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FOUR SEASONS BREEZE | AUGUST 2023 31 By Bruce Hammett God said LET THERE BE LIGHT, and that sun creates the wind and the solar energy that we heat with, generate electricity with, store and consume. Except for stand-alone applications, designs for renewable energy generating systems remain useless without baseline energy grid to integrate into and are generally forced to turn off when a grid is saturated. The national grid (the reservoir) has historically been the storage vessel and simultaneously the source needed for frequency and voltage capacity for synchronization of renewables to the grid and without it, re-generators do nothing. In 1881, an inventor discovered that we could turn sun energy into electrical generation. Solar is now the lowest cost form of electrical generation. But converting light into electricity has only recently become competitive with rotating electrical generation. Scientific advances converged in many other technologies to make solar electrical energy viable and cheap in the 1990s, which exploded in roughly 2010 into what we see as home, commercial, and utility scale applications. Simultaneous development of the modern electronics capabilities, computer-based technology, and other engineering applications bring us to today. But solar energy is DC, suitable for battery charging and limited DC applications. Thus, DC needed to be converted to AC energy with automatic conversion to the voltage and frequency of the grid so that our refrigerators and air conditioners could be used without self-destruction. That miracle-cure was an electronic product called power control inverter making it possible to electronically convert the DC energy into a reliable, perfect AC wave. At the end of the 1880s, two engineers, Thomas Edison and Nikola Tesla, began manipulating magnets and electrical wires to create rotating electrical fields called motor-generators, Tesla developed AC electricity and Edison offering DC electricity. These rotating machines convert any power source into electricity. The search for lighting became our national grid. Today's normal utility grid capacity overwhelmingly comes from thermal steam-powered generators and hydroelectric dams that use motor generators to generate baseline voltage and frequency power. Hydro generators use stored water from rivers, dams, and other large power plants are fueled by petroleum-based gas and diesel fuels, natural gas, coal, wood, trash, and nuclear-type steam boilers. The steam is introduced into spinning turbines which connect to a generator. That is how we get our baseline frequency and voltage making great use of inverters. Modern wind-turbine generation uses electric generators very much like those that Edison and Tesla designed. By example, plug a common house fan into a wall socket to measure the performance, you might find that it creates wind at six miles per hour (mph) and consumes about 2 amps. Put that fan into a six mph outdoor breeze and it would consume zero amps because the wind is doing the work. Now place the fan into a 12 mph wind. It will try to overspeed but is held back by the voltage and frequency of the grid. You will likely see up to 2 amps, but it is flowing back into the wall in reverse direction, now generating, not consuming. What you have is effectively show how modern wind energy plants work. Arguably, wind turbines do not create electricity. They use the voltage and frequency of the grid to deliver amps in the form of kilowatts. Nearly 98 percent of the 1980 to 1995 vintage turbines would overspeed standard AC motors which would generate current back into the grid. Propeller pitch would control the overspeed to not burn up. Thereafter the systems are more efficiently regulated with computers and inverters. Batteries are now common form of stored DC energy. We use it to provide emergency backup storage in our houses AND to provide emergency capacity for the grid. Modern storage plants use inverter technology to integrate with utilities. Automobiles store DC in batteries but use inverters and AC motors to move. Large wind turbines now are utilizing inverter technologies to convert AC to DC and back to AC making local DC storage viable and more useful to the grid. In the next article we will answer the questions of who owns all this technology and where it is located. Living On The Grid

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