Wind Turbines Generate Electricity and Controversy: a series on whats in the wind.
Critics claim that intermittent and variable wind is reason to halt development and support of an ill conceived energy plan. Wind Turbines (obviously) require wind to generate electricity. If the wind speed is too low it will not be strong enough to turn the giant propellers, if the wind speed is too strong the machines must be shut down to protect the equipment. Consumers expect 100% efficiency from their appliances not 30 %. Sometimes the day starts as a gentle breeze and then has strong gusts which quickly stop and then there is calm possibly followed by the slightest breeze later in the evening. This would be comparable to listening to a phonograph playing at a normal speed and then spinning madly, stopping on and off and resuming at a very slow revolution. Who could live with that? Could you imagine your lighting fluctuating between dim and glaring throughout the day? Winds are seasonal and more or sometimes less energy would be generated throughout the year. What if there was a wind drought? On and off intermittent wind power does not seem like a logical investment if conventional generators are still required for back up when the wind dies.
The How to Power the World. Com website is about how the future depends on access to cheap, widespread energy. There are references to nuclear fission and sources of alternative energy. One page goes into detail about the disadvantages of wind energy. The disadvantages of wind energy include: the intermittent availability of the wind producing a variable output. As the production one moment can change in an instant, wind energy would have to be coupled with an advanced energy storage system. Not only do wind turbines not operate all of the time, but they can also never extract 100% of the energy stored within the wind which passes through the turbine.
Wind-Watch.org says it’s a SwindLE. ‘It is also known to do next to nothing for reducing dependance on other fuels or carbon and other emissions, due to the winds intermittency and high variability’. The North American Platform Against Windpower (NA-PAW.Org) states ‘wind power’s contribution to reducing CO2 emissions or fossil fuel use is limited, because power plants must be kept on line – and used more often and less efficiently to compensate for the intermittent and variable nature of electricity generated by wind turbines’.
David Schnare writing for The Washington Times (August 16, 2011) chides Republican presidential candidates for considering ‘dirty, costly wind energy’ as an essential element in energy policy. He uses an example of how intermittent wind is unreliable – “In the afternoon of Feb. 26, 2008, the winds died down in a stretch of west Texas that is home to thousands of tall wind turbines. Over a span of three hours, the turbines’ combined contribution to the state’s electricity grid fell by 75 percent. ” Schnare goes on to say in his article ” Wind isn’t just unequal in terms of reliability; windmills actually cause more air pollution than coal plants operating as designed. Texas is a nasty reminder of this. Along with other facilities, state utilities often depend on two coal-fired plants to “balance” the wind power, which means they fill in when the wind stops and must continue to “spin” when the wind blows. They still must burn coal to prevent the windmills from crashing the electrical grid when the wind drops, so they can instantly fill in electricity when needed.’
A scientific report making the rounds titled The impact of wind generated electricity on fossil fuel consumption by C. le Pair & K. de Groot concludes : the wind projects do not fulfill sustainable objectives. They cost more fuel than they save and they cause no CO2 savings. in the contrary they increase our environmental impact. Calculations in the report show this: The amount of fossil fuel used in a situation where wind is providing electricity as well thus becomes: F – ΔF = ( E – Ew) / ( R – ΔR) and the fuel “saving” ΔF is equal to: and the fuel “saving” ΔF is equal to: ΔF = F – ( E – Ew) / ( R – ΔR ) ΔF can become negative, and then wind power does not save fossil fuel, but causes extra fossil fuel consumption and also extra CO2 emission. The turning point where no fuel is saved is reached when ΔF = 0 When combining equations (1) and (4) for ΔF = 0 we find: E/R= ( E-Ew) / ( R- ΔR ) and therefore ΔR = Ew*R/E.
The modern world depends on a reliable consistent source of electricity. City infrastructure (stoplights), factories, hospitals, office building elevators and on a personal level my refrigerator and this computer I’m typing on all require steady electrical current or chaos will ensue. Electric power stations work just fine with conveyor belts of dependable coal feeding the fires or pipelines of petroleum fueling the furnace. We need an energy source with substance not something vague and slippery like the wind that you can’t even see, besides the wind does not blow all the time and who would want it to. Too much wind makes people go crazy.
