Capacity factor

Efficiency is generally the ratio of the actually achievable and the maximum possible value of a reference variable, eg areas or machine utilization. See also use ( technology).

Most commonly it is used as a technical term for energy efficiency. The efficiency of a power plant or a device consists in a certain time, energy harnessed for energy fed into the relationship. In the periods under pause, idle, start-up and shut-down may be included. It can also be formed an exergetic efficiency as the ratio of usable made ​​Exergy and exergy supplied.

Heating

The efficiency of a boiler is the heat, based on the supplied fuel with the heat energy available during a year become. The utilization ratio is determined according to DIN 4702 T8 and specified in the device documents the manufacturer as a standard efficiency, which is estimated at gas condensing boilers up to 111 %, since reference is made to the lower calorific value, condensing boilers but also in the flue gas latent heat here can use the heat of the water vapor. ( The reason for this relative to the lower calorific value by the device manufacturer is probably the use of the same by the gas supplier. The price of gas is calculated by the supplier for the kilowatt hour. Conversion of the amount of gas supplied in the size of kilowatt hours is done by using a formula, in accordance with the factor condensing the net calorific value estimated, although this does not consider the total energy contained in the gas. )

Standard efficiency

The standard efficiency is determined according to DIN 4702 Part 8 and contains, among other tests at 5 typical power levels to reflect a realistic efficiency of the heat generator (boiler, central heating ). It is calculated on the test benches of the manufacturers.

Annual efficiency

The supplied heating energy is from the actual amount of fuel consumed is determined ( gas meter, oil meter ). Reduced by flue gas loss, boiler loss, downtime losses, losses of hot water storage tanks and distribution losses results in the actual usable heat energy. This important parameter can only be measured with heat meters and is therefore rarely known.

Measured over a year and divided by the amount of energy contained in the fuel, there is the annual efficiency of the system. This can, based on the higher heating value, with good equipment amounted to 90 %, ie 10 % of the energy contained in the fuel can not be used.

A " standard efficiency " of 85 %, an actual annual efficiency faced by only 30%. Especially in summer, the deployment of a common heating system losses are relatively high. Thus, without further 30-50 % of the fuel requirements apply only to the operation of the plant (see boiler # wasting energy ).

CHP plants

With power generation facilities with combined heat and power generation is called with efficiency or overall efficiency, the ratio of the total energy used tax ( sum of electricity and heat ) to the use of energy, in contrast to the ( electrical ) efficiency, in which only the current output is taken into account. Since the utilization rate is also determined by the heat demand and thus can vary greatly seasonally, the annual utilization rate is used for the valuation of investments in general. Typical values ​​of plant and equipment where the heat can be used all year round useful lie, at 85-90 %, but in older or not properly adjusted assets and values ​​of only 50-60 % are possible.

Spring

For springs, the utilization ratio is the ratio of the real to the ideal energy absorption capability of a spring. A distinction is made in Artnutzungsgrad (? A ), volume (? V ) and weight efficiency ( ηQ ).