Solar Panels: 18 Day Assessment (Part 3)


In Part 3 of this article, I present our household and individual carbon generation data as a case study.

In Part 2 of this article I introduced a role for residential solar power generation facilities in helping us meet our Green House Gas commitments.  While individual contributions may appear inconsequential, they add up.  The goal doesn’t need to be to generate enough  green power to replace all generation methods, just the carbon emitting ones, which in Ontario seems possible.  

The commitments our Governments are making are expressed as tonnes of carbon.  Science has estimated how much carbon can be pumped into the atmosphere to stay below the 2C temperature increase and with that goals can be set for global carbon generation level reductions [1]. Countries are in the process of working out their contributions to these reductions.  

To make carbon reduction more tangible to each of us, carbon generation footprint calculators have been developed [2] to help each of us understand individuals contributions with respect to the targets.  In my mind such calculators raise many questions of efficacy however, I do accept that having individual goals does make these notions more tangible, it can provide a sense of involvement, and it does help one better grasp the nature of the challenge we face. 

I’ll restate my caveat from the previous part, that I am not an expert in this area, so conclusions should be treated accordingly.  

To recap, Ontario has stated the following targets for Green House Gas reductions [3]:

  • 2014: 6% less than 1990 levels or 171mt or about 12.51 tonnes / person
  • 2020: 15% less than 1990 levels or 154mt or about 10.97 tonnes / person
  • 2030: 37% less than 1990 levels or 114mt or about 6.87 tonnes / person
  • 2050: 80% less than 1990 levels or 36mt or about 1.79 tonnes / person

In 2013, the average generation per individual Ontarian was 12.60 tonnes of carbon.  

Calculators will often categorize carbon generation behaviour activities under one of two classifications: [1] primary activities, where the amount of carbon generated is directly under ones control and [2] secondary activities where one has limited control over the amount of carbon generated.  The first group includes: home lighting, appliances, entertainment; home heating; home cooling; other home power consumers; car; motorcycle.  The second group includes: food preference; choice of imported vs. local food; fashion; packaging; furniture and appliances; recycling; car manufacture; services.

The control we have with the first group is relatively direct. For example, we can reduce energy consumption by turning off lights, lowering inside temperature in winter, etc.  The second group is different because while we can control whether we buy something or not, we have no control over how those things are manufactured and thus the carbon efficiency of the production process.  For example, we can buy high efficiency furnaces but we have no control over how many tonnes of carbon are emitted in the manufacturing process.  Note: look at the Carbon Footprint Calculator referenced above to see more details on what is included in the primary and secondary groups.  

Broadly what this implies is that there are things individuals can do to reduce energy consumption (and thus carbon generation) but there are things that others must do.

In our case, individually we generate about 8.84 tonnes each.  That’s good news because we’re basically done until 2020.  We’ve got to this level by upgrading to high-efficiency appliances,  light bulbs,  furnace and air conditioning.  As we are retired, we don’t drive as much as we used to and we need only one car. We recycle a lot. Our current carbon generation profile is:

  • Household: 3.81 tonnes each
    • Electricity: 0.88 tonnes
    • Natural Gas: 4.55 tonnes
    • Car: 2.19 tonnes
  • Secondary items: 5.31 tonnes each
  • Solar Generation: -0.28 tonnes each

Splitting the total household between the two of us, adding the secondary carbon and subtracting the solar power comes to 8.84 tonnes.

To meet the 2030 targets we need to reduce carbon generation by 2 tonnes each.  There are life style changes we could make that would move us in that direction, but I’m not ready to become a vegan.  Another, more straightforward option is to switch completely to electricity: electric heat and electric car.  Our carbon generation profile would look something like:

  • Household: 1.56 tonnes each
    • Electricity: 2.94
    • Car: 0.15
  • Secondary Items: 4.40 tonnes each
  • Solar Generation: -0.28 tonnes each

This would take us down to 5.67 tonnes each or just over 1 tonne under the 2030 targets. 

To meet the 2050 target of 1.78 tonnes per person is just not possible on our own.  It is the secondary items that are particularly challenging.  Electric power generation has to improve from 80 grams / kWh to, say,  3 grams. I pick 3 grams because that is where Quebec is now.  If that can be accomplished then our household carbon generation drops from 1.56 to 0.06 tonnes per individual.  

I can only assume that there would be a corresponding reduction in the carbon emissions of secondary items, but here I am not able to determine what that would be.   

Just as a final note, in 2050, I’m scheduled to be 96 years old so I just may not be here any more, so discussion on those targets is a theoretical exercise and included just for completeness.


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