Solar PV Integrated with Seasonal Thermal Storage and District Heating

Sammanfattning: In order to contribute to reaching the climate goals of the future, power-to-heat (P2H) technologies are a possible solution. A heat pump (HP) or an electric boiler (EB) can be used to produce warm water by utilising cheap electricity from photovoltaic (PV) parks in the summer when there are many hours of sunlight. The warm water can then be stored until winter for use in district heating (DH) when the heat demand is big. This thesis investigates whether this is economically viable and what the most impactful factors are on the business case, as well as which P2H technology and which type of storage is most promising. This is done by designing a model in Microsoft Excel which allows different system configurations to be tested. The investigations show that the pit heat storage seems most suitable for this type of system, and that whether the HP or EB is the best choice depends on the local conditions. It seems like the EB is most suitable for situations where a low number of operating hours are desired, while the HP is better suited for a high number of operating hours. The most sensitive parameters appear to be the heat sales price and storage capital expenditures. The spot price distribution also affects the results a lot, and so the results depend on how much the spot prices will vary in the future and how high they will be. The DH fuel costs are also an important factor, as they determine which heat sales price is acceptable on the market.