Global energy system is a source of serious threats to human welfare because of the widespread use of fossil fuels and nuclear energy, because of scarcity of natural energy resources. Long-term energy security to a large extent depends on a balanced energy production and consumption. Energy security is a multidimensional concept that includes both external and internal actions and players. This is more than sustainable, competitive and safe consumption, supply and transportation. Due to the fact that governments and corporations have focused their resources and development strategy for fossil fuels and nuclear power, the transformation of the global economy in a healthy, safe and sustainable energy system will not be easy.
The significance of this theme is without any doubts, because the world is currently facing with the interrelated challenges, such as energy poverty, environmental degradation and economic decline. Thus, the most important factor of successful economic development is sustainable development, which means such energy consumption to meet the needs of the present, and also to ensure such ability in future. In the energy sector must be balanced the needs of different users: from industries and agriculture to residential and public works. In order to plan a sustainable energy in future, a special energy-saving measures and monitoring should be designed.
This work is devoted to an approach to achieve active energy saving, that can be used in new and existing buildings: commercial, industrial, private, public and residential buildings.
How to achieve sustainable energy through active energy saving
Today there is no doubt that energy saving is important for people, but nevertheless, there is no complete understanding of what actually forms this concept and how it is possible to implement initiatives to conserve energy. Given this, some companies have formulated two approaches to providing energy saving: Passive Energy Efficiency and Active Energy Efficiency. Active saving is defined as achieving sustainable change through measurement, monitoring and managing energy use. Under the passive energy saving is understood the implementation of measures against heat loss, installation of equipment with low power consumption, etc. (Directorate-General for Energy)
The use of cost-effective equipment and devices (for example, lighting) with low power consumption is vital, but not sufficient enough. Without proper management, these measures often simply imitate the struggle with loss of energy, but do not provide a real reduction in energy consumption or changing ways of using energy. If we want to achieve a sustainable economy for all energy consuming devices, it is necessary to introduce an active energy conservation. It also implies to changing the culture and mentality of people and groups, and as a consequence, changing their behavior at work and at home. Nevertheless, greater use of technical controls makes this need less acute. (UNDESA 2001)
For many people the problem of energy consumption is reduced to the heat losses in building materials, and can be solved by such means as insulation, glazing and the removal of heat loss. For others it is problems of lighting, though often they are limited to just installing the systems with low power consumption. People who spent a lot of energy for heating can solve the problem by installation of efficient water heaters. All these measures are necessary and should be encouraged, but in fact they represent only a passive counter-measures, which mainly restrict energy loss without affecting its distribution. Though to ensure the active energy-saving, people must not only establish a cost-effective device, but also to control them, using only the necessary amount of energy. That factor of management is critical to achieving maximum efficiency in sustainable energy. (InterAcademy Council, 2007)
To ensure a permanent change, it is necessary to manage the use of energy by means of monitoring and managements. Moreover, compared with the cost of introducing thermal solutions (and the technical skills necessary to prevent risks), the energy control and management measures can be deployed with reasonable cost and get a very quick return. This is particularly true due to the rapidly rising energy prices, and most of the solutions for energy management can be recouped within a few years. (UNDESA 2001)
Another very important factor, which in the future should promote the active energy conservation, is the need to implement ambitious targets for reducing carbon dioxide emissions, set by Governments in accordance with the Kyoto Protocol. This is due to the aspects of energy use and its impact on the environment. Greenhouse gas emissions are in the spotlight around the world, and it is time for everyone to take steps to save energy through effective use of technology to provide an active energy conservation. For example, in relation to buildings, it is clear that the 2020 goals can not be achieved if not to ensure energy efficiency of existing buildings and all new constructions. At the European level has been introduced the Directive on the energy efficiency of buildings. It requires to assign all the buildings (including residential), energy rating similar to the one currently used for home appliances, and post information about such a rating in public places or buildings (residential buildings) in the documentation for the building. The governments of some EU countries hope that this law will help reduce energy consumption by an average of 25%. (European commission)
Speaking about buildings nowadays there is an opportunity to control technology energy consumption in buildings for lighting, heating, ventilation, air conditioning, building management and distribution. Only one light can take up to 40% of electricity consumption in a typical business organization. Large increase in energy consumption in offices is also associated with rapid development of information technology and the popularity of air conditioning systems. Wide dissemination of data centers and the emergence of new industries have also contributed to the sharp rise in energy consumption.
In short, there is no reason that would prevent the active saving of electricity and other forms of energy, it is necessary only to understand the importance of the problem and to do something to fix it. As according to the latest projections of Enerdata, the energy consumption in the world will grow by 2020 to 30%. (European commission)
It is obvious that if not to take steps to save energy, its consumption in the coming decades will grow. This is especially true for third world countries and countries with emerging economies, where is used more and more new electrical equipment, and much of the population of certain regions is getting access to electricity.
