Free market and economic theory tell us that as prices rise, the market responds by increasing supply and the added supply causes prices to fall.  However, when you factor natural capital into the equation, and that natural capital happens to be oil which is getting increasing difficult to discover and extract, then theory quickly becomes fallacy.  See this post on Gregor.us for more.

Until recently, wind turbine manufacturers and operators were challenged by the tasks of keeping machines operating reliably and improving energy capture. Although dramatic improvements have been made in both areas, there have been occasions when acoustic emissions proved so vexing they overshadowed performance and reliability issues. For example, some wind turbines suffer an unfavorable reputation for noise problems associated with high tip speeds, furling, or blade flutter. Because of the potential for installation near residences, noise may be even more important for small turbines than for large turbines installed in wind power plants. – 2004 NREL Report

Complaints (from customers or others) about sound characteristics are rare, but are usually related to turbines with flexible blades and side furling mechanisms. – Canadian Wind Energy Association, Small Wind Purchasing Guide

The market for small residential and rural wind turbines (up to 10KW) has been growing at double digit rates for several years and is now entering its young adult stage as venture capital enters the market and certification standards are being introduced in both the U.S. and U.K. markets.  Wind energy is roughly on par with PV in return on investment, but faces much tougher zoning issues due to the visual impact of towers and the lack of reliable and easy to use acoustic criteria for use by zoning officials.  As a result, the greatest market challenge for small wind turbine manufacturer’s and early adopters that want to take advantage of the technology, is getting zoning approval in the more 25,000 different zoning districts within the U.S.

In my view, zoning ordinances should focus on easing height restrictions to recognize the physics of wind power, building permits to assure adequate tower foundations and anchoring, and on protecting consumers from unwarranted sound pollution.  Setbacks should be a function of both tower heights and the need for acoustic buffers.  I’ve attached my version of a model ordinance based on a review of what I think are best practices from the U.S., the U.K., and Canada including a method of assuring that no unwarranted sound disturbance crosses a property line.  The balance of this post will focus on the sound issue.

The American Wind Energy Association [AWEA] recommends the following noise provision in it’s model small wind ordinance:

For wind speeds in the range of 0-25 mph, small wind turbines shall not cause a sound pressure level in excess of 60 dB[A],  or in excess of 5 dB[A] above background noise, whichever is greater, as measured at the closest neighboring inhabited dwelling.  This level, however, may be exceeded during short-term events such as utility outages and severe wind storms.

In the sense that most small wind turbines operate below ambient noise levels under most conditions, this provision seems reasonable.  However, it is filled with loopholes that serve the small wind industry, but fail to protect the public from unwarranted sound pollution.  For example:

1. Sound restrictions end at 25mph (presumably the definition of a “severe wind storm”) prior to the acoustic problems of furling and blade flutter start starting to become objectionable.
2. When there is a blackout or “utility outage” and therefore no load on a grid-tied wind system, some turbine designs “free wheel” or spin a much higher rpm’s causing spikes in the acoustic emission.  This may also be true of off-grid systems whose batteries reach a full charge.
3. 1)According to British Standard 4142 a “noise rating level” (i.e. the noise level once corrected for the presence of tones or other noise characteristics) of 10 dB above the background noise is likely to give rise to complaint, [and] one only 5 dB above background would be marginal…”. The proposed “5 dB[A] above background noise” is therefore right on the edge of being complaint worthy.  In addition, the “measured at the closest neighboring inhabited dwelling” takes the sound provision over the property line and does not account for future adjacent construction (i.e. the rights of future property owners).

In short, the AWEA model noise ordinance provision seems designed to protect legacy designs that have not been optimized for sound emission and to create the smallest possible acoustic buffer in an effort to open the market to smaller lot sizes.  However, the concept of a provision based on some level of emission in excess of background noise is a step in the right direction.  What that provision might be and how it might reasonably be enforced is another matter.  Before I tackle that topic, I think it’s important to review the new Small Wind Safety and Performance Standards sponsored by the American Wind Energy Association [AWEA] and the British Wind Energy Association [BWEA].

