Tuesday, July 27, 2010

Bergey Excel 10KW tear-down and rebuild


Having successfully collected our Bergey turbine from its former home, we needed to tear down and inspect the various components of the power head to see what was wrong.

The wind workers got a little help from Maintenance Director Roger Duval, pictured, a Master Electrician and an old hand with generators and like equipment.

Some problem-solving was required. The alternator on these machines bolts directly to a mainframe, composed of the yaw bearing and slip ring assembly and mounts for the tail boom, furling mechanism, and the alternator itself.

The mainframe is easily disconnected from the alternator at the connection flange. The alternator itself is somewhat less easily dismantled. In our case we hooked our tractor's fork lift to the flange and applied upward tension, tapping lightly on the magnet can with hammers.

The magnet can slid more or less gently off its own backing plate, revealing the stator and magnets.

We already suspected from the obvious misalignment of all the alternator parts that we would find damage, and we were right. The magnet can had been hanging loosely on its bearings and grinding on the stator.

There was less damage to the stator than we thought, but the magnets themselves were fairly heavily damaged.

Cleaning off all these iron filings and chunks of magnet will reveal the full extent of the damage, but at this point it looks as if we need at minimum a new magnet can and bearings.


BPI in Brooks

Dear Energy Professional,

Build Green Maine LLC of Brooks, ME is pleased to announce that it has been welcomed as an Affiliate to the Building Performance Institute (BPI) of Malta, NY. Leveraging on its tenure as Maine State Housing Authority’s leading building science trainer, this agreement with BPI permits Build Green Maine to offer accredited Building Analyst I training throughout the state and region. Nearly all federal/state energy efficiency rebate programs require BPI certification for participation.

Our inaugural 8-day Building Analyst I class is scheduled for Belfast at the Hutchinson Center, starting Monday, August 16th and concluding Wednesday, August 25th. The class will consist of five classroom days along with two “in field” sessions. This period includes both the Online and Field portions of the BPI Examination. The Online Building Analyst I test will take place during the fifth classroom day. One-on-one Field examinations will begin on Tuesday afternoon the 24th, individual tests are scheduled on a first to register, first preference basis.

Build Green Maine’s proprietary curriculum and in-depth field experience are what set us apart. Our trainers have extensive field experience, ranging from old construction to new, large to small and from traditional to high-performance. We have lectured and taught building science widely, delivering energy evaluation training for federal and state programs, to architects, engineers, contractors and homeowners alike. BGM schedules test houses for “hands on” field training. Each student will use all pertinent diagnostic equipment ranging from the blower door and IR imagers to combustion analyzers. Advanced topics (e.g., Zone Pressure Diagnostics) will be taught in the field, under real world conditions.

The cost of the course is $1,395, which includes BPI’s Online and Field Examination Fees and meals. A $300 discount is available to those holding a Maine Housing Energy Auditor Certification. Reservations can be made by calling 207-323-1974 or by emailing info@buildgreenmaine.org. A $250 deposit will guarantee your place. We also offer a test-only option.

Take a step in the right direction and get your BPI BA I certification with Build Green Maine today!


George Callas, CEO

George Callas
Build Green Maine

gcallas@buildgreenmaine.org
(207) 323-1974

Monday, July 26, 2010

"Have they no grandchildren"

A quote from Friedman's editorial this weekend, slamming the US Senate for failing to enact (or even really debate) a climate bill.

He's entirely right, of course. Some of us will live to regret this. The older among us will probably not. But our children and grandchildren will almost certainly wonder what we were thinking.

We're not thinking.

That's the problem here.

Sunday, July 18, 2010

Heat engines


Driving over the Mount Harris "pass" from Dixmont to Jackson yesterday I had an all-too brief flash of cosmic understanding.

This saddle between hills is 900 feet above sea level, while Jackson spreads out several hundred feet lower. On a good day you can see all the way to Acadia National Park, where the First Family is currently on vacation.

