Daniel Lemire's blog

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Science and Technology links (November 24th 2018)

7 thoughts on “Science and Technology links (November 24th 2018)”

  1. Ali says:

    Re: electric cars

    The 2012 study is a bit outdated, as solar and wind energy have increased substantially in the past few years, with even larger increases coming in the next 3-4 years. Wind generation alone is increasing in double percentage digits annually, with new projects being licenses without subsidies. Currently, about 30% of Europe’s energy needs are supplied by renewable sources.

    In May this year, Portugal run for 107 hours on renewable energy. In summer months, Germany regularly surpasses 50% of its energy requirements from renewables during weekends, with some weekends reaching 80%+.

    As for the second, more recent study, I couldn’t find the full text online, so I’m missing the full picture of the paper’s analysis, but comparing the manufacturing environmental impact is a flawed hypothesis. Even ignoring exhaust emissions, ICE powered cars produce a lot more pollution than their electric counterparts. How much lubrication oil will an ICE engine require over its lifespan? How many filter changes will it require? What about the environmental impact (toxic waste, etc) of refining the oil or gas needed to power the car for a given number of kms/miles?

    Unlike ICE engines, whose efficiency and pollution characteristics are defined (and largely locked) during the engine’s design, an electric car doesn’t care were it’s energy comes from (coal, fossil fuel, solar, wind). Car batteries have a second life in home or other similar static energy storage facilities, after reaching their end of life in a car. Even when the battery cells degrade to the point where they can’t be used for any practical application, the entire battery can be recycled as it’s full of valuable chemicals. The battery recycling sector is still new, and technologies are still nascent, as commercial viability depends largely on volume.

    An electric car itself can be easily fitted with a new battery with higher capacity, longer lifespan, less weight, less toxic chemicals, or any combination thereof. The cost per kwh of battery capacity is decreasing constantly. Musk said earlier this year that Tesla can lower their battery production costs by a further 20% just from production process optimizations of their current battery chemistry. With cheap enough batteries, electric cars can continue to circle for much longer than a comparable ICE powered car (ICE engines are becoming increasingly more expensive due to efficiency and emissions requirements).

    The whole ICE vs electric car debate is a lot more complex than a few simple studies about the environmental impact of production, or how they are powered at one point in time.

  2. Maynard Handley says:

    The birth order thing (like pretty much all non-physical-science breaking news [and even half the physical science breaking news…]) seems very much up for debate.
    It may well be one of these things where you have to look for the right thing to see effects.

    But here is a fairly in-depth (but easy to read) counterpoint:

  3. I have been told that the Gauls used a vigesimal system

    We don’t know that much about the language of the Gauls, which wasn’t really written. The few inscriptions in Greek or Latin script are insufficient and may not even be representative of the everyday language. However, modern celtic languages use a vigesimal system, so the claim looks credible.

  4. Oren Tirosh says:

    Can you build an airplane with no moving part? It turns out that you can. Researchers built a model airplane that moves the air using
    an electric field. (credit: degski)

    Aircraft based on ion wind for propulsion have been demonstrated a long time ago:


    Efficiency is low. There was no energy source with sufficient power and energy density for self-sustained flight without a power tether. Modern lightweight battery technology makes this airplane (just barely) possible. It is still very inefficient.

  5. The data for electric cars is out of date, as is the data for energy production.

    Ontario (for example) burns zero coal, and averages over 90% zero CO2 https://cns-snc.ca/media/ontarioelectricity/ontarioelectricity.html. Further, most cars will be re-charged at night, during off peak times. These times are more likely to be supplied by green energy.

    Further, as someone else stated, while (I have read) the initial manufacturing footprint is between 17 and 50% worse, the maintenance footprint is more than 50% better. J.D. Power has re-assessed their initial predictions to give a green payback in less than three years in the average north american jurisdiction.

    For those with high mileage and green electricity it is even shorter.

    1. There are two issues.

      One is CO2 emissions. This clearly depends on where the electricity comes from. If it comes from nuclear or hydro, you are doing well. However, as I outlined, if you live in Germany or Japan, it may be a false assumption to think that your electricity is “CO2-free”.

      Another issue is that of toxicity. The assumption seems to be that we will cleanly recycle batteries. When you make this assumption, everything is nice… However, this industry and technology does not exist currently. I think people ought to be more critical of such claims. It won’t arise out of thin air.

  6. Huw says:

    The Welsh language also uses the vigesimal system.

    You could postulate that since Gaulish and ancient British (which has evolved into modern Welsh) share the same Celtic origin, that’s it’s possible the Gauls used a vigesimal system.