The impact of climate change on the cost-optimal electricity system composition in Sweden
Examensarbete för masterexamen
Sustainable energy systems (MPSES), MSc
Climate change has an impact on both the supply and demand of the electricity system. Amongst the affected areas are both electricity demand for temperature control and hydropower. The aim of this thesis is to support the understanding how the climate change impact on these two areas will impact the cost-optimal electricity system composition in a subregion of Sweden. There is a large spread on reported magnitude of the climate change impact on the two areas depending on the utilised climate model, studied climate scenario, studied years, and used hydrological model. With a temperature increase of about 2°C, a maximum increase of yearly hydropower potential in Sweden of 20% is reported. The hydro inflow will be more spread out across the whole year with a lower, and earlier, spring flood. Electricity demand for temperature control during wintertime can decrease by 15% and increase by 70% during summertime. The absolute decrease in electricity demand wintertime is larger than the absolute increase during summertime. Both the change in electricity demand and hydropower reduce the strain on the electricity system during wintertime, either by reducing the demand or introducing more available hydropower during the winter season. At the same time, the strain during summertime is increased as demand is increased, and available hydropower is reduced. While wintertime remains the dimensioning season in terms of generation capacity and energy required, the reduction in strain of the electricity system in wintertime does impact the cost-optimal composition. The change in electricity demand and hydropower production is investigated separately as well as in combination. The largest change in the cost-optimal composition is seen when both the electricity demand and the hydropower changes simultaneously, where a greater change in the two areas bring a larger change in the cost-optimal composition. For the case with the highest climate change impact, the installed capacity of offshore wind, which offers great amount of energy and generation capacity wintertime, is reduced by up to 15.4% while the installed capacity of solar power increases by up to 37.7%. With impacts on this scale, it is important to take climate change impact on hydropower and electricity demand for temperature control into consideration when planning future electricity systems.