In this second part I look a little more into broader questions around the benefit of residential solar power generation for the environment and addressing climate change targets.
I am not an expert on this subject so any conclusion should be suspect. As best I can I've tried to collect information from reliable sources, such as Statistics Canada, and the Ontario Government. I've also used our own experience as a source of data, which I will present as a case study in Part 3 of this article.
Is residential solar power generation the most effective way for an individual to reduce Carbon?
May be not, but... Implementing a solar power generation system comes with a price tag (currently about $3.60 / watt) and in our case delivers an annual reduction in carbon output of about 0.56 tonnes per household (note: this is the saving for someone in Ontario. In Alberta the saving would be about 5.7 tonnes; in Quebec it would be 0.021 tonnes. The differences are the result of different electric power providers having different mixes of generation methods from hydro to coal fire).
On the other hand, savings through lifestyle changes can be realised, often at little or no cost (although there may be a discomfort cost). For example:
- Reducing red meat consumption and eating mostly fish will save 0.67 tonnes per person per year. Switch to mainly white meats delivers a savings of 0.35 tonnes
- Buying some organic food, food in season and mostly locally grown will save about 0.65 tonnes / person / year
- Going from no recycling to recycling everything will save a whopping 3.12 tonnes / year
- Going from 2 to 1 car will save 1 tonne per year.
And now for the but. The steps above -- the life style changes -- are really about avoidance, yet the electricity that continues to be consumed produces a lot of carbon in its generation. No matter how much we avoid, we will continue to consume the "dirty" electricity and thus will continue to generate carbon. To meet the climate change targets we will need to use electricity that is greener, and it is here that solar can play a role.
The green energy generation options include: nuclear; wind; solar; hydro; and geothermal. In Ontario, the mix of generation methods includes these plus Gas and Biofuel. Gas contributes in the range of 800 - 2,500 mega watts (or 6% - 17%) [1, 2] power to the grid. To put that number into context, in Ontario's current mix, at peak, wind can generate over 2,000 mega watts (on a monthly basis wind generates in the range of 1/3 to 1 time the power produced by gas). The point here is that it is realistic to think in terms of replacing gas with wind. There is the solar option as well, which currently ramping up.
What does installing a residential solar power generation system mean for meeting carbon reduction targets set by governments?
It could mean a lot, especially in the "last mile." Green Energy (that is low carbon emitting energy) will be essential for meeting international targets; the rationale follows. To start, Ontario has stated the following targets for Green House Gas reductions :
- 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 Ontario the current average carbon emission is 12.60 tonnes per person which is pretty close to the 2014 objective. This average per individual needs to be reduced nearly 2 tonnes by 2020. As noted above, 2 tonnes can be reduced through life style changes and more efficient use of energy, such as energy saving light bulbs, high efficiency appliances, etc.
However, meeting the 2030 targets of 37% lower than 1990 emissions will require some major change, and specifically it means the individual will need to significantly reduce consumption of fossil fuels, such as by:
- Converting all fossil fuel household appliances (e.g., heating) to electricity
- Driving an electric car
To meet the 2050 targets requires changes beyond what an individual can do on their own; it requires "greening" of electric power generation infrastructure. As an example, even at 80 grams of carbon per kWh, the current generation system in Ontario emits too much carbon to meet 2050 targets. Therefore, Ontario Power generation needs to become greener, say to the same level as Quebec (at 3 grams / kWh).
This move will significantly reduce individual carbon emissions for primary activities, such as heating, lighting, personal transportation and secondary activities -- where one has only indirect influence on carbon generation -- such as food choices, fashion, services, etc
It is in the greening of the electrical generation infrastructure that residential solar generation can play a role. It is an obvious source