Monday, November 19, 2012

Solar-powered eCars

At the Envision 2032 "inspirational session", we heard a very interesting talk from city councillor Judy Cullington, from Colwood (near Victoria). The City of Colwood has recently embarked on a big initiative to reduce energy use, with a big push to get folks to do energy audits on their homes and to get solar hot water installed. Do visit their website, it has a ton of great information on grants and programs for homeowners, businesses, and even some info for renters. A lot of the stuff is available to us here in New West as well! Solar hot water makes economic sense here in BC, and is pretty low-tech. Definitely a "low-hanging fruit" that we should be looking into here as well.

Anyways, one of the things mentioned in Ms. Cullington's talk was that one business (a bakery, as I recall) in Colwood had installed solar panels on the roof (fed into the grid) and was also using an electric vehicle (probably a Nissan Leaf). The business owner had done some calculations and claimed that his panel was giving him enough power to drive.

whoop whoop whoop ...there went my skeptic's alarm...

So. Off for a little one-on-one with my friends Google and Wikipedia...

A Nissan Leaf consumes 34 kWh to drive 100 miles and costs $38k (I'm not adding the cost of the plug-in at your house). A single solar panel delivers 4kWh/day and costs ~$10k to install (here in the Lower Mainland).

This means it would take 8 days of charging to enable the Leaf to drive 100 miles (which is about its maximum range). Put another way, on this energy diet, you are allowed to drive a maximum of 100 miles, once per week (or you can spread it out over the whole week). This isn't very much; it is very easily achievable by bicycle. A reasonable commute on a bike is 10km twice a day, or 12 miles total (this takes a moderately fit person about 20 mins each way) - exactly what the solarLeaf lets you drive. But at a 100x higher price point! So, yes, the solar panel is adding to the grid...but Mr. Bakery is very likely not self-sufficient in the energy for his driving. Although that's likely not his goal, I guess I would have been more impressed with him if he had decided to get an electric bakfiets (electric cargo bike) to pick up his supplies.

To put the costs into perspective, 100 miles per week of solar-powered driving has a capital cost of $48k. If you want 200 miles per week, you need to shell out another $10k. So, while it is entirely possible to "drive solar", it is very expensive and hardly a realistic option; most people who "need to commute" 24 miles/day are not going to be willing to pay $68k for a small car when you can get a gas-powered Yaris with a basically unlimited travel radius for a quarter of the price.

To relate this back to my "energy pie" post, we can reduce the amount of electricity required for transportation by making everyone who wants an electric car also purchase a solar panel or two, but this will still not enable us to run our current model of trucking and commuting without also adding significant new power sources (like a big dam or two).

It makes far more sense to invest in "solar powered e-bikes" for local (<30km/day) trips, as these are about 10x more efficient than the car (and much cheaper) - they are charged much more quickly to the same range.

Our current driving habits cannot be economically sustained on electric cars, with or without help from the sun. We shouldn't be fooling ourselves that this is an option.

1 comment:

  1. Reena, this is kind of cool too:

    http://www.kickstarter.com/projects/842248593/roll-out-the-elf-to-your-city

    Pricey, but keeps you out of the rain, lets you carry stuff, and flattens hills. Plus you might be a bit safer than on an upright bike.

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