But what I saw yesterday wasn't the President and family, or even Air Force One which must have flown overhead at some time or other, but photosynthesis, on a grand scale. The Maine woods are in full leaf, and Jackson, indeed all of northern Waldo County, is of course just one big broad leaf forest, with a light scattering of dwellings and hayfields here and there.

A hazy, green, abundant, massively productive forest countryside. A New World Sherwood.

Yeah, Robin.

Under the shade of the trees, this time of year, it's much cooler than it is in the sunlight. Buggy, but cooler.

So, an obvious science geek question is, where does all this abundant solar energy go to if it's not reaching the ground under the trees? At this time of year more than a kilowatt of energy is hitting every square meter every hour the sun shines. That's like having a two-bar electric toaster oven in each square meter.

This of course makes for a lot of heat anywhere the sun's light hits the ground.

Sunshine energy is primarily ultraviolet light: invisible moving photons. Some of this light energy is reflected back to space as visible light in that part of the spectrum that humans experience as green.

Very green, in this case. The whole of Maine seems green, this time of year.

Some of the energy heats the air, which moves the energy around a bit. The more humid the air, the more energy the air can hold, the more energy the air moves around. This is why shade doesn't work as well, and why thunderstorms are more frequent, on humid days.

But an awful lot of energy is being absorbed by the leaves of the trees and used to combine carbon dioxide with water to make sugars and cellulose. I'm not sure how much, but enough to help make it feel much cooler under the trees.

A square meter of solar panels properly positioned on a day like this will capture about 15% of this energy in the form of electricity.

But I wouldn't cut down trees to put up solar panels. That would be a waste. Trees are probably much more efficient at collecting sunlight and reducing carbon levels than solar panels are. That doesn't mean to say I wouldn't cut down trees, though.

Here's our Womerlippi Farm woodpile, about four cords, 70% white or gray ash. At 24 million BTUs per cord, and 3.4 million BTUs per MWH, that's 7 MWH per cord, or 28 MWH total.

These four cords were harvested from an area less than 20 meters square. That's only 400 square meters. And, although the cutting was heavy, big trees were still standing on that 400 square meters when I was done cutting. No tree cut was older than 15 years, and most were around 10 years old.

28 MHW divided by 400 square meters is 700 kilowatts per square meter for the whole time period the trees were growing.

700 kilowatts per meter divided by ten years is 70 kilowatts per square meter per year.

Our square meter of solar panels, by comparison, will collect 200 watts per hour, average 4.5 hours per day, 365 days per year, or 328 kilowatts per meter per year.

So solar panels are more efficient, right?

But that doesn't count the energy taken to make the panels, while the trees grow without this help.

Nor does it count the energy in leaves, which in this case were cycled through sheep, although in the fall the remaining energy in the leaves of the trees still standing will cycle through the soil.

So this is all very philosophical, isn't it. What do I think about all this?

I think I'm glad to have my firewood cut, split, covered and drying for winter.

And I'm glad to live in a beautiful Maine forest.

Saturday, July 17, 2010

"Stochastic arts"

There are some kinds of work that require the most perfect, precise planning. These are very few, in my opinion. Most jobs have their surprises. And then there are types of people who think that prior planning for everything is the hallmark of the professional. Holders of this opinion are fairly common, because it's taught at colleges and universities, especially in the business and administrative classes.

The theory is that it's the job of the modern manager to anticipate every eventuality, perform total "due diligence" and have a plan in hand at all times.

But my job isn't like this, and while I often make detailed, extensive plans, my personality has evolved over the years to the point where I actually enjoy those surprising days when nothing goes according to plan.

Yesterday was one of those days.

Our wind power research crew was scheduled to motor over to Newport, Maine, with a truckload of tools and equipment to begin the dismantling of a Bergey 10KW wind turbine. This is parked in a field not far from town, and the owners have come to dislike it, and want it gone. They want to run cattle in the field, and they want their young children to be able to play there without having to warn them about the tower. It doesn't help their opinion of it that it produces very little power on this site, and that it has already fallen down once. It isn't very well installed, and they've come to fear it in wind storms, which are frequent in this neck of the Maine woods.

