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Global Futures Report 2013

40 n Low-Energy Buildings Cities and local governments are shifting their focus from traditional “percentage savings” goals for efficient buildings to new goals of “near-zero” or “net-zero” energy use that includes on-site renew- able energy. This approach utilizes a variety of planning approaches, new building codes, and building demonstrations. In Europe, the “Energy Performance of Buildings” directive took effect in 2011, requiring all new and retrofitted buildings to be near-zero energy use by 2020. The directive is driving many local communities in Europe to establish renewable energy targets for buildings, to revise building codes, and to alter permitting and land-use policies so that renewable energy is required or favored.10 Globally, hundreds of cities have demonstrated carbon-neutral and net-zero-energy buildings, using practices suited to local renewable resources. Experts envisioned that by 2050, most new and reno- vated residential and commercial buildings worldwide will be highly energy efficient and rely on renewable energy systems to ensure zero or near-zero energy use—that is, to produce at least as much energy as they consume. Experts saw net-zero-energy and/or car- bon-neutral buildings becoming a key aspect of local infrastructure and planning. Such buildings have already begun to populate urban landscapes and are proving cost-effective compared to traditionally constructed buildings, experts said.11 Examples of Low-Energy Building Plans Amsterdam has directed that all new developments be “energy neutral” starting in 2015. Portland (Oregon, USA) aims to achieve zero-net greenhouse gas emissions in all new buildings and homes by 2030. Hamburg (Germany) in 2009 enacted a Renewable Heating Act and Energy Efficiency Ordinance that will require new buildings to use renewable energy for a share of heating in real estate contracts. Other cities with low-energy building planning and codes include Adelaide (Australia), Albuquerque (USA), Austin (Texas, USA), Cape Town (South Africa), Chicago (USA), Edinburgh (Scotland, U.K.), Freiburg (Germany), Gothenburg (Sweden), Kyoto (Japan), Malmö (Sweden), Miami (USA), Munich (Germany), Sacramento (California, USA), Seoul (South Korea), Sydney (Australia), Vancouver (Canada), Växjö (Sweden), and Wellington (New Zealand).12 Examples of Heating and Cooling Infrastructure Solar hot water and/or heating in new building construction is mandated in Barcelona (Spain), Lianyangang (China), Rajkot (India), Rio de Janeiro (Brazil), and San Francisco (USA). Rosario (Argentina) is adding solar water heaters to public buildings. Xianying (China) plans to expand geothermal space heating six-fold. Copenhagen (Denmark) plans to supply heat to virtu- ally all homes by 2025 with district heating and biomass CHP plants. Hamburg (Germany) allows individually owned solar thermal collectors to supply heat to the local district heating network. Hong Kong (China) plans a district cooling system using an ocean-source geothermal heat pump. Paris (France) is expanding a district cooling system using geothermal. Many cities have already reached high levels of heat supply from renewables: for example, Reykjavik (Iceland) meets 95% of its heating needs from geothermal, and Växjö (Sweden) supplies 90% of heat demand from renewables, primarily biomass.16 RENEWABLES GLOBAL FUTURES REPORT 04 FUTURES AT THE LOCAL/CITY LEVEL: INITIATIVE, PLANNING, AND POLICY n Heating and Cooling Infrastructure Cities and local experts increasingly envision a future where urban district heating and cooling systems meet a large share of heating and cooling needs. Such systems incorporate a variety of renewable resources in heat-only and combined heat and power (CHP) con- figurations and can supply clusters of buildings or entire neighbor- hoods. Many contemporary examples exist of local district heating with renewables, particularly using biomass in CHP plants. Other sources of heat include deep geothermal steam or hot water, waste incineration, and waste industrial process heat.13 Experts also foresaw a larger role for CHP systems at the building level—so-called “micro-generation” using a variety of renewable fuels such as biomass and biogas, along with natural gas and landfill gas. In the absence of district heating or on-site CHP (or comple- menting them), renewable heating and cooling on a building level can come from solar-thermal collectors and ground-source (geo- thermal) or air-source heat pumps. One expert coined phrases for two [complementary] heating and cooling approaches: the “electric- ity building” that uses electric heat pumps and the “co-generation building” that uses CHP either on-site or through district systems.14 District cooling and on-site cooling can similarly make use of all types of renewable heat sources and configurations to provide space cooling with chillers, including geothermal heat pumps using ground, ocean, or lake sources. District cooling can also draw upon existing sources of heat like combined-heat-and-power plants. Indeed, district heating and cooling systems can be made to complement each other when there is a demand for both, and can also incorporate thermal energy storage. Some experts foresaw intelligent and integrated district heating and cooling systems using a variety of heat and cold sources and meeting a variety of customer needs. And experts emphasized that on-site renewable heating and cooling systems can integrate with or supplement conventional (HVAC) heating and cooling systems.15

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