This is the Tesla Roadster:

It is all electric, runs on 6,000 cells of Lithium Ion battery (essentially the same cells that are in a laptop). It accelerates to 60mph in 4 seconds, and has a range of about 200 miles. It’s wildly exciting to ride in.

A fillup takes 3.5 hours of 220V at 70A, which is 15kW x 3.5 hours or 54kWh or about $5 of full-price electricity at Northern California prices (about $.10/kWh). (In practice, you’d get a special night-time rate that is cheaper.) That comes to about 250Wh/mile or $.025/mile.

Compare that with a fleet average vehicle getting about 25mpg. With California gas prices at $3.50/gallon, that’s about $.14/mile, or nearly 6 times more expensive (and that “fleet average” vehicle certainly won’t accelerate like the Tesla!)

Here in California, that electricity is probably produced by natural gas - that generates about 650 g of CO2 per kWh of electricity generated (source: UK goverment report), which gives the Tesla a footprint of about 125 gCO2/mile.

Compare that with a “fleet average” 25mpg car burning gasoline, generating 8800 g CO2 / gallon burned (source: EPA), which translates to about 352 gCO2/mile.  In fact, a delicately driven Prius getting 60mpg is roughly equivalent.

But the good news is that with 10 square meters of solar panel, you can generate enough solar power to drive your Tesla 200 miles per day with zero (first-order) carbon output!

More broadly, developing expertise in electric power storage and automotive drive trains opens the door to leveraging future more efficient electricity generation opportunities, such as hydroelectric, wind, industrial PV, or even nuclear power for personal transportation.

I am trying out Adobe Lightroom as a workflow tool for my photography hobby.

Offline Photos

I have been using Picasa II for a while now, and it’s missing one really key feature: if some of your photos go offline (e.g. they are on a removable disc), they are removed from any collections they are in. This is unfortunate if you have been building long-term cross-shoot collections of favorites, or photos by category. Keywords can partly substitute, but don’t allow for ordering or naming the whole collection. Lightroom claims to maintain records of offline photos in it’s database; we shall see.

Keyboard Shortcuts

I am frustrated by lack of documentation on keyboard shortcuts. I found this reference on the Adobe Labs website, but it’s demonstrably incomplete. Please comment if you have other shortcuts to add, and I’ll edit them into here.

Handling XMP

In Picasa, picture titles or captions are written into a JPG file; they are read by Lightroom, although it isn’t trivial to get them to show up. If you check the metadata in the right panel (you have to scroll far down in the default layout), you’ll see the titles shown there (under the field called “caption”, not “title), and they can be made to display in slideshows, etc. However, if you edit the caption, the revised data is stored in a different format.

If you leave “Automatically Write Changes into XMP (Preferences > File Management)” unchecked, then apparently the caption is only recorded in the lightroom database; checking this box does seem to make LR record the change into the JPG file, but in a separate XML segment that isn’t read by Picasa, Exifer, or the Windows XP property viewer. And worse, checking this box apparently causes LR to rewrite all the files on your hard-disc. Not quite what I had in mind.

Anyone know whether there is a keyboard shortcut to move focus to the caption entry field? It’s tedious to mouse and click the field for each photo. Also, does anyone know how to enter a caption in a mode other than library grid mode?