Eurostat energy balances in the European Union. This amount can be reduced when 1) People could change their habits: Switch off when appliances are not in use, standby consumes energy! Select energy efficient domestic appliances, Use low energy light bulbs, Increase levels of recycling, Monitor energy consumption, Ensure systems correctly, Adjust central heating setpoint, correct distribution of sensors, Double glazing of windows against heat and cold, Insulation of walls, Etc.
Fig. 6. Examples of possible energy savings (Source: Directorate general for Energy and Transport, European Commission, 2005)
2. ENERGY GENERATION With energy ‘waste’ levels in the process of electricity generation running at 66 %, this sector possesses great potential. Using standard technology, only between 25 and 60 % of the fuel used is converted into electrical power. Combined-cycle gas turbines (‘CCGT’) are among the most efficient plant now available as compared with the old thermal solid fuel ones, some of which were commissioned in the 1950’s. The biggest waste in the electricity supply chain (generation – transmission, distribution – supply) is the unused heat which escapes in the form of steam, mostly by heating the water needed for cooling in the generation process. The supply chain is still largely characterized by central generation of electricity in large power plants, followed by costly transport of the electricity to final consumers via cables. This transport generates further losses, mainly in distribution. Thus, centralized generation has advantages in the shape of economies of scale, but also wastes energy. Decentralized generation of electricity and heat in regional or local units (including single buildings) could be of advantage. Such units are under development based on gas, or fuel cells in buildings. A combination of wind-, solar- energy, hydropower, energy from biomass, and fossil fuel in small units could provide electrical energy and heat in regions isolated from grids. These hybrid energy concepts are demanding advanced, but low cost controls.
2) People are lazy; automatic control can give support through managing the consumption of household appliances. The so called “intelligent home” could provide solutions, but anyway people have to be aware of unnecessary energy consumption. The table 1 below shows possible savings of electrical energy in households of the EU.
Table 1: Energy savings and consumption (Source: Directorate general for Energy and Transport, European Commission, 2005). 4. COMMERCIAL BUILDING SECTOR Energy and therefore costs can be saved with a suitable and intelligent automation. Energy management control systems (EMCS) are centralized computer control systems intended to operate a facility’s equipment efficiently. These
3
3
transport management system. These problems of information control could be solved. Of course, achievements of automatic control in motor-management and electrical drives reducing the consumption of energy can be seen. Hybrid drives in cars with automatic control of the power management are favored. But more effort is necessary to find acceptable and costeffective solutions.
systems are still evolving rapidly, and they are controversial. Some applications are appropriate for computer control systems, and many are not. A range of simpler alternatives are available. Advantage of building automation systems includes monitoring, report generation, and remote control of equipment. Pitfalls, includes system cost, skilled staffing requirements, software limitations, vendor support, maintenance, rapid obsolescence, and lack of standardization. These systems are also known by a variety of other names, including “energy management systems” (EMS), “smart building controls,” “building automation system” (BAS), etc. A system typically has a central computer, distributed microprocessor controllers (called “local panels”, “slave panels”, “terminal equipment controllers”, and other names), and a digital communication system. The communication system may carry signals directly between the computer and the controlled equipment, or there may be tiers of communications. Building Automation can be a very effective way to reduce building operational costs and improve overall comfort and efficiency of a building. There are many definitions and examples of building automation. Simply put, building automation uses software to connect and control electrical functions in a building. Those functions usually include but are not limited to the HVAC (Heating, Ventilation, AirConditioning) and lighting systems.
6. INDUSTRIAL SECTOR An enterprise should always observe and improve its energy consumption at all levels - the energy improvement cycle. A pre-condition for entering the cycle is commitment at all levels of the enterprise. The table 2 below describes an uncommitted enterprise on the bottom row and an enterprise that is highly committed to the energy improvement on the top row. It is important that the enterprise demonstrates commitment to sustained energy improvement before the process of delivering that improvement can begin.
Table 2. Three levels of observing an improving energy consumption. (Source: M. Pattisson, ABB, 2006)
5. TRANSPORTATION SECTOR Transport consumes 20 % of the estimated gross energy consumption of 1725 Mtoe in 2005 according Eurostat energy balances in the European Union. To reduce the consumption is not only a technical problem, but mainly a political a hot potato. Road transport of goods gets direct or indirect subventions. The mostly state-owned railway-organizations in Europe are not able to install a common system to reduce inefficient road transport. Low cost air travel are rising polluting the air. Public transport offers not always an acceptable alternative to individual car using. To get persons or goods from A to B we have ways via the air, road, rails, and water. Today no interoperable information system is available. But this would be an assumption for an efficient
Fig. 7. Energy improvement strategy in an enterprise. (Source: M. Pattisson, ABB, 2006). The energy improvement strategy (Fig. 7) need not be long or complex but it is vitally important, as it will set the direction of all efforts to manage and improve energy consumption. The figure
4
4
above shows that essentially there are two ways to cut energy bills: Pay less for energy or consume less energy. For to reducing the consumption of energy it is necessary to analyze all possible sources of wasted energy: buildings, machines and equipment, the production process of goods, recycling of wasted energy (heat, etc.), and transport of raw material, pre-manufactured parts, and the manufactured products. Developed automatic control concepts can help (less energy consuming drives), but control concepts for an enterprise as a whole may be of advantage regarding the reducing of energy consumption.
Table 4. Final energy demand. (Source: Directorate general for Energy and Transport, European Commission, 2005). REFERENCES
7. CONCLUSIONS
Directorate-General for Energy and Transport, European Commission (2005). Doing more with less. Green paper on energy efficiency, http://europa.eu.int/comm/energy/effici ency/index_en.htm Pattisson, M. (2006). Energy prices are rising and will continue to rise. Conference paper, Quito, Ecuador.
Energy saving strategies and also individual solutions for reducing energy consumption are challenging politicians, the public, and the researchers. The conference on Energy Saving Control presents surveys of the situation in the different sectors mentioned above, the state of the art of solutions with automatic control and the challenges in the future. The cost aspect is very important. Components of controllers like sensors and actuators could be expensive, but one has to calculate the savings on energy costs of a certain period or a life cycle of a building or plant. The following tables 3 and 4 show potential savings of energy, and the estimated final energy demand respecting the available energy resources.
Table 3. Potential energy savings. (Source: Green paper on energy efficiency (Directorate-general for Energy and Transport, European Commission, 2005))
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