The theme of our MIT Reunion 2007 was energy. John Fernandez, a professor of architecture at MIT, gave a talk about how the urbanization and wealthification of humanity has led to climbing energy consumption. Here are some interesting facts:
- half of all of the construction in the world occurs in China
- concrete accounts for 6-8% of CO2 emissions
- Percentage of Chinese urban households with air conditioners: 24% in 2000; 87% in 2007.
- Shanghai every year adds more building space than exists in all of Manhattan
- World population is heading to 9-10 billion, of which 6 billion will live in cities (up from 3 billion today)
- In the U.S., residential and commercial space accounts for 40 percent of our primary energy consumption; 38 percent of CO2 emissions are from operating buildings.
- Globally, lighting accounts for 19 percent of electricity usage.
- an American will consume 3.6 million lbs. of materials in his or her lifetime
- the percentage of renewable materials in a building constructed in 1950: 15%; in 2000: 5%.
- the folks at http://www.globalfootprint.org/ estimate that humanity is currently consuming more than one Earth’s worth of stuff; i.e., we are dipping into stores of forests and water faster than they are being replenished
Fernandez talked about a lot of ways to build energy-efficient structures: glass that reflect heat in the summer; double-walled houses that don’t offer easy thermal exchange interfaces; etc. He did not mention what seems to me to be the easiest way to reduce energy consumption: stop heating, lighting, and air-conditioning houses in which nobody is home. A toilet knows whether you are standing in front of it. Why can’t a brand-new house know when everyone has left? Consider the House-as-Smart-as-a-Toilet (TM) in the summer. When the last person leaves, it lets the temperature rise to 80 degrees, turns off the lights, and closes the blinds. When an owner of the House-as-Smart-as-a-Toilet (TM) programs his or her car GPS to “destination home”, the car communicates the ETA to the house and the A/C is turned back on. When the owner arrives home, the House-as-Smart-as-a-Toilet (TM) opens the blinds, evaluates the resulting light levels, and turns on lights as necessary.
MIT’s president Susan Hockfield spoke briefly. She seemed charming, competent, and energetic. Her talk was also boring, insipid, and laced with cliches such as “herding cats”.
At lunch, the oldest alum stood up. He was apparently in great health, a member of the Class of 1935. Each class’s fundraising manager stood up to report on the total amount raised ($1-15 million) and the participation rate (25-70%), after which everyone was supposed to clap (my offer of a gift to MIT was rejected a year ago (story)). In the spirit of MIT competitiveness, I suggested that our table of 1982 graduates should actually boo the other classes, but this policy was not adopted.
We 1982ers had dinner in the new Brain and Cog Sci building, a magnificent structure. Compared to modern students, it is striking how few of us went into finance, law, or medicine. Seemingly everyone was doing science, engineering, or business management (usually of a fairly technical business). Despite the fact that our class was more than 80 percent male, a lot of women alums showed up and the guys managed to find wives and have children somehow.
While it certainly would never be bad to have the house know enough to shut off these things when nobody is there, it actually saves much less than you would hope on modest duration trips. A friend of mine did experiments on his house just to see what was saved by turning the thermostat down at night — it was barely detectable. I would have thought it should be more — after all heat loss depends on the temperature difference as well as the insulation factor — but real world experiments showed the furnace came on for as long in the morning for heat-up as it saved going on in the night.
In Asia however they are nuts over this. As you probably know, most hotel rooms in Asia require you to put your room key into a slot to turn on power in the room, including your air conditioner, to stop you from running the AC when you are out, or when the room is not rented. Annoyingly it also means you often can’t charge your batteries while you are out, until you realize that just about any card (ie. library card) of standard size fits in the slot and turns on the power.
Turning off lighting makes more sense, and better support for suspend-to-ram in computers would also save a lot of power. What would be good would be a super low power semi-suspended state where the disks are spun down but tcp sockets are preserved, alert functions take place and disk writes are cached to flash so that all computers would give the appearance of being always on but draw only a watt or two like a PDA when nobody is actually doing stuff on them.
I saw a recent article in Government Computing News: GSA paves way for IT-based buildings that explains how the state of Missouri is achieving upwards to $30M in savings using some IT/Energy solution, on existing infrastructure, from some firm named Gridlogix.
The state seems to have a pretty novel approach to achieve a large near term savings. While the Ice Caps melt, maybe its time to look for better technology oriented solutions.
energylover@gmail.com
I always notice how often air conditioners run when the outside temperature is fairly cool. The glass would help, but why not some sort of smart heat exchanger?
We could even account for forecasts:
Indoor temperature 76 degrees F
Outdoor temperature 65 degrees F (it’s 2:00 AM)
Forecast high tomorrow: 82 degrees F
Conclusion: turn on the attic fan.
Likewise, in the morning as the temperature is rising, the system would be smart enough to button things up at the appropriate time in the morning.
There is another factor to consider: While the AC unit may be adequate to maintaining a comfortable temperature, it may not be beefy enough to lower the temp very far if you let the house warm up.
Does anybody know why geothermal heating and cooling is not popular in US? From what I read the installation costs are similar to conventional systems but efficiency is a LOT higher (i.e. around 80% reduction in utility energy use).
I agree about residential AC’s having trouble if house warmed up too much while nobody was home. If I leave thermostat at 85-90 F during the day it almost impossible to cool back down until very late at night (DC area)
Maybe it’s just a California thing, but I’ve never embraced A/C of any kind. Not in my car, and not in my house. People that put their ambient comfort in the responsiblity of work or heat devices, generally haven’t been inhabiting a place that was built with comfort in mind. Without giving vendors (as I don’t have a commercial interest), a really good device for heat/moisture regulation in the summer/winter is a solar powered attic fan. Any and every house with an attic space, also has a pocket of air that heats and seeps down at night by default. There is less of a need for A/C if people spend the two hours to drop a self-powered unit into their roofs or pay a pro to cut a pie hole in the roof for them. Within minutes once the pie hole is even cut, 90% (observational guestimation) of the heat escapes. Using the sun to regulate the heat evacuation and draw it out (1,800 cfm) just makes solid sense. People put all their energy into pumping cool air into their homes, when they haven’t even used 1/1000th of a percent of the total energy consumed to help let a little hot air out. If you don’t know what E=W+Q means yet, call a pro to do the design and to play with the details for a while. If you’ve got a fresh build, please contact someone who knows what they’re doing with heat transfer.
FYI – British Petroleum makes the best solar attic fan (that’s just the functional classicist in me speaking up for a well crafted product I’ve used and installed).
Best Wishes in Terms of Efficiency and Novelty,
imightbethatguy@yahoo.com
marriagedestroyer,
we installed a geothermal system in ’99. I think it was about $12,000 complete (with ductwork). I’m pretty sure I could have gotten a propane furnace and AC unit installed for about half that.
Cooling is very economical. Heating is more than expected, some of our electric bills are $300/month (avg is probably about $125 over 12 months)
Our system is the “pump and dump” style, using well water. That can only be done if you have acreage. Another style uses underground tubing for heat exchange, that also requires quit a bit of space.
The house is owner built (1984 – now…), double-wall superinsulated. We heated with wood for the first 15 years – my poor, suffering wife.
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I don’t think current construction practices allow a house to be unheated during the winter. Even if you drain the pipes, moisture gets in the drywall and destroys it – must maintain at least 45 degrees or so. So I’ve been told.
take a look at Green House exhibit at National Building Museum in Washington, D.C.: http://www.nbm.org/exhibits/greenhouse2 This is a gem of a museum located in the Old Patent Office — oft-pictured during Inauguration Balls held there.
Doesn’t Bill Gates’ house in Seattle area have a lot of energy-saving features, in addition to the sensors which play the type of music the family member/guest who’s just walked into a room likes to hear?
Sorry, but I generally find that people who complain about energy use and CO2 emissions lack the courage of their convictions. Smart homes and insulating glass are NOT going to cut energy use or CO2 emissions. At best they will slow growth in use by a couple percentage points. Sort of like a Federal “budget cut” that leaves the budget larger year after year.
Want to cut U.S. carbon emissions nearly in half? Convert all electrical generation to nuclear. Build reactors to reprocess spent fuel rods. Quit fighting over a permanent storage facility for truly spent rods and just build it.
Yes, nuclear waste is dangerous. Yes, it must be managed. Yes, there’s always the chance of an accident. But if you really believe the ice caps will melt and our cities will flood, well then it’s a pretty easy choice. Energy efficient light bulbs and geothermal AC aren’t going to cut emissions in half, I guarantee that. They won’t “cut” it at all, just barely slow growth. When I hear ‘experts’ talk about such silly band aids, I’m forced to conclude they don’t really believe global warming is going to do any serious harm.
And the other half? We either need cheap fuel cells or really good batteries for our cars. But note that neither of those technologies will do squat in terms of actually cutting CO2 output unless they are backed by an energy source that doesn’t produce CO2. Wind won’t cut it. Solar is too expensive to get the masses on board. That leaves…
Nuclear.
Yes. Nuclear is by far the most practical and ultimately the most “green” energy source. When fuel is reprocessed, the physical volume of the high level waste is absurdly small.
Many of the safety problems faced in the past are the result of a pernicious regulatory environment rather than regulatory lapses.
The US Navy has built and operated _hundreds of nuclear vessels. The design and operation of their power plants is far less prone to error than what exists commercially.
In the commercial environment, the biggest hurdle was regulatory rather than technical. The challenge was/is getting the design approved. With billions of dollars at risk, the “safe” way to go was to merely replicate an older, poor design that was already approved.
There are many (old) innovations available to make nuclear even safer.
The history of this type of reactor is worth reading about. http://en.wikipedia.org/wiki/Pebble_bed_reactor
Re smart houses, ground loop heat sinks, etc. Right, it’s quite odd we don’t have such systems. But consider that most people can’t program a VCR. Major companies – NSP, Philips, Honeywell, even Microsoft have had prototypes for years (acutally decades). You can find some products at smarthome.com. Yes, latent heat issues mean that it is usually almost as or more efficient to keep a fairly steady temperature in conventional structures. There are sizable savings available in heat sinking into something more efficient than outdoor air (again often constrained by an inexplicable array of regulations). In Hong Kong, all the major office buildings heatsink their AC to the harbor. Not going to happen in the US.
Regarding notions such as “renewable” building materials, I revel in amazement at the intellectual dishonesty scientists are able to get away with.
Practically speaking, there is no usefulness in this term as applied to building materials except to propagandize. Why do we care that we cannot “renew” clay for bricks as fast as we use it up? Can anyone seriously argue that we are running out of Fe, Si02, Gypsum, Al, limestone, or clay?
Buckminster Fuller designed buildings out of light-weight aluminum shells arguing that we would soon run out of stuff to build houses out of. To him, wood was what we were sure to run out of. Of course, the main “renewable” building material is wood. But if we take one set of environmentalists at their word and start to build extensively from wood, we quickly run into another group that decries timber farming. Philosophically speaking, a true-blue Green won’t be happy until the human population is reduced to a few thousand of us wearing grass skirts and eating nuts and berries.
Two things not mentioned:
1. paint the flat roof of a commercial building WHITE to avoid heat buildup during the summer.
2. In many places in the USA, simply using a solar hot water heater (or a Trombe wall with/without a fan) to pump heat into the house during the winter would greatly reduce heating costs.