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Wind Power in America

An attempt at unbiased from a position of bias


Politics. While in some circles it can be a dirty word, it is also our reality. In highly regulated sectors such as the power generation, it should be no surprise that transitions of governing administration or party control can bring with them changes in legislation that steer an industry in entirely new directions. It is the nature of our two party democracy that a caucus will align in mass around a grouping of often unrelated or even at times inconsistent platform positions but that over time become collectively cemented into the biases of their electorate — often reinforced by the somehow uncoordinated but efficient alignment of party and media channel messaging. In some cases these platform components may be originated by resonance with targeted voter demographics, in others directed from party leadership due to their appeal to highly concentrated sources of campaign support. Focusing on the context of the power generation industry, in the preceding decade a notable bifurcation has coalesced along party lines, one tied to the pressing direction of how (or for that matter even if) our nation should participate in a global initiative to mitigate the potentially catastrophic risks facing our collective society associated with carbon emission induced climate change.

One thing this post won’t attempt is a defense of the broad consensus conclusions of climate scientists for a causal link between increasing atmospheric carbon concentrations and global warming. Plenty of people have covered this ground much better than I could. Instead it will be my purpose to turn an eye towards one specific category of renewable energy that has served as a key strategic focus for our nation’s climate strategy to date, wind power. Although I have been actively blogging on medium for over a year now, I have mostly refrained from walking down this road. Having spent majority of the past decade employed in various capacities in the wind power industry, it first seemed prudent to steer writings (which have admittedly often veered toward a more creative end of the spectrum) away from arenas where they could interfere with a paycheck. For a second reason, as Warren Buffet is known to say in his letters to Berkshire shareholders, “Don’t ask a barber whether you need a haircut.” In the case of wind power, I am certainly in the position of a barber, my incentives are aligned to advocate for the platform and as such any reader would be wise to bear in mind that I personally stand to benefit from a robust wind turbine development pipeline (primarily from a job security standpoint). I am writing here despite these points simply for the reason that over my decade in the industry (in roles of O&M and turbine sales or procurement) I have developed a fair bit of domain expertise that I think could help to facilitate a more informed debate on the subject of wind power risks and benefits for any interested reader. One of my objectives here will be to step away from a purely partisan or one-sided presentation of merits. The journalist tradition of covering “both sides” of an issue, despite a tendency at times to exaggerate the reasonableness of outrageous positions, is I think still a worthwhile aim, although admittedly one that is commonly abused in partisan media outlets from a straw man standpoint, a fallacy I will try to avoid. That is not to say that I will refrain from drawing conclusions or advocating a position, but the goal is to arrive at any conclusion independently from a position of neutrality based on legitimate reasoning. I draw a certain inspiration for my tone here from evaluations and reports from the likes of traditionally nonpartisan government agencies such as DOE, EIA, NREL or any of the other national laboratories that provide research and leadership to important missions such as high performance computing, national defense, or energy. For any reader looking for more objective investigations into the energy industry these institutions are certainly authoritative in their evaluations and publish on a range of relevant topics.

Negative aspects of wind development

In the interests of unbiased discussion, I’ll start here right out of the gate by facing head on those issues that could be used as ammunition in opposition to wind developments:

Landscape Views — This is probably the most subjective of the issues to be addressed here. It is my opinion that wind turbines are by far the most photogenic forms of large scale power production. However their land use at large scale certainly has a not insignificant impact on landscape topology in areas of high penetration. For iconic postcard views there is certainly some value to preserving what has been enjoyed by the generations before us. Alternatively, some may argue that our national energy policy should not be dictated by a select few influential golf resort developers or coastal property owners.

Noise — wind turbines are not silent, they do produce noise which at their source can approach 100dB, although the rule of thumb is that sound intensity level decreases with doubling of distance from a source by ~6 dB (thus at a distance of 400 meters similar to the noise level of a common refrigerator). Unless there is some problem with mechanical vibrations, the largest noise emitter for a turbine will be the tips of the blade, which due to their impressive diameters (currently in range of 120m+ for the newest machines) can have speeds near 180mph based on the configured rotational speed. Wind farm design noise profiles are kept in check by local ordinance and permitting. Although some regions (such as Ontario) can have more strict caps on noise, most regions will have consistent restrictions that when exceeded will trigger an independent audit of sound profile — any offending units can then be addressed by either mechanical repair to address vibrations or alternatively a de-rating of the unit via reduced blade rotational speed.