Wind Farms are a negative – a con. That’s what the critics would like you to believe. The real problem with wind farm development is obfuscation. Critics try to Confuse the population about the facts and prefer to continue using conventional fossil fuels. Some refuse to believe in any anthropogenic cause to global warming or if it even exists. Others believe that clean coal, tar sands and newly discovered natural gas resources are in sufficient supply to continue fueling furnaces just as they have for the past 100 years and up to 100 years into the future.
Lets clear up some myths and misconceptions. First of all wind does not start and stop instantaneously, sporadically or automatically. Variable is a more appropriate term than intermittent since the latter suggests on/off and the reality is that wind is usually on but varying. Wind farms are built in locations that are studied and have a recorded yearly number of days with wind speeds sufficient to operate the turbines. Most turbines operate in a range of 6 to 28 mph wind speed. The aggregate wind power capacity is variable but because there are wind farms in many different locations chances are the wind will be blowing somewhere. Wind patterns and predictions can be calculated.
Opponents to wind farms and right-leaning think tanks are quick to disseminate scientific papers that ‘prove’ traditional power plants will need to switch on and off, a very inefficient process causing an increase in CO2 emissions, because wind power is intermittent. One often cited paper is by Dutch wind critic and retired physicist C. le Pair who posted a non-peer reviewed study on his web site of a theoretical scene featuring a hypothetical wind farm at an unlikely location. Robert Gross, director of the Centre for Energy Policy and Technology at Imperial College, London said “Extreme estimates usually result from flawed or overly simplistic methodologies, unrealistic assumptions, or misallocation of costs.” The claims of le Pair have been widely rejected by industry professionals. Robert Gross goes on to say ” Electrical engineering based modelling and simulation, and increasingly empirical data from countries where the penetration of windfarms has reached a significant level (such as Ireland, Denmark, Spain, Germany and some US states), demonstrates conclusively that wind does reduce emissions.”
Another concern voiced by critics is that wind energy fed at sporadic intervals into the grid would destabilize the entire grid system. They say new power plants will need to be built to make up for and match every megawatt not delivered by wind farms when they are not on line. Findings of a 2005 report by the International Energy Agency found that barriers to greater penetration of renewables into the existing grid were economic and regulatory rather than technical. The UK Energy Research Center (UKERC) convened an expert group that reviewed more than 200 studies on wind power integration and issued an internationally peer reviewed report that found -none of the 200+ studies- suggest that intermittent renewable energy would lead to reduced reliability and 100% ‘back-up’ for individual sources is unnecessary.
It is important to remember that wind energy is only one component of future energy supplies. There will still be traditional sources plus a combination of renewables. Penetration of wind energy is expected to reach the target of 20 to 25 % in the US and European Union over the next few years while some countries like the Netherlands may reach 50%. The German Energy Agency Dena has demonstrated that large scale integration of wind energy into the electricity system is technically and economically feasible. They found that wind energy requires only minor expansion of the grid and does not require construction of additional ‘balancing ‘power. The European Wind Energy Association (EWEA) calculated that when 10% of total electricity consumption is produced by wind the back-up power needed is 2-4% of capacity – not total electrical consumption. A groundbreaking Minnesota wind integration study finds up to 25% wind can be incorporated reliably to the power system and that adding an additional 1,500MW (enough energy to supply 400,000 homes) that less than 0.5% back-up would be required.
As new technologies evolve questions of variable power may become non-issues. Research and development is being done for systems that can pump water uphill to storage ponds and release it at a later time to turn turbines and a similar concept is being tested to compress air to be stored in underground shafts then released to turbines when needed. Duke Energy Corporation will have the worlds largest power-storage for a wind farm go into operation late in 2012. The 36MW battery manufactured by Xtreme Power will be used at the West Texas 153MW Nortrees wind farm. The Laural Hill wind farm in West Virginia also has a similar type battery power storage. These systems will help wind and solar projects interact with the electrical grid and manage potential negatives from variable wind or a peak- solar resource.
Reduction of CO2 emissions into the atmosphere is one of the greatest challenges of our time. Clean renewable energy from solar and wind will help meet that goal. Protests of intermittent wind by critics is a con because wind farms are proving they can be a reliable source of energy.