The BWEA standard was released in February 2008 and the AWEA standard is in process and currently available as a “Draft Document”.  Both standards will require a much needed third party verification of energy conversion performance and assure that minimum safety and quality standards are met.  This will allow consumers to easily compare the performance of competing designs and trade that performance off against cost, warranties, and other features.  It will also provide government incentive programs and zoning officials with an reasonable and acceptable list of “approved designs”.  Both standards are virtually identical relative to the provisions for energy conversion, safety, and quality.  However, language and requirements of the two standards diverge significantly relative to “Acoustic Sound Testing”.

The current AWEA “Rated Sound Level” states that:

The sound level that will not be exceeded 95% of the time, assuming an average wind speed of 5 m/s (11.2 mph), a Rayleigh wind speed distribution, 100% availability, and an observer location 60 m (~ 200 ft.) from the rotor center1, calculated from IEC 61400-11 test results, except as modified in Section III of this Standard.

In contrast, the BWEA “Rated Sound Level” provides for two conditions at higher wind speeds.  One appropriate for larger turbines and one for smaller residential zone turbines:

BWEA Reference 60m Sound Level, Lp,60m. The sound pressure level in dB(A) re 20 μPa rounded up to the nearest dB, at an observer distance of 60 m [~197 ft] from the rotor centre (i.e. a slant distance) and calculated from the Declared Apparent Emission Sound Power Level when the turbine is subjected to a wind speed of 8 m/s [17.9 mph] at its rotor centre. The 60 m distance is representative of the closest observer distance expected for a turbine toward the larger size of small wind turbines.

BWEA Reference 25m Sound Level, Lp,25m. The sound pressure level in dB(A) re 20 μPa rounded up to the nearest dB, at an observer distance of 25 m [~82 ft] from the rotor centre (i.e. a slant distance) and calculated from the Declared Apparent Emission Sound Power Level when the turbine is subjected to a wind speed of 8 m/s [17.9 mph] at its rotor centre. The 25 m distance is representative of the closest observer distance expected for a micro or domestic size turbine.

Both standards provide for a method of determining sound levels at X distance from a turbine relative  to ambient(background) sound levels.  However, as currently written the AWEA standard only provides information to make this calculation at the 5 m/s [11.2 mph] rated wind speed which bypasses the issues of furling, blade flutter, high wind speeds, free wheeling, and power outages.

In contrast, the BWEA standard includes the provision for an Emission Noise Map in their labeling requirement which maps the sound emission of the turbine relative to the distance from the turbine hub and the wind speed.  The map starts at the turbine cut-in speed and ends at the cut-out speed.  However, for turbines that do not “cut-out”(i.e. stop operating), “but achieve protection to high winds by various mechanisms such as furling their blades or yawing the turbine to cross-wind. In these cases the red and orange zones of the Noise Map will continue up to the wind scale maximum”.   This still doesn’t address free-wheeling and power outages, but I’ll get to that in a moment.  It should also be noted that the BWEA standard assesses a noise penalty of 5dB[A] if the turbine emits any specific tones that may be objectionable to the human ear.

In the appendix, the BWEA standard provides a method of  using the noise map to assess site suitability for U.K. zoning purposes based on the red, amber, and green zones.  In addition, using the Sound Power, Noise Slope, and Noise Penalty the standard provides equations for calculating the noise level at any wind speed and any distance from the turbine.  It also provides a conservative formula for estimating the ambient noise level in a “country field” as a function of wind speed.  According to the BWEA standard, the values from this background noise formula “can be taken as a worst-case scenario (i.e. the lowest ambient noise) for a rural background.”

In all fairness, the AWEA standard is still in draft form and may end up addressing small wind turbine acoustic issues in a better way, however from a consumer viewpoint the BWEA standard is currently far superior.  That said, how should zoning officials protect the public interest regarding small wind turbine sound emissions?  I’ll start with a list of basic premises:

1. What’s at issue is not so much the sound emitted by the turbine, but the sound emitted in excess of the ambient noise conditions, especially night time noise conditions.
2. The noise or sound limitations should be established at the property line.
3. The sound emission criteria should include all conditions including high winds (furling, yawing, and flutter) and power outages (free wheeling).
4. For some turbine designs, the effect of the above will be to increase the effective setback (and indirectly the minimum lot size) by creating an acoustic buffer in excess of any setback based on tower height.

