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Risk Analyis of Off Shore Wind Power near Narragansett Bay by Capers Jones
Major Risks to Windmills Based on Insurance Claims Mechanical failures of generators, broken or damaged blades, lightning strikes, hurricanes or strong winds; metal fatigue of hubs and transmissions; fatigue and distortion of fiber glass and carbon composite blades; poor manufacturing quality control. Proposed Wind Farm Location Various web sites list the location of the proposed Block Island wind farm as being latitude 41 120° and longitude of -71 520°.  This is past the normal mouth of Narragansett Bay but many local residents still consider the wind farm to be part of Narragansett Bay even though it is not. The map above shows their location Introduction The need for clean energy has caused an infatuation with wind power among state governments and the federal government and some municipal governments.  Unfortunately the infatuation has not been accompanied by due diligence or even by a realistic risk analysis. Worse, offshore wind farms are not truly clean energy.  For example the energy savings calculations for offshore wind farms often omit the fact that construction of each wind mill may use thousands of gallons of diesel fuel in the ships, boats, and sea-going construction cranes used to deliver wind mill components and support the work crews.  To provide a Rhode Island context, while under construction the ships and boats supporting the Block Island wind farm might use more diesel fuel than all of the buses of the Rhode Island public transit system put together.  Annual usage of diesel fuel for the boats and equipment needed for repairs and maintenance may burn up thousands more gallons of diesel fuel per year.  This is a much higher usage of diesel fuel than land-based wind mills.  To provide a Rhode Island context the diesel fuel used for maintenance and repairs of the Block Island wind farm might use more diesel fuel than the Block Island ferry. A growing problem in Europe where wind farms are plentiful is the fact that carbon-composite blades cannot be recycled and if burned emit carbon and other harmful materials into the atmosphere.  Reinforced fiberglass is also hard to recycle and especially for objects the size of wind mill blades and other components. The high failure rate of wind mill components is creating a huge new waste-disposal problem that wind-power enthusiasts have chosen to ignore.  If consumption of diesel fuel for construction and repairs plus fuel for the disposition of damaged and obsolete wind mills and broken wind mill blades are included in the total energy calculations, wind power is much less “green” than originally hypothesized. The annual maintenance of offshore wind farms uses substantial volumes of diesel fuel in the engines of the maintenance craft and heavy equipment.  Offshore wind farms probably use 50 times more diesel fuel for construction than land-based wind mills.  Offshore wind mills may use more than 10 times the amount of diesel fuel as on-shore wind farms for maintenance and repairs. As of 2013 no one even knows how much energy will be consumed in disposing of damaged wind mill blades made of fiber glass or carbon composite materials.  All that is known so far is that thousands of broken blades and components are piling up around Europe waiting for some kind of solution to their eventual elimination. A set of five large offshore wind power plants adjacent Narragansett Bay off Block Island has slipped past their initial rejection based on poor economics (they will raise Rhode Island utility rates possibly forever.) While the lobbyists and initial investors will make a lot of money, Rhode Island tax payers and National Grid rate payers will be facing higher fees for electric power and potentially higher taxes for as long as they live.  The costs are probably worse than Studio 38 in terms of their impact on Rhode Island tax payers because the dollar amounts are larger.  The political tricks to get the wind farm through the legislature are similar to Studio 38.  Specifically the initial requirement that wind mills had to be commercially viable was removed; they no longer have to be a good investment and they are not. An interesting article on the power of wind farm lobbyists was published in the British newspaper The Telegraph on February 11, 2012:  Wind Industry’s Extensive Lobbying to Preserve Subsidies and Defeat Local Opposition. For every dollar spent building an offshore windmill there will be other significant expenses, as shown by this possible scenario for a single offshore windmill: Expense/Value Factors  Relative $ Amounts Lobbying $0.15 Political contributions $0.15 Wind mill construction $1.00 Maintenance for 10 years $2.00 Disposal of damaged blades $0.50 TOTAL PHYSICAL COST $3.80 Environmental damages $1.00 TOTAL RI COSTS $4.80 Useful electricity  $0.95 Net Value                       -$3.85 (In addition the construction process will probably damage fish and lobster stocks, as will the vibrations from the operating windmills.  Let’s assume another $1.00 in environmental damages.) If any reader has different cost patterns for offshore wind farm construction and maintenance it would be useful to see them.  No web sites visited by the author show positive value for offshore wind mills when construction, fuel costs, maintenance, repair costs, and disposal of damaged blades are included in the total and compared to the value of the electricity that is generated. With a net value to Rhode Island of a negative - $3.85 for the electricity generated, who would profit from such as negative cost to value ratio?  