Powering a Green Planet

Summary

Detail

"Supplies of wind and solar energy on accessible land dwarf the energy consumed by people around the globe. The authors' plan calls for 3.8 million large wind turbines, 90,000 solar plants, and numerous geothermal, tidal and rooftop photovoltaic installations worldwide. The cost of generating and transmitting power would be less than the projected cost per kilowatt-hour for fossil-fuel and nuclear power. Shortages of a few specialty materials, along with lack of political will, loom as the greatest obstacles." - Scientific American, A Plan to Power 100 Percent of the Planet with Renewables

"It is clearly feasible to replace the present fossil fuel energy infrastructure in the US with solar power and other renewables, and reduce CO2 emissions to a level commensurate with the most aggressive climate-change goals (Fthenakis et al., 2009, p. 397)."

See Scientific American: Green Planet Interactive for solar, wind, and other renewable energy options.

A concern with some types of renewable energy is their variability. 100% renewable energy is possible by addressing these concerns in a number of different ways. "There are at least five ways to mitigate variability or its effects: (a) interconnect geographically-disperse naturally-variable energy sources (e.g., wind, solar, wave, tidal), (b) use a reliable energy source, such as hydroelectric power, to smooth out supply or match demand, (c) use smart meters to provide electric power to vehicles in such a way as to smooth out electricity supply, (d) store electric power for later use, and (e) forecast the weather to plan for energy supply needs better."

Economic policies will be a critical force in driving these changes. Eliminating subsidies on fossil-fuels will start to bring the price of renewables into parity. The most effective model proven so in Germany, Denmark, Spain and Ontario/Canada is the feed-in tariff (FIT) model. See Hope for a Change for some of the history behind this rate payer incentive program as it has evolved successfully in Germany. "Feed-in tariffs (FITs), which essentially are subsidies to cover the difference between generation cost and wholesale electricity prices, are especially effective at stimulating generation from renewable fuels (Fthenakis et al., 2009; Sovacool and Watts, 2009). Combining FITs with a so-called "declining clock auction," in which the right to sell power to the grid goes to the bidders willing to do it at the lowest price, provides continuing incentive for developers and generators to lower costs (New York State Energy Research and Development Authority, 2004). As the cost of producing power from WWS technologies (particularly photovoltaics) declines, FITs can be reduced and eventually phased out.

Other economic policies include eliminating subsidies for fossil-fuel energy systems5 or taxing fossil fuel production and use to reflect its environmental damages (e.g., with 'carbon' taxes that represent the expected costs of climate change due to CO2 emissions). Note, though that current subsidies and expected environmental-damage taxes generally are smaller (and hence less effective) than FITs for the costliest WWS systems versus the cleanest fossil-fuel systems (Krewitt, 2002; Koplow, 2004; Koplow and Dernbach, 2001). They also may be less feasible politically than are FITs." - Energy Policy, 2009, - Scientific American, A Plan to Power 100 Percent of the Planet with Renewables

"Summary

A large-scale wind, water, and solar energy system can reliably supply all of the world's energy needs, with significant benefit to climate, air quality, water quality, ecological systems, and energy security, at reasonable cost. To accomplish this, we need about 4 million 5 MW wind turbines, 90,000 300-MW solar PV plus CSP power plants, 1.9 billion 3 kW solar PV rooftop systems, and lesser amounts of geothermal, tidal, wave, and hydroelectric plants and devices. The obstacles to realizing this are primarily social and political, not technological. As discussed above, a combination of feed-in tariffs and an intelligently expanded and re-organized transmission system may be necessary but not sufficient to enough ensure rapid deployment of WWS technologies. With sensible broad-based policies and social changes, it may be possible to convert 25% of the current energy system to WWS in 10-15 years and 85% in 20-30 years. Absent that clear direction, the conversion will take longer, potentially 40-50 years." - Evaluating the Feasibility of a Large-Scale Wind, Water, and Sun Energy Infrastructure, Mark Z. Jacobson and Mark A. Delucchi

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