Large number of block of flats are today often connected to municipal district heating grids. Such systems became very popular in Sweden some fifty years ago. The reason for this was that cheap low-quality oil was abundant on the energy market but normal building owners could not use it in their...

In accordance with a public referendum held in 1980, Sweden will phase out nuclear power completely by 2010. One way to compensate for an immediate, appreciable scarcity of electric power is to construct new fossil-fuel power stations. Another is to reduce the burden on electric power by...

Mathematical models are extensively used in energy analysis and have increased in scope as better and faster computers have become available. With complicated systems, it is difficult to predict accurate results if doubtful input data are changed. Traditionally, sensitivity analysis with a...

We describe a mathematical model of a linear program for optimization of the following: the use of purchased and produced electricity (for power and for heat), the fuel mix in a district-heating plant, and implementation of energy-conservation measures in the building stock of the Malmö...

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...