Yesterday I had errands to do. I wanted to pick up a couple of 3/8 flare plugs at Plumber's Supply; get a loaf of Multigrain Sourdough at Rickards Bakery; go to the bank; pick up a piece of glass at the frame shop; get something at the hardware store; and get some coffee beans at the store. Where I lived for many years in NH, this would mean driving into Lebanon and West Lebanon, a round trip of 20-25 miles. Here down Island on Martha's Vineyard, where we live and work, I can do it in 5 miles. It's also flatter and warmer in the winter, so a bike is the perfect form of transportation. If I lived in a dense urban area, where everything is even closer, I could do it all walking.
As I mentioned in a previous post, close to half my carbon was in driving my car (currently a Honda Fit.) Here, the car may stay parked from week to week. In order for a bike to be a useful vehicle for transport and errands, I think it needs several characteristics:
- It must have enough cargo capacity to do your periodic food shopping
- It must have fenders and brakes that work in the wet weather
- It must have lighting.
For carrying cargo, we've traditionally had racks and panniers, and baskets. The trouble is that if you have something larger it's really hard to fit it easily on a bike. Bike trailers are one solution to this. But trailers add the drag of additional wheels. The Dutch have all manner of nifty, carry-a-boatload bikes called bakfiets:
This one has a rain tent to keep the kids or groceries dry. I've never ridden one. You can see that this one fulfills my other conditions - it has fenders and lights, and it looks like the brakes are enclosed drum brakes, that retain effectiveness in the rain. Makes sense for the Netherlands (heck, with climate change, it should have amphibious capability!) Meanwhile, on this side of the pond, we have bikes that are beginning to be known as cargo bikes or longtail bikes. This bike species began commercially with the Xtracycle. This is a tubular subframe that bolts on a mountain bike frame and adds about fifteen inches to the wheelbase, which enables the bike to take a pair of purpose-built racks and bags. Here's my Klein MTB set up with the Xtracycle free Radical kit:
All of a sudden what you can consider carrying on a bike expands considerably, and yet you know you are still on a bike that behaves predictably like a regular bike. You can use a bike you already have, or pick up an older MTB that is obsolete as a mountain bike but makes a great platform for a cargo bike.
I liked my Xtracycle a lot, and once I proved to myself this was a good option for a utility bike, the bike manufacturer Surly obliged the cargo bike fancier with a purpose-built cargo bike called the Big Dummy. Because the frame is fully triangulated it is stiffer than an Xtracycle. In the fall of 2009, in the middle of the Great Recession, retailers were cutting the price 40% on a Dummy frameset and I bit. Here's a shot of the bare bike:
It took me a while to shake down the build and decide what parts I wanted on it. I built it up to be a tank. The rear wheel, for bike connoisseurs, has a Phil Wood cassette hub. The front wheel has a German Schmidt Nabendynamo hub, which is the best generator hub available. Both hubs accept disc brake rotors, for major stopping power even in the rain. Planet Bike Cascadia fenders and a long mudflap keep me dry when riding.
The LED light revolution extends to bicycles, where we have very bright and very long lived lighting systems that pair with the generator hubs. My headlight is a Busch & Muller Lumotec IQ Cyo R. Both the headlight and taillight benefit from a capacitor built into the headlight, which gives about 4 minutes of light at a reduced level once the bike stops, so I still have light at a stop sign or when I get home. Lighting IMO is what transforms a bicycle from a recreational item into a means of transportation, because you can safely go places after dark. (A good place to buy bicycle lighting is Peter White Cycles, and he has a web page on which he has posted photos comparing the different headlight beams at night). A week and a half ago was the West Tisbury Town Meeting, and riding home at 10:30 pm was a short and exhilarating trip. I sometimes supplement my generator lighting with a phenomenally bright battery-powered taillight from Dinotte (NH made!) that can be seen in broad daylight from 1/4 mile away.
