PECO does not install solar power to generate electricity. Solar panels are not economically sound for the generation of electricity. The solar panel project in Northampton is an insider deal that penalizes the people. They are a political sound-bite that are so expensive they do not make economic sense.
Solar panels are very expensive to make, and of course they won’t work at night or in foul weather. Some of the processes needed to manufacture them have recently been called into question environmentally. Not all of the sunlight striking a solar cell is converted into electricity, and boosting efficiency has been slow work. Yet, the idea of harnessing all of that free sunlight remains a powerful driver for solar power just like the fairy tales we learned as children.
But the adult world must face reality. Here’s an easy first course about electric generation from http://americanhistory.si.edu/powering/generate/gnmain.htm
There are a many ways to produce electricity. Electrons can flow between certain different materials providing a current, as in a common battery. While reliable and portable, chemical batteries run down quickly. To provide the large amounts of steady power demanded by modern societies, large power plants have been built. Most power plants make electricity with a machine called a generator.
Generators have two important parts: the rotor (which rotates) and the stator (which remains stationary). Generators use the principle of electro-magnetic induction, which exploits the relation between magnetism and electricity. In large AC generators, an outer shell with powerful magnets rotates around a stationary “armature” which is wound with heavy wire. As they move, the magnets induce an electric current in the wire. It is important to recognize that electricity is not mined or harvested, it must be manufactured. And since it’s not easily stored in quantity, it must be manufactured at time of demand. Electricity is a form of energy, but not an energy source. Different generating plants harness different energy sources to make electric power. The two most common types are “Thermal Plants” and “Kinetic Plants”.
Thermal plants use the energy of heat to make electricity. Water is heated in a boiler until it becomes high-temperature steam. This steam is then channeled through a turbine, which has many fan-blades attached to a shaft. As the steam moves over the blades, it causes the shaft to spin. This spinning shaft is connected to the rotor of a generator, and the generator produces electricity.
Fossil-fuels are the remains of plant and animal life that lived long ago. Exposed to high temperatures and pressures for millions of years underground, these remains have been transformed into forms of carbon: coal, oil, and natural gas. Unlike electricity itself, fossil fuels can be stored in large quantities. After 100 years of research and development, fossil-fueled plants are generally reliable, and problems that do occur are usually confined to a local area. Many electric utilities have operated fossil-fuel plants for decades, and these plants (now fully paid for) are very profitable to run. This not only increases profits to the utility, but keeps down the direct cost to users. However, fossil-fuel plants can create serious environmental problems. Burning these fuels produces sulfur-dioxide and nitric-oxide air-pollution requiring stack scrubbers. Wastewater from the used steam is recycled.
It’s wrong to say fossil-fuels are not renewable. Yes, they took millions of years to make, and some say at some point they will run out. But plants and animals return to the earth and become fossils. So more fossil fuels are being formed everyday. Strip-mining of coal is fast, economical and desirable but mis-guided politics and political correctness have stopped coal mining. That’s like not eating food because excrement is a pollutant. (It’s a fertilizer). Not using things like coal and fire makes no sense.
Politics makes oil prices higher. Oil has become expensive for most power plants. Coal and natural gas are currently cheap in the US. The use of coal and natural gas is under attack by many low-information voters. These two fuels are being used more efficiently in “cogeneration” plants. Cogeneration is not a new idea, and takes advantage of the way many large electricity users operate. Many factories use steam in their production process. Utilities often make and sell steam for these customers, as well as for running their own generators. Rather than simply condensing and exhausting waste-steam after it has passed thru the turbine, “top-cycle” cogenerators pipe this usable commodity to nearby customers. “Bottom-cycle” cogenerators operate in reverse and use the waste steam from industrial processing to drive turbines. By reusing steam, thermal-efficiency at cogeneration plants can exceed 50%. Recently developed cogeneration plants use new materials and designs to improve reliability, and control both thermal and atmospheric pollution. Since these new technologies are designed into plants from the start, they are less expensive to install. The economy and capability of cogeneration technology allows many plants to return to burning coal without exceeding air-quality standards. “Circulating Fluidized-Bed” boilers, “Selective Catalytic (and Non-catalytic) Reduction”, and “Zero-Discharge” water treatment systems are examples of technologies being used to control various environmental problems.
