I chose energy efficiency as the topic of this thesis, especially the efficient energy use of large customers. The extraction of energy carriers and consumer prices are increasing and therefore the efficient use of energy plays an important role. Two areas of energy consumption are studied, electricity and heating energy use.
Electricity is produced by power plants, where the primary energy source is converted in several steps to electricity, and then the transmission and distribution networks transfer it to the consumer. The consumer has to pay for the delivered and consumed energy. The price of electricity consists of several parts. The most important is the market purchase price, which depends on the service provider, and system usage, which is determined by regulation.
There are several ways to reduce energy consumption.
One of these is the LED technology, which is an increasingly important field of the interior lighting technology of buildings.
Another important aspect is to consume energy with better power factor. At large comsumers as factories, restaurants, department stores, it is important to compensate reactive power, because above certain limits a penalty must be paid to the provider. The compensation can be performed in several ways depending on the installed device, and the installation site as well. At the compensation we should also take into account the harmonic relations, which also cause many problems in the networks.
Nowadays the most common method of heating is boilers, and the most common is the gas boiler, which also exists in several versions. The rapid growth of the price of the used energy source (natural gas) increased the importance to improve efficiency and to replace the natural gas with another energy source. We can improve the efficiency of existing systems to install flue gas heat exchangers, and we can replace natural gas if we install a universal oil burner that allows burn almost any kind.
A cost-effective method for heating and cooling is the application of heat pumps, which will also be analyzed.
During the case studies, at Alcoa-Köfém I studied and modeled the reactive power compensation. The other study, which was an energy survey of a fast food restaurant, more cost-cutting methods have been identified, and investment return calculations are made too.