The Big Dummy can accept Footsies, which allow one to carry a passenger; the Longloader, for items like ladders and surfboards; and Wideloaders, for the heavier loads. Here's a couple of Wideloader loads on the Dummy:
In the photo above you can just make out that the tires are my pair of carbide-studded Nokians, for icy winter conditions. I put a pair on Jill's bike this winter for her commute, since the dirt roads ice up more than the paved ones, and her commute is mostly dirt.
Always carry a spare!
My six errands today took about an hour out of the middle of my day, including the riding time. Riding hardly adds more than 5 minutes to that trip (driving in the vicinity of Vineyard Haven is never very fast) and gets the heart pumping - it's a brief pleasure rather than a chore. I haven't kept careful track, but I'm pretty certain I have more miles on the Dummy than on the Honda since I moved here, if I only count miles on the Island. I still have many more auto miles all together, from the off-Island work forays, but on MV, the Dummy is king.
Last Saturday Dick and Tim Mavro, with the help of a large friend of Tim's named Justin, came and took the oil heating system away. On the trailer you can see the boiler shorn of its blue Buderus jacket and strapped to a dolly. Also in the photo is the old oil fuel tank and the indirect tank that the boiler heated for our hot water, as well as a 55 gallon drum that holds the remaining oil that we pumped out of the tank with a portable pump and hose set-up. I was fortunate because Tim works for a major fuel oil supplier here, so he knew what to do to get all this stuff disconected and ready to move. I'd drained the boiler and disconnected the piping and wiring, and pulled the flue pipe and fresh air inlet. I patched the flue pipe hole, and filled it with rigid polyisocyanurate foam, and added another three inches of foam against the rim joist - now this small area is the best insulated portion of my house :-(
I noticed that as the oil fill line and vent line were removed that they slid right out, letting me know that there wasn't any air seal around them. At the moment they are temporarily filled with foam sealant:
What really struck me during this process was how dirty the burning of fuel oil is. The flue pipe was half blocked with soot (it should be cleaned annually, but because it is sealed no one wants to pull it apart and then re-seal it) and the boiler had about an inch of soot inside. And of course the oil itself is a smelly liquid hydrocarbon that we risk spilling in our homes and creating our own little Superfund site. I was clear to people that I was focused on not spilling any oil during the removal process and we pretty much achieved that.
The Buderus is headed to replace a 40 plus year old boiler, so I felt good about moving it on, because it's possible that this modern boiler will save 10-20% of Tim's fuel bill, even more if his present boiler has a tankless coil for producing hot water. This is a heat exchanger immersed in the boiler water that has cold water coming in and hot water leaving, heating it as it passes through the coil. Boilers with tankless coils are set to maintain themselves at high temperature all year around, regardless of heating load, because it has to be hot enough to make hot water at any moment. Setting a boiler up to heat an indirect tank allows the boiler to cool off once the tank is up to temperature, and perhaps not come back on until there is a call for hot water again.
I was glad to see the truck drive off with all that equipment on the trailer. Now I have to find a home for the Vermont Castings gas heater and we'll be fossil fuel free, at least as far as site energy.
I came home this evening and noticed as I passed the meter for the Fujitsu heat pump that it's just turned over 1,000 kWh since we switched to the heat pump for heat the day after Christmas. During that time, we've experienced about 3,250 heating degree days base 65˚F (HDD65 ) A degree day is a measure of heating demand, in which the average temperature for the day is subtracted from a base temperature, traditionally 65˚F. This is about 55% of a typical annual HDD total for Martha's Vineyard, and since 300 or more of those HDDs occur June - September, when the heat isn't on, it's even a bit higher. I'd expect to use more heating energy during the first half of the heating season, because of lower solar availability - December and February have similar average temperatures but there's more sun in February. This effect isn't as powerful in House 5 as it was in Nerdwood, back in Meriden, because the NH house had more south glass and less shading. Nonetheless, I think it's reasonable to say that we might expect to heat the house for under 2,000 kWh annually with the heat pump. I like this better than 300 or so gallons of fuel oil.