Under most conditions wind turbine sound emissions disappear into the background offering only a faint whoosing sound to the human ear.  However, for zoning purposes an acoustic buffer should be required to encompass all operating conditions and to protect residents from turbine designs that have not been optimized for acoustic performance.  The best way to achieve that is to establish a property line sound level based on ambient noise levels plus some standard.

European noise standards tend to be more developed, so I’ll use those as a baseline.  In the U.K. the guideline is:

• Daytime: A background noise + 5 dB[A] or 43dB[A] whichever is greater
• Nighttime: A background noise + 5dB[A] or 35 to 40 dB[A] whichever is greater
• Plus a 2 to 5dB(A) penalty for tones

In France the guideline is:

• Background noise + 5dB[A] during the day
• Background noise + 3 dB[A] at night

Since 3 dB[A] over background noise is barely discernible outside of the lab, and sleep disturbance should be the key criteria for a small wind turbine sound provision, I believe that 3dB[A] over background noise should be the property line limit for a zoning ordinance.  This is conservative in that any habitable building on an adjacent property will be setback an additional distance which provides additional acoustic buffer.

Language for the sound provision of my model Small Wind Turbine zoning would look something like this:

Acoustic Setback Requirement – The acoustic emission sound level of the Small Wind Turbine as measured at the property line, shall not be more than 3dB[A] over the background noise level under any operating conditions, including high winds, yawing, furling, and power outages.  Background noise may be calculated using Equation A.1 of the British Wind Energy Association [BWEA], Small Wind Turbine Performance and Safety Standard (February 2008) as plotted in Figure 1 below.

Measured site specific background noise levels may also be used provided that they are verified via a survey and report prepared by a qualified engineer.  The acoustic setback from the property line required to meet the 3dB[A] over background noise level requirement can be satisfied/calculated in two ways:

1. For Small Wind Turbines that are certified to the BWEA Small Wind Turbine Performance and Safety Standard (February 2008),  the wind turbine manufacturer shall provide calculations that use BWEA Equation A.2 to quantify the required acoustic setback.
2. For Small Wind Turbines not certified to the BWEA standard, the wind turbine manufacturer shall provide certified data and calculations prepared by a qualified engineer that quantify the required acoustic setback.  These calculations must include a 5dB[A] penalty for any tonality according to ISO 1996-2:2007 Annex D based only on 1/3rd octave band data as follows:

The turbine is declared tonal if any 1/3rd octave band (in any of the spectra from section 3.4.16) is higher than its adjacent bands by

15 dB in the low frequency bands (50 to 125 Hz)

8 dB in the mid-frequency bands (160 to 400 Hz)

5 dB in the high frequency bands (500 to 10000 Hz)

The maximum wind speed used for the submitted calculations shall be the cut-out speed or for wind turbines that do not have a cut-out speed no less than 50 mph.

A proposed model small wind turbine ordinance is attached below in pdf format which includes provisions for height limitations based on physics, turbine size limitations based on turbine blade size and lot size ( consideration of scale),  requirements for building permits, and the acoustic provisions outlined in this post.

A Model Small Wind Zoning Ordinance

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Detroit, the country’s most depressed metropolis, has zero produce-carrying grocery chains. It also has open land, fertile soil, ample water, and the ingredients to reinvent itself from Motor City to urban farm. Mark Dowie’s immodest proposal…

This may also be a future vision of a post carbon, post-industrial America.

Hear a first-hand presentation and analysis of the second edition of the Green Building Market & Impact Report by the report’s author Robert Watson, GreenerBuildings.com Editor, industry leader and LEED “founding father.” This report is an integrated assessment of the land, water, energy, material and indoor environmental impacts of the LEED for New Construction (LEED NC), Core & Shell (LEED CS) and Existing Building (LEED EB) standards.

To register for this November 5 [12:30pm EST] event go here

Can renewable energy save the world from climate change, and do so at a reasonable cost?  A report by Geoffrey Heal on VOX  says we can replace some fossil fuel power with renewable power without a major cost increase, but we cannot hope to replace a major fraction of our fossil power with intermittent power sources such as wind and solar energy unless we can develop energy storage technologies.

