European Cities Need Major Investments to Improve Grid Resilience
Research out of Lund University quantifies the extent of Europe’s urban infrastructure needs as member states transition to renewable energy resources.
A research team from Sweden’s Lund University recently conducted a study to measure the expected impact of the “urban heat island” phenomenon on electricity grids as cities become more vulnerable to extreme weather events.
A study from Lund University researchers in Sweden draws upon climate variations and energy system models to determine the cost of urban grid improvements in Europe’s energy transition. Image used courtesy of Nature Energy, via Lund University
Their findings suggest a significant increase in funding is needed to improve grid resilience in urban areas as the European Union’s 21 member states pursue aggressive renewable energy targets, eyeing a 55% reduction in greenhouse gas emissions by 2030.
The researchers wanted to study the impact of climate variations and changes in urban densification on renewable energy deployment in 18 cities across Europe. As wind speed and temperature changes tend to drive up the peak and annual energy demand, cities must weigh urban density in their electricity infrastructure planning.
Assuming the current pace of building technology innovation, the study found that cities need to up their grid investments by 20% to 60% to ensure weather events won’t wipe out the power grid. Failing to do so could downgrade their supply reliability by up to 30%.
Impact of Urban Density on Energy Transition
Urban densification has long been considered a compelling strategy for modernizing spatial development while increasing sustainability and curbing emissions. For example, cities can reduce fuel consumption by consolidating populations near public transport hubs. Densification also prevents urban sprawl from spreading to agricultural and ecological preservation sites.
Urban sprawl. Image used courtesy of Pixabay
However, as a 2021 paper in Buildings and Cities pointed out, this strategy requires a nuanced understanding of the direct, indirect, and cumulative socioeconomic and environmental impacts on- and off-site. Other studies have noted that urban densification policies assume that growth in the consumption of building stock and infrastructure should be accommodated, which weakens environmental sustainability.
Per data from the United Nations, cities’ share of the global population more than doubled from 25% in the 1950s to 56% in 2021. And it’s expected to steadily increase to 68%, or 2.2 billion new urban residents, by 2050.
According to World Bank estimates, the European Union already has a high population density of 112 people per square kilometer of land area. That figure for the global population is 60, though there’s significant variation between countries.
How the most populous EU countries stack up against each other by density. Image used courtesy of World Bank
Research Sheds Light on Europe’s Grid Resilience
The study, published in Nature Energy, developed a spatiotemporal modeling framework incorporating climate patterns with city-level building and energy system data.
The researchers produced simulations of urban microclimates to understand how heat waves and cold snaps impact the grid in over a dozen European cities. The data also considered several scenarios from the Intergovernmental Panel on Climate Change, the top international agency on climate assessments. The data reveals that peak demand increases more than previously known when such extreme weather data is considered.
Vahid Nik, one of the authors and a professor in Lund University’s Division of Building Physics, stated in a press release that current data is limited in linking all three points of energy, climate, and urban development. Microclimate data fills in some of those gaps, with the announcement citing the example of a 68% spike in cooling demand in Stockholm, Sweden, coupled with a 43% jump in Madrid, Spain, on the hottest day of the year.
Insufficient planning may lead to power shortages and blackouts when this piece is left out of the equation. In the above example, current urban climate models could overestimate Madrid’s cooling demand by around 28%, the researchers said.
Overall, the study’s key finding is that 20 to 60% of additional funding would be needed to prepare European power grids for renewable energy integration while avoiding impacts from extreme weather. The study also found that parts of southern Europe with energy infrastructure in dense urban areas are more vulnerable to the collective effects of climate events. This requires design-level improvements to increase flexibility when making the transition to renewables.
As high-density areas create urban heat islands, cities are naturally more at risk in extreme weather. Lund’s press release noted an example of outdoor temperatures increasing by 17% while wind speed plummets by 61%. Thus, urban densification should be factored into electricity network needs and energy system design.