Expanded weekday hours

We're moving into a summer schedule at the store now and have expanded our weekday hours. We'll now be open:

Tues 10-6

Wed 10-7

Thur 10-7

Fri 10-7

Sat 9-6

Sun 12-5

Mon closed

Also, you will be seeing a new face around the store. Please welcome Erica to our team of helpful staff!

Solar at Shakori Hills: does it make sense?

We had the pleasure of making it out to the Shakori Hill Festival today to let the kids participate in various events such as the Paperhand Puppet Intervention, and to listen to a bit of good music.

The organizers had a booth there, asking for contributions towards a solar electic system that would power the event in the future. The card indicates that 10,000 kilowatt hours (kWh) of electricity are used to put on the event. I applaud their goal to get off the grid. But the sea of cars I saw in the parking lot left me wondering: how much energy was used in just getting people to/from the event, in comparison to the 10,000 kWh goal?

Here's my attempt to figure it out. When we were there on Sunday, there were perhaps 700-900 cars around. We can estimate from that a total of about 5,000 cars were driven to/from the event during the course of the four days (that's an average of 1,125 cars/day, or 2,250 people per day if it averaged 2 people per car, probably a low estimate). The location is 17 miles from Carrboro, 40 mi from Raleigh, 35 mi from Durham, and 10 mi from Pittsboro. So we'll average all of those at 25 mi (each way), for an average round trip of 50 miles. The fleet average for the US automobiles as of 2003 was 25 miles per gallon, so on average, 2 gallons of gasoline were burned per car trip to/from the festival. If our estimate of 5,000 car trips is accurate (maybe an underestimate?), that's 10,000 gallons of gasoline burned up (526 barrels of oil).

Now, hold onto your seats. Each gallon of gasoline contains about 37 kilowatt hours (kWh) of energy. So, we have 10,000 * 37 = 370,000 kWh of energy burnt up to get people to/from the festival in their cars/SUV's/trucks/motor homes.

That is, 37 times more energy were used to transport people to/from Shakori Hills, than would be saved if the festival organizers reach their goal of going all solar.

Here's another way to look at it. An efficient generator will extract about 7 kWh of energy out of a gallon of gas (no, they are not very efficient, they only recover a small part of the 37 kWh contained in a gallon). So, to generate the 10,000 kWh of energy that the festival needs to run, that is about 1,429 gallons of gas, if they were to use local generators. Compare that 1,429 to our estimate of 10,000 gallons burned up getting people to and from. I.e., even using inefficient gas generators, generating all that power to run the festival would only take 1/7th the power that is consumed to get all those people to/from the event. 1/7th. That is sobering. (and note: even if everyone drove a super efficient hybrid like the Prius out there, and averaged 50mpg, it would still consume more than 3x more energy to transport people there).

And this is why all the peak oil people are so concerned about our future. They realize how much energy we are just burning up driving around in our gasoline burning cars. But most people don't think about that. Even very "green" people just don't realize how much energy is contained in each and every gallon of gas put into their cars. And, while I applaud the goal of Biodiesel, I had a look at the Piedmont biofuels website to see how much they produce. They produce "thousands of gallons per day" - so, basically, if every person going to the festival used biodiesel instead of fossil fuel, there would be none left in this area for any other purpose (such as powering tractors that help grow our food).

I don't want to come off as overly critical of these efforts. Every small bit helps. But if people think these are solutions to fossil fuel dependency, they are clearly not. They are drops-in-the-bucket.

Anyway, I think if the Shakori Hills organizers can get the solar panels, it will save energy and have a positive effect - not only by the direct power saved, but by the example set. At the same time, they could have a vastly greater effect on energy usage for the festival (and also local pollution/noise/danger created by the cars) by implementing a bus system to/from the event. Or getting people to go out there on their electric bikes :)

Why some days just need an electric bike

Some may accuse me of being heavy handed in promotion of electric-assist for bikes. To me, this is not a marketing schtick. It is an education schtick. Ever since I got my first electric motor kit for my bike in '94, I've shown it around, and many people - especially avid cyclists and bike shops - have been dismissive. I think this stems from an attitude that bikes are a recreational tool rather than a transportation tool. After hearing that attitude for all these years, perhaps I've grown a bit defensive about it over time. But, really what I want to accomplish is education - letting people know that electric bikes exist, and can help many people with the goal of biking more often (i.e. from none at all to at least once or twice a week would be a big step!).