“All of humanity is in peril, if each one of us does not dare, now and henceforth, always to tell only the truth and all the truth, and do so promptly – right now.” – Buckminster Fuller

I started posting to this blog in March of 2007.  It’s been as much a journey as a journal and my posts have been the cairns left on the trail of my search for meaning and truth.  The direction of my search has been open-ended, non-directional, and often both troubling and unexpected.  I changed the name of the blog from “The Sustainable Home” to “Sustainable Dwelling” as my vision expanded and my subject matter broadened in scope and reach.

As a result of one my posts, I was asked to make a presentation this summer to the International Association of Public Participation about making sustainable decisions in the context of the four pillars of sustainability.  In preparation, I was compelled to look back on my journey and ask if I really “knew” anything.  Would I be able to humbly “tell the truth” or fail and spew forth some grossly ego-contaminated version of pseudo truth?  As a result,  this blog has been mostly silent as I struggled to  resolve and make peace with what I’ve written and what I’ve learned, including my readings of others who have walked a similar path.

Much like the journey of this blog, the process of preparing the presentation became it’s own journey and I began to question the mythical foundations of humanity and how they shape our actions and beliefs.  How simple things like canvas shopping bags, electric cars, buying local, and recycling give us a false and comforting sense of “going green” that masks the imminent peril of our ecological overshoot.

In the end, my presentation – my humble attempt at the truth, would attempt to ask and answer two questions:

1. Can humanity achieve a sustainable balance within our closed ecosystem, or have we reached the point where that vision is just another example of the hubris of human exceptionalism?
2. Is it time to switch our focus from sustainability to one of resilience in the face of societal collapse and industrial decline?

I’ve posted a copy of the presentation including the speaker notes on SlideShare.net.  You can find it here.

Is a warning about the future a prediction of doom or a call to follow a different path?

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Michael Pollan (The Omnivore’s Dilemma),  Annie Leonard (The Story of Stuff), Joanna Macy (The Great Turning) are just some of the speakers at what promises to be a great conference.

Bioneers Conference 2009





I’ve spent the last month painting and re-roofing the house and enjoying the slow emergence of spring in the rockies as the aspen grove turned a vibrant green.  I’ve also been watching the bear market rally in stocks as less bad news leads investors to believe that the fed can induce another debt bubble of false prosperity and growth.  So as the rain falls and temperatures hover in the low 40’s, I’m inspired to comment on the symbolism of the GM bankruptcy.  Amid all the chatter about “Government Motors” I was struck by Dan Neil’s (the L.A. Times) view of the larger lesson within our nation’s largest bankruptcy.

“This is the lesson of GM’s bankruptcy, and it has little to do with market share and miles per gallon.  It’s a rebuff of the notion of exceptionalism.

Any organization that fails to sufficiently safeguard its means of self-correction and reform, that forsakes long-term investment for short-term gain, that piles up debt year after year, will eventually fail, no matter how grand its history, or noble its purpose.  If you don’t feel a tingle of national mortality in all of this, you’re not paying attention.”

Neil doesn’t go beyond the “tingle of national mortality”, but it is no secret that the U.S. is technically bankrupt and avoids default only because of our reserve currency status and foreign purchases of our growing debt.  But the inevitable decline of the American empire only begins to describe Neil’s “rebuff of exceptionalism”.

American hubris, our excessive pride in our specialness or “exceptionalism” was born in ernest as we exited victorious from WWII.  With the rest of the  world’s industrial capacity lying in ruin,  GM and corporate america dominated the world industrial stage and American quickly transformed its vast war economy and productive capacity into a consumer economy that would eventually lead us onto a treadmill of crushing debt.  Post war retail analyst Victor Le Beau best describes the reasoning that would lead to America’s 5% of the world population consuming 30% of the world’s resources.

“Our enormously productive [war] economy…demands that we make consumption our way of life, that we convert the buying and use of goods into rituals, that we seek our spiritual satisfaction, our ego satisfaction, in consumption…. We need things consumed, burned up, replaced and discarded at an ever-accelerating rate.”