Combined Cycle and bio-plants. Some natural gas plants can produce electricity without steam. They use turbines very much like those on jet-aircraft. Instead of burning jet-fuel and producing thrust, however, these units burn natural gas and power a generator. Gas-turbine generators have been popular for many years because they can be started quickly in response to temporary demand surges for electricity. A newer twist is the “Combined-Cycle” plant which uses gas-turbines in this fashion, but then channels the hot exhaust gas to a boiler, which makes steam to turn another rotor. This substantially improves the overall efficiency of the generating plant. In addition to these innovations some thermal plants are being designed to burn “biomass.” The term applies to waste wood or some other renewable plant material. For example, Okeelanta Cogeneration Plant in Florida burns biomass waste from surrounding sugar-cane processing operations during one part of the year, and waste wood during the growing season.
My personal favorite is Nuclear Generation. Although there are some important technical (and social) differences, nuclear power stations are thermal plants that make electricity in much the same way as fossil-fuel plants. The difference is that they generate steam by using the heat of atomic fission rather than by burning coal, oil, or gas. The steam then turns a generator as in other thermal plants. Diagram of a Nuclear plant in the Hydro-Québec system copyright, Hydro-Québec
Nuclear plants don’t use large amounts of fuel and do not refuel often, unlike a coal plant which must have fuel shipped in regularly. The fact that green-house gasses and air-borne particulates are minimal during normal operation makes nuclear power attractive to many who are concerned about air-quality. Waste water is hotter than that from a fossil plant, and large cooling towers are designed to address this problem. However, the drive to field nuclear power in the US faltered in the face of public concerns over safety, environmental, and economic issues. As more safety mechanisms were specified, construction costs and system complexities grew. Also, plants have shown some unexpected quirks, such as boiler tubes wearing out prematurely. Nuclear engineers contend that early problems with nuclear plants are subject to technical fixes, and are working on new “inherently safe” plant designs. Opponents argue that simply using uranium and plutonium as fuel creates too many problems and risks, not worth any benefits the technology might have. So far, one problem which has not been solved is that of disposing of spent fuel cores and contaminated accessories which may remain dangerous for thousands of years. Permanent burial in geologically stable locations is the plan being pursued at this time, though this is still very controversial. High-profile accidents at Three Mile Island in 1979 and Chernobyl in 1986 were, for the nuclear industry, public-relation disasters. Continuing economic problems have made nuclear plants much less attractive investments. Even though it produced 22% of America’s electricity in 1996, nuclear power’s future in this country is uncertain and hotly debated. Hydro-electric plants and wind-mills also convert energy into electricity. Instead of heat energy, they use kinetic energy, or the energy of motion. Moving wind or water (sometimes referred to as “white coal”) spins a turbine, which in turn spins the rotor of a generator. Since no fuel is burned, no air pollution is produced. Wind and water are renewable resources and, while there have been many recent technical innovations, we have a long history of harnessing these energy sources. Problems exist even with these technologies, however. Hydro-electric Plants Two basic types of hydro-electric plants are in service. One type, a “run-of-river” plant, takes energy from a fast moving current to spin the turbine. The flow of water in most rivers can vary widely depending on the amount of rain-fall. Hence, there are few suitable sites for run-of-river plants. Most hydro-electric plants use a reservoir to compensate for periods of drought, and to boost water-pressure in the turbines. These man-made lakes cover large areas, often creating picturesque sport and recreational facilities. The massive dams required are also handy for controlling floods. In the past, few questioned the common assumption that the benefits outweighed the costs. These costs stem from the loss of land submerged by the reservoir. Dams have displaced people, and destroyed wild-life habitat and archeological sites. A dam-burst can be disasterous. Some environmental costs can be avoided by thoughtful design; using fish-ladders to permit fish to travel around a dam is one good example. However, other costs remain, and protests against some recent hydro-power projects have become as angry as anti-nuclear protests. A special type of hydro-power is called “Pumped Storage”. Some non-hydro plants can take advantage of periods of low demand (and low costs) by pumping water into a reservoir. When demand rises, some of this water is channeled through a hydro-turbine to generate electricity. Since “peak-load” generating units (used to meet temporary demand surges), are generally more expensive to run than “base-load” units (which run most of the time), pumped-storage is one way to boost system efficiency. Wind Power Wind-farms do not need reservoirs and create no air pollution. Small wind-mills can provide power to individual homes. Air carries much less energy than water, however, so much more of it is needed to spin rotors. One needs either a few very large wind-mills or many small ones to operate a commercial wind-farm. In either case, construction costs can be high. Like run-of-river hydro-plants, there are a limited number of suitable locations where the wind blows predictably. Even in such sites, turbines often have to be designed with special gearing so that the rotor will turn at a constant speed in spite of variable wind speeds. Some find less technical problems with installations that can turn a scenic ridge or pass into an ugly steel forest, or that can take a toll on birds.
Notice the absence of Solar Panels to generate electricity. They are just expensive political toys so far as generation is concerned. .