Energy conservation potential

Energy conservation is the goal of reducing current energy consumption in the future.It can therefore encompass all types of energy or limit itself to specific energy sources or sources of energy. And it can be understood both globally and related to a particular economy or a single farm or household.

In a narrower sense, energy conservation refers to all measures that are suitable for achieving reduced energy consumption. The goal of energy-saving measures is often to increase energy efficiency, ie the amount of useful energy achieved in relation to the primary energy used. But it can also be aimed at reducing the amount of useful energy needed.

Potential savings by energy sector
Against the background of discussions on energy policy, in addition to technical energy-saving measures, the conscious use of energy and the reduction of consumption by individual measures of each individual are also repeatedly demanded. According to the EU Commission, 90% of all apartments in the EU are not energy-efficient. Insofar there is considerable savings potential.

The actual amount of energy consumed by households, without the consumption of cars in Germany, is about 30% of the total energy. The energy saving potential is regarded as high because the “typical” household technology is often inefficiently constructed for price reasons.

The largest share of individual energy consumption is provided by building heating and water heating (about 25 to 33% of the total German primary energy budget) and electrical energy, one part for lighting energy (about 2% of the total German primary energy consumption), but also a large part for electrical household appliances.

In order to make it easier for the consumer to decide on the purchase process for energy-efficient appliances, the Energy Efficiency Class award has been introduced.

In a study in the UK, the ten most common “energy-saving sins” were found in English households:

71% are running electrical appliances in standby mode,
67% cook more tea water than they need
65% leave unused chargers in the socket,
63% let light burn in empty rooms,
48% also take the car for short distances
44% wash the laundry too hot,
32% run the engine in the stationary car,
32% use clothes dryers instead of clotheslines,
28% heat the empty house,
22% prefer to turn on the heating instead of putting on a sweater

Heat utilization

Heating energy
Today, about 40% of energy in the building sector is consumed in Germany. Of this, around 70% (28% in absolute terms) is accounted for by domestic private energy consumption. Private households consume the most energy for heating or cooling the living space. In Central Europe, heating is the most important factor.

A lot of energy can be saved by a well-planned installation and control of the heating system as well as good thermal insulation of the building.

Many obsolete heaters have only 64% efficiency (scale for efficiency), newer low-temperature heaters up to 94% and modern condensing heaters up to 104% (values related to calorific value). The replacement of an old heating system by a condensing boiler can save up to 40% energy and thus also reduce the emission of carbon dioxide. The renewal of the heating system is one of the energy saving measures, which pays off most economically.

The average age of the heaters in Germany is 17.6 years, more than a third (36%) is even older than 20 years. Over 70% of installed heaters would only reach efficiency class C, D or E. In August 2015, the Federal Government adopted the legal basis for implementing the “National Efficiency Label for Heating Systems”. From 1 January 2016, the new efficiency label will apply to boilers over 15 years old.

In the 1980s, energy wastes were estimated to be around 70% of gross calorific value due to possible heat losses from wood-burning stoves as individual room heaters.

Almost all of the individual ovens installed in rooms (heated with coal, oil, wood or biogenic pellets) use the fuel poorly due to their simple construction – much of the heat generated is lost through the exhaust pipe. Even with cheap fuel, this type of heating is uneconomical. This is especially true for open fireplaces. In 1986, there were 2.6 million tiled stoves, open fireplaces and wood-burning stoves in German households with an annual growth rate of around 10%. Most solid fuel stoves pollute the environment with increased particulate matter emissions.

In a 2003 study on heating optimization, the savings potential for the Federal Republic of Germany was estimated to be between 20,000 and 28,000 GWh per year (for comparison: the Brokdorf nuclear power plant fed 11,360 GWh of electricity into the grid in 2010)), The countermeasures were relatively inexpensive (2003) with costs of € 2 / m² to € 7 / m² living space. A lot of heating energy (and thus heating costs) at low cost can be saved by optimizing the return of radiators. In (central) boilers of modern design can standstill losseswhich can account for up to 50% of the total fuel costs (depending on the age of the heating system and fuel) (see boiler # energy wastage).

Although all electric heaters (eg night storage heaters) convert the electrical energy completely into heating, but since only about 30% of the primary energy can be converted into electricity in thermal power plants, this type of heating is extremely energy efficient and only then energetically appropriate when heating is rarely required or the electrical energy needed for heating comes from renewable energy sources. Ideally, electric storage heaters should recharge when there is an oversupply of, for example, wind or solar power. This will be possible in the future with the help of intelligent electricity meters.