Wind Turbine Syndrome — A common point of opposition by the NIMBY crowd (aka ‘Not In My BackYard’) is based on a claim that low frequency sounds (‘infrasound’) emitted can contribute to a ‘wind turbine syndrome’, with attributed affects varying by claimant but can include annoyance, nausea, sleep loss and anxiety, among many other seemingly unrelated and sometimes more extreme symptom claims — a 2009 book is often sited. I don’t feel qualified to authoritatively speak on this issue, but most reputable sources I have found dismiss this syndrome as an example of a nocebo effect — just as a sugar pill placebo can trigger health improvements in patients when represented as a medicine, a nocebo is the mirror of this effect where an inoculant exposure, when coupled with negative expectations, can either produce psychosomatic effects or be mistakenly attributed for otherwise unrelated symptoms. This concern around the syndrome is reminiscent to this author of luddite fears around other common staples of infrastructure or society such as electromagnetic frequency in the non-ionizing part of the spectrum emitted by high voltage transmission lines, the radio frequency emissions of cell phones, or perhaps dangerous fear mongering sometimes directed towards childhood vaccinations.

Flicker — Flicker is the effect caused when a bystander or residence is positioned from the sun such that a turbine is directly in between during certain hours of the day, with the rotation of the blades causing a strobe effect from the backlit sunlight. Not expected to cause health effects, the flicker can still be a nuisance, especially with repeated exposure on a daily basis at dawn or twilight hour. It is certainly possible to model and have advance knowledge of window for occurrence prior to construction such as to address by curtailment or repositioning. Some regions will address this issue via ordinance, in others residents should consider inquiring on mitigations during the permitting public comment stage.

Birds — The issue of bird deaths justifiably draws attention of wind power opponents and environmentalists. Some might try to downplay bird deaths from wind turbines by drawing statistics demonstrating more deaths from the like of house cats, cell towers, or tall buildings — I would caution though that there are certainly more cats in the wild than wind turbines for instance so this is somewhat of a spurious means of comparison. Bird takes are not taken lightly by operators, technicians will record instances of found caucuses for tracking and reporting. This issue especially deserves attention in cases of endangered species, one susceptible example worthy of attention being golden eagles. Besides mitigations such as siting considerations, operating around migration patterns, or modern taller towers with slower blades, the industry is moving in direction of a more intelligent resources for address. Modern machine learning classifier algorithms coupled with high definition cameras will have the ability to spot approaching birds and intelligently curtail in instances of endangered species incursion.

Bats — A similar problem to bird fatalities, bats are another species subject to the influence of turbines. The mechanism of bat deaths can differ from birds, while bird fatalities are mostly from collision, bats are also subject to organ damage when traversing the rapid decrease in air pressure around operating turbines. Fortunately there is a simple way to address, intelligent curtailment around twilight hours based on wind speed is an effective mitigation. There are some active debates around appropriate regulatory requirements for bat curtailment, which serves as a trade-off verses the economics of a project.

Hazardous Materials — The primary hazardous materials present on a wind farm are the oils and greases used for mechanical lubrication. Just as the oil in your car must be disposed of by a designated receptacle as opposed to pouring down a drain, these materials are subject to environmental regulations dictating their treatment for disposal or cleanup in cases of accidental leakage or spill.

Commodity Prices — It is possible that at a higher level of penetration the rare earth content of wind turbines could drive commodity prices higher. Rare earth metals are an important and limited resources used in technologies ranging from personal electronics, electric cars, or missiles for instance. Fortunately, at least in the American market and for the time being, the dominant technology platform for wind has proven to be gear driven units (where the rotational speed of the shaft is stepped up from the blades to the generator by a gearbox) without notable rare earth metal content — as opposed to the rare earth metal dense permanent magnet generators used in the alternative direct drive machine platform. The other major commodity component of a turbine is steel (primarily used in the tower), although I would expect that the steel market is deep enough that a surge in demand of wind turbines would not have as dramatic effect as is possible with rare earth metals.

Radar — There are many cases where prime development land with healthy wind resources goes unused due to proximity to airports or military bases. This is necessary because of a local interference with radar caused by the turbine operation. This issue can potentially be resolved by booster radar installations strategically sited around the farm perimeter, or alternatively one day may be addressed by stealth technology (such as might be used on a military aircraft) being incorporated into turbine coatings.

