20 December 2008

Solar comes to Minneapolis

Whilst the HOURCAR at the 46th Light Rail Station is not yet a plug in Hybrid (look for it in the next couple of weeks) the solar panels at the station are up. For now, and whenever the 46th Street LRT car is out on the road, the panels will feed power back in to the grid to power nearby things like, oh, the light rail!

We had an event with Mayor Rybak and Representative Frank Hornstein (60B) and we will have pictures from that soon!

The HOURCAR in front of the Metro Transit building which has 2kV of solar capacity on the roof.

A closeup of the building.

When not powering the HOURCAR, the panels feed in to the grid, helping to power various local users, including the Hiawatha Line!

And if you think that a few car-powering solar panels can't come close to running the LRT, well, you're partially right. We can't run the whole line. But light rail trains are very efficient (you can see a long website which compares different transportation modes here) so we'd make a dent. For example:

The Combino light rail vehicle [similar in size to the Hiawatha Line] is about the same energy efficiency as a Porsche Carrera GT; the Porsche seats 2, the Combino seats 67 and can carry 180. The efficiency advantage is huge, though the Porsche obviously accelerates better and has a higher top speed!

Obviously a Prius is more efficient than a Porsche. But when you are on the Light Rail, you're in a vehicle as powerful as a sports car, but which carries 50-100 times as many people! That's efficient.

09 December 2008

Word of the year: Hypermiling

In a year when gas prices topped $4.00 per gallon, the word of the year is hypermiling.

What is hypermiling? Well, according to Wikipedia it is:

Hypermiling is a term used in North America that refers to a set of techniques used to maximize fuel economy. Those who practice the techniques are referred to as "hypermilers." The term was originally coined by Wayne Gerdes, who is considered by the media to be one of the top hypermilers in the world, and is known to hold the record for gas mileage in some common vehicles, including 30 miles per gallon in an Acura MDX and 59 mpg in a Honda Accord.

Okay, but HOURCARs are all Priuses, so why hypermile? Well, two reasons:

1. Hypermiling can significantly increase fuel economy even in Priuses. My record is 69.5 mpg over 58 miles. That's right, 60 miles on a gallon with gas to spare.
2. The Prius makes it easy. If you switch to the "consumption" option on the touch screen, the Prius will tell you your current mileage and your mileage every five minutes for the past half hour. This makes it easy to adjust your driving on the fly. By avoiding jackrabbit starts, driving evenly and slowly on the interstate, and not braking unless necessary, you can hypermile, too!

If you reset the mileage at the start of your trip, you can see how well you can do (note that drivers of our two solar-powered plug-in cars have a bit of an advantage). Shoot us an email if you do really well. Pictures are cool, too. We'll post 'em if they're good.

A few tips:

* The optimal speed for the Prius is 41 miles per gallon. Above that speed, physics dictate that the gas engine spin even if it is not powering the drive train, increasing drag.
* During cold weather, mileage will suffer, especially after a cold start. This is because the Prius is optimized for emissions, so the gas engine warms up the catalytic converter to better emissions.
* Drive as smoothly as possible. The Prius's brakes do recover some energy, but braking always loses some energy. If you see a red light ahead, let off the gas and coast, and when you leave the light, accelerate firmly but evenly.
* And, of course, safety first.

For more information:

* The hypermiling website
* An article in Mother Jones about hypermiling.
* A great depiction of how a Prius's powertrain works.
* Stats about watt hours and drag (a bit geeky. Okay, really geeky.)

04 December 2008

Why car sharing works

Here's a chart of a single HOURCAR's use from 9:30 a.m. to 11:00 p.m.:

Green segments are different reservations. We often see cars with three or four reservations per day (this particular day saw three other cars with four separate reservations each) but I'm not sure I've ever seen five. This means that five people who would have otherwise needed a car each were able to all use the same car. Instead of five parking spaces, one. The average car is used for only about an hour per day, and only by one person. This HOURCAR was used nearly half a dozen times by as many people in one day — and the next day it will be driven by others. This spreads out the cost of insurance and parking and maintenance and depreciation, making the utility of the resource much more efficient.

Car sharing works because it allows for the efficient use of automobiles — and the efficient use of other transportation modes. HOURCAR members bike, walk, take the bus and who knows what else (ski? paddle? skate? This is Minnesota after all) and when they need a car, they hop in and HOURCAR and go. Sometimes five times in a single day.

Update: We've since had a single day with two cars each receiving five reservations, although they were not in use for such solid periods of time. Still, it's great to see the cars being use so efficiently!