The answer to this question is that only a very small set of special interests would profit: 1. Politicians who receive political contributions 2. Lobbyists paid by the wind industry 3. Investors in the wind farm 4. Wind mill equipment manufacturers 5. Wind mill construction companies 6. Wind mill maintenance companies For ordinary Rhode Island rate payers and ordinary tax payers in Rhode Island the offshore wind mills will raise utility costs and probably raise taxes forever.  There is no positive economic value from offshore wind mills so long as construction, maintenance, and repair costs are as high as they are in 2013. The Block Island wind farm is stated to be precursor to an even larger wind farm of more than 200 offshore wind generators. If this happens the costs will be much higher than Block Island but the value will still be negative for perhaps 30 years. Following are some of the risks that both state and affected municipal governments should consider. Physical Risks Because off-shore wind mills are located in inconvenient places, all repairs and maintenance have added costs compared to land-based electric power generation due to the need to use either boats or helicopters, or both, to reach the windmills.  Almost any kind of minor service is more than twice as expensive as fixing the same problems on shore.  Worse, serious repairs that may require sea-going cranes or industrial barges to transport heavy items may raise the costs to more than 10 times higher than similar land based repairs.  While Deep Water says that “National Grid will pay for repairs” that statement is not accurate.  Rhode Island taxpayers will pay for the repairs through higher utility bills, increased taxation, or both.  There are no financial benefits for Rhode Island taxpayers; only higher utility bills and higher taxes probably forever. Another issue is that physical repairs of off shore wind mills cannot occur at all during high winds and rough seas.  Important questions regarding the Block Island wind farm, to date unanswered, are: 1. What is the maximum wind speed that allows repair boats to visit the wind farm? 2. What is the maximum wave height that allows repair boats to visit the wind farm? 3. What is the expected average time interval from incident to full repair? From incident to full repair, it is probable that the number of days needed to repair a damaged off- shore wind mill would be at least 5 days longer than repairing a land-based wind mill or on-shore power facility. When these costs and repair delays are added to the intrinsic high costs of wind power itself, there is almost no chance of offshore wind power being less expensive than alternate forms of electric generation for another 30 years or more.  Currently offshore wind is one of the most expensive of any form of electric power generation.  Every Rhode Island taxpayer should read a revealing large-scale statistical analysis of all wind farms in England published in the British newspaper The Telegraph on December 11, 2011 by Edward Melnick and Robert Mendick.  (Why is the Providence Journal so passive on wind power problems?) This alarming article included 5 years of statistical data.  It showed a total of 1,500 accidents and failures or almost one a day.  About 300 of these accidents injured workmen and there were four deaths. Among the problems cited in this article were wind mill blades blowing off in winds of 150 miles per hour; wind mill blades throwing clumps of snow and ice for long distances; wind mills falling over in strong winds; mechanical failures; and instances of faulty engineering by wind mill manufacturers.  This is such an important article for Rhode Island that a URL that leads to it is included here:  Hopefully the costs and risks cited in this article will be at least considered by Rhode Island officials such as the general assembly and the CRMC.  Here are some of the specific kinds of physical risks that need to be considered for the long-term use of off shore wind farms: Hurricane damages to the windmills:  Long-range weather predictions for the North East indicate a probable increase in numbers of hurricanes per year and another possible increase in severity levels.  Unless a wind farm can withstand winds that approach 150 miles per hours they may be toppled.  The odds of hurricanes or other major storms damaging the Narragansett Bay windmills are probably 10% per year.  An interesting study called Quantifying the Hurricane Catastrophe Risk to Offshore Wind Power by Stephen Rose et al noted about a 10% chance of windmills being damaged or out of service due to hurricanes.  Narragansett Bay, as we all know, has had frequent and severe hurricanes and this pattern will continue perhaps forever. Hurricane damages to the utility lines and poles:  The original plan for routing the high-voltage line from the Narragansett Beach to the collection station was by underground cable.  This changed to overhead lines due to cost consideration. This seems to be a big mistake.  Every year for more than 10 years portions of Narragansett have had lengthy power failures due to hurricanes and nor’easters severing power lines due to trees falling on them or the poles being blown over, or both.  The annual odds of losing power from the overhead lines and poles are at least 30% per year; and possibly above 50% per year.  