Performance evaluation of domestic solar power installations in Sweden

Sammanfattning: In the past two decades the global electricity demand all over the world has increased by 82%, thisis a result of improved living standards, growing populations, electrification of vehicles and growing demand for digital devices. In Sweden, electricity generation from solar power is relatively small and equates to about 0.79% of the total electricity demand. The combined installed capacity in 2020 was 1109 MWp, with 86% of these installations being residential. Even though the share is small, the industry has seen a massive increase in the past couple of years. Simultaneous with the increase there has also been a growing a amount of sales companies. This thesis was performed to identify and quantify the techno-economic performance gap of Swedish PV systems. Where inconsistencies in PV installation company assumptions was evaluatedand studied. This was performed by answering the following research questions: 1. How are the systems performing in comparison to their expected energy yield (kWh/kWp)? 2. The impact of the feed-in subsidy and electricity price in economic profitability of a solarsystem? 3. Has the customer been monitoring their system to see whether it is performing as predicted? 4. How was the modelling was conducted for individual systems? 5. What was the customer incentive in choosing a certain system?  Conclusively it can be said that the systems are only performing as expected during the more sunny years. Whilst when the weather represents a more historically average year, the production is on average 12.89% less than expected. It was also proven that the feed-in subsidy was paramount in the profitability of the system, making this assumption more worth while to emphasize in proposals to customers. The system owners were also generally very content and happy with the installation company. It can also be concluded that a majority of the system owners regularly look at their production even though it’s been almost three years since they had their system installed. The final question that was to be answered in this study was whether the customer knew how the modelling for their system had been conducted. Most people said that they felt that it had been optimized for their prerequisites. Looking more closely into the system sizes, it could be seen that many of the systems had the capacity of covering their annual electricity consumption demand. This does not mean the system owner knew how the modelling was conducted, rather they had trust in the company and potentially banking onthe premise of the feed-in subsidy remaining for 30 years, hence being a lucrative investment.