Ice — It is a safety issue when a turbine’s blades accumulate ice, which can be thrown in operation to become projectiles. This problem is more prevalent in weather conditions close to the freezing point when air carries more humidity. Such conditions can be detected in advance with optical or vibration sensors, or alternatively with binoculars. Some wind farms may be installed with deicing capabilities where a mild current is used to heat and prevent icing in the blade. In such conditions technicians avoid approaching an affected turbine and the public would be wise to do likewise in conditions of recent icing as a precautionary measure.

Fire — Although it is quite rare, one failure mode for wind turbines involves catastrophic fire in the nacelle (the mechanical enclosure at the top of the tower). Surprisingly, these fires are rarely (if ever) caused by lightning, which is easily dispersed through grounding connections that extend to the tip of a blade. Instead an explosion can result from a short circuit or overpressure in a nacelle’s transformer or electrical gear, subsequently fueled by flammable oils or greases in the enclosure. While it is possible to install comprehensive fire retardation systems in a nacelle, most turbine fires are instead resolved by evacuating the area and allowing them to burn themselves out. These rare occurrences certainly make for some dramatic imagery between the smoke and flames (which sometimes make it into propagandic publications), but one should certainly keep in mind that as long as no technicians are uptower during the incident there is relatively little safety issue as fires can be detected early and the area evacuated.

Blade Liberation — A still rarer failure mode involves the liberation of a blade (or in other words the rotational energy throwing a blade due to some failure in material or attachment). This type of occurrence obviously has dramatic safety implications, and blades thrown at high rotation can potentialy travel surprising distances. In the aviation industry, the safety record of air travel has climbed every year due to the learning more about failure modes from each occurrence of plane crash. In the case of wind power, the rare instances of blade liberation are treated with comparable intention for determination of root failure cause and mediations so as to improve industry performance in each occurrence.

Overspeed — The rarest (and arguably the most catastrophic) form of wind turbine failure involves overspeed, when high winds produce forces exceeding the design loading, with either flexing of the blade causing collision with the tower or simply excessive force causing buckling and then toppling of the structure. Wind turbine controls are designed with failsafe stops such as brakes or pitching of the blades (rotating their orientation) so as to minimize wind harvesting once gusts exceed a design cut-out speed (on the order of 25 m/s (55 mph)). Were an attacker or foreign adversary to attempt to highjack a turbine’s industrial controls such as to destroy their operation I suspect this would be a possible route of sabotage.

Intermittence — A turbine is a variable power resource, as the winds rise and fall so too will a turbine’s production, which outputs zero energy below the cut-in wind speed, then ramps up with increasing wind speeds to a max rated power level, and then levels off through increasing speeds until it finally falls back to zero above the cut-out wind speed. To some degree a fall in output from one wind farm can be offset by variations associated with geographic distances producing a global reversion to the mean, however that is only on average and there will certainly be times when randomness produces small time scale variations that lead to changes in grid reactive power (i.e. causing the current and voltage to fall out of phase) — although some variability here is normal, when taken to an extreme an imbalance in reactive power and load can eventually impact grid performance or eventually lead to voltage collapse and brown out. Production will also experience long time scale variations in weather patterns that occur over large distances — for instance wind conditions have been known to vary even on a national scale over time scales of months or years which can have material impact on the profitability of the industry. It is this variability in production, beyond the control of operators, that is a key limitation of the technology and I think the most important of all of those listed here. Although it has been demonstrated that 100% renewable energy on a national scale is feasible, (with a combination of wind, solar, hydro, and storage), that certainly does not mean that it this is the most economical approach, especially at current cost of solar and batteries (that being said it is hard to project exactly how far exponential cost reductions will take us — see Swanson’s law in solar for instance). At current penetration levels of renewable energy output variations in wind or solar are offset by ramping up or down alternate production — hydro power is ideal for this use from a renewable standpoint but not present universally so a more common method is load shedding or ramping with gas turbine peaker plants (ideally with simple cycle configurations or if necessary combined cycle) based on real time forecasted renewable production guided by weather forecasts and the like. Modern gas turbine power simple cycle plants are capable of ramping from startup to near full load in a matter of minutes, and so are ideal for this purpose in contrast with coal or nuclear power which are much better suited for base-loaded applications (one of many reasons why a recent proposal from DOE to exempt loss making coal and nuclear plants with sufficient fuel storage from market pricing is bad policy). There is an important tradeoff here that is worth note and one that has not been sufficiently quantified by renewable energy proponents yet (at least that I have seen), that of increased gas turbine emissions associated with ramping or shedding loads to address variations in production from renewable energy. Such variation of gas turbine loading can cause them to operate outside of peak efficiency, increasing per kWh rates of fuel usage, NOx emissions, and carbon output relative to their operation at base load. Such costs of integration are hard to quantify — it is a complex problem that to date has not been answered in a satisfactory manner, although DOE has indicated that integration costs are almost always below $12/MWh — and often below $5/MWh — for wind power capacity penetrations of up to or even exceeding 40% of the peak load of the system (these figures include costs of transmission lines for instance).