So, to do that, I like to tell little stories about my experiences, and here is the latest. We recently became a Madsen Bicycles dealer, and got some of them in stock. One of the things that is exciting about this bike is the ability to haul up to four kids at a time, all sitting nicely seat-belted on benches in the rear bucket.


This is a Good Thing for those of us with families that exceed the carrying capacity of the Xtracycle, Yuba Mundo, or Big Dummy (all of which carry only two kids, max).

So, I have been using the Madsen for short trips hauling kids around the local area, and it is great. But our area is hilly enough, that hauling 120 pounds of kids up the hills is a slow endeavor. The first hill starts right at my driveway, with a 50 ft climb. And there are many more hills riding around Carrboro and Chapel Hill (this is the Piedmont, after all). So we have been planning on putting an eZee electric hub kit on the bike, but presently they are out of stock at our store, so the bike is currently un-assisted.

Anyway, on the Saturday of Easter Weekend, I was taking the kids for an Easter Egg Hunt activity put on by a local organization. I really wanted to bike over there with them, rather than use the car, because it was a beautiful, sunny, 70-degree day. By the time we got the stuff together, we only had 45 minutes to get there. If I knew exactly where I was going, and if it was on the closer side of town, that would have been enough time to ride. But I didn't know that area of town well, and I recall that part being quite hilly. Well, anyway, we loaded up into the bike and started up the first hill out our driveway, and I quickly realized that I just didn't have the energy to haul these kids over all those hills for about 20 miles round trip, while being in a hurry to get there on time (and possibly getting lost in a hilly area of town). So we turned around, back down the hill we went, and we got in the car and drove instead.

Now, if we had already had the electric assist installed on this bike, I would not have hesitated to go by bike. The hills would have been much less of an issue, and I also would have felt less time pressure, since I would have saved 10-20 minutes of riding time.

So here is a case where if I had electric assist, I would have gotten well over an hour of moderate exercise pedaling the assisted bike to and from the activity, whereas instead I got none (and didn't have time for another bike ride that weekend). And, I burned up well over 37 kWh (kilowatt hours) of energy by driving the car over, when the e-bike would have burnt up much less than 1 kWh.

Someone who lives in a flat place (e.g. Davis, California or much of Texas) reading this might not be able to relate. One thing I've noticed with my Big Dummy cargo bike is that when it is fully loaded, pedaling it on the flat lands is only a tiny bit more energy than pedaling it unloaded. But once it gets to a hill, all that extra load weight becomes very noticeable. So, anyway, if I lived in a flat place, pedaling the Madsen with the kids 10 miles each way wouldn't have been such a big deal. But with these hills, it is a big deal - enough so that it makes me much less likely to use the bike, and instead, just take the car. I'm looking forward to having that assist on there! (Aside: These bikes are now available for rent for trying out).

Bike ride to Triad Electric Vehicles Association meeting

Today I just got back from a nice bike trip with my daughter, to the Triad Electric Vehicles Association meeting, in Burlington, NC. I was invited to their monthly meeting to give a presentation about Lithium batteries and battery management systems, since some of the members are starting to contemplate moving away from lead acid batteries. In fact, two of the members have recently commissioned us to build custom packs for their EV's.

We rode over there on my electrified Surly Big Dummy, with an eZee electric kit on front. We had 3 different LiFePo4 battery packs (48V x 10 amp hour (Ah), 2 x 36V x 10 amp hour, totaling about 1200 watt hours, which equals a 100 watt lightb

ulb running for 12 hours). I didn't really expect to use that much battery power on the 33-mile each way ride, but I brought them for show and tell (and glad I did). I also brought some BMS boards (designed by the folks on Endless Sphere), PSI cells, and more. We also had all our overnight gear. So the bike was well loaded with us and all our stuff. I estimate that the gross vehicle weight was close to 400 lbs with us included.

While a round-trip 65 mile bike ride may not sound like a big deal to some folks who ride their road bikes 60+ miles in a day, this was a ride with precious cargo on the back, and a fully loaded bike, on some sections of busy road. I planned the route using Bikely.com, which allows mapping out a route using Google maps. I tried to choose a lower-traffic route most of the way, but some high-traffic stretches were unavoidable (why don't they put shoulders on the roads in this part of the USA????)

