Our electric power supplies are largely taken for granted – we turn the switch on, and go about our leisure and business activities. But, behind that switch is a vast, complex and vulnerable network of critical infrastructure that is essential to our survival.
Government environmental “sustainability” programs involve our electric power supplies. U.S. government sustainability programs emphasize actions that: 1) create and maintain conditions where humans and nature can exist in productive harmony, and that 2) permit fulfilling the social, economic and environmental needs for present and future generations of Americans. Principles such as natural resource conservation, recycling, population and pollution control and renewable energies have become central in the pursuit of sustainability.
Renewable electric power energy sources deemed to be “sustainable” include solar, wind, hydro-electric, geo-thermal, and to a lesser extent biomass, biogas and wave power. The four most important renewable energies are solar, wind, hydro-electric and geo-thermal because they are deemed to be “zero carbon” alternatives. That is, they operate without fossil fuels, and therefore, neither produce nor release the greenhouse gas carbon dioxide (CO2) into the environment. Governments, foreign and domestic, have focused on carbon dioxide(CO2) air pollution as the historic cause of climate change – among other more potent greenhouse gases such as methane (CH4), oxides of nitrogen (N2O), ozone (O3), chlorofluorocarbons (CFCs) and water vapor (H2O, clouds).
Solar: Pros – Zero–carbon photovoltaic panels are effective and common on residential and commercial rooftop and remote facility applications. Solar panels are not regional public power utility sources. They absorb direct sunlight energy with a solid-state cell of chemical converters that turn photo energy into electromotive energy (electrons) with no moving parts. Cons – Only intermittent daylight-dependent production, with no long-term energy storage capacity. Solar panels are subject to reduced electric output by cloud cover, rain, snow and surface dust and debris accumulations. The Ivanpah “solar reactor” in California’s Mojave Desert focuses sunlight from 300 thousands mirrors onto massive boilers 339 feet in the air to make steam that drives turbines to produce electricity. Ivanpah, is the world’s largest solar reactor using mirrors to focus the power of the sun on solar boilers at 1000 degrees atop three towers. Ivanpah would produce enough electric power to serve more than 140,000 homes – approximately the size of the city of Pasadena. Covering 3,500 acres (the area of Los Angeles International Airport) in the Mojave Desert, the Ivanpah Solar Reactor cost $2.2 billion. Cons – Large solar power arrays can be unsightly or cover protected habitats such as the endangered Desert Tortoise, and birds flying through the array of mirrors get roasted.
Wind: Pros – Zero-carbon wind turbines are effective, and are the fastest growing grid-scale renewable producers of electric power world wide. Wind turbines are generally deployed in arrays (“wind farms”) as massive mechanical structures towering 100 to 400 ft. over land and sea, where prevailing winds average about 15 mph for extended durations. Most turbines are horizontal-axis electric generators with pitch-controlled, three-bladed propellers and an elevated control module. Beginning in the 1970s and by the year 2000, California had more installed wind turbine electric power than all the rest of North America. Cons – Wind turbines operate intermittently with no long-term electric energy storage capacity. Critical prevailing wind strengths limit wind turbine location suitability and performance capabilities. Wind turbines must be placed in remote areas due to rotary operating noise, large wind farm area footprints and visual impacts. Also, turbine rotor blades kill birds, disrupt aircraft navigation radar, and can self-destruct in winds above 50 mph (“rotor failure”), as well as be toppled in hurricane or tornado events.
Hydro-Electric: Pros – Hydro-electric power is the use of falling water through electric power turbines inside dams to produce zero-carbon electricity. This technology has been around for hundreds of years — turning millstones along rivers since the Middle Ages. Today’s hydro-electric facilities are massive concrete dams holding back millions of tons of water in rivers and lake reservoirs which may be otherwise used for fisheries, water sports and drinking water storage – think of the historic Grand Cooley Dam or Boulder Dam. Hydro-electric dams are considered to be reliable, conventional base-load public utilities with capacities comparable to fossil-fueled coal or gas-fired electric power plants. Cons – Hydro-electric dams can have impacts that disrupt up and downstream aquatic habitats. And, dams are susceptible to reservoir water shortages in drought-prone areas, and can be threatened with collapse in flood and earth quake events.
Geo-Thermal: Pros – Geo-thermal electric power taps into naturally-occurring steam geysers or shallow thermal vents that are heated from the earth’s molten core. Geo-thermal power plants produce zero-carbon electric power by capturing geo-thermal steam at the earth’s surface and directing it through electric power turbines. Geo-thermal power has been a staple of public utilities generation for more than a century. Cons – Accessible and productive geo-thermal formations are rare on the earth’s surface, and few nations have significant geo-thermal resources.
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