A report done by a German university for Siemens takes as its test case Munich, the mid-sized but high-tech city where the electrical engineering and electronics conglomerate is headquartered. The postulates and conclusions of the Wuppertal Institute for Climate, Environment and Energy are rather eye-catching, as are its examples and arguments. The authors believe it''s realistically possible, in just 50 years, to cut per capita carbon emissions in Munich from 6,500 kilograms to between 750 kg and 1300 kg, in keeping with the ambitious goals of the Intergovernmental Panel on Climate Change.
The report''s starting point is the observation that over half the world''s population now lives in cities. Those city dwellers consume 75 percent of the world''s energy and account for 80 percent of its greenhouse gas emissions. So if it can be shown that energy and carbon can be sharply cut in cities, then there''s hope for everybody.
The Wuppertal researchers see the greatest potential for savings in a program of thorough-going building insulation and re-insulation, together with installation of triple-pane windows and heating-cooling systems that recover and resuse warmth. Other big gains can come from smart electrification and smart vehicle management, together with much more reliance on electrified vehicles and public transportation. Electricity supplies will be more localized and small-scale''right down to building developments and houses''with the lion''s share of energy coming from renewable, carbon-free sources.
The authors may at times be accused of pie-in-the-sky, ''best case scenario'' thinking. Many a critical reader will be forgiven for refusing to believe that all the good things the report anticipates will actually come true. What saves the report from irrelevance and makes it truly interesting are its many detailed examples, which may not always convince, but do always provoke.
' For insulation, the report says tiles made from polystyrol, polyurethane, or fibrous materials are ready-at-hand for exterior mounting, but for full effect these need to be as thick as 30 centimeters. Under development, however, are vacuum-core insulation panels, a little as 3.5 cm thick. Even more intriguing: phase-change waxes that melt when ambient temperatures get warmer, absorbing heat, but then harden when it''s cooler, releasing heat.
' To discourage extravagant use of the gasoline car, Singapore has had a toll system since 1975 that''s cut time sitting in traffic jams by 45 percent and helped double use of public transportation. London has had similar success with its inner-city congestion pricing system, and some of its red double-decker buses are now hybrids, consuming up to two-fifths less fuel and registering corresponding cuts in CO2.
' To show that cities don''t actually have to consume depletable fuels and emit greenhouse gases, Sweden''s Malm is constructing a new district with 3,000 inhabitants who, by next year, are to rely entirely on renewable energy or waste combustion. Much of the district''s heating and cooling will come from a geothermal system, in which water will be pumped to the surface at 15 degrees Celsius. (In summer the water will provide cooling at that temperature; in the winter it will be further warmed by means of heat pumps and solar-thermal devices, to provide heating.)
' A U.S.-Israeli venture is getting ready to deploy experimental networks of car charging and battery exchange stations. If successful, networked electrical and hybrid vehicles will be able to store energy, helping to stabilize grids by consuming it when it''s plentiful and feeding it back when scarce. (The reference is to the scheme concocted by Palo Alto''s Better Place, which has alliances with the state of Israel and Renault-Nissan''s Carlos Ghosn. In January, Better Place announced it would soon start deploying its first network in Denmark, to feed wind-generated electricity to cars.)
' Assessing the general potential for smart grids, the report reckons that as all households are equipped with real-time electricity meters, every home appliance will have the potential to help with load stabilization and electrical system management. For Germany alone, it calculates that aggregate contribution at 1300 to 3000 MW.
The Wuppertal/Siemens researchers do not shy away from big ideas, which is why their report is worth perusing. Right now it''s available only in German, but keep your eyes out for an English edition.