• Green Math or Putting the Moron into Oxymoron

    Green Math or Putting the Moron into Oxymoron

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    As engineers we like applied math that is grounded in reality. Over the decades I have been playing with numbers and relating them to reality. I have developed a gut feel for when something looks ‘off’. It is not perfect in detecting every incongruity but it is rarely incorrect. This article from our venerable state broadcaster in Canada got that reaction from me:


    This article states that by 2035 all new cars and light trucks sold in Canada will be electrically powered.

    I am always wary when the government interferes in the free market. If electric vehicles were a superior product then almost no-one would not buy them. The government only compels you to do something when it is something you would not do by choice.

    The first level reading of this can be interpreted as “By 2035 the government believes that electric vehicles will still suck compared to gasoline vehicles”.

    This is disappointing as we are being told that battery technology is improving all the time. If the government believes that it will still be rubbish, it is not good news.

    Let’s take the government at their word. I was curious regarding the amount of energy this would pull from the power generation and supply grid.

    A typical family car gas tank holds about 14 gallons of gasoline – so with some simple math I ran some numbers. 

    How much energy is carried by a full tank of gasoline?

    Energy Density of Gasoline =8900wh/L
    Energy Density of Gasoline (US Gallons) =33690wh/gallon
    Typical Family Car Gas tank size =14gallons
    Amount of Energy in a Typical Fuel tank =471661wh/fuel tank
    Amount of Energy in a Typical Fuel tank =472kwh/fuel tank

    Ok – so I have a number, but what does it mean? I went and grabbed our monthly utility bill – for the month of May we used 743kwh of energy.So a tank full of gas carries enough energy to power our family home for over 2 weeks.

    This underlines how amazing gasoline is as a store of energy. Now we have to understand the implications of everyone plugging their family cars into the grid every night.

    Lets make some simple sweeping assumptions and ignore relative efficiencies and all nuance. We are just after a rough order of magnitude assessments to let us judge if this is clever or stupid. I don’t know the answer to that question until I have run the numbers but I am starting to think that it might not be clever.

    OK – let’s ignore light trucks and assume that each household uses 2 tanks of gas a month for their motoring needs (this is probably a gross underestimation).

    Lets then round everything up and say that for each household to use exclusively electric vehicles each household will double their power requirement from the grid in Canada.

    Let’s ignore population growth and immigration and just use the baseline increase of doubling the power requirement for each household.

    The latest numbers (2016: https://open.canada.ca/data/en/dataset/2cdf43fc-d4aa-4604-9f21-29777d955810) shows that Canada’s current Power Generation capacity is 146GW and this breaks down as follows:

    Hydro 55%
    Biomass 2%
    Solar 2%
    Nuclear 10%
    Coal 7%
    Natural Gas 15%
    Oil and Diesel 3%

    Assuming that the aim is to get rid of all Hydrocarbon sourced energy – Coal, Natural Gas, Oil and Diesel. There is no point exporting your carbon dioxide generation to the local power station (I am assuming the government position actually makes sense here, so let’s go with this). We have to remove 25% of the current power generation from the mix.So we have to meet twice the demand by increasing from 75% of our current capacity. This means that we have to decommission 25% of our current power generation and increase the other components by 2.66 times.

    I am sure this enormous infrastructure program has been fully costed and is available somewhere on the seemingly endless network of government of Canada websites.

    Despite looking for it for ‘some time’ I could not find anything regarding the level of massive investment required or a plan to execute it. There is lots about adding solar and wind power to make the current system ‘greener’. Oh good.

    To summarize: The government of Canada has created a plan to replace gasoline vehicles that would at least double the load on the power generation and distribution system. The government of Canada has no plan to double the capacity of the power generation and distribution system.

    So we can draw one of several conclusions:

    1. This is just virtue signaling (or a ‘lie’ as we used to call it) from the Canadian Government.
    2. This is a serious policy and they are not going to increase the capacity of the power generation system so Canada will have to restrict car ownership.
    3. This is a serious policy and they have a covert plan to invest trillions of dollars in power generation. But Shhhhh. It’s a secret.

    Like most green policies, from a basic math or very simple engineering point of view, this green policy is either complete rubbish, is a subversive way to restrict the ability to travel for individuals or it’s success depends on some other magical yet to be defined or completely secret and impractical supporting public policy.

    Most ‘green’ policies look like this and it is faintly depressing that the media reports on them as if you can trust the government when they make these kinds of pronouncements.

    So lets dial the thinking down to the lowest level.

    Are gasoline powered vehicles ‘the problem’? If the answer is ‘yes’, what is the solution?