When the annual costs of replacing downed poles and repairing broken cables are added to the cost analysis, underground cable probably wins.  Only the initial construction costs favor overhead lines; not long-range maintenance and operational costs. Mechanical failures:  Rhode Island already has had a land-based windmill fail in Portsmouth and the repair costs were so high that they destroyed the positive economic value of the windmill.  No one knows the reliability intervals of the Narragansett Bay windmills because they are a new model.  However windmill generators in land-based wind farms in California and elsewhere might provide statistical data.   The annual odds of a specific windmill failing for mechanical reasons are perhaps 7% per year. Because Europe has many offshore windmills the European literature has more empirical data than the U.S. literature.  Several interesting articles can be read from the web:  Review of Offshore Wind Turbine Failures and Faults by Bill Lau et al; Estimating Costs of Operations and Maintenance of Offshore Wind Farms by P.J. EEcen are both solid studies.  Both of these studies are from the Netherlands.  An Indian study of insurance claims against Indian windmills noted that 55.9% of all claims were due to mechanical failures. Metal fatigue, fiber-glass fatigue, and carbon-composite fatigue:   Small wind mill blades, hubs for fiber glass or carbon composite blades, rotating metal parts in gears and generators, and to an extent the towers themselves are subject to metal fatigue.  As we have seen in the aircraft industry, metal fatigue leads to cracks in wings and in some cases to disastrous ruptures of a fuselage in flight.   Because windmills are in almost constant motion, the impact of metal fatigue will probably shorten the effective life span of both offshore and land-based windmills.  The worst-case scenario of metal fatigue would be the abrupt loss of a blade in motion due to hub failure; these do occur.  Blades are large enough and heavy enough to sink good-sized boats if any are in the immediate area.  The odds of metal fatigue and fiber-glass fatigue causing damage go up with time.  It is very low for the first year, but after 10 years it might top 5% per year and these odds will get worse every year thereafter.  It is obvious that every hub and every blade on every windmill needs annual checks for cracks caused by metal fatigue and fiber-glass farigue, among other risks.  The web site Metal Fatigue Solutions (  has interesting data on this topic in the context of windmills.  Fiber-glass reinforced plastic blades (FRP) are also subject to fatigue and rotational distortions.  An interesting study by Sandia National Laboratory on fiber-glass blade fatigue noted that with continued use the blades weakened.  The paper Acoustic Emission of Wind Turbine Blade During a Fatigue Test by A.G. Beattie provides background data.  The study was commissioned and funded by the U.S. Department of Energy.  A google search on “failure of fiber glass and carbon composite wind mill blades” will show many alarming studies. An important question for the State of Rhode Island is whether or not metal fatigue and fiber-glass fatigue have been factored in to the reliability and cost predictions for the Narragansett Bay wind farm.   If not that indicates possible professional malpractice by the engineering team. Since wind mills are being advertised as “green energy” which does not pollute, it is an interesting fact that carbon blades cannot be recycled and if burned emit carbon into the atmosphere. As wind farms increase in numbers, disposal of metal, fiber glass, and carbon composite materials is creating a huge new source of future pollution that to date has not been discussed in the wind-power literature. Lightning strikes and electromagnetic pulse (EMP):  Windmills on land and at sea are susceptible to lightning strikes and also to electromagnetic pulse (EMP) which could produce unrepairable damages should it occur.  Hopefully the odds of EMP are very low. Deliberate EMP attacks would probably only occur during a state of war because EMP attacks require space detonations several miles above the atmosphere.  However such EMP attacks would damage more than windmills:  they could shut down the entire grid and almost all electronic devices. Natural EMP caused by major lightning storms is another issue.  It would be interesting to know if the Narragansett Wind farm is protected against major lightning strikes or against EMP caused by severe lightning storms.  Probably the physical structure of offshore windmills would attract more than their fair share of lightning strikes. It would also be useful for the State of Rhode Island and Deep Water to study the extensive literature on lightning and windmills.  Apparently lightning strikes are among the most common reasons for damaged blades and generators for both land and offshore windmills. The Narragansett Bay windmills should clearly be insured against lightning strikes and also against EMP. A useful paper is a statistical study called Breakdown Risks in Wind Energy Turbines by J. Ramesh Babu and S.V. Jithesh.  This is a study of damages to wind farms in India, but the same statistics are relevant here.  According to this study lightning damage was the #2 insurance claim against Indian wind mills at 17.5% of total claims.  