Active energy conservation in buildings
One of the variants of energy control and saving provide modern intelligent systems for measuring energy: they provide vital information on energy consumption of the building , and can help to identify areas of possible energy saving. Naturally, investment in systems that reduce energy consumption help to reduce operating costs. Smart building management systems allow to anticipate problems and plan ahead; also it is possible to use one system to monitor the use of gas, electricity, water, air and steam. Thus, intelligent control systems and active energy saving can be deployed with minimal investment and without any damage. The result is an attractive building, which provide people with comfort, convenience, functionality and efficiency, but at the same time offering long-term energy cost savings. (wbcsd.org)
Residential buildings are rarely used for precise measurement and monitoring of energy. Nevertheless, in them it is also possible to use technologies of active energy saving. Earlier in the residential sector the focus was made on the installation of passive energy conservation: thermal insulation of hollow walls and attics, double glazing and the damper is often found in both new and existing houses.
It is possible to give recommendation and options to energy saving in building:
1. Construction of buildings
The energy of building as a single enclosed volume is of fundamental importance, given the very long lifetime of buildings. Construction design should take into account all types of climatic conditions during the year, its quality directly affects the results of the implementation of many energy-saving technologies. For example, the benefits of the improved heating system will be lost if the heat will not be stored in the building. The more severe climatic conditions, the more important will be the roof, walls, windows, doors and foundations. This is true for both hot and for cold climates, as air conditioners are becoming commonplace in residential and commercial premises. (Environmental and Energy Study Institute)
There is a wide range of measures aimed at improving energy use of buildings and constructions. The costs of implementing them differ depending on the measures, type of buildings, individual conditions and circumstances of the improvements. In general, it is much more economical to improve the efficiency of buildings during their construction and not for their modernization. In carrying out modernization costs will generally be lower if the activities are carried out to improve the efficiency by replacing obsolete equipment. Payback period of improvement of buildings can be between one year and less to 20 years and over. Due to the long period of exploitation of buildings and their equipment their improvement, even with long payback periods, can be economically attractive. (Environmental and Energy Study Institute)
In many cases, the costs of improving the design of buildings will be lower per kilowatt-hour saved, than the cost of kilowatt-hours using conventional heating or cooling. For owners of buildings such kind of savings is beneficial, even in the short term. But as a rule, the economy requires substantial investment at the initial stage, whereas the effect would be achieved in subsequent years. This leads to the need for funding. Modernization of the high-rise residential buildings to improve energy efficiency at the stage of conversion can lead to significant energy savings at negative cost (savings of more costly). Return on modernization of individual houses and small terraced houses are usually lower. (wbcsd.org)
The question of energy efficiency in building construction is not simple, it includes standards insulation, windows, heating systems, cooling systems, lighting and other domestic energy consumers, as well as the interaction of all these systems. Energy efficiency is not usually a priority in the new buildings. There is a need to develop a holistic approach, but it is often not applied, as to coordinate the activities of architects, consultants and builders is very difficult. Buildings are objects with a very long life, and their use for the comfort change over time. But, for example, people are always aware of the need to improve insulation in existing buildings, despite the fact that an optimum level of insulation of buildings may have advantages in both cold and hot climate (in this case the demand for cooling is largely reduced). However, the conversion of many buildings is very difficult structural problem, which increases the cost of additional insulation. Poor quality insulation or the installation of its components may cause problems with humidity levels, which complicates the assessment of the savings due to changes in the level of comfort. (wbcsd.org)
There are many options for economic regulation, but strict technical standards are probably the most effective. Building codes should require the optimum level of insulation, installation of doors and windows for a particular climate, taking into account the costs over the period of exploitation of buildings. Such regulations should be designed for both new and existing buildings, and at the same time standards should be regularly edited to reflect new technologies, energy costs and climate trends. The standards may include gradual increase of requirements to reduce energy consumption over time. There is a need of a deep understanding of the world’s best samples of building and exploitation. People need to know how specially improved windows, doors and isolation facilities could reduce energy consumption and costs, and also bring other benefits from the fact that the building will be warmer and more dry in terms of insulation. (Environmental and Energy Study Institute)
2. Technologies of heating and cooling
These technologies encompass a wide range of activities: from conventional heating with oil, gas or electricity to heat pumps, thermal batteries and air conditioning systems. The potential of new technologies of heating and cooling is very high compared to previous, for example replacing old, inefficient boiler can reduce overall consumption of energy by 30-35%. Electric heat pumps typically consume a quarter to half of the electricity consumed by conventional (resistive)electric heater, that is why they can reduce energy consumption by 50% compared to boilers with fossil fuels. The least effective portable air conditioners can have efficiency less than 1.5 W / W (cooling capacity per unit of energy), while the most efficient room split systems has more than 6,5 W / W. Further energy savings with room and central air-conditioning systems can be achieved by optimizing their efficiency at partial loads by various regulators of the compressors.( wbcsd.org)
