Archive for the ‘energy and stuff’ Category

Another reason we need wind, solar, electric vehicles, and heat pumps

June 15, 2014

A semi hauling diesel and kerosene tipped over in a rotary less than a mile upriver from us on Wednesday.  The image below is from the Portland Press Herald:

gorham stroudwater fuel truck crash

The article said that 6000 gallons were recovered and “Emergency crews were able to prevent the spill from entering the Stroudwater River”.  However the crash was only 1/2 mile north of the river, and  it rained heavily on Friday.  By Saturday morning the river smelled strongly of petroleum.

Modern life requires energy to power our transportation and heat our homes, but we can (and must) do better than dirty, unsustainable, de-stabilizing liquid fossil fuels.  We need to accelerate the development of efficient technology that uses less energy to get things done, and cost-effective renewable sources to meet the remaining demand.


19th century clean energy technology in Maine

November 10, 2013

As some readers know, we are fortunate to inhabit a beautiful spot on a small river in southern Maine, which was long ago the site of a water-powered mill.  One of the enigmatic relics of the ruined works was a 3″ diameter steel shaft sticking out of the muck in the riverbed, with a Lovejoy coupling on the upper end the size of a dinner plate.  Soon after we arrived, we made a preliminary effort to unbury it one spring afternoon, but if I remember it was hot and buggy, and we ran out of steam after digging down and finding the runner pinned under some chunks of broken metal.

runner in hole

18 months intervened, and I had basically given up the thought of finishing the job before winter, but Saturday dawned pleasant for working, so I took some buckets, a shovel, and a digging bar down to the site and was soon hip-deep in a mucky hole.  By a combination of bailing, digging, and pitching out rocks, I was soon able to get back to where we had previously stopped, and was able to rock the runner. With a bit more excavation I could see what I was up against – about half the circumference was trapped under a semi-circular cast iron ring, which had clearly been some sort of inflow nozzle that directed the flow downward onto the axial-flow runner.  The cast iron parts were not going to move, since they were bolted down to some structure buried even deeper in the mud, but I was pretty sure if I could pull the one main chunk off (to the right in the photo above), I could lift the runner clear.

At this point I was pretty confident of victory, so I texted Tony and invited him to join the fun.  Together we toted our light oxy-acetylene cutting rig down into the riverbed, and without too much effort we were able to burn off 3 nuts (or bolt heads; hard to tell with that much rust):

torching off nutsfire in the hole

The old metal was wet and covered with mud, so the cutting was pretty mangy, but I got them burned off and then knocked the slag away with the digging bar.  I lifted off the iron chunk, and then we had a pretty good view of the runner.  it appeared to be about 3′ in diameter, with 10 graceful sweeping vanes.

The runner was free, but it was way too heavy to lift.  However, we were fortunate to have two good-sized forked trees in line with it on either side; an ash on the manmade island between the main watercourse and the ruined spillway, and a pine on the high ground,directly beyond a steep  cliff that rose about 15′ above the riverbed.  We rigged a chain in the ash, a snatch block on the runner, and a second snatch block in the pine, and used our trusty orange worm-drive hand winch to take up the strain, with the red Ford as an anchor.  Once we levered it clear of the remaining bits of metal in the hole, it rose smartly thanks to Tony’s efforts on the winch:

starting to rise

coming out of the hole2013-11-09 14.51.14

We were about out of winch by the time the runner was clear of the hole, so I guided it over onto the riverbed and Tony set it down.  We lowered the attachment sling to just above the balance point, re-rigged to pull directly with the truck, and tied on a rope-a-long that was hitched to the south shore.  Then with the truck we quickly raised it until it was even with the cliff edge above:

runner suspended

We then winched it south with the rope-a-long while gently lowering it with the truck, to arrive at its new resting place on high ground:

closeup of runner up top

All in all a fun project, and a neat piece of Maine renewable energy history – I’m curious now to learn more about the mill that was at this site, and more generally about this type of small water mill.  My first impression is that this runner seems much bigger than appropriate for the flow of the river (which can be judged from the photo above, which shows the outlet of the millpond, roughly at the location of the ruined dam) – at least during typical summer and early fall flows.  Of course there are times in November and early spring when the entire valley fills with a raging torrent (see canoeing pictures from earlier this year) but I wouldn’t think you would build a larger-than-needed mill just to run on those few days or weeks of the year.  Maybe the process (sawing wood or what-have-you) had a relatively low duty cycle, and they’d let the millpond fill up between cuts, then open the floodgates to get more power when they needed it.