When considering the items in this list of negatives, an important framing is to distinguish between those risks or attributes that are localized vs those that may escape beyond the boundaries of a wind farm and its immediate surroundings. From this standpoint the two primary issues that have potential for global externalities to my account are first the impact on endangered species populations, and second the impact on grid performance due to intermittence. In the case of the birds or bats, we’ve identified mitigation tactics involving intelligent curtailment. For intermittency effects on the grid, mitigation and address is simply an engineering problem (as opposed to an ethical one). As we journey along the experience curve, costs of storage technologies like Li-ion or other batteries should continue to fall, helping to keep in check these integration costs for thresholds potentially even higher than 40% penetration.

Positive aspects of wind development

image source

We’ll now turn focus to several benefits of increased wind power penetration. Please note that I don’t consider this summary comprehensive, these are merely highlights — some obvious and some that may at times be overlooked.

The most striking and obvious benefit of renewable energy is achieved via negativa. Wind turbines do not consume fossil fuel in their operation outside of what might be associated with a small current sourced from the grid when winds are not blowing, and as a result do not emit the toxic substances from fossil fuel combustion like NOx or SOx which can cause smog and acid rain, or perhaps more importantly do not emit carbon dioxide which contributes to global warming. The framing of the risks in the prior section by local vs global externalities is certainly relevant here. The offset of fossil generation by wind production means that we are shifting all of these broadly distributed pollutant externalities into manageable impacts to the local region of influence. The atmospheric climate is a complex system that no one can predict perfectly — but the crucial point is that there is ample evidence of high likelihood warming, and even if we can’t know with exactitude how much warming will transpire from any specific concentration of carbon, the potential impacts of this warming — rising ocean levels decimating whole coastal regions, multi-nation scale famine or drought, mass extinctions (even beyond levels of today), strengthened hurricanes, ocean acidification, etc — well these type of risks have potential to disrupt the whole human trajectory, and as such fall under the systemic risk category, meaning the precautionary principle applies.

Renewable energy doesn’t only offset the environmentally intense extraction and combustion of fossil fuels, another major input to fossil plants that doesn’t get as much attention is H2O, which is commonly evaporated in cooling towers as part of the thermodynamic cycles of combined cycle gas, coal, or nuclear generation (and to a smaller extent also used in the harvesting of fuels via mining or drilling). Wind turbines use no water other than what is drunk by the service technicians, and so for water constrained regions at risk of drought wind generation is a useful dampening on needs of thirsty alternatives.

The environmental benefits are only one side of the coin, also of importance are the economic ones. Even at today’s penetration levels (around 80GW, currently producing around 6% of US energy production) the domestic wind industry employs more than 101,000 full-time workers at healthy wages near or exceeding the US median for a household total earnings. The wind technician professions carries the distinction of the fastest growing job in the United States of the past decade. A part of this success story that is often overlooked though is the nature of these jobs. A wind turbine is a long term asset that can continue generating and requiring maintenance for 25+ years before decommissioning — these aren’t short term jobs subject to the whim of the market, these are stable professions that are not expected to be disrupted by automation as we may see in other parts of the economy in the coming years. And not only are these jobs stable and high-paying, but they are also located in rural farming communities that are otherwise losing population to urbanization trends, thus helping to anchor and strengthen the economies of small towns across America.

Image source: link

Not all wind industry jobs are associated with maintenance technicians, many are employed in construction or manufacturing. While these jobs are more exposed to market dynamics for stability they are also distributed across the US — there are currently more than 500 wind manufacturing facilities spread across 41 states. As of 2011, 70% percent of the turbines installed in the United States were built domestically, up from 35% in 2006. (While the domestic manufacture percentages vary by major component such as tower, blades, or nacelle, as of 2016 each of these components still fell in this range, with nacelles now having reached thresholds of >90%.)

Although the fracking revolution has certainly brought about some recent changes to the cost of drilling for oil and gas, it would be a mistake to assume that the market will never return to periods of volatility. Historically fossil fuels like oil, gas, and coal have moved at times in tandem, and so diversification between these resources still leaves the economy exposed to potential for shocks from cost of energy. Renewable energy resources are a hedge against this volatility, and thus dampen our exposure to shocks in the price of fuels that can resonate to other parts of our economy.