(By the way, any wind turbine will do this, produce inefficient quantities of power, if not properly sited. Be sure to consult with a qualified anemometrist and have your site tested before investing in an expensive wind turbine. Steer clear of the contractors who are selling these things until you have your site's wind numbers and an independent power production estimate. The contractors often don't know how to properly measure the wind or find the precise wind map data, nor how to interpret it for a given site. Their job is to sell you the machine, otherwise known as a pig in a poke, if you don't take this advice. And they don't mind selling you the follow-up service when it doesn't work, or falls down, or whatever, either.)



We were to be helped in this endeavor by some experienced Bergey operators, Verne LeCount of MOFGA, and his regular consultant in all things renewable, Dr. Jay LeGore, a retired materials science academic and engineer who lives in our area and who experiments with solar, biofuel and wind systems. I've handled a lot of towers, but I'd never lowered a Bergey, so I was pleased to have them there. I also figured they could help pass some knowledge on to our two student apprentices.

Of course, they motored to the site in Jay's white Prius. Not trying to be stereotypical at all.

Anyway, long story short, we assembled our equipment, began the lower, which uses an electrical winch, and things were going well until...

the winch cable was frayed at the half-way point!

How this damaged bit of cable found it's way onto our winch drum is an interesting mystery. The winch had been systematically checked, and the cable completely replaced, just a few short days ago.

The supervisor (me) was on hand for this process and watched the wind worker spool most of the cable onto the drum. But I didn't watch it all. It's also possible that the tangle that caused the fraying occurred out of sight.

Suffice it to say the wind power crew and their supervisor are undergoing a process of memory- and soul-searching this weekend...

Ultimately, snafus like this are the supervisor's problem though.


Matthew Crawford, author of Shop Class as Soulcraft, a great read I plan to require for all our Sustainability Design and Technology students, suggests that mechanical work of this kind has what other forms of professional work in this country increasingly lack: an objective standard of performance.

Managers in today's society, he suggests, can "spin" their performance endlessly, because often there's no way of telling whether or not they are actually producing good management.

He likens their predicament to that of the Soviet apparatchik, who has to have two whole spearate languages, one in "party-speak" for spinning her performance, another in more realistic and/or colorful Russian for trying to get things to work at all.

Good management is like composition or poetry. There's a lot of room for opinion. The eternal rhetorician's question, "what is good, Phraedrus?" applies. Since most students at colleges or universities are studying for these white collar types of jobs, they have to be taught, if possible, good judgment on questions like a good format for a report, or a good way to summarize a policy. Objectivity is difficult with such nebulous problems. Students grow up learning that effort and application will put them ahead of the pack, not necessarily being correct or right.

But for an old-fashioned machinist or wind engineer, or a climate scientist, for that matter, there are objective and time honored standards like "square," "level," "within tolerance," or "within specifications" (as opposed to without), and objective devices to use to gauge the quality of what is produced. The supervisor comes by with his level or gauge or micrometer, and the thing either is or isn't right, runs or doesn't run, produces the expected kilowatts per hour, or doesn't. Your planet either heats up and people begin to die, or it cools off and we manage to avert disaster.

Or, almost as obvious, and thus objectively, and with less time clock to run out while spinning endless excuses, your turbine is down on the ground safely.

Or not.

Crawford also notes that technical work is a "stochastic art" in that outcomes are inherently unpredictable and subject to intervention of random variables. Craftsmanship is found when the craftsman (or craftsperson, if you prefer) has mastered the process of his or her labor, including learning to cope with random problems.

I've come to think of teaching and mechanical work as having this stochastic feature in common.

Teaching is stochastic in that you never know when a teaching moment will occur, and the teacher has to be light on her feet to capture the moment, give the timely lesson, and drive it home. In today's distraction filled world, young minds are open to change only for very short windows. You can't afford to waste any of these window-open periods. A superb teacher is probably one who knows how to create those teachable moments really well, even predictably, and follow them up with the right lesson every time.

Anyway, this is all a very philosophical way of saying, we almost killed our wind turbine here. The day was saved mostly by experience. We had three grizzled veterans of many a battle with renewable energy equipment, including among the three, two PhD's, one of which was in engineering, and enough experience and coolness that we could talk it out calmly, study the problem, and come up with a solution.

We improvised a back-up system to support the weight of the turbine and tower while we passed the frayed cable, and then "sistered" in a reinforcement for the frayed section. The frayed wire plus sister wire held until the very last minute of the lower. We're actually not sure why it parted in the end. That will have to wait for a careful autopsy of the damaged equipment. This made for a "hard landing," but the damage was limited to one tower section, for which there is already a replacement on-site.

Following the final short drop, our two apprentices were somewhat shaken. The day's stress had shredded their nerves already, and the noises of twanging wires and twisting tower were truly scary. No-one was ever in any real danger; We made sure of that. We were all very close to the tower, though, fielding different bits of it, the way the manual says. The apprentices were at the head, fielding the blades to keep them from the ground, when the tower fell it's last two feet right next to them. They immediately let go their blades and ran!

But the tower was already almost down when this happened, so the only way it could really have hurt them was if they had ignored the instruction not to get under it at any point.

Even so, they were shaken by the noise and sudden movements of the big scary tower.

But the experience just shrugged their more aged shoulders, tidied up a bit, and headed for lunch.

Disaster averted. Lessons learned. One for the casebook.

When I repair that winch this week, I'm thinking I'm going to spool all the wire on there myself. Every inch.

But then I think again. How do we learn to be the most responsible and capable people we can be, if we don't get given the chance to make mistakes, even expensive ones, and live through them? Especially when the standards are objective, like these are.

And while we may not be training blue collar technicians and certified engineers with our Sustainability Design and Technology program, we do need to train our people to deal with objective facts, such as climate emissions reductions, and to not spin their results.

It also occurs to me that if things do go to crap with the climate, we will need a few people seasoned in handling emergencies, too.

Friday, July 16, 2010

Waterfall Arts Presents:

Introduction to Timber Framing with Raivo Vihman



timber frame

July 26 - 30 M-F 9 - 4 Age 18-Adult

52 Kingdom Road, Montville, Maine 04941

$210 tool list will be provided



Get ready to cut a frame! This will be a five-day introduction to the craft of timber framing in which we will build and erect a small timbered outbuilding to house a handmade cob oven. Students will develop an understanding of the structural parts of a frame, and build confidence with the layout and execution of timber joinery, walking away with the skills to build their own structure.

Raivo Vihman has been avidly studying and building wood and vernacular architecture all over North America and Europe since he cut his first house frame of timbers in 2000 in Freedom, Maine. Last winter he studied French techniques of drafting and timber building with the Compagnons in Angers, France.

Please RSVP:
207 338-2222 or click HERE

Reigning opinion

The Prince of Wales has come out strongly against climate deniers.

Not sure how I feel about this, actually. On the one hand, I'm pleased to have another high-profile voice helping out. On the other, having lived in a republic for 25 years now, should I really care? Monarchism in Britain, I tell my hyper-meritocratic American spouse, is kept primarily for tradition and for tourism, and we turn a nice profit on it.

So if I pay any attention to the Prince on climate, I'm perpetuating the power of the monarchy?

Actually, I'm quite fond of the Royals, as are most Britons. I tend to see the Queen not so much as head of state, but as the nation's great-grandma, and was pleased to see her on TV the other week in NYC. Charles has always been a strong advocate for environmental causes. Charles is a kind of eccentric cousin who's job it is to enliven family parties with strange opinions.

And, once a cause becomes monarchical, at least in Britain, you know it's mainstream.