By Don Bogard – Re-Blogged From http://www.WattsUpWithThat.com
The tale below is fictional, but every one of its elements and issues has been or will be experienced somewhere in the process of switching electrical power production from fossil fuels to renewable wind and solar. Hopefully this tale will illustrate in a non-technical way some of these complications and potential issues that can and often will arise. My reference to “city” and “government” and “city fathers” are generic and could apply to different entities and scales.
Visualize a medium-size city with two very functional electrical power plants, each producing 500 Mega-watts of electricity, with one fueled by coal and one by natural gas. (About 2/3 of U.S. power is produced from these two sources.) The government decrees that this city must reduce its CO2 emissions. The city fathers decide to retire their coal-fired plant because it generates more CO2 and replace it with 350, General Electric (G.E.) 1.5 Mega-watt wind towers (total rated capacity 525 M-watt). The entire city celebrates over their good fortune in moving into a modern era of green energy. The mood is jovial.
The city planning begins. Each of these G.E. wind towers consists of 116-ft blades atop a 212-ft tower for a total height of 328 feet, and the blades sweep an area just under an acre. Each tower weighs 164 tons and is mounted on 1,000 tons of concrete and steel rebar and must be outfitted with flashing red lights.
City Problem #1. These 350 wind towers are expensive, about $2 million each. Luckily the government will subsidize most of the cost (paid by taxpayers elsewhere).
City Problem #2. Whereas the coal plant occupies fewer than 20 acres, each GE 1.5-megawatt turbine requires a minimum of 32 acres and needs 82 unobstructed acres in order to optimally utilize wind from any direction. This is a total of 28,700 acres, or about 45 square miles of land. That much space is way too expensive to purchase, so the city fathers convince the county and state to fund subsidizes to surrounding farms to host such towers, or decree eminent domain to force their location on unwilling farmers.
City problem #3. The coal plant was located close to town. To service these new wind towers new expensive access roads and power transmission lines must be funded and constructed.
Some grumbling begins, mainly among those whose farms were forced to accept the towers, among coal plant workers who are soon to be fired, and among those long range planners of future city budgets.
The wind towers are finally constructed and tied into the city power grid.
City Problem #4. Before the coal plant is retired, which operated 24/7/365, the city planners realize that the wind does not always blow. Further, even when it does blow, it often does not blow enough, and at these times the wind towers generate less than their rated electrical output. Often some towers will be out for maintenance.
The city fathers decide to keep the coal power plant in operation (after all, it was paid for) and only use it as back-up power for when the wind does not blow.
City Problem #5. It is discovered that when the coal plant must be fired up to replace wind power that has suddenly diminished, it cannot come to power quickly enough to prevent brown-outs (voltage drops), even an occasional black-out (no power). Further, these times of rapid cooling and heating of the boilers are degrading them much faster than when they operated continuously.
Citizen grumbling increases over the power issues they individually are experiencing.
The city fathers decide to build another gas-fired plant to replace the coal plant.
Grumbling increases among city dwellers over the increased taxes and electricity costs required to pay for the second gas plant. For the first time in many years, serious challengers arise in the upcoming city council election.
The second gas plant is constructed. One gas plant operates continuously, and the second plant operates in a near idle mode (but still burning some gas and producing CO2) so that it can be rapidly fired up when the wind dies. Keeping both gas plants operating, even at lower level for one, is more expensive than expected, but now they offer adequate back-up for when the wind-towers generate too little power.
Some city citizens forget that they are now paying sizably higher electricity bills and are happy that their CO2 production is now somewhat lower than originally. But many other citizens grumble and discuss recall elections.
Time passes. The city grows and needs more power. Further, the government gives a new decree to lower CO2 emissions even more. The city fathers decide to construct more wind towers. The reasoning is threefold: a) adequate power would still be available when the wind blew only lightly; b) extra power generated by wind could be sold to the surrounding cities; and c) the city’s gas plants would not have to operate as often, thus lowering CO2 generation. The plan sounded reasonable to city council.
City Problem #6. Large citizen protests erupt. The city mayor and two city council members are recalled. Yet under demands from the government, the new city government barely convinces the annoyed citizens to proceed. Active animosity develops between those who support this rapid move to renewable energy and those who do not.
City Problem #7. With the prospect of large flows of energy among various cities, extra and expensive long-distance transmission lines must be constructed.
The city goes even much more heavily into debt and several hundred extra wind towers are constructed. Counting total power capability from two gas plants and many hundreds of wind towers, the total potential power production is much more than twice what the original power capability was, although the city has only grown by 20%.
City Problem #8. The city is now sharply divided over this issue. The “green” citizens emphasize the good that wind power is doing in reducing CO2 emission and think that good justifies the many extra costs. Financially practical citizens complain that city electricity costs are now much higher than before, that much more open land is being compromised, and that the wind towers are noisy and unsightly, whereas CO2 emissions have only modestly been reduced.
The city fathers argue than the extra wind power produced by the new turbines can be sold to ally some of their costs.
City Problem #9. However, when the wind blows hard and extra wind power is produced, the city fathers discover that surrounding cities, which by now also have converted heavily to wind power, often also have too much wind power and are not in the market for any more. The city cannot sell its unused power, and having no way to store the extra power, must simply “dump” it unused. City fathers also realize that sometimes the wind quits blowing not just over a local region, but over a very widespread one. In these cases most or all of the local cities produce too little total power, and regional brown-outs develop.
The city fathers have a new idea — develop solar energy. Often the Sun shines when the wind does not blow and the wind often blows at night. But the city citizens would never permit a huge central solar power facility, and there is no suitable place to locate such a facility. But, the city fathers learn that the government heavily subsidizes PV-solar equipment for individual homes and businesses. The city fathers again decide to utilize government subsidizes paid for by others elsewhere. The city fathers appeal to the “green” citizens to use some of their funds along with the government subsidies to install PV-solar systems on their roofs. To give further enticements, the city fathers decree that the city electrical power company must purchase at full retail prices all excess solar power than these “green” citizens may produce. Many “green” citizens comply and a few hundred extra M-watts of solar power becomes available.
City Problem #10. However, the city fathers soon discover that when the Sun is brightly shinning, these PV-solar panels feed so much solar power into the grid that sometimes either the gas-fired plants or some wind towers must be curtailed in their power production. This produces further complications in keeping power fed into the local grid precisely in balance with the local and total power demand, as it must be if equipment damages are to be avoided. The city power company strongly complains about the new problems it has been handed.
City Problem #11. Further, the city power company discovers that on sunny days, it is buying so much solar power at retail prices, that it must raise power rates to those customers who do not have PV-solar grids.
Citizen complaints about power costs increase. Some prospective new industries with sizeable power demands decide to locate elsewhere.
Surrounding cities, which have also encouraged rooftop PV systems, find themselves with similar problems.
The city finds itself in a catch-22 situation. Both producing too much power and too little power, both at significantly increased prices, have negative and unintended consequences.
MORAL OF THE TALE. Conversion of electrical power generation from fossil fuels to renewable wind and solar is a process that can readily be both quite expensive and filled with unexpected negative consequences. For governments to rush into such a transfer too quickly or without a fully thought out a plan may be a recipe for higher electricity costs, customer dissatisfaction, social disruption, and ultimate political consequences.