Such reasoning rested on the post war belief that American ingenuity and the miracle of science and technology would overcome any limits and endless growth would lead us to a utopian future.  In his forward to William Catton’s “Overshoot”,  Stewart Udall posits the exact date that America’s post war euphoria jumped the Happy Day’s shark.

“It is easy to fix the exact date when our euphoria reached a zenith.  It was the July week in 1969 when the astronauts walked on the moon.  We celebrated this triumph with a mixture of awe and self-congratulation.  President Nixon proclaimed that it was “the greatest week since the creation of the earth.”  A NASA official opined that the feat demonstrated we were “masters of the universe.”  This proves that we can do what ever we decide to do,  Americans concluded from this climax event.”

However the 70’s would mark the first cracks in our shinning edifice of hubris.  Domestic oil production would peak in 1970 and OPEC would give us the first taste of our dangerous dependency on oil.  Honda and Toyota quality and fuel efficiency would begin to threaten the supremacy of GM.  Reacting to the costs of our failed adventure in Vietnam, Nixon would take us off the gold standard and set the stage for massive deficit spending.  Real incomes would begin to decline, saving and thrift would lose favor and combine with debt and two income families in an attempt to keep the consumer economy  alive and growing.  Our post war euphoria would be replaced with the lament, “If we can put a man on the moon, why can’t we ….”

President Carter attempted to raise the issue of limits and lead us in direction of conservation and renewable energy, but Fed Chairman Paul Volcker’s war on Nixon’s policy induced inflation set the stage for Reagan’s promise of a return to post war euphoria.  Reagan delivered with a “deficits don’t matter” war on the evil empire and launched a 20-year bull market built on a phantom foundation of deregulation, easy credit, and a mountain of government and private debt.  As W added more to the national debt than all previous presidents combined, our national house of cards collapsed in a pool of financial sector greed and overreach.

As GM attempts to pull itself from the ashes of bankruptcy and politicians around the world promise the oxymoron of “sustainable” growth, nearly 7-billion humans are still mostly blind to the reality of ecological limits and harsh retribution of overshoot and collapse.  This is the ultimate hubris—the hubris of human exceptionalism.

“The whole human enterprise is a machine without brakes, for there are no indications that the world’s political leaders will deal with the realities until catastrophes occur.  The rich countries are using resources with extravagant disregard for the next generation; and poor countries appear to incapable of acting to curb the population increases that are erasing their hope for a better future.  In such a world, declarations and manifestos which ignore the imperatives of the limits of growth are empty exercises.  All the available evidence says we have already passed a point of no return, and tragic human convulsions are at hand.” – Stewart Udall, Charles Conconi, and David Osterhout,  The Energy Balloon

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Those who labor in the earth are the chosen people of God, if ever He had a chosen people, whose breasts He has made His peculiar deposit for substantial and genuine virtue. It is the focus in which he keeps alive that sacred fire, which otherwise might escape from the face of the earth. Corruption of morals in the mass of cultivators is a phenomenon of which no age nor nation has furnished an example. Thomas Jefferson

On March 30th, the Post Carbon Institute released their Food and Farming Transition document.  As I’ve come to expect from this organization, it is a carefully researched and offers both a clear and concise description of the current situation combined with a broad roadmap for a transition to a post fossil fuel food delivery system.  I’ll provide a brief summary, however I would encourage anyone to read the entire document.  You can download a PDF version by clicking here.

The document starts with premise that industrial agriculture and our global food delivery system, both of which are highly dependent on fossil fuels, is patently unsustainable.  We have managed to triple the world’s agricultural output in the last hundred years, but the entire system depends on the exploitation of fossils fuels which are non-renewable and whose extraction rates will eventually peak and decline.

This unprecedented achievement in humanity’s quest for food security and abundance was largely made possible by the development of chemical fertilizers, pesticides, and herbicides; new hybrid crop varieties; the application of irrigation in arid regions; and the introduction of powered farm machinery.