I wrote in in an earlier post (Out with the Old, In with the New) about my heating energy usage with the oil-fired boiler vs. the usage with the minisplit heat pump. The average daily energy input to the heat pump in BTU/day was 43,000 BTU, compared to somewhere around 290,000 BTU into the boiler (note that the boiler also uses electricity, a fact often ignored in comparisons between heating systems - the controls draw power all the time, and the burner uses about 300W, so maybe 1-1/2 kWh/day - that's over ten percent of the energy going into the heat pump!) So is the heat pump really over six times as efficient at heating my house?
Well, sadly, no. The electricity going into that heat pump, at least for now, comes from the utility grid. Somewhere, often far away, are generators, powered by coal, natural gas, fuel oil, hydropower dams, and nuclear fission. When electricity is generated, no matter what the process is, there is energy lost, usually as heat - recall those plumes that come off of the cooling towers at powerplants. Closer to home, maybe you have a small gasoline-powered generator - that exhaust is pretty hot when it's running, right? That's energy that isn't being used. (An aside - the most sensible thing to do with power plants is to use the waste heat energy also - that's called cogeneration or combined heat and power, and it's more common in Europe than North America, where district heating systems are fed with hot water heated by powerplant waste heat.) So energy is lost in the generation process, and that number in fuel burning generating stations is 40 percent for the best plants to 70 percent for poor ones.
Once the electricity is generated at the powerplant, it has to be transmitted down the grid to us. In this step, energy is lost to the resistance of the conductors, and also at transformers, where voltages are changed. So we take another hit!
Overall, depending on the mix of power generators in a region, the generally-accepted figure for the US power grid is that about two thirds of the energy that goes into the powerplant is lost before it gets to us at our homes. At our buildings, we call the amount of energy we use "site energy" - it's energy consumed within the site boundary. As you can see, if that energy is electricity, the "primary energy", sometimes called "source energy", used to produce that electricity is three times the site energy. So the Primary Energy (PE) Factor for electricity in the US is three.
So maybe my Fujitsu heat pump isn't as good as it seems - if I multiply that 43,000 BTU by three, it's about 130,000 BTU of primary energy consumed to deliver that electricity to my heat pump. That's still under half of the energy in the oil the boiler was using, so the heat pump is still looking like a good climate choice in addition to the great cost reduction of operation.
We should note that fossil fuels also take energy to extract and refine and transport to the end user. Some sources assign a PE factor of 1.1 to these fuels, although this is clearly a catch-all, since the extraction energy needed for an oil well in Saudi Arabia is likely quite different from that required when drilling in the Gulf of Mexico (if one were so foolish as to do such a thing.) The Germans who run the Passivhaus Institute assign a PEF of 0.7 to solar electric systems. This says that it takes 0.7 kWh of energy input to produce the system for every 1 kWh of energy it produces. This number is more debated than the electrical generation factors. Even so, there's no question that with on site generated renewable electricity, the heat pump looks a lot better than it does with grid power.
What about biomass? Advocates often say that biomass is carbon neutral, because a tree absorbs carbon as it grows, and as it decays, that carbon is released. By burning biomass, we're just hastening the release. I don't think it's quite that simple. Pellets, especially if they are made from wood chips (they used to be wood waste, less so today) need to have the wood chipped, then dried, then ground up and pressed into pellets. There is some fractional PE factor there. Firewood cut on your own place with a handsaw has a pretty low PE factor!
