Owing to the city’s characteristics and size, key stakeholders joint responsibility between several actors. Among them, must pay attention to the following elements to be able to municipalities have an essential role to play in planning meet the goal, on a cost-effective basis, of exclusively using activities in this area. Onshore and offshore wind power and renewable energy: solar photovoltaic capacities provide almost 80 percent of •Ensuring the implementation of heat saving in buildings to Denmark’s gross electricity consumption (Copenhagen Climate reduce energy demand; Plan, Carbon Neutral by 2025, 2009). •Increasing investments in supply and distribution technology for heating; Smart energy systems are crucial to Copenhagen’s bid •Promoting the implementation of renewable energy sources; to achieve 100 percent renewable energy use. The main •Increasing the integration ratio of smart energy technologies. assumptions behind the plan are (Copenhagen Climate Plan, Carbon Neutral by 2025, 2009): In the Greater Copenhagen Area, the highpopulation density, • Power plants can contribute to the goal of creating a 100 which creates good potential for innovative energy supply percent renewable energy system; systems and use of renewable energy, creates a high demand • The highest share of potential savings in the city will come for energy. Copenhagen’s building stock is old, and so there from heat. is enormous potential for energy-efficiency improvements. It has been shown that, on average, half of the heat in Danish Copenhagen is firmly committed to the Paris Agreement, and buildings can be saved (Copenhagen Climate Plan, Carbon it is aiming to reduce its carbon footprint by two million tons. Neutral by 2025, 2009). Housing and energy represent a critical area that needs to be leveraged if Copenhagen is to succeed in that endeavor. Potentially, heat savings could reach more than 50 percent in a Therefore, the city is seeking to reform its current urban few years (Copenhagen Climate Plan Carbon Neutral by 2025, infrastructure so that it uses energy in a smarter way. 2009). Implementing heat-saving solutions requires long-term planning and concrete strategies executed in cooperation with Retrofitting is the approach that the city is applying (Copenhagen building owners, housing associations, and other stakeholders. Climate Plan, Carbon Neutral by 2025, 2009), with a view to Reductions in the demand placed on heating infrastructure decreasing buildings’ electricity usage by up to 10 percent and decrease both fuel consumption and the investment costs reducing their heat consumption by 20 percent by 2025. bound up with supply and distribution of heating energy. Advanced technology that monitors overall water and energy 4.2 Implementation of renewable energy technology for flows is also being implemented in buildings. Cutting-edge heating and electricity supplies heat-sensing devices will be able to indicate how much heat is lost from a building. Implementing renewable energy technologies is based on Figure 4.4 – Electricity consumption in Copenhagen municipality, 2005 8% Land based wind turbines 5% Off-shore wind turbines 9% Biofuels 5% Waste incineration 23% Natural gas 8% Oil 42% Coal 128 Quélin and Smadja | HEC PARIS | SMART CITIES | The sustainable program of six leading cities | 2021