We started out mid Friday afternoon, hoping to make it there before the main rush hour traffic hit. As soon as we got on the road, there were some serious headwinds. The national weather service reports winds averaging 15mph, with gusts up to 43 mph - coming straight from the direction we were going. I was sooooo glad to have electric assist. That would have been a miserable ride without. At one point, I was going full throttle (using about 1,200 watts) and pedaling full tilt, on flat ground into the wind, and only going about 15 miles per hour. Without electric, that would have been about 6 miles per hour. There were also some nice hills, too (totaling about 1,200 feet of up and down). Without electric, and with that headwind, the trip would have easily taken at least 4 hours. Despite the winds, we made it there in 1hr 45 min, at an average speed of just under 18 mph. But we burned up way more energy than I planned - about 24 watt hours per mil

e. (i.e., four miles riding would equal a 100 watt light bulb running for an hour). I had planned on 20 watt hours per mile. Glad I had those extra batteries!

Jack, one of TEVA's leaders, graciously hosted us for the evening and let us crash at his place. We had a nice dinner and after-dinner discussion about quantum mechanics, consciousness, God, and evolution (I am making slow progress on a book about these subjects). We also had the obligatory discussion of the current financial "crisis". Anyway, to bed very late, and up somewhat early next morning to head out for the meeting.

So I'm not someone to get shy in front of groups of people, since I give scientific lectures fairly regularly (just gave one last Thursday to an audience of 40-50 people). But this group was a bit intimidating, because there was only one other woman present, and it was about 20 guys, who were obviously quite tech savvy. Well, after some introductions and whatnot, we got down to business and I started describing the ins and outs of Lithium Iron Phosphate (LiFePO4) batteries for electric vehicles. I talked about keeping cells healthy, the benefits and drawbacks of these batteries, and discussed some basic design elements for battery management systems (BMSs), the electronic systems that keep cells healthy. There was some good discussion and questions. Afterwards, we went out to the parking lot to check out the various EV's there.

Here's an interesting observation that one of my hosts made: I was one of only 2-3 people who actually used an electric vehicle to get there, and mine was a bicycle.

This was a very interesting observation, so I'm going to sidetrack for a second on that. Why didn't more people drive their EV's over there? I can only guess: I think the biggest reason is that of the various people I talked to, many people had lead-acid battery packs that weren't performing too well anymore, or didn't have sufficient range, or... etc. One guy mentioned a story about being out in his EV one day and getting stranded when the batteries ran out, and having to walk 3 miles. So here's the interesting thing. If a bike battery runs out, you can still pedal the bike. Even my nearly 400 pound cargo bike, if I had to, I could pedal it that whole distance. But I think the bigger take-home message is this - the main impediment to people using their EV's more often is the batteries. For a bike, the battery is relatively small, and hence (though not cheap), not nearly as expensive as for a car or truck-sized vehicle. So nowadays, many people use lithium or at least nickel batteries on bikes, whereas most electric cars of the hobbyist variety are still lead acid. One older gentleman even prodded me a bit because he said he had access to very cheap lead acids, so he didn't see why it was worth buying lithium batteries. I understand that point of view, that in an ideal world lead acids can run for a very long time, so why pay (lots) extra for LiFePo4? But, being in the e-bike repair business, I have seen so many "dead" e-bikes simply because the batteries died, and people hate having to replace them every few years. And it gets worse when you put them in a series string to produce higher voltage. Aside from the longer life and lighter weight of lithium, there is the lower hassle factor. If you get a working system with a good BMS (very important), it should give many years of service without issues. I used lead acids for many years before I switched. But now that I've "seen the light," it is hard to fathom ever switching back to the heavy, bulky (though cheap up front) lead acids.

But anyway, some people tried out my Big Dummy and had lots of fun. Then a bunch of the members headed off to the Earth Day fair in Greensboro, and we got headed back to Chapel Hill/Carrboro.

This time, the wind was at our backs, and still pretty strong. Sweeeeet! There were a bunch of times we were cruising along with just pedaling, no electric power at > 20 miles per hour, a good clip for a 400 lb cargo bike. We made the return trip in just under 1:30 hrs, averaging almost 19 miles per hour, and using about 16 watt hours per mile. After a nice stop at a friends' house along the way, we got back home. And after just having biked 68 miles on a fully loaded cargo bike in 1.5 days, I wasn't totally wiped out (I definitely got some exercise, but not to the point of being wiped).

Total stats for the trip:

-Average 18.4 miles per hour

- 67.85 miles

- 3:40 minutes riding time

- 19.9 watt hours per mile

- total energy used by bike, 1,350 watt hours (for perspective, a typical gasoline powered car would use this much energy to go about 4-7 miles). I probably burnt another 400-600 watt hours from leg power.

