energy Archives - Page 9 of 14

Toward a Zero Energy Home by David Johnston and Scott Gibson

I’ve been looking, apparently in vain, for a good book (that’s not in German!) detailing Passive House building and modeling techniques. The best I’ve been able to do so far is Toward a Zero Energy Home, and it must have been pretty good, since I read it cover-to-cover in less than 24 hours. It’s not particularly dense or detailed, but it was a nice quick overview of low energy building systems, with lots of pretty pictures, and a dozen case studies from all over North America, including a couple right here in Boulder.

The goal that the authors have chosen to highlight — “Net Zero” — means that the buildings in question produce as much energy as they consume on an annually averaged basis. This necessarily means that they all have some on-site production, wind, PV, solar-thermal hot water, etc. However, to keep such projects reasonably cost effective, it’s necessary to focus first on energy efficiency measures. Most important among these is a very tight building envelope, much more insulation than code requires, and appropriate glazing for passive solar gain. Then the internal power loads need to be minimized, by using energy efficient appliances and LED or CFL lighting. Only after doing all that is it financially worthwhile to start adding on-site renewable generation, capable of meeting the overall annual energy demands of the dwelling. Financially worthwhile, that is, if you have already decided that you want to create a Net Zero building.

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German Passive House building robots

A short video from German home fabricator Hanse House. They do both stock and custom homes, but both are fabricated off-site. The video shows their production facility, and some of the techniques for putting together a building in pieces. It’s pretty awesome. Half robotic assembly line, and half humans, building to what’s essentially a CAD specification, with pipes and wires already laid in place within the structural elements before it gets loaded on the truck that takes it off to the building — or rather assembly — site, where the foundation awaits:

http://www.youtube.com/watch?v=joNGqfLMZxY

And here’s a time-lapse of one of their Passive Houses being assembled on-site:

I wonder if they do multi-family buildings too. What it would take to get a facility like this operating in Boulder County? Other than a rebound in the housing industry of course.

A life cycle analysis of incandescent, CFL and LED light bulbs

Life cycle analysis of incandescent, CFL, and LED light bulbs – It’s important to make sure when you’re using a new technology that supposedly saves energy, that you haven’t just shifted the energy consumption from the operational to the manufacturing portion of the product’s life cycle. This study compares three different lighting technologies: incandescent, compact fluorescent, and LED bulbs, and asks what the total energy input is to get ~400 lumens of light for 25,000 hours. Both CFLs and LEDs save about 80% of the energy over incandescent bulbs. For all bulb types, the embodied energy of manufacturing is only about 2% of the total energy consumed over the bulb’s life. CFLs and LEDs were roughly equivalent energetically at the time of this study, but the LEDs produced less in the way of toxic byproducts. The general expectation is that the efficiency of LED lighting will continue to improve, while CFLs are a pretty mature technology. The two best LED bulbs on the market today, with warm yellow light, compatible with dimmer switches, and giving about 800 lumens of light output (equivalent to a 60W incandescent bulb), seem to be this 13W one from Lighting Science ($30) and the 12W Philips A19 EnduraLED ($40). The prices seem high, but as with gas furnaces and boilers, electric motors and pumps, the cost of the electricity or fuel you run through the device ends up dwarfing the capital cost over its lifetime, so paying top dollar for efficiency is worthwhile.

Boulder’s Passive Aggressive Building Standards

Usually when people say that “better is the enemy of good enough”, they’re pointing out that striving for perfection can be a distraction from just getting the job at hand done. There are other dynamics that involve these concepts too. As social animals, we tend to judge ourselves against those around us. Once our basic needs have been satisfied, our relative wealth or deprivation often becomes more important to us than our absolute level of well being. We have little concept of how much is enough. This can lead to the familiar runaway acquisitiveness (keeping up with the Joneses) when there is a well established (or constructed…) social norm favoring consumption. Less obviously, it can also lead to an inappropriate lack of ambition when faced with an objective task that is not supported by widespread social norms.

Over the last couple of years Boulder has upped its building energy efficiency standards. The new permitting regime requires buildings to perform better — net of on-site generation like photovoltaics — than the 2006 international building codes (IBC). Smaller dwellings (< 3000 square feet) have to use 30% less energy than the baseline. Medium homes (3000-5000 sq ft) need to do 50% better, and large ones (> 5000 sq ft) have to beat it by 75%. Obviously this is an improvement over the previous situation, but in comparison to what is possible, and what is necessary to combat climate change, it’s actually pretty unimpressive. Homes of all sizes built to the Passive House standard use 80-90% less energy than the baseline code, and they do it without counting any on-site power generation against the building’s energy consumption, whereas the HERS index that is used in the Boulder code does count on-site generation. This is an important distinction, because the atmosphere doesn’t cancel out your nighttime coal-fired emissions with the solar electricity that you sell onto the grid during the day. All it cares about is the total amount of CO2 released.

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Links for the week of December 9th, 2010

If you want to follow my shared links in real time instead of as a weekly digest, head over to Delicious. You can search them there easily too.
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The Yeti Homeland Project

I’m not sure what to make of our willingness to participate in the terraforming of the Earth. To explore it, I’ll consider an alternative history in which Antarctica was marginally habitable, and colonized a million years ago by woolly hominids who developed a Yeti civilization. Our whaling vessels meet up with them in the 1820s, but it’s so cold down there that nobody feels the need to molest them except for few hardy anthropologists, the occasional overzealous missionary expedition, and the usual cohort of scientists who will study the ends of the Earth, no matter how inhospitable. Inevitably, the Yeti spend some late nights with the scientists in their hot tubs watching the aurorae.

They get to talking about the magnetosphere, some atmospheric physics, and the geology of their ice-clad homeland. One day they decide their lives would be better if they could inhabit the entire continent, instead of just clinging to the coastal fringe, and so with the help of some misguided sympathizers, they develop a vast clandestine industrial complex pumping long-lived fluorinated super greenhouse gasses like CF₄, C₂F₆, and SF₆ into the atmosphere to warm things up. These compounds are vastly more powerful warming agents than CO2 and methane. They are also long lived atmospheric species, sticking around for up to 50,000 years. If a serious industrial complex were set up to produce and release them en masse, they would close a good chunk of the atmosphere’s thermal infrared window and radically alter the climate for tens of thousands of years. This atmospheric engineering could be done over the course of an election cycle, especially if the Yeti bastards had help from the cold-hearted Canucks and Russkies.

Would the G-20, the OECD or the UN Security Council stand by while a rogue Yeti nation threatened the billions of people who live in coastal cities, or depend on glacial water supplies, all in the name of Manifest Destiny? Of course not. We’d be more likely to bomb their furry white asses back into the Ice Age.

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Links for the week of December 3rd, 2010

Links for the week of November 26th, 2010

If you want to follow my shared links in real time instead of as a weekly digest, head over to Delicious. You can search them there easily too.
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A Thousand Splendid Power Plants

Xcel Energy’s Valmont East Terraforming Station in Boulder, CO. As a side effect, it powers all the lights you see in the background.

James Watt’s industrial revolution was fired by coal, is fired by coal, and shall be fired by coal under the current plan, until death do us part. Anthracite, lignite and bituminous — it is all nearly pure carbon, sequestered in the shallow inland seas of the Carboniferous, scavenged from a powerful greenhouse atmosphere by the first macroscopic life to colonize the land, 350 million years ago. It was into these scaly fern tree forests, club mosses, cycads, and giant horsetails that we tetrapods laboriously crawled so long ago, to gasp our first desperate breaths.

Industrial power, carbon and coal are deeply synonymous. The SI unit of power is named for Watt, and the word “carbon” is derived from the Latin carbo, which means coal. Many of the super-human abilities we are accustomed to wielding today are intimately bound up with this strange rock that burns. Our purpose in burning it is to release usable heat, and we consider the release of carbon dioxide and other pollutants to be a side-effect of that process. In the fullness of time I suspect we will come to see that relationship reversed. When we look back at today’s coal fired power plants a few centuries from now, we won’t see them as electricity generators. We will instead see them as components of a massive, coordinated and yet unintended climatic engineering project. We are effectively terraforming the Earth, participating in the transformation of our planet as a new force of nature. It’s not the first time life has done something like this. The cyanobacteria began pumping oxygen into the atmosphere 2.5 billion years ago, incidentally making both fire and macroscopic organisms possible for the first time. And also incidentally oxidizing away a lot of previously stable atmospheric methane, a powerful greenhouse gas, plunging the Earth into the deep freeze for three hundred million years. I hope that we can be more mindful of the consequences of our actions than the blue-green algae were, but honestly I’ve got my doubts.

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Tag: energy