A problem in the field of district heating is the oil burners needed to provide power when a peak load occurs. One possible way of reducing the needed amount of oil is to reduce the power demand for space heating in the district-heating substations when the need for district heating water exceeds a certain limit. This can be done by use of a locally working controller function. In this Thesis the options concerning load priority are evaluated. To evaluate the potential for using controller functions concerning peak load priority an experiment was brought out in a chosen district-heating substation. The impact on the indoor thermal comfort during a heat reduction was also taken into account. With simulations and mathematical models the building and the indoor air cool down was evaluated. Also a survey was given to the residents to validate how the indoor thermal climate was affected during the experiment. Possible savings by using these kinds of functions were also accounted for. The result demonstrates that a simple controller function provides a possible way of reducing the power demand, but is not sufficiently reliable. This is mainly due to the used regulating parameter. With modifications or by adding additional regulating parameters such as water flow into the controller, the functionality can be improved. The result from the survey shows that during the experimental period the residents experienced a minor impact on the thermal comfort. Parameters, such as ventilation and heat losses also have a major impact on the building´s thermal inertia, especially at the lowest occurring outdoor temperatures. The simulations confirm the theory regarding the building heat capacity to prevent a negative impact on indoor thermal comfort. In addition, the indoor air temperature can initially decrease faster than the building framework, especially under the influence of ventilation. This must be taken into account when applying functions for load priority. Calculations indicate that the economical benefits by adapting functions for load priority are primarily for the heat-producer, due to reduced oil dependence and also other system aspects. The current ownership structure in Uppsala provides for a possible obstacle when it comes to expanded use of load priority functions. More incentives for the consumer are needed to provide for an increased usage of load priority functions in their district-heating substations.

Issues related to global warming and weather changes have forced people start to pay attention to energy saving. We expect that Smart Home Energy Management (SHEM) would be an important development over the next decade. In some environments cost is important, in other environments living quality is important and in other environments a tradeoff between cost and living quality is important. SHEM means being able to manage electrical loads so as to meet different purposes in homes. In this thesis, we develop a SHEM to curtail some electrical loads at peak time to meet predefined circuit level demand limits while minimizing the effect on users¡¦ living quality. The core of our SHEM is an electrical control loop which is developed based on heuristic modifications through lots of case studies and trials. To this end, we study several utilization characteristics of household loads including air conditioning, water heaters clothes dryers, and electric vehicles and model their behaviors through computer simulations. Finally, we implement the whole ideal of our SHEM in LabVIEW (Laboratory Virtual Instrument Engineering Workbench). Several simulations are conducted to verify the robustness and efficiency of our SHEM. keyword : Quick Charge,Load Priority,Convience Preference,Severity Indices,Duration Indices.