The great energy transition from fossil fuels to renewable sources of energy is under way. As fossil fuel prices rise, oil insecurity deepens and concerns about pollution and climate instability cast a shadow over the future of coal. A new world energy economy is emerging
The great energy transition from fossil fuels to renewable sources of energy is under way. As fossil fuel prices rise, oil insecurity deepens and concerns about pollution and climate instability cast a shadow over the future of coal. A new world energy economy is emerging, powered by wind, solar and geothermal energy. The Earth’s renewable energy resources are vast and available to be tapped through visionary initiatives. Our civilization needs to embrace clean energy on a scale and at a pace we’ve never seen before.
We inherited our current fossil fuel-based energy economy from another era. The 19th century was the century of coal, and oil took the lead during the 20th century. Today, global emissions of carbon dioxide (CO2) — the principal climate-altering greenhouse gas — come largely from burning coal, oil and natural gas. Coal, mainly used for electricity generation, accounts for 44 percent of global fossil fuel CO2 emissions. Oil, used primarily for transportation, accounts for 36 percent. Natural gas for electricity and heating accounts for the remaining 20 percent. It is time to design a carbon- and pollution-free energy economy based on renewable energy for the 21st century.
U.S. Coal Plants Are Being Phased Out. The burning of coal is declining in many countries. In the United States, the No. 2 coal consumer after China, coal use dropped 13 percent from 2007 to 2011 as dozens of coal plants were closed. This trend is expected to continue.
Oil Is Becoming a Relic of the Past. Oil is used to produce just 5 percent of the world’s electricity generation and is becoming ever more costly. Because oil is used mainly for transportation, we can phase it out by electrifying the transport system. Plug-in hybrid and all-electric cars can run largely on clean electricity. Electric motors are so much more efficient than gas engines that wind-generated electricity to operate cars could cost the equivalent of 80-cents-per-gallon gasoline.
Nuclear Is Too Expensive. Although nuclear reactors supply 13 percent of the world’s electricity, nuclear power’s limited role in our future has been clear for some time. It is simply too expensive.
Natural Gas Has Been Oversold. The scientific community is challenging the industry’s claim that natural gas is fairly climate-benign. Natural gas produced by hydraulic fracturing, or “fracking” (a much-touted key to expanding production), is even more climate-disruptive than coal because of methane gas leakage. (Methane is a potent contributor to climate change.)
Countries around the world are richly endowed with enough renewable energy to easily double, in some cases, their current electrical generating capacities. As the U.S. Electricity Generating Capacity by Source chart in the Image Gallery shows for the United States, a revamped clean energy economy will harness more energy from the wind and sun, and from within the Earth itself. Climate-disrupting fossil fuels will fade into the past as countries turn to clean, climate-stabilizing, nondepletable sources of energy.
Plant-Based Energy Is Attracting Some Attention. As oil reserves are being depleted, interest in plant-based energy sources is emerging.
Crops can be used to produce automotive fuels, such as ethanol and biodiesel. Investments in U.S. corn-based ethanol distilleries became hugely profitable when oil prices jumped above $60 a barrel following Hurricane Katrina in 2005. The investment frenzy that followed was also fueled by government mandates and subsidies. In 2011, the world produced 23 billion gallons of fuel ethanol and nearly 6 billion gallons of biodiesel.
The more research that’s done on liquid biofuels, the less attractive they become. Every acre planted in corn for ethanol means pressure for another acre to be cleared elsewhere for crop production. Clearing land in the tropics for biofuel crops can increase greenhouse gas emissions instead of reducing them. Ethanol and biodiesel crops cannot compete with land-efficient wind power.
Solar Is Exploding. The growth in the use of solar cells that convert sunlight into electricity can only be described as explosive, expanding by 74 percent in 2011. Early photovoltaic installations were all small-scale — mostly on residential rooftops. That’s changing as more utility-scale projects are being launched. The United States, for example, has under construction and development more than 100 utility-scale solar projects. Solar-generated electricity is particularly attractive in desert regions such as the U.S. Southwest, because peak generation meshes nicely with peak air conditioning use.
The world’s current 70,000 megawatts of photovoltaic (PV) installations can, when operating at peak power, match the output of 70 nuclear power plants. With PV installations climbing and with costs continuing to fall, cumulative PV generating capacity could surpass 1 million megawatts in 2020. (Current world electricity generating capacity from all sources is 5 million megawatts.) Installing solar panels for individual homes in the villages of developing countries is now often cheaper than supplying them with electricity by building a central power plant and a grid.
Geothermal Is Abundant. The heat that comes from within the Earth — geothermal energy — can be used fo