PROLOGUE
Reuben Goldberg (1883-1970) was an American cartoonist famous for conceiving very complicated and impractical machines that accomplish little or nothing. The term “Rube Goldberg” has passed into the lexicon as shorthand for describing such machinery and their products and services. Contemporary industrial wind turbines epitomize this concept. Physically, they are taller than many skyscrapers, with 300-foot rotors that move nearly 200 miles per hour at their tips. They are usually placed in a phalanx numbering five to eight per mile, which, if erected on forested ridge tops, also require the clearcutting of at least four acres per turbine, with another 35-65 acres needed for infrastructure support. Functionally, they produce little energy relative to demand and what little they do produce is incompatible with the standards of reliability and cost characteristic of our electricity system. Moreover, wind plants are unable either to mitigate the need for additional conventional power generation in the face of increased demand or to reliably augment power during times of peak demand. Ironically, as more wind installations are added, almost equal conventional power generation must also be brought on line. Crucially important, wind technology, because of the inherently random variations of the wind, will not reduce meaningful levels of greenhouse gases such as carbon dioxide produced from fossil-fueled generation, which is its raison d’etre.
To understand the limitations of wind technology, one should know how energy use enables complex modern society and, especially, how energy in the form of electricity is produced and transmitted to hundreds of millions of people on demand. Enormous energies are required to support the way Americans choose to live and work. Industrial modes of transportation and heating/air conditioning technologies have made it possible for large numbers of people to live in regions historically limited to only the hardiest of souls, such as the swamplands of Florida and the ice of Alaska, while newer communication technologies have encouraged widespread development not only for residential suburbanites but commerce and industry as well. The majority of our energy use involves heating and transportation. Demand for electricity accounts for about 39 % of all energy use, even though electricity accounts for 30% of the energy used for heating. (1) We increase both our demand for energy and for electricity at a rate of approximately 2% each year, nearly doubling our consumption every 30 years, as we did from 1970 through 2000.
Electricity is the cleanest and most important form of industrial energy; its supply continuity is essential to enable and protect a vast range of services we often take for granted—modern hospitals, traffic controls, information storage and retrieval, entertainment, food storage, to name only a few. As the British engineer, David White, has written, “It is a truism that electrical power supply at a competitive cost underpins the world’s economies….”
THE GRID ENSEMBLE
Unlike the municipal water supply, electricity at industrial levels cannot be stored in reservoirs. It must be used immediately. Above all, it must be reliable, accommodating demand instantaneously, while its costs, ideally, should be affordable to all. Over the last hundred years, large regional networks known as electricity “grids” have evolved to collect, rhythmically organize, and dispatch a mixture of power sources, considering, among other things, expectations of demand levels, availability, predictability, cost, exactly balancing forecasted supply with demand at all times and transmitting power over a range of distances to a variety of users within their respective regions. In the United States., the North American Electric Reliability Council, working with its regional reliability councils, develops and monitors the reliability standards each grid’s power line owners and operators usually follow, taking into account scheduled and reasonably expected unscheduled outages while also accommodating “contingencies”—the unexpected failure or outage of a system component such as a generator, transmission line, circuit breaker, switch or other electrical element.
Although the mix of power fuels varies among grids in the United States, on the whole fossil fuels account for 70.7% of the nation’s electricity generation (coal 51.4%, natural gas 16.3% and oil 3%) with the balance coming from nuclear power (20.7%) and renewable sources (8.5%, of which 84% is hydropower).
Collectively, along with biomass, geothermal, and a few other fuels, these are known as “conventional generation.” Except for hydro, they are also called “thermal generation.”
Except for hydro, they are also called “thermal generation.” The conventional fuels heat water (or gas) to create steam that drives turbine rotors around an electro-magnetic motor. In the case of hydro, the turbines are driven by water either falling on or moving past turbine rotors. Conventional generation has a proven ability over many years to produce reliably and continuously at industrial scales. Nuclear and large coal plants, along with certain hydro facilities, are best at providing a base level of supply upon which other levels of supply can be built. Smaller conventional generators are often highly responsive to commands and can be dispatched to cover a range of tactical, even immediate, needs. In fact, this quality of “dispatchability” is highly prized by grid operators.
CAPACITY MATTERS
In grid parlance, the term “capacity” is used as a measure of firm generation and transmission capability—that is, how reliable a power source is for meeting various levels of demand in timely fashion. Each power plant is engineered to produce a specified amount of electricity over a year’s time, a concept known as its “rated or installed capacity” (also known as “nameplate” capacity). However, because of equipment damage, routine maintenance, machine or human error, etc, no machine works at full power all the time. The energy community has developed a concept known as a “capacity factor” to project the average amount of production a machine will yield in a specified amount of time; this is expressed as a fraction of rated/installed capacity. Grid system operators also use a concept known variously as “capacity credit” or “effective.
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