Jari Mower RIP

June 16, 2013

jari on fire

I am sad to report that the Jari mower bit the dust this weekend.  I purchased it about two years ago from a guy upcountry, and put several hours into getting it running well.  I sorted out most of the issues, including the frozen-up cutter bar and rotted gas tank, but the replacement tank never quite fit right – there was a slight intermittent gas leak between the top of the tank and the carb, and I never could figure out why.  However, on Saturday it finally caught up with me.  The mower ran out of gas so I shut it off, filled the tank, and as soon as I cranked it up a small flame started on the surface of the carburetor. I tried to bat it out with a mat of fresh-cut green grass, and it almost worked, but the flames persisted.  I ran over to the neighbor’s and grabbed two fire extinguishers, and exhausted them on it, but by that time the metal was hot enough that it re-ignited after the powder stopped flowing.

I didn’t think it would explode, since the gas seemed to be escaping from the tank – at first through the leak, and subsequently through the zinc carburetor, which melted into a puddle on the ground.  Still, I ran down the hill for some hoses, to tap the neighbor’s water.  At peak the flames reached 6-8 feet high, but by the time we had the hoses up there the gas had burned itself out, and the fire was reduced to burning the rubber tire, belts, and the thermoformed plastic fairing on the front.  Ben Wilkins tossed a couple of pails of water on the smoldering heap and the excitement was over.

Once it cooled off, Bodhi and Kieran rolled the machine down the hill and I took stock of the damage.  The engine was pretty well baked (as I mentioned the carb had completely melted), the left tire and shroud were shot, and the belts were burned down to the fiber cores.  But the frame was intact, and even most of the paint was still in good shape – I tipped the machine over on its side when it caught fire so the tank was up, and there wasn’t much to burn up forward.  One of the idler pulleys looks pretty baked, so it would probably need to be replaced.  Joshua and I toyed with the idea of doing an electric retrofit, since sickle mowers don’t use a lot of power compared to rotary machines, and using two separate motors would significantly simplify the mechanicals.  Unfortunately, I haven’t got time to do a major rebuild (or an electric conversion), so today I bought another used sickle mower (Troy-Bilt make) from a nice retired couple in Cornish – I’ll tune it up next weekend and see how I like it.

On Manipulation: a skeptical stance is appropriate in a world formed by evolution

April 13, 2013

If I am climbing a remote snow-filled couloir deep in the mountains, and a rock breaks loose from the cliff above me, it is reasonable for me to believe that the flying piece of stone is indifferent to my presence as it bounces down the slope – it might brain me by pure chance, but it gains nothing by doing so.  I can look at the distribution of similar rocks arrayed on the gentler slope below and verify this randomness.  But the case is potentially very different for the teeming horde of microorganisms, invertebrates, and buzzards that would take great pleasure in eating my remains.  And if I drink straight from the stream below and ingest Giardia lamblia organisms, it is probably not a coincidence that the resulting frequent bathroom breaks will increase the probability that I make a deposit near open water.


There is a fungus in South America that reproduces by infecting an ant and commandeering it’s nervous system, causing it to perform odd behaviors that are not in the normal ant repertoire, but happen to be especially conducive to the propagation of fungal spores.  This sort of relationship has been discovered all over the place – I remember reading about another critter (maybe a fluke) that causes a different species of ant to depart from its customary routine and hang out on the tips of blades of grass, where the ant is likely to be eaten by the sheep whose gut is needed to complete the life cycle of the fluke. These phenomena illustrate the incredible power of evolution – that the chance appearance by mutation of an incidental cause in one species with a marginal effect on another species can be amplified and honed over thousands of generations into the appearance of an ingenious stunt. 

In the time since Darwin laid the keel of biology, we have come to understand that the living world is full of replicators that have survived from ancient times to the present by possessing heritable traits that made them slightly better than anyone else around at levering themselves into the next generation.   There are a lot of strategies for doing the levering, and one particularly effective one is manipulation – why do the hard work of slithering up a blade of grass, when it might be easier to grab the controls of the body of an ant and make it do the work for you?  And this is at least as true of our fellow humans as it is of viruses, fungi, and ants.  One theory of why humans are so darn smart is that we evolved high levels of intelligence not to outsmart other species, but to out-manipulate one another – a sort of evolutionary arms race in the direction of cleverness.

An understanding of the evolutionary benefits of manipulation should lead us to a healthy skepticism, especially about the motives of unfamiliar agents.  I was thinking about this after a recent discussion of belief, skepticism, and the scientific method, and I realized that the relationship between skepticism and evolution is stronger than I had previously understood.  Skepticism is associated with evolution because the discovery of evolution by natural selection is one of the great achievements of the scientific project, and evolution is a major flashpoint in the ongoing turf battle between reason and received tradition.  But more fundamentally, a worldview informed by skepticism is a logical conclusion that flows from an understanding of humans as an evolved species.

As much as the nature-documentary view of evolution involves carnivores running down and chomping herbivores, a lot of the evolutionary action has got to be intra-species, and in social animals there’s a tension between manipulation, aggression, and dominance on one side and cooperation for mutual benefit on the other.  If manipulation were the whole story, we never would have managed to work together enough to build this amazing computer I’m typing on. Theory shows how  pro-social behavior can emerge under suitable conditions, and how it can out-compete ruthlessness.  Altruism towards family members is easy to understand, but under the right conditions it can extend further – particularly where living arrangements allow for repeated interaction, and the critters in question (e.g. us) have sufficient intelligence and memory to sort out and recognize the reliable characters from the shifty ones. But these conditions are fragile and limited in scope, and powerful motivations for betrayal are never far beneath the surface.   Accordingly, manipulation, loyalty, and betrayal are constant preoccupations among people everywhere, and a perennial staple of fiction.

The principles of evolution offer some guidance about when to suspect manipulation most – especially single-shot interactions (for instance buying a used car far from home) and anonymous settings (e.g. emails from ‘friends’ in Nigeria).  But far beyond outright fraud, on average a random person who is trying to make you believe something is far more likely to be doing it for their benefit than for yours. The most obvious example is advertising: the product might be good and it might be shoddy, but the person producing the ad copy probably may not even know – their bonus (and their continued employment) hangs on their ability to get you to open your wallet.

Understanding the incentives that are motivating the people (and other organisms) we interact with is a powerful tool.  If your doctor receives 30% of his income in the form of clandestine ‘gifts’ from drug manufacturers, it is reasonable to expect that this will have an impact on his prescribing behavior – whether he admits it to himself or not, you are unlikely to be the beneficiary of that influence.  But a flight to ‘alternative’ or ‘holistic’ practice is no refuge – indeed the skeptical worldview is frequently under attack by people who would love to convince potential customers that the scientific establishment are fascist storm troopers, so they can sell more herbs or crystals or whatever type of dubious product they have on offer.

Others are skeptical of skepticism for reasons of iconoclasm – ‘it comports with my self-image as an edgy person to claim that all ways of knowing are equally valid’ – or simply aesthetics and wish-fulfillment: ‘true or not, I am happier believing that powerful forces want me to be beautiful and successful.’ (There may even be a strange evolutionary logic to illogic – if I truly believe that warpaint protects me from arrows, I will surely act with more courage, and in a world of less deadly weapons, the added benefit of banishing fear could conceivably more than compensate for the cost of miscalculations about the effects of pigment on projectiles.) Still others condemn the skeptical stance as heartless and austere; that – even if  true – it is too thin and hard a pillow for the average mortal to rest their head on at night, and that ordinary people would be better off believing in comforting fictions.  But this is condescending. People can handle unvarnished reality, and they make better decisions when they understand it.

Evolutionary insight brings the realization that the world is jam-packed with finely-tuned organisms that in no way have your best interests in mind – ranging all the way from viruses to used car salesmen.  This understanding is very different (and potentially a lot less attractive) than conceptions of a stern but loving God – or a fluffy New Age optimism that the universe cares about you and everything happens for a reason – but it has the virtue of being true.The skeptical view is consistent with our best understanding of how the universe works, and it is of a piece with hard-won, durable, practical knowledge of how matter, energy, and living organisms interact. This same body of knowledge amplified our power (and our environmental impact, alas) a hundredfold by harnessing thermodynamics, cured deadly diseases through detailed knowledge and intricate manipulations of  invisible biological machinery, built us microscopes and telescopes that allow us to visualize the stuff of the universe across 20 orders of magnitude, and landed a few lucky dudes temporarily on the moon. And it says that the universe doesn’t care about you, no matter how much you wish it did, and furthermore that many of its living pieces would much rather use you for their own purposes than do you a favor.

Open Source Ecology

September 29, 2012

A day or two ago I heard a piece on NPR about a guy named Marcin Jakubowski who is on a mission to design and build the Global Village Construction Set, “a modular, DIY, low-cost, high-performance platform that allows for the easy fabrication of the 50 different Industrial Machines that it takes to build a small, sustainable civilization with modern comforts.”   As described in a short TED talk, Jakubowski explains that he was a theoretical physics student, started farming when he felt that he lacked practical skills, and had bad experiences with old farm equipment that motivated him to design simple, practical open-source tools. This evening I checked out the website of his organization,,  which has a work-in-progress wiki-based compendium of concepts, specifications, designs, fabrication videos, and test images.  The group is big on modularity, hydraulics, and structural steel, and they’ve done a pretty impressive amount of development on a few of their concepts, including a skid-steer tractor and an automated press for making rammed-earth blocks. They are based at Factor e Farm in Missouri, which reminds me a lot of stuff I’ve read about the New Alchemy Institute.


Pika Energy: Home wind and solar power

April 17, 2012

Posting has been light and progress limited, but there’s a good reason: my colleagues and I have launched a startup, Pika Energy, to develop affordable, high-performance home wind power systems. When I was a kid growing up in Five Islands, we lived off the grid, since the power company hadn’t yet brought lines out the North End Road, so naturally I was fascinated by electricity. On a cross-country trip to California I saw tons of water-pumping windmills, and when I got home I started experimenting with wind turbines to make DC power. Here are some pictures of a turbine I built and mounted on the roof of our barn:


cloth diapers

August 18, 2011

The contents of our shared washing machine this AM reminded me of an NPR piece I heard the other day; it was from the national news but featured a local company that’s doing great selling cloth diapers – not so much for ecological reasons, as because it can cost 80% less (not counting labor) to use cloth. And from the sounds of it, the technology has come along significantly since my sister and I were little -back then it was folded cloth rectangles and the safety pins with the plastic ducks on the heads.

the romance of iconoclastic ideas

August 14, 2011

An online person named Kris de Decker writes an interesting website called “Low Tech Magazine“, where he offers a unique read on technologies old and new. He recently linked this blog in an article on pedal powered equipment. But the latest article, on solar powered factories, er, ‘crystallized’ (more on that later) a theme that’s I’ve been digesting mentally for quite a while.

I am a lifelong enthusiast in renewable energy technology, and I’m currently working with friends on our own project in this field, so I hope nothing here leaves the impression that I am sour on the potential of renewable energy to make a difference. But this article set me off a bit, both in terms of technical accuracy and this more subtle complaint.

The basic idea of his article is that while there’s a lot of focus on renewable energy as a source of electricity, well over 50% of our energy needs go to heating, a need which (he says) is poorly met by electricity. Which has a grain of truth to it, but in his enthusiasm he goes un-necessarily off the rails. Consider:

Although it is perfectly possible to convert electricity into heat, as in electric heaters or electric cookers, it is very inefficient to do so.

This almost qualifies as a howler.


The potential of pedal power

June 4, 2011

There have been some visitors here from an interesting article in a series on pedal power by Kris de Decker in Spain. It turns out that a significant amount of work on pedal-drive human-powered implements was done in the few decades between the invention of the bicycle and the widespread implementation of internal combustion and grid power, with another small bump during the 1970’s oil crises, and interesting demonstration projects here and there since.

We built our first pedal-powered apple grinder more or less on a lark, and we thought it was a good idea, but despite our expectations it was a real epiphany for me to see just how effective it was, and how pleasant it was to use. We went from operating a 3/4 horsepower electric garbage disposal right at the edge of its thermal limit, and cooling it (albeit in a grossly inefficient manner) with a 1 horsepower electric compressor, to a system powered by one pedaler that was much quieter, much faster, and produced nearly as fine a grind.

I think the real lesson here is less about pedal power than about the way that the availability of cheap energy and cheap goods leads to thoughtless waste, even among the well-intentioned. In cider year two, we had a pile of apples that would soon go soft, a brand new garbage disposal was 75 bucks, and the electricity to run it and the compressor cost a few pennies per hour – so we ended up using over 10x the energy we needed to do the job. The aesthetic attractiveness of pedal power mostly serves as a counter-incentive to cheap energy – ‘That would be so cool – let’s see if we can make this process efficient enough that we can power it with 100W…’ It took some engineering skill and some R&D time to figure out the right way to do it – over the next two years we fine-tuned the geometry of the grinding drum, added custom-machined post-crushers, etc. And the improvements we made are independent of the source of motive power – the same grinder assembly could easily be driven with a good quality electric motor with an efficiency of around 90%.

So once we started thinking that way, all sorts of possibilities came to mind. Right away we realized that the pressing half of the cider operation was another perfect case, where efficient application of well under 100W could do an impressive amount of practical work. Again, it took some engineering to select a suitable hydraulic pump, connect it appropriately to a bicycle drivetrain, and work out the picky details that only matter when you’re trying to be really efficient. For instance, we learned that a standard hydraulic check valve has a metal-to-metal seat, which leaks a tiny amount of oil when there’s significant back-pressure. We realized that we needed to get a check valve with a soft (o ring) seat, so that the press would hold pressure after the pedaler stopped pedaling. Normally this would not be an issue, since an engine-powered hydraulic system the engine is always running, so the pump is always working. Also, the pump would only make full pressure at a relatively high RPM, which was hard for pedalers to sustain for a long time, but with the check valve, a flywheel, and an accumulator we built out of an old dive tank, we could easily put in a short burst of vigorous pedaling and drive the system up to full pressure. The actual amount of mechanical work needed to press the cider is so modest that next year we’re going to demonstrate by hooking the press up to a junior-size bike, and let the growing crowd of kids press all 200 gallons.

Since then a whole list of promising practical applications have come to mind. High on the list is log splitting, where typically a large, loud single-cylinder gas engine runs at full-bore continuously, even though the full horsepower is only needed a tiny fraction of the time. I have a suspicion that our pedal-hydraulic power system could be hitched up almost unmodified to a log splitter with good effect, and there are probably other high force, low speed hydraulic applications as well. At the extreme end, it would be pretty sweet to see a mini excavator operating on the combined hydraulic power of five or six pedalers. Food preparation is another obvious area where a reasonable amount of work has been done, especially focused on the developing world. I’m interested to try a low-head pedal-powered irrigation pump, and possibly even a four-wheel, two station pedal-powered cultivation tractor, though the odds of any of these making it to the top of my engineering to-do-list are slim.

I guess the most obvious demonstration of the point I’m trying to make is those setups with a stationary bike where the pedaler attempts to make one or more incandescent light bulbs glow. Kris seems to go out of his way to point out that converting pedal power to electricity isn’t always the best approach; I think the discussion above should make it clear that his point is well taken here. But the futility of the pedal-light bulb demo isn’t really so much a demonstration of the limits of pedal power as it is of the lameness of incandescent bulbs – it would be interesting to do a demo with single pedaler, a well-engineered drive and generator, and an array of LEDs or compact fluorescents. I have a similar sense that a single pedaler could produce an impressive amount of audio, again given an efficient drive and a class D amplifier. And with the dramatic progress in low-power processors for mobile applications, and the availability of low-power electronic ink screens (developed by my former roommates, and used in e.g. the Kindle), pedaling could power an impressive amount of computation as well.

Decoupling resource consumption and economic growth?

May 15, 2011

We take as our text this morning a recent report from the UN, which says that on current trend global resource consumption will nearly triple by 2050. The report discusses various constraints on resource extraction, including scarcity, steadily decreasing ore quality (which thus requires more energy and water to extract), the accompanying increase in local environmental impact, and global environmental impact (chiefly climate change), and emphasizes the need to take steps to ‘decouple’ continued economic growth from resource use. This decoupling appears to happen naturally to an extent; while over the last hundred years resource use has increased dramatically, economic growth has significantly outpaced it, so the ‘resource intensity’ of the economy has decreased, despite generally downward trend in (inflation-adjusted) resource prices. But despite growing slower than the global economy, steadily increasing resource use will eventually bump up against the constraints of a finite planet, and we see evidence of this happening in the last decade or so, with commodity prices reversing their century-long downward trend:

Two questions come to mind – first, how far is it possible to go in terms of reducing the material inputs to the economic sphere, while still improving (or at least maintaining) something that most people would recognize as economic wellbeing? And second, assuming that it is possible to substantially decrease resource consumption while maintaining or increasing economic activity, will a meaningful fraction of the world’s economies actually execute that trajectory?