The leveraging of fossil fuels to create this tripling of food abundance has also supported and made possible an increase in human population from 1.6 billion in 1900 to about 6.7 billion today.  One way to look at this is that we have created an artificially huge increase in human carrying capacity based on a specious and temporary foundation of non-renewable and unsustainable resources.  In that context, the stakes become very high, as billions of lives will depend our ability to produce and deliver just as much food in the future without the leverage of fossil fuels.

Natural gas provides the hydrogen and energy used to produce most nitrogen fertilizers, and both gas and oil are the sources for other agricultural chemicals, including pesticides and herbicides. Meanwhile, oil fuels most farm machinery (often including irrigation pumps), and has enabled growth in the scale and distance of transportation of crop inputs and outputs. Today, food items are shipped worldwide and enormous quantities of food are routinely transported from places of abundance to sites of scarcity, enabling cities to be built in deserts.

The authors are hopeful but not certain that such a transition can produce sufficient food for the current and projected population, however under the best of circumstances the changes required will be both massive and disruptive.  They hope that these changes can be made gradually and proactively, but history suggests that they will be made reactively and in the clear face of a global food crisis.  There are many powerful vested interests dependent on the current system and agricultural giants like ADM and Cargil are not likely to quietly into the night.  If the powerful get their way, we are likely to revert to a version of ancient Rome’s latifundia, a crude industrialized agriculture dependent  on captive and abundant cheap labor and the huge land holdings of an agrarian oligarchy.

The Post Carbon Institute’s authors provide a more hopeful vision of the future than the slave labor model of ancient Rome and outline seven key elements that provide us with a transition roadmap:

1. More or Mostly Locally Grown Food (follow this link to learn more about Food Miles)
2. Smaller Farms Powered by Human, Animal, and Renewable Energy including bio-fuels grown to power a diminished fleet of farm machinery
3. Natural Soil Fertility based on Composting, Animal Manure, and Crop Rotation
4. Transforming the American Diet – Less Meat more Vegetables and Grains – A Diet that is Seasonal, Fresh, and Local
5. Knowledge-intensive, Holistic Farming Systems – Reviving the Tribal Knowledge of our Great Grand Parents crossed with todays best Organic Farming Practices – PermaCulture versus Mono Culture
6. Open-pollinated Seed Varieties adapted to Local Soils and Climates
7. Decentralized Processing and Distribution

Ideally a post carbon agricultural and food delivery system will look like a modern version of Thomas Jefferson’s agrarian ideal married to business models like community supported agriculture (CSA) and using solar, wind, and liquid bio-fuel technologies to augment human and animal power.  With this new/old vision, the huge industrial farms of middle-america would be carved back into pre-industrial 100 acre operations and some 25-million americans would reverse migrate from the cities to re-populate the heartlands.  Imagine a section of land (640 acres) farmed by four well and newly educated families sharing 100 acres devoted to animal fodder, another 100 acres devoted to bio-fuels, and a few more acres given over to shared wind and solar power.  The balance of the acreage would be devoted to the free market ingenuity of each family.

None of this will happen quickly and as idyllic as it sounds, not without hardship and suffering.  It would have been interesting if the authors had devoted some space to what the transition might look like in crisis mode.  I can imagine victory gardens and backyard chicken coops to help build a tenuous food bridge to the future.  Homeowner associations turning the front lawns of suburbia into agricultural co-ops.  A massive natural agriculture training program to prepare us for the migration back to the heartlands.  A government sponsored mechanism to breakup large land holdings into smaller, family size parcels, along with government sponsored rationing, food relief programs, and the National Guard stationed in front of grocery stores and other food distribution centers.

Peak Oil makes this painful and hopeful transition not a question of if, but of when.  It may be sooner rather than later and it is likely that once in motion, events will unfold very quickly.

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I recently took the time to wade through Chris Martenson’s (free) online Crash Course and found it to be a brilliant and accessible summary of the economic, energy, and environment forces shaping our very unsustainable future.  If you have that uneasy feeling that the current financial meltdown is much more than just another business cycle, then this course is a must.  Martenson makes the case that a financial system that must grow to survive married to energy and environmental systems that cannot grow is a ticking time bomb that will make next 20 years VERY different from the last.

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