Category Archives: Blog

Meta-braindump from our work and play

Which has a Bigger Footprint: Dogs or SUVs?

In their new book, Time to Eat the Dog: The real guide to sustainable living, Robert and Brenda Vale explain that dogs and cats eat a lot of protein, and our agricultural practices have a big impact on the environment. Their research showed that the eco-footprint of a Land Cruiser driven 10,000 miles per year is about half that of a medium-sized dog.

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New Scientist has a good summary of the study: Link

via Good

We've Got Hemcrete!

Northwest Corner of Nauhaus Prototype
Northwest Corner of Nauhaus Prototype

………………………..

Well, one wall anyway.

Yesterday Ian and Mario from Lime Technologies came out in the rain to help us install some Hemcrete, starting the first home in the United States to be built with the product.

The rest will be installed after the Eco Panels go up.

Click here to view the entire Nauhaus Prototype Construction Chronology.



Click here to watch the full interview with Ian Pritchett.

Electrical Completed, Lime Technology Pays a Visit

Click here to view the entire Nauhaus Prototype Construction Chronology.

We were excited to have Ian Pritchett and Mario Machnicki from Lime Technology, makers of Hemcrete, come by to check out our building for the first time.  We had some great discussions about Hemcrete, earthen blocks, construction details and more.  The electrical work has been completed, and the walls are ready for the hemp installation.

Jeff Buscher, Tim Callahan, Ian Pritchett, Mario Machnicki
Jeff Buscher, Tim Callahan, Ian Pritchett, Mario Machnicki
Ian Pritchett and Jeff Buscher talk about earthen blocks.
Ian Pritchett and Jeff Buscher talk about earthen blocks.
Southeast View
Southeast view of the nearly-completed framing of the Nauhaus Prototype
Electrical Box Installation
Electrical Box Installation
The electrical boxes are mounted on blocking so that they will be flush to the inside of the 12" walls.
The electrical boxes are mounted on blocking so that they will be flush to the inside of the 12" walls.

Thwart the Diabolical Extraterrestrials: Buy Local Paint

This is the tenth in a series of articles for the New Life Journal.

By: Clarke Snell

Are you going insane like me? Do you ever sit in a parking lot and imagine the forest that used to be there? Do you ever look at the eastbound river of cars while you’re flowing westbound and ask yourself, “Where are we all going? Why can’t they stay where they are and do what I need to do there, while I stay where I am and do what they need to do here?” In the deep of night while the bedbugs bite, do you ever ask yourself, “What do rabbits know that I don’t?”

Yes, I must be crazy. So crazy that I’m completely baffled by how we humans come to find ourselves in the present world of our making. I’m so bent that to me we seem to be the only critters on the planet that can’t go with the flow. You know: live, eat, have babies, die, become compost for plants that are in turn eaten by our babies…repeat cycle. Is it my demented ramblings, or is our obsession with experimentation and childish competition grinding us to dust? Here’s my call for entries to all scientists, priests, freaks, and super-models: What the hell are we doing here?

My favorite theory about the existence of human life on planet earth is that we were seeded here by extraterrestrials. Sort of like bees making honey, they knew that we’d bring all the raw materials of the planet to the surface, process them into useful compounds and units like plastics and alloys, then concentrate them in piles (cities, landfills, etc.) where our masters could then easily harvest these goodies for their own use. If this process eventually killed the worker drones (us) or adversely effected the lifecycles of the planet itself, that would be of no concern. The point was efficient resource extraction. Though admittedly ridiculous and based on no facts (sort of like our present foreign policy), this theory has a compelling internal consistency and does offer an explanation for certain strange human behaviors such as packaging small amounts of water in plastic bottles. At the very least, it allows us to feel like we’re doing a good job.

Whatever the origin of our shenanigans, we’ve become so intransigent that the planet itself seems to be trying to throw us off. That’s the image that scientist James Lovelock used in an interview I heard recently. He said that humans have become an invading virus on the organism that is planet Earth. Global warming is the response, the fever attempting to combat the virus. The earth, though, is in the latter stages of its life, and therefore, like any senior citizen, may not be able to survive the fever.

Gawd. The more it all sinks in, the more I understand Disneyworld: Attention Citizens, just don’t think about it and watch the big mouse with the white gloves… I mean, how do we stop being a virus!?