Major improvements in energy efficiency can be achieved at low cost if to select the most effective options of heating and cooling technologies during exploitation of the equipment. Replacing old inefficient boilers can be profitable certain circumstances, but it’s more expensive option. In Europe, the cost of installing a heat pump is about 5,000 euros, although they can be 2-3 times more efficient than conventional electric heaters. In colder climates, heat pumps can provide significant savings throughout the life cycle. Through the use of more efficient heating technologies can be achieved savings in between 0,025 dollar / kWh for new buildings in cold climates, and up to 0,02 USD / kWh for renovation of the building. The most efficient cooling systems have the potential for significant energy savings at low cost, since more efficient system, despite the higher initial cost, requires less costs during the period of operation. (www.energysavers.gov; wbcsd.org)
Speaking about the obstacles in the installation and use of this option of energy saving, for heating the initial cost of installing of more efficient systems is a major obstacle. At the same time improving the control systems is very important and has considerable potential for energy saving, especially when using more efficient heating appliances. Another important aspect is installation of the technologies, as for thermal batteries the barrier is the lack of consumer confidence in this technology. Since in the market there are a large number of air conditioning systems, there is a lack of understanding among people of what technology is better to use in a particular situation. (Wilson 1993)
Thus, strict standards for heat preservation for new buildings and major reconstruction of the old can contribute to the introduction of more efficient technologies for heating and cooling. For example, new building codes should include the installation of more efficient boilers. Such steps require special training and certification of many assembly companies, for that such tightening does not turn into a problem. Development of the better systems of control of heating, along with measures to stimulate their introduction, may be of great value. (wbcsd.org)
As for thermal batteries, in most countries it is a new technology and it wide use will require further research. Demonstration of the new projects, support of the studies and international cooperation are important measures in this case. As for the air conditioning systems it is important to provide more complete information on appropriate technology for specific purposes. The best of existing technologies are still not widely spread in the market. More complete information is particularly important in the design stage of public and commercial buildings. Tough energy standards and labeling are very important for mass production of air conditioners.
3. Centralized heating and cooling systems
Centralized heating has the potential to reduce CO2 emissions. In countries with economies in transition, there are great opportunities to increase the effectiveness of existing district heating systems, but the reduction in CO2 emissions as a result of the expansion of such systems is not great. (www.iso.org)
There are a number of low-cost options to improve the effectiveness of existing district heating systems in countries with economies in transition. Many of these systems do not reach the performance indicators that demonstrate similar systems in OECD countries. Improving the design and operation of systems, replacement of inefficient or ineffective insulation of pipes, improving the distribution systems of buildings can lead to significant energy savings. Improvement of heat supply systems in transition countries may reduce or make lower the costs of CO2 emissions reducing.
Capital expenditures during the construction of new centralized heating systems are the major obstacles. The combined heat and power stations (CHP) can produce heat for district heating. However, the sale of electricity generated is not an easy process, despite the fact that the CHP has advantages in reducing CO2 emissions. The economic value of the program in general may depend on the sale of electricity generated in the network.
In most cases all of these technologies are commercial and were introduced decades ago in many countries. Nevertheless, district heating must be considered as an important variant of the new urban construction. More stringent environmental regulation, a better legal regime and more complete information could facilitate this process. District heating should be provided in a climate in which cooling and then the district heating system can bring benefits throughout the year.
In general, the systems and the use of thermal batteries for the centralized heating and cooling nowadays require further technical improvements. There is a need in more research on the application of district heating in areas with low heat demand and optimization of the size of the networks.
4. Systems of energy management
Energy management systems have already been used for a long time, but the development of control technologies, improved sensors, the use of computers and telemetry systems have changed the approach to building management. Nowadays there is a possibility to centralized management of security systems, air conditioning, lighting and ventilation. As technologies are improving , an increasing number of appliances can be managed through a variety of energy management systems. In addition to reducing energy consumption and CO2 emissions, such systems allow companies to manage the energy supply during peak periods. (Energy management and control systems, 2010)
To date the benefits of using an integrated approach, or that such technologies can already be used to create complex systems, building management and energy supply are not well known. In many buildings, especially in individual and multi-family homes, the control system is limited to room thermostats, and information about the possibilities of energy savings, which provide more sophisticated systems, is not available. In many cases, there is no convenient system of sales and installation service of such systems. Overcoming of these obstacles include various options for news programs (including the world’s best examples), which are important for targeting the audience, including the private sector and commercial buildings. Regular updates in the building codes are designed to encourage architects and builders to use all available opportunities for energy savings and energy management systems in buildings. This will lead to increased use of management systems and reduction in CO2 emissions at low cost. (Energy management and control systems, 2010)
In conclusion it is necessary to say that the technology, design and technical maintenance of buildings, economic policy with regard to product quality, incentive schemes based on measurement of energy consumption and many other mechanisms may help promote and create a market for energy-efficient solutions. There is a need to develop and promote new advantages of efficient technologies to achieve maximum efficiency in sustainable energy.
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