A study by the consulting firm Arthur D. Little of 15 of Spain’s largest cities showed that, with appropriate local policies and without major home renovations, Spanish cities could achieve annual savings of 3.3 billion euros, a reduction of 18.8 million tons of CO2 emissions and a 25% drop in the amount of suspended particles in the air.

In Spain, urban dwellers currently account for 43% of total energy consumption, which is mainly used for heating and cooling and keeping the lights on. Businesses and the service sector consume 31% of total energy, which includes everything from retailers to health care. Twenty-six percent is used by transport, mainly private transport. Considering overall energy consumption, current efficiency practices and the city’s commitment to sustainability, Bilbao is the most energy efficient city in Spain, closely followed by Zaragoza.

Large cities such as Madrid and Barcelona middle the list, demonstrating that size has little to do with energy efficiency. Gijón and Valencia have the worst rates, largely due to high domestic heating costs and limited public transport options. As in many cities around the world, the inhabitants of Spain’s urban centers have the potential to dramatically improve energy efficiency in their homes and transportation. In older homes and apartments, modest upgrades to the most energy-intensive equipment can generate savings of up to 40%.

As new generations increase population rates in Spain’s urban centers, local and regional authorities must prioritize reducing overall energy consumption through comprehensive policies that encourage residents and businesses to invest in energy-efficient housing, operations and transportation modes. Working with technology experts, energy companies and the automotive industry, urban policymakers can develop smart city initiatives that ensure Spain becomes a leader in urban energy efficiency.