I was nicely surprised by how well most drivers treated us. There was only one situation that made me nervous, a stupid dude in an ancient camper truck passed us at the same time there was oncoming traffic, and only gave 6" to spare. I don't know what his deal was, but maybe his engine couldn't handle slowing down on the somewhat steep uphill we were on, without stalling. Anyway, here's a plug for rear-view mirrors: I knew the guy was cutting it close, and I was prepared to bail out onto the grass if he got any closer, long before he was upon us. I don't know how any cyclist can stand riding without a rear-view mirror. I use mine constantly.

But anyway, most drivers gave us wide berth, and we had a really nice ride through the countryside of the piedmont.

3 cheers for human-electric hybrid vehicles!

Red light guy

Most days that I ride my bike there are good things that happen. But some days, there are things that just make me a bit awestruck about the human condition (and not necessarily in a good way).

Take today for example. I'm riding along on my electrified Big Dummy in the nice sleepy town of Carrboro, NC. I'm doing a reasonable clip down a two-lane road (no bike lane), around 20 mph, because I'm late for a meeting. I'm coming up to an intersection, and this big dude comes flying out on his bike, without stopping at his stop sign (my direction had no stop sign), and proceeds to turn right then take the lane in front of me. Ok, slight bonehead move, but no problem, I cruise around him to avoid slamming into him. A few blocks later, I stop at a red light. Here comes "the dude" again, this time cruising right through the red light I am waiting at.

It always makes me a bit angry when I wait at a light and some other cyclist cruises through. My reason for this is that I think it is important for cyclists to give a good impression to drivers, because if we act like regular vehicles, we are more likely to get the respect that other vehicles on the road get. The number one complaint I hear from non-cyclist drivers is that cyclists never obey the rules and do stupid things. In many drivers' minds, that is an excuse for doing obnoxious things back to cyclists. I'm not saying that it is right, I'm just making an observation. And in a war of obnoxiousness, the cars are going to win - they are a lot bigger and more deadly. So, I try to counter that, by showing that cyclists can actually manage to follow the rules and act like a regular vehicle on most occasions. I find that I get far more courteous treatment from the drivers around me, when I do that.

So, back to the story. It is not long before my light turns green and I catch back up to "dude." In the past, I've on occasion made some comment as I went past people about their red light running. However, I'm not perfect. I make mistakes. So these days, I'm trying to not be "holier than though," so I just keep my mouth shut. I figure that yelling at people or lecturing them is not going to be conducive to them seeing my point of view. (So instead, I write on the blog, where there's actually opportunity to discuss my point of view without it being a yelling match). Anyway, I cruised past the guy, by moving into the main traffic lane (he was in the bike lane), and I thought, that was that. Hopefully he'll figure it out someday.

Now, get this. After I go past, he yells a lecture at me: "let other cyclists know when you're passing!". Ok, dude, come on. Do you expect every single car passing you to yell? It's not like I went past him inside his bike lane with 2" to spare. No, I was at least 3 feet out from him by going into the main traffic lane (there were no cars, I checked before entering the lane). I think he was just angry because a woman on a big cargo bike was passing him for the second time. But anyway, that was enough to set me over the edge. I yell back "don't run red lights!".

I figured we are fair and square. He lectures me, I lecture him. Enough, right? No. I get to the next red, where I stop, then turn right. As I get going, he pulls up to the red and again says loudly: "It is common courtesy to let other cyclists know when you're passing." Hey dude, I get your point, did you get mine? I yell back "It is common courtesy to not run red lights!"

This interaction has me baffled. Where does this dude get off lecturing me about how I pass him (in a perfectly legal way, like any other traffic would pass him, giving him plenty of room)? This is a guy who ran a stop sign to turn right in front of me (and I would have hit him if I hadn't moved out into the lane), and he passed me while I was waiting at a red, then he feel justified in lecturing? Sure, it would be courteous to say something to cyclists as I pass, and I often do if I have to pass closely. But if I'm 3-4 feet away in the main traffic lane, I feel no such compunction. But the bigger point is this: here is a guy who violated the law twice, and endangered my own physical health once, and he has the gall to tell me this?

(Shake head). Sometimes I pity our race. It is no wonder we keep getting ourselves into problems like financial meltdown/peak oil/war/whatever. So many people do not have one ounce of introspection. And that's really all I would hope for. Again, I am not perfect - but at least when I do something, I think about what I did, and what effect it might have on others. And I try to use that to better guide future actions. Why isn't that one simple skill taught in our families or our schools?