Image via The Energy Collective

A renewable energy future is not the only path to resolving the issue of carbon emission induced global warming. Some industry factions include those developing novel modular scale nuclear generation, fusion reactors, or even more far-fetched interventions such as geo-engineering. Some of these platforms may still prove valuable but only once they are demonstrated at scale should they be counted on (and I would suggest that interventionist tactics of large scale geo-engineering would be best held in reserve unless via negativa approaches fail). Wind energy has been demonstrated as effective for mass deployment today. Now is not the time to sit on our heels.

Image via NASA

2017 has been an interesting year for the US energy industry. The new executive administration and associated appointees have turned policy focus towards paradoxically conflicting priorities of extreme deregulation on one hand, while on the other proposals for strong interventions in the energy industry to resurrect or at least slow the decline of coal generation (along with our aging nuclear fleet). With coal emitting around twice as much carbon per kWh as base loaded natural gas, there has certainly been a call for developing policy to move our generation mix away from dependance on this resource (which the US is blessed or cursed depending on how you look at it to have hundreds of years of reserves still in the ground), but characterizing policy trends from recent administrations as a “war on coal” overstates what has been achieved to date. There is no current national price signal for carbon emissions, no tax or cap and trade in place. Instead, recent years have (by some divine intervention) found coal becoming uncompetitive in the market primarily from new drilling technologies creating cheap natural gas base load alternatives. The Clean Power Plan, our nation’s attempt at long term policy to facilitate reduced emissions called for by the Paris agreement climate accord (which the current administration is actively trying to dismantle) would have given each state flexibility in their approach for how to achieve carbon reduction targets, recognizing that different economies have unique exposures to various generation paradigms — just as the Paris Agreement gives participating countries the freedom to select the means and methods for address that they find appropriate. The current administration has not proposed any alternative means to mitigate risks of climate change, instead they have demonstrated prioritizing denialism for apparent purposes of protecting legacy industries that the market is already ruling against.


The story of wind power in the preceding two decades is of an industry driven by government subsidy. The production tax credit (aka the PTC), a straight tax credit subsidy that is doled to wind farm developers as a function of the kWh generated during the first 10 years of operation, has had the intended effect of driving growth. It has enabled the development of a domestic manufacturing base, it has driven product development cycles for ever bigger equipment sizes enabling more efficient harnessing of the wind, it has employed 100,000 Americans in well-paying jobs, and most importantly has driven down the cost of new installations to the point where in many regions of the country it is now cheaper to produce a kWh from wind than it is from fossil fuel sources. The industry anticipated these events, and the latest iteration, passed in 2015, was structured to step down the level of subsidy each year until a complete phaseout in 2020.

One of the most frustrating parts of a two party system of governance is how even unrelated issues can get grouped into a platform, and through precedent get stuck on one side of the ledger. To me the worst part of seeing our political leaders attempt to steer our energy industry away from the proven success of renewable resources is how it is so blatantly counter to the will of the people. Renewable energy enjoys wide bipartisan support. As a voter, I suggest in cases like this you ask yourself, is this point driven by the electorate, or by the the will of some special interest. Just who exactly is your politician representing here?

In the case of carbon emissions, it is quite amazing how those states with the highest carbon emitting power sector lined up to vote into office our current administration. So it does make some sense that a campaign of climate denialism would be intended to benefit one party’s electorate. But at it’s root these campaigns are based on a cynical tactic of creating ‘alternative facts’ as a means to enable changes in policy. Both parties probably engage in these tactics to some degree, but with so much on the line it is certainly disheartening.

Regulatory certainty is necessary for business to make investments — in hiring, in production, or R&D. When you make a commitment to an industry, pulling out the rug midway through a short term program damages not just the industry in question, but signals that our government can’t be depended on for more than a few years at a time. This lesson doesn’t just apply to economic policy but to any arena where our government relies on the good faith of our partners to implement our objectives — whether from business interests, international alliances, or bond investors for that matter. This isn’t about Republican or Democrat, it’s about maintaining a nation’s credibility by following through on our commitments to the rest of the world even during changes in political headwinds.

Jimmy Buffett — One Particular Harbor

*For further readings please check out my Table of Contents and Book Recommendations.

Books that were referenced here or otherwise inspired this post:

Berkshire Hathaway Letters to Shareholders — Warren Buffet

Berkshire Hathaway Letters to Shareholders

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For further readings please check out my Table of Contents and Book Recommendations.