Mechanical breakdown was the number #1 claim at 55.9%. Ship and boat collisions with wind mill towers:  In Europe where offshore windmills are common, collisions with base towers by both large ships and small boats have occurred.  In fact most European countries have created new navigation rules and guidelines to reduce the odds of these collisions in the future.  A google search using the phrase “boat collisions with offshore windmills” will turn up dozens of reports.  In February of this year a supply boat collided with a windmill tower at the Bard wind farm off Germany.   This collision caused serious damage to the boat itself, but did not seem to harm the wind mill tower.   A 2005 study entitled Collision Safety Analysis of Offshore Wind Turbines by Florian Biehl of Hamburg University of Technology provides background information, and there are many other studies as well. The Block Island wind farm has some unique issues that may not have been properly addressed and analyzed.  Most offshore wind farms are located more than 30 miles at sea and hence outside the normal range of small open pleasure boats. The Block Island wind farm will be very close to, and highly visible from, Block Island, which is a major tourist destination with hundreds of small boats in the summer.  It is quite likely that the wind towers will become an “attractive nuisance” that will draw many small open boats and possibly even one-person jet skis. Some of these small boats will no doubt be crewed by untrained civilians some of whom may be partly inebriated.  Some of the crews might possibly be armed and take pot shots at blades or hubs.  The Block Island wind mill plan needs analysis of the odds of collisions with small boats as well as the odds of collisions with supply boats, fishing boats, and those with trained and certified crews.  However amateur crews who are partly inebriated may be the greatest risk for Block Island and the odds of a collision need to be calculated. Earthquakes in Narragansett Bay:  The author’s book The History and Future of Narragansett Bay has a list of local earthquakes in or near Narragansett Bay from 1638 to the present era.  More than a dozen local quakes have occurred and two of these were or Richter 7 or above; the most recent being in 1925.  The last significant local quake in Narragansett Bay was of magnitude 5.2 and occurred in 1973.  These quakes are intermittent and unpredictable, but from looking at 300 years of earthquake data the odds of a significant quake occurring within 10 years may be about 2%. It would be prudent for the Narragansett Bay wind mills to be able to withstand earthquakes of Richter 7.  It is also important to know whether the State of Rhode Island, the federal government, or Deep Water has included possible earthquake damage in either the construction plans or the long-range maintenance cost estimates.  The literature on earthquake damages and construction techniques from Japan should be reviewed by State and Deep Water engineers.  In fact unlike the nuclear plants in Japan which were heavily damaged by the earthquakes, the Japanese windmills continued to operate and even increased their power output.  The web site had an interesting article entitled “Japan’s Wind Turbines Survive 1000 Year Earthquake. The relevant question for Rhode Island and Deep Water is whether or not the Narragansett Bay wind farm will use the same kinds of construction as those used in Japan to guard against earthquake damages. Unless local windmills can withstand shocks of Richter 7 they are at some risk.  This is true for both land and offshore windmills. Eco-Terrorist Attacks on wind farms:  A real danger to both land and offshore wind farms is that of attacks by eco-terrorists, militant extremists, or foreign terror groups such as Al Qaida. These are not hypothetical:  they have occurred in several wind farms already.  Unfortunately off shore wind farms are probably the most vulnerable known form of electric generation when it comes to terrorist attacks.  A psychotic high school student with a boat and a bag of fertilizer could blow up a windmill very easily.  A website called had reports on land-based windmills being toppled in the Tehachapi-Mojave region of California.  Since these were land-based windmills they were toppled by cutting their base supports. While home-made explosive devices are the most probable terror risk, wind farms are also vulnerable to attacks by surface-to-air missiles such as Stingers which are widely used by terror groups.  These missiles could easily blow away the generator and blades from offshore windmills from a boat and from land-based windmills in a drive-by attack. Wind farms are not alone in being targets of terror attacks:  all kinds of power plants are at a risk.  However in the context of the Narragansett Bay wind farm, it is urgent to know if either National Grid or the State of Rhode Island or Deep Water plans to include protective devices.  Among the kinds of protective devices that might be needed would be 24-hour video and infrared monitors feeding into a shore-based security site; fairly frequent patrols by the Coast Guard or National Grid; and possibly the use of drones to monitor all approaching boats. It is difficult to predict the odds of some kind of terror attack on power generation plants, but it has to be at least 1% per year in the modern world. Specific Risk Questions for the Deep Water Wind Farm As part of a due diligence process, there are a number of specific questions that should be examined about the safety and cost structure of the proposed Block Island wind farm.  