Modern central heating appliances with calorific value utilization (whether for installation in the basement or as a so-called gas boiler) have a relatively high degree of fuel efficiency. This is achieved by cooling the exhaust gases down considerably, thus allowing less heat to escape through the chimney.

Ventilation
In houses with a ventilation system with heat recovery, additional manual ventilation during the heating period always leads to an energy loss. It should be noted that some systems of heat recovery ventilation systems are expected to provide better efficiency, longer life and lower maintenance than others. In particular, the use of electrical energy for the fans should be balanced.

Energy-efficient ventilation requires the attention of residents. In homes without heat recovery, forced ventilation is superior to permanent ventilation in all aspects, both for achieving good indoor air quality and for saving heating energy. All rooms should be exclusively ventilated. Post-installable automatic window closure systems ensure windows that are tilted for ventilation do not stay open too long.

Thermal insulation
A lot of energy is also saved by a good thermal insulation of the building. Examples are the thermal insulation of all external surfaces (walls, floors, roofs, doors and windows). The heat loss through the windows can be reduced, especially by thermal insulation glazing.

In the modernization of buildings, thermal insulation, the use of solar energy and more efficient heating technology (eg heating pumps with classification for the energy label for circulating pumps in heating technology, demand-oriented heating and ventilation) can save up to 90% of the heating energy originally required. In recent years, thermal insulation measures have been mandatory in many countries for many years. In the renovation of facades of old buildings can also perform thermal insulation measures. If the facade is not to be changed, there are now a number of proven insulation systems that are suitable for insulation on the inside of the outer walls. In the private sector here are mainly natural materials such asHolzfaserdämmplatten, as they are capable of capillary and sorptive on the wall surfaces forward where it evaporates capillary and sorptive accumulating during the internal insulation.
The insulation of top floors or the roof is mandatory in the German Energy Saving Ordinance as an immediate measure for all buildings.

Essential, however, is a perfect airtightness of the closed building. Even low drafts can carry significantly more heat from the building than the heat conduction through the outer surfaces. At the same time, the drafts caused by conventional kitchen extractor hoods, unused stoves and badly closing attic doors should not be neglected.

The thermal insulation in the industrial environment above 700 ° C takes place by means of high temperature wool. Compared with traditional thermal insulation materials such as light-weight bricks (calcium silicate and microporous materials), heavy bricks (firebricks and earth masses) and fire concrete, high-temperature wool (HTW) as a thermal insulation material can lead to energy savings in many heating processes:

in the production and processing of steel and non-ferrous metals.
in industrial furnace, furnace and heating construction
in the automotive industry, especially in the hot end area of exhaust systems, as storage mats for catalytic converters and diesel particulate filters
in the ceramic and porcelain industry
in the hot gas filtration
but also in the household appliance technology (for example, thermal insulation of ceramic hobs, microwave ovens and ovens).
In some areas, energy savings of up to 50% are possible compared to conventional stone / concrete infeeds. Industrial furnaces and plants with HTW thermal insulation are to be heated up and cooled faster due to lower heat capacities. As a result, energy consumption is reduced, especially in the case of discontinuous processes.

A simple means of saving energy is to close the shutters in the dark. The air between window and roller shutter acts as additional heat insulation.

Hot water use
Second in the energy consumption of a household is the water heating.

As with space heating, there are the three paths

Reduction of consumption
more efficient deployment
Recovery of heat energy

Reduction of consumption
The highest hot water consumption in the household arises from the body care (bathing, showers). A shower requires depending on the duration of about 40 to 75 liters of hot water, a bath 160 liters on average, that is about three times (the heat but can help by cooling to space heating, which is barely practiced when showering with the water in the shower tray). In water-saving showerheads, the exit velocity of the water jet is significantly increased, creating a feeling of a richer jet despite reducing the flow rate. Savings of up to 50% are possible. Ultimately, however, the behavior of users is also crucial here.

More efficient deployment
In general, the generation of hot water via electric power is to be avoided, because the primary energy consumption in the production (and transport) of this electricity is about three times as high as the useful energy.

According to this principle, washing machines are designed that take their hot water from the hot water network instead of heating it purely electrically. Also, the connection of the dishwasher to the hot water network could be useful.

The losses in the hot water tank of a central hot water system can be reduced by a better insulation and a lowering of the storage tank temperature.

60 ° C must not be permanently fallen below, otherwise there is a danger of the propagation of dangerous Legionella. These bacteria can cause pneumonia or flu-like illnesses (Legionnaire’s disease, Pontiac fever). Alternatively, a can Legionella circuit are used that these highly heated at boiler temperatures