Climate change could boost Swedish PV generation by 5%

Researchers in Sweden have investigated how climate change could affect the country’s solar power generation potential throughout the 21st century, aiming to provide more accurate projections of PV output in high-latitude regions. The study accounts for factors such as panel orientation, temperature and snow cover, which are often overlooked in conventional assessments of PV potential, potentially leading to inaccurate estimates in cold climates.

“We found that the combined effects of air temperature and snowfall are as crucial as solar radiation for PV production in high-latitude regions,” corresponding author Wujun Wang told pv magazine. “This is quite different from the case in low- and mid-latitude regions. In Sweden, climate change will lead to an approximate 5% increase in PV generation, which means global warming might be positive for PV generation.”

The researchers assessed PV generation from 1951 to 2100 in four Swedish cities: Malmö in the south, Gothenburg on the west coast, Stockholm on the east coast, and Kiruna in the far north. Malmö recorded the highest temperatures and solar radiation levels and the least snowfall, while Kiruna had the coldest conditions, lowest solar radiation levels and approximately twice as much snowfall. Stockholm and Gothenburg represented intermediate climatic conditions. The team combined an hourly snow-PV model with climate projections from the HCLIM43-ALADIN regional climate model at a spatial resolution of 12.5 km.

The researchers considered two climate scenarios: a low-emissions scenario involving strong climate action (SSP1-2.6) and a high-emissions scenario involving limited climate action (SSP3-7.0). Their model calculated direct, diffuse and reflected solar radiation reaching the modules, accounting for incidence-angle and snow-related losses. It also estimated cell temperatures based on ambient temperature, irradiance and nominal operating cell temperature, before calculating electricity generation using module efficiency and its temperature coefficient. For south-facing modules, the researchers tested tilt angles ranging from 0 degrees to 90 degrees in 0.1-degree increments. They compared projected yields with a historical baseline covering 1951 to 2014 and a reference tilt angle of 15 degrees.

“The projected trends depend on both location and scenario,” the researchers said. “Under SSP1-2.6, annual generation increases by 1.52–2.60 kWh/kW per decade, corresponding to less than 0.5% per decade. Under SSP3-7.0, PV output increases in Stockholm and Kiruna; however, it decreases in Gothenburg and Malmö. Nevertheless, the net change remains within approximately 30 kWh/kW by 2100.”

Compared with the historical period, annual PV output variability is projected to decrease in the three southern cities but increase in Kiruna. The frequency and duration of consecutive periods with zero generation are also generally expected to decline, potentially reducing energy storage requirements.

“In the future, an installation tilt of approximately 35° is suitable for all selected cities and can increase annual generation by about 3–6% relative to the commercial angle currently used,” the researchers said.

“The findings provide valuable insights into photovoltaic potential in a changing climate,” the researchers concluded. “It provides a powerful tool for a wide range of stakeholders, including researchers, policymakers, PV plant owners, power grid operators, investors, and engineers, to estimate the impacts of local climate change on PV generation, particularly in high latitude cold regions with long snow seasons.”

The findings are presented in “Impact of climate change on the photovoltaic power potential in Sweden across 21st century,” published in Communications Earth & Environment. The research team included scientists from Sweden’s KTH Royal Institute of Technology and Swedish Meteorological and Hydrological Institute, as well as China’s Zhejiang University of Technology.