Hot water tank application in domestic heating system which use electricity as energy source – dimensioning and economic benefits

Abstract

There are many households in Serbia, which use electricity as energy source for heating. Many of them have a classical central heating system with hot water boiler and radiators, but without a heat storage tank. Such systems use electricity during all day, which is very expensive, due to the price of electricity which depend on period of the day. In Serbia, there are two tariffs, daily tariff which lasts from 8 to 24 h and nightly tariff which lasts from 24 to 8 h. In average, nightly tariff is nearly four times cheaper than daily tariff. In this paper several types of heating systems with heat storage tank are presented. Furthermore, a methodology for dimensioning of heat storage tank volume is given. In addition, the basic techno-economical analysis is done, with the aim to prove economical benefits, taking into account present electricity price and rising electricity price trend in the future. The analysis considers a model house behaviour during a typical meteorological year. The price of investment is also calculated, together with the savings which could be achieved using the presented system and finally a simple payback period.