Following are 30 questions that need answers: 1. What is the maximum wind speed before blades break or receive damage? 2. What is the maximum wind speed before the towers are likely to fall? 3. What is the maximum wind speed that allows repair boats to be launched? 4. What is the maximum wave height that allows repair boats to be launched? 5. What is the expected repair interval in days from incident to full repair? 6. How many days per year will the windmills be out of service waiting repairs? 7. What are the annual costs for sea-going cranes, barges, and repair boats? 8. What is the life expectancy for a blade? 9. Have there been fatigue calculations for metal, carbon, and fiber glass parts? 10. Will local blades have the same failure rates as European wind farm blades? 11. What is the replacement cost of a damaged blade? 12. What is the replacement cost of a toppled windmill? 13. What is the disposal cost of a damaged blade? 14. How will a damaged blade be disposed of? 15. How will toppled wind mills be disposed of? 16. Where will damaged blades be taken for disposal; Rhode Island or elsewhere? 17. Will the odds of local failures be equal to those of existing European wind farms? 18. Are maintenance costs based on actual results from existing European wind farms? 19. What specific risks are covered by wind mill insurance? 20. What are the annual costs of insurance per windmill and for the wind farm? 21. What are the expected costs for repairing utility poles and lines damaged by storms? 22.  What are the odds of damages caused by blades throwing ice and snow? 23. Are we likely to have the same percentage of construction injuries as in Europe? 24. Will the wind farm include protection against deliberate attacks? 25. Have there been impact assessments of blade damage from hail or bird strikes? 26. Will the local wind farm use Japanese methods of minimizing earthquake damage? 27. What are the expected routine maintenance costs for 10 years after deployment? 28. What would be the 10 year costs if 3 blades and 2 windmills are replaced < 10 years? 29. What are the replacement costs of a generator and associated gearing? 30. What are the planned maintenance costs of all cables leading to the mainland? There are other questions besides these; but at least this is a start on a list of specific questions that should already have been addressed. Summary and Conclusions Wind power seems to offer attractive advantages in terms of generating power without using fossil fuels.  Unfortunately both construction and maintenance of offshore wind farms use large quantities of diesel fuel in the boats and sea-going construction equipment.  The disposal of carbon-fiber and fiber- class windmill components is a huge new environmental problem that has not been addressed by wind power enthusiasts.  Carbon components cannot be recycled and if burned may possibly release more carbon emissions than a wind mill prevents.  The “green” claims of wind power are exaggerated and omit the huge new issue of wind mill waste from damaged blades and carbon components. The current state of the art of offshore wind farms is highly negative in terms of cost-benefit analysis.  Worse, off-shore wind farms are subject to a variety of physical risks, none of which seem to be considered by the State of Rhode Island and perhaps not by the Deep Water engineers. It would be useful to know the exact plans for the Narragansett Bay wind farm for the risks of:  1. Hurricane damages at sea  2. Lightning strikes and EMP  3. Hurricane damages on land  4. Mechanical failures of generators  5. Metal fatigue to blade hubs  6. Fiber-glass and carbon composite fatigue of blades  7. Earthquake damages  8. Terrorist attacks  9. Ship and boat collisions with towers 10. High costs of off-shore repairs Hurricane damages have the highest risk probability, but all of the risks might well occur within 10 years.  Lightning strikes haves the second highest risk probability and are globally a major source of damages to both land and offshore windmills. References and Readings The literature and web pages dealing with offshore windmill risks are quite extensive.  Readers are urged to do google searches using the phrases of: Hurricane damages to offshore windmills Lightning damages to offshore windmills Boat collisions with offshore windmills Risk analysis of offshore windmills Reliability of offshore windmills Failure rates of windmill blades Manufacturing defects of windmill blades Terror attacks on offshore windmills Terror attacks on land based windmills Injuries, deaths, and property damages caused by windmills Earthquake damages to offshore windmills Bird damages to offshore windmills Environmental hazards of offshore windmills Economic analysis of offshore windmills Cost of construction of offshore windmills Maintenance and repairs of offshore windmills All of these search phrases will bring up dozens of reports and a smattering of statistical analysis. A good overview of offshore wind power economics was produced at the University of Maine.  This study is The Economics of Offshore Wind Energy by Caitlin M. Howland, published in 2012. It can be accessed by the URL  It also turns up when doing a google search using the phrase “economic analysis of offshore windmills.”
Capers Jones is a recognized expert in anlysing risks from software development through major business risk for industry and government. more at
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