Efficient energy use

Energy efficiency is a measure of the energy required to achieve a specified benefit. In contrast to the efficiency of energy use needs no definition here. A process is efficient if a particular benefit is achieved with minimum energy expenditure. This corresponds to the economic principle (namely the minimum principle ).

An increase in energy efficiency usually results in an economy to energy savings. However, the efficient product can stimulate to increased demand. If the price elasticity of demand is high, it may come to the rebound effect (see Jevons ' paradox). Example: 10% greater efficiency → 10% → 11% lower energy prices higher demand → no energy savings. Usually, the price elasticity of demand is low.

Rising energy prices (oil price, gas price, electricity price, coal price, price for firewood, wood pellets and others) increase for every agent the incentive ( possibly also pressure or compulsion) to reduce its energy consumption. This often leads to an increase in energy efficiency - most if he does so maximizing utility (homo economicus ).

Standards and legislation

With the EC Directive 2002/91/EC Energy Performance of Buildings Directive (EPBD ), the term energy efficiency came (Energy Performance) in the common German usage.

This directive was transposed into German law with the Energy Conservation Act ( EnEG ) and, based on this, with the Energy Saving Ordinance ( Energy Saving Ordinance ), which in § 20 performs the improvement of the energy characteristics for improved energy efficiency. Here, the final energy demand is the measure of energy efficiency. Differences, the overall energy efficiency, in addition to the final energy demand nor the upstream chain (exploration, production, distribution, conversion ) is taken into account the energy used in each case (eg oil, gas, power, renewable energy, etc.). Based on the pre-standard DIN V 18599 Energy performance of buildings energy efficiency can be determined and documented in the Energy Performance Certificate.

The EC Directive 2006/32/EC Energy Service Directive ( ESD) enhthält indicative targets and ensures development of a market for energy services and for the delivery of other energy efficiency measures at the end user. This Directive has now been superseded by the Energy Efficiency Directive 2012/27/EU of 25 October 2012, which prescribes, among others, mandatory energy savings.


Many industrial processes require large amounts of heat and mechanical energy, these are provided for the most part by means of fuel, and electricity. In some areas ( eg cement production ) so-called secondary fuels will used. Due to the variety of industrial processes, there are numerous ways to increase efficiency. Often these are specially adapted processes and technologies.

Conventional power generation by steam power plants, where the heat produced is released as waste heat, typically converts more than 30 % to at best 60 % ( combined cycle ) to the energy used in electricity. By combined use of electricity (combined heat and power) combined efficiencies of over 90 % can be achieved.

Improved boiler and burner can operate at higher temperatures and at the same time burn less fuel. This makes them more efficient at lower pollutant emissions. Conversely, combustion temperature can be lowered for example by use of suitable catalysts and porous burners, whereby the formation of nitrogen oxides is reduced and thereby the power consumed for the reaction enthalpies of considerable heat energy may be saved and the energy efficiency increases.

Of the fuels that burn American industrial companies that serve (as of about 2005) about 45% to produce steam. The typical operation can reduce by 20 % the energy required for this purpose, according to a fact sheet of the Washington Environmental and Energy Study Institute, by thermally insulates the pipes for steam and condensate leaks closes in the steam lines and steam traps used.

Many electric motors run at constant speed, but with an electronic speed control, the power output of the engine can be adapted to the current load. Thus, depending on the type of engine use, reductions of 3 to 60 % can be achieved.

The industry uses a variety of pumps and compressors. Their efficiency depends on several factors; often can be improved through better process control and improved maintenance efficiency. Compressors are typically used to generate compressed air for tools, sandblasting, spraying equipment, and more. The energy efficiency of compressed air systems can be improved by 20 to 50 % by installing speed controller and preventive maintenance will leak and seals.

The German Initiative for Energy Efficiency ( DENEFF ) has introduced the first industry report energy efficiency in May 2013. She has to examine market structures, figures and trends in the energy efficiency industry. The market for energy efficiency generated accordingly in 2012 a total turnover of 146 billion euros. This is in comparison to the previous year, an increase of 16 percent. The number of employees increased during the same period by 10 percent to extrapolate about 800,000 employees. The report is based on a survey of 63 companies from various fields like engineering, building energy consulting, building materials, banks and home appliances, as well as on existing studies and statistics. So far lacked such a comprehensive overview of market data, trends and sentiments among companies whose business is the saving of energy.


Improved energy efficiency is one of the possible methods to save energy. Energy saving is the broader term, because it still includes other measures that reduce energy consumption, such as changes in behavior. For example, it is also possible without improved efficiency to save energy by heating a room less in winter or less travel by car.

The energy consumption of the world can be reduced through improved energy efficiency in buildings, transport and industrial processes in 2050 by 17 to 33% according to a study by the International Energy Agency ( IEA).

In Germany, according to a study by the German Initiative for Energy Efficiency ( DENEFF ) through efficiency measures by 2020 the annual power consumption can be reduced by 68.3 billion kilowatt hours, which is about the power of ten nuclear power plants.

A study of forecasters and the Institute of Power Systems and Energy Aachen ( IAEW ) comes to the conclusion that the energy transition to 2035 by several billion euros can be made more effective if the incentives for electricity savings would be strengthened. A reduction in power consumption by 10 to 35 percent compared to the planned development reduces the costs in 2035 by 10 to 20 billion euros. This could be the electricity bill significantly reduced, also the need for expansion in the high-voltage grid would ever increasing efficiency decrease by 2050 of about 8500 kilometers on 1750-5000 kilometers.

In September 2013 21 experts called the policy of halving waste of energy. " Without a new energy-saving policy, the energy transition would be more expensive, slower and more difficult to be " because ". , The lower the energy demand, the lower the need for new generation, grid and storage " To be known for years that Germany more than 60 percent economically and sustainably conserve the energy consumption would be more than half of them alone. during the next 20 years In order to limit the cost of the energy transition to a reasonable level, the authors therefore urge an integrated energy efficiency policies for a balanced " energy balance ", in which the development of a sustainable supply structure with the reduction of energy demand go hand in hand.

Efficiency promotion in Switzerland

As a counter-proposal to a popular initiative for the nuclear phase following constitutional provision was introduced in Switzerland already in the 1980s (Article 89, paragraph 3): " The Confederation shall legislate on the energy consumption of equipment, vehicles and equipment. It promotes the development of energy technologies, particularly in the area of energy conservation. " The determination has as yet only sporadically implemented.

This directive was conveyed to the cantons in the Energy Act of 1998 ( EnG, Article 9, Section 1 ) " The cantons provide in their legislation favorable conditions for the economical and rational use of energy and renewable energy. "