Well, I’m no genius, but one thing I can do is pay attention. When you do that, you start hearing a lot of good ideas. Here are a few: Let’s not drive lettuce in from California when it’s being grown right here. Let’s not drive wood in from Oregon when it grows right here. Let’s not drive paint in from who knows where when it’s made right here….What?

That’s right, if you live in the distribution area of this magazine, you have access to locally made, non-toxic, environmentally conscious paints, masonry sealers, and wood finishes. The company, based in Asheville, is called Earthpaint. It’s founder, Tom Rioux, started his career in painting at the age of 14. After many years as a professional painter, Tom become deathly ill. His kidneys, liver, and lungs were failing and he had horrible arthritis. After 3 years of chemotherapy and major diet and other lifestyle changes, Tom pulled through. He was convinced that it was paint that almost killed him, so he decided to dedicate himself to researching and developing better paints.

After literally more than 1,000 failures and a major investment in lab time and other entrepreneurial necessities, Tom has developed a line of finishes that are truly amazing. They are biodegradable; made up of non-toxic, native ingredients from plants, minerals and other basic elements. Except for a single ingredient in one product, all of Earthpaint’s materials are harvested within an eight hour drive of Asheville. Most travel less than four hours. What’s more, they not only compare to modern synthetic finishes in price, but in many cases outperform them. For example, Earthpaint’s Interior Clear Skies wall paint carries a full 25 year warranty!

Talking with Tom about paint is a true inspiration. Not only because he’s fun and really knows what he’s talking about but because, well…you’re talking to him. He’s not just a billboard, a label, or a trademark. He’s your neighbor telling you real-world, no BS stories about the reality of paint. (Ask him about VOC’s, for example, if you want to hear a real nail-biter with a surprise ending.) Tom’s business is family-owned (no pesky stockholders demanding his soul) and truly local which allows his intentions to be personal and passionate. It also makes him accountable to us.  If we have a problem, we can talk to him about it. Such a set-up will by definition be “green” to the max. The rationale won’t be based on barely meeting provisions in compromised government regulations vetted by corporate interests, but on the simple and obvious credo that you don’t soil your nest.

To me, that’s the transformative power of building a truly local economy. Earthpaint’s success is our success. If Tom fails, we all loose. Perhaps our only problem is that we don’t really believe that we’re all in this together. As long as there is a mythical Bahamas to retire to, then people will continue to soil their bed before they sell it to someone else. What we need is more Earthpaints. They are out there trying to be born. All they need is our help. It’s a no-brainer, people. Buy, sell, eat, drink, build, live, and die local…unless you want some two-headed ten-eyed aliens coming down here to steal plastic from our cold dead hands.

For more information about Earthpaints, visit their website www.earthpaint.net) or call them at 828-258-2580.



Asheville GO Helps Out

Today, the folks from Asheville Green Opportunities came to help out.  In the meantime, Matt and his crew started putting up rafters.

Click here to view the entire Nauhaus Prototype Construction Chronology.

Asheville GO
Asheville GO
asheville go 2
Asheville GO Volunteers
Installing Blocking for Electrical
Installing Blocking for Electrical
Tony Beurskens Directs Asheville GO Volunteers
Tony Beurskens Directs Asheville GO Volunteers
Elijah and Chris
Elijah and Chris

Finished Scaffolding
Finished Scaffolding
Matt Installing Rafter
Matt Installing Rafter
East Gable
East Gable

Framing and Drainage

Today the framing of the second floor began, and measures were taken to provide proper drainage from the building.

Click here to view the entire Nauhaus Prototype Construction Chronology.

Tim uses a custom-made tool to measure for the Hemcrete.
Tim uses a custom tool to measure for Hemcrete.

David Madera stopped by to discuss Hemcrete.
David Madera stopped by to discuss Hemcrete.
A strip drain is placed at the bottom of each wall.
A strip drain is placed at the bottom of each wall.
Gravel is shoveled into the Eastern trench.
Gravel is shoveled into the Eastern trench.
East Wall
Wast Wall Framing

Micro-Inverters

Since there are no moving parts, PV doesn’t require any maintenance except cleaning the glass.  The photovoltaic collector doesn’t fail.  If a panel fails it’s usually because a solder joint connecting the cells fails.  Most manufactures warranty their panels for 80% of rated output for 25 years.

Inverters have traditionally been the weak point in the system. Mean failure rate has been 5 years. 2 year warranties were the norm in the late 1990s. 5 year warranties are common now, and some manufacturers offer 10 year.

Central String Inverters

PV panels produce DC power which is either used directly by DC lighting and appliances or wired to a central inverter, typically located indoors. An NREL study (PDF page 41) found that inverters have needed to be replaced every 5-10 years while panels last 25 years or more.

Central inverter PV systems are wired in series like Christmas lights. Central inverters use a Maximum Power Point Tracking (MPPT) algorithm to determine the optimal output of the system. Therefore, the output of the whole system was only as good as the worst performing module. If there is one bad solder connection, one dirty cell, or one partially shaded cell the whole system is affected. Just like Christmas lights it is impossible to find a problem without testing every individual part.

http://www.ratechsolar.com/galery/watsonville_b/2.jpg

German and Austrian central inverters are the best quality because their government incentive programs require installers to warrant the system for 10 years which put pressure on manufacturers to improve their reliability to stay competitive. North American manufacturers have not kept up.

Micro-Inverters

That’s all changed with micro-inverters. They mount outside attached to each panel. With micro-inverters AC power leaves each panel. There’s less inefficiency due to DC voltage drop. The Christmas light problem is solved. Micro-inverters get as much energy out of each panel as it can produce, so partial shading is no longer a problem. If an inverter fails the rest of the system still functions, and it’s a relatively small replacement cost compared to a central inverter.

Enphase micro-inverter

Micro-inverters are also designed to be much more reliable. Enphase credits four things:

  1. Micro-inverters process relatively small amounts of power at low DC voltages which allows them to incorporate more components on the semiconductor chip rather than soldering together a bunch of analog electronics.
  2. Because of the small amount of power processing, the temperature rise is lower. In fact they use passive cooling rather than fan cooling like traditional inverters.
  3. NEMA 6 enclosure is air, water, dust, and insect tight. Traditional inverters are like computers with cooling fans actively flowing dust into the enclosure.
  4. Potted design. The enclosure is filled with “an encapsulating compound” which improves heat dissipation and provides component protection.

Traditional inverters use electrolytic capacitors which are notorious for their short life. Microinverters still use them, but they use a more durable design. From Enphase Reliability Study for Electrolytic Capacitors:

“For traditional power converters, an acceptable useful life of capacitors is as low as 2000h at 85°C. Out of desire to increase the reliability of its inverters, Enphase Micro-inverters use capacitors rated from 4000 to 10000h at 105°C. The capacitor lifetime is very sensitive to temperature as its useful life doubles for every 10°C temperature drop.”

Enphase also parallels their capacitors. When one fails the quality of the current wave degrades because it gets a little more ripple in it, but it’s not catastrophic to the inverter.

Since micro-inverters are a new development there’s no lifespan data. In an Enphase white paper they compare their Mean Time Between Failures (MTBF) determined from accelerated lifecycle testing to other electronics:

Sun Microsystems:

“The concept of MTBF is often confused with a component’s expected useful life. In fact, these concepts are not the same. For example, a battery may have a useful life of four hours and have an MTBF of 100,000 hours. These figures indicate that in a population of 100,000 batteries there will be approximately one battery failure every hour during its four hour lifespan.”

Enphase has a 600 year MTBF goal, which would make integrating micro-inverters with solar panels at the factory the default. At that point solar panels will be truly plug and play.

The one downside to micro-inverters seems to be for off-grid systems. Since each panel is putting out AC power, you have to have another central inverter to convert it to DC to store it in the batteries.

There are at least a dozen companies working on micro-inverters, but Enphase is the only company shipping a product that we’re aware of.

Chameleon Roof Tiles

These Thermeleon tiles are white when it’s hot and black when it’s not. When they’re white they only absorb 20% of incident sunlight, but when they’re black they can capture 70% of it.

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They use a polymer suspended in water with a dark background layer. When it’s cool the polymer stays dissolved, and the dark background is exposed. When heated, the polymer condenses into tiny droplets which appear white because scatter and reflect the radiation.

The Thermeleon project won the 2009 MIT Making and Designing Materials Engineering Contest. They need to find out if their tile is durable enough to stand up to the harsh conditions on a real roof before they have a real product, but they say the ingredients are all cheap and readily available.

:: Thermeleon.com