Study: Climate change may boost Swedish PV generation by 5%

A new study suggests that climate change could increase solar power output in Sweden by approximately 5% over the 21st century. The research was conducted by scientists from KTH Royal Institute of Technology, the Swedish Meteorological and Hydrological Institute, and Zhejiang University of Technology. Corresponding author Wujun Wang noted that this projected rise implies global warming might be positive for photovoltaic generation in the region.

Methodology and Scope

The study examined solar potential across four Swedish locations: Malmö, Gothenburg, Stockholm, and Kiruna. Researchers established a historical baseline using data from 1951 to 2014, then projected changes over the full period from 1951 to 2100. To account for varying future climate trajectories, the analysis utilized two distinct scenarios: SSP1-2.6, representing a low-emissions pathway, and SSP3-7.0, representing a high-emissions pathway.

The projections relied on the HCLIM43-ALADIN regional climate model, which operates at a 12.5 km resolution.

Regional Projections

The study reveals that climate change impacts on solar generation are not uniform across Sweden. Under the low-emissions SSP1-2.6 scenario, annual generation rises by 1.52–2.60 kWh/kW per decade, a rate of less than 0.5% per decade. In contrast, the high-emissions SSP3-7.0 scenario produces divergent outcomes: photovoltaic output increases in Stockholm and Kiruna, while it decreases in Gothenburg and Malmö. Despite these opposing trends, the net change by 2100 remains within approximately 30 kWh/kW.

Scenario	Generation Trend
SSP1-2.6	1.52–2.60 kWh/kW increase per decade
SSP3-7.0	Increases in Stockholm/Kiruna; decreases in Gothenburg/Malmö

Operational Implications

• Wujun Wang, the corresponding author, noted: "We found that the combined effects of air temperature and snowfall are as crucial as solar radiation for PV production in high-latitude regions."
• Projections indicate that annual PV output variability will decline in three southern cities, whereas it will rise in Kiruna.
• The optimal future tilt angle is approximately 35°.
• Adopting this 35° tilt angle enhances annual generation by roughly 3–6% compared to the current commercial angle.

Shifting from standard commercial configurations to a 35° incline results in a quantifiable 3–6% improvement in efficiency.

Model Mechanics and Historical Context

To estimate power output, the investigators integrated an hourly snow-photovoltaic simulation with climate forecasts, quantifying direct, diffuse, and reflected solar flux at the panel surface while adjusting for tilt and snow-induced efficiency drops. Module temperature was derived from surrounding air conditions, light intensity, and standard operating cell temperature parameters, which then informed generation calculations using panel efficiency and thermal coefficients. For arrays oriented toward the south, the analysis evaluated inclinations from 0 to 90 degrees in 0.1-degree steps, benchmarking future production against a 1951–2014 historical record and a 15-degree standard tilt. Additionally, the findings indicate that the occurrence and length of zero-output intervals are likely to decrease, which could lower the demand for energy storage capacity.

What to watch

The complete results are published in Communications Earth & Environment with the title "Impact of climate change on the photovoltaic power potential in Sweden across 21st century."