This paper deals with the interaction between different types of building energy retrofits. The means for finding this interaction has been via the OPERA model, which is used for energy retrofit optimization. The solution is an optimum when the total life-cycle cost, LCC, for the building, i.e....

Time-of-use tariffs, which reflect the cost of producing one extra unit of electricity, will be more common in the future. In Sweden the electricity unit price will be high during the winter and cheaper during the summer. A bivalent heating system, where an oil-fired boiler takes care of the...

Nowadays, when powerful computers are on almost every one's desk, it has become more and more common to use complex energy-system models in order to predict the use of electricity and heat in buildings. At the same time, it has been harder to grasp the overall solution because of all the details...

When a building is refurbished, energy conservation measures might be profitable to implement. The profitability depends, among other things, on the electricity and district-heating tariffs, the unit price for oil, etc. The cost for the retrofit is of course also important as well as the...

New office buildings in Sweden are thoroughly insulated due to the Swedish building code. This code, however, does not consider the type of activity occurring in the building. This means that the heating equipment is designed as if no activity at all is going on. In modern offices there is a lot...

This paper describes the district heating and electricity load of Kalmar, Sweden. Unfortunately, it has not been possible to examine one full year because the monitoring of the energy use for district heating and electricity, and the outdoor temperature, did not exactly overlap. However, more...

In recent years it has been more common to use linear or mixed-integer programming methods for finding optimal solutions to the complicated operating options in modern Combined Heat and Power (CHP) networks. Electricity may be bought from the national grid or it may be produced in ordinary...