For the third time, you do not need to argue nuclear power with me. I like nuclear power. The topic of this thread is wind energy.
Then let's compare the fuel costs between a 100 MW LNG plant and 400 MW of wind turbines. Hmm... my calculator keeps saying something about divide by zero...
Why compare it to a fossil fuel power plant when the idea is to generate emission free power?
But what are the maintennace costs of 400 wind turbines compared to one large turbine? What about the operating life of those turbines compared to a single large turbine?
We need power 24/7/365 and intermittent power generators aren't the way to get it
In what accounting does any power generator that only produces 25% of it rated capacity a good deal?
Would you buy a car that only got you 25% the way to your destination?
Would you buy a furnace for you home that only heated your home to 25% of the thermostat setting?
I compare wind to fossil fuel plants because people here, including you, have been trying to claim that power from a wind turbine costs more to the end user than power from a fossil fuel plant and that is simply not true. One of the primary reasons for that is zero fuel costs. I regard the wind turbines PRIMARY value to be it's zero-carbon output and the cost savings just an added benefit.
The average capacity of a wind turbine in the US (just asked Google) is 2.43 MW. The average size of a combined cycle (gas and steam) plant is 500 MW produced typically by 5 shaft sets. So, we're talking about roughly 50 wind turbines to match the output of 5 shaft sets. The reliability of these systems is dependent on multiple factors. Complexity, temperature and pressure extremes, fatigue cycles, and others. A wind turbine consists of a large variable-pitch rotor attached to a gearbox attached to a generator. With no combustion there is no serious heat anywhere in the system. There are no working fluids, so no fluid pressure issues. The typical COGAS system consists of a gas burner feeding a low pressure, high temperature turbine the outlet of which goes into a heat exchanger to produce steam which feeds another turbine. It is considerably more complex and under considerably more stressful normal working conditions . Wind turbine technology, on the other hand, is not as mature as fuel powered generation. Then keep in mind that if a typical CODAG plant loses one shaft, they have lost 20% of their capacity. A 400 turbine farm losing one turbine still retains 99.75% capacity. That 10-to-1 ratio works in both directions. There is not a great deal of information on the net to support either side of this argument, particularly if one tries to avoid real or perceived bias in one's sources. I did find the following discussion on wind turbine reliability from what appears to be an objective source:
*****************************************
Wind Turbine Reliability Challenges
Reliability is defined as the probability that a product will perform its intended function under stated conditions for a specified period of time. Reliability engineers and researchers use field data, experiments, and analytical techniques to determine the failure rates of products over time under specific conditions, and then work with design engineers to make products more robust.
Determining the reliability of currently installed wind turbines is an active and challenging area of research. There are a number of databases globally that track wind turbine failures and downtimes, but there is no uniform method for deciding what data to collect, how to collect it, and how to record it. Researchers7,8 have identified other problems as well:
- Necessary data may not be available because it is considered proprietary by wind turbine operators.
- It is difficult to compare data from one wind turbine to the next due to differences in component technologies and construction.
- It is difficult to compare data from similar wind turbines operating in different environments (dry vs. wet, hot vs. cold, etc.).
- Wind turbine designs and technologies are evolving rapidly, making it difficult to compare data from newer wind turbines to data from older, smaller wind turbines.
- Wind turbines are typically designed for a 20-year lifetime, but most of the turbines in the field were installed less than 20 years ago. Complete lifecycle field data does not exist in most cases, and the oldest wind turbines with the most field data available are not representative of the latest designs and technologies.
- There is also a limited amount of published work regarding failure analyses of wind turbine components, and much of the data that does exist is from older wind turbines. This makes it difficult to compare failures of similar components in different turbines. For example, there are many ways a gear box could fail. Without knowledge of exactly how the gear boxes failed in the field, it can be challenging to analyze gear box failures on similar wind turbines.
Despite these difficulties, researchers have made estimates of wind turbine reliability. In general, about half of wind turbine failures are due to electric components and to the control system, but these failures have low downtimes. Generator and gear box failures are less frequent but have longer downtimes. One study found that 25% of wind turbine faults caused 95% of the downtime. Reliability of wind turbines has improved with time and has achieved an availability of 98%, but wind turbines fail at least once per year, on average, with larger wind turbines failing relatively more frequently. A recent study of US wind turbines found that when all sources of downtime are accounted for, the average wind turbine actively generates power for 1.5 days between downtime events and that the average downtime is 1.6 hours.
*********************************************************************************************************************************
See how our experts foster connections between technical disciplines and industries to deliver breakthrough insights.
www.exponent.com
We do need power 24/7 but we also need to reduce our GHG emissions. The solution to that is not to restrict ourselves to single-technology solutions. An integrated approach including smart grids, Wind, solar PV, high efficiency combined gas and steam, hydroelectric and nuclear can achieve both aims. Wind turbines have infiltrated markets worldwide and we have not seen the decrease in system reliability you and others have been predicting.
A system that you expect to produce 25% of its rated output is the proper choice when other factors (zero carbon output, zero fuel consumption) dramatically affect long term prices, when lower capitol expenditures offset the rated output issue and, at the small but compassionate end of the scale, when the technology will produce far more skilled job openings than older technologies.