The climate impact of our houses is proportional to primary energy consumed, not site energy. If you use electric resistance heating (COP of one - one unit of energy in, one out; efficiency on site of 100 percent) supplied with grid electricity with a PE factor of three and another house consumes the same amount of site energy of natural gas (assume an efficiency of 90%) with a PE factor of 1.1, the climate impact is 3/(1.1/0.9) or 2.45; the climate impact is almost two and a half times worse. So don't use resistance heat, use your electricity in a highly efficient heat pump (which incidentally doesn't mean a ground source heat pump, commonly mistakenly called geothermal...) and then you can do better than natural gas, and you also can make that energy on site, which is hard to do with natural gas-fired equipment. Of course, you could bone up on your fracking...and I don't mean what Starbuck meant.
Finally - the climate is affected by all the energy used in a house, not just thermal energy. And the fastest growing portion of residential energy usage is in stuff we plug in, all using electricity with that lousy PE factor. So please turn that damn big screen plasma TV off once in a while!
LED lighting has been continually evolving over the past few years. I attended a session at Better Buildings By Design in February given by Peter Romaniello on LED lighting, and Peter warned us that there was a lot of junk on the market. He gave us some criteria with which to evaluate LED products.
- Does it have a Lighting Facts label? If not, pass it by
- Is the color temperature between 2700 and 3000K?
- Is the Color Rendering Index (CRI, called Color Accuracy on the label) at least 80?
- If it is dimmable, does it need a special dimmer (some do...)?
- Is the distribution of light appropriate for the use (Peter showed some examples where good conventional lighting was changed haphazardly to LEDs, resulting in alternating pools of light and dark)?
- Is it a viable replacement for existing technology?
- Will it become rapidly obsolete?
One of the flagship companies making LED light engines is Cree. They've partnered with Home Depot to sell the EcoSmart LED downlight, designed to retrofit into existing standard six inch recessed lights. It's marketed as a direct replacement for a 65W incandescent that many of these fixtures were intended for. According to the Light Facts label, its light output is 575 lumens, it draws 10.5W, its color temperature is 2700K, and its color accuracy is a high 92.
Our kitchen has three six inch Halo cans with a white trim ring and a gold reflector cone. The lamps in these fixtures were 23W compact fluorescents, the ones that look like dairy whip cones. They are rated at 1640 lumens, almost three times higher than the Ecosmart lamp. They have a CRI of 82 and a color temperature of 3000K. I took my light meter out and measured light levels at my counter of 12-15 footcandles - not too bright, really (no comments about similarity to the blogger, please!). The interaction of the lamp and the gold reflector didn't produce a pleasing light quality. Armed with how-to info from watching a couple of Youtube videos on how to install the Ecosmart lamps I swapped them in and the CFLs out in fifteen minutes - you remove the trim ring and reflector, then the mounting plate that holds the porcelain lamp socket in place, then you screw the LED lamp in place, and snap it into the recessed can, where it is held by three leaf springs mounted on the LED.
The difference in lighting quality is profound. The kitchen feels brighter and cleaner. Jill noticed it last night when she came home and she thought it was a huge upgrade. Interestingly, the light levels are barely higher - maybe 15 - 17 footcandles. This shows that the lumen output of the lamp doesn't tell the whole story - what matters is how the system of the lamp and the fixture move the light of the lamp to the place we want the light to fall. The CFL lamp is not well matched to the recessed can application, so it was easy to do better with fewer watts and a lot fewer lumens.
Other advantages of the LEDs are even longer lamp life (but who knows really, they haven't been around 35,000 hours yet :-) and no mercury (fluorescent lamps have small amounts of mercury in them.)
I like the light quality, but I really want a 20W version to boost the light levels for my middle aged eyes. That would likely be a true replacement for the 65W incandescent lamp in most six inch cans. These things aren't cheap - even through Home Despot they're $30 (earlier they were $20, and some places they are more - I think the targeted list was $50.) I figure these three Ecosmarts will save me a bit over 40 kWh/year, currently costing about $7.50. Not horrible economically, and less money than what it would cost to purchase solar electric panels to generate this energy.
Of course, one can always keep the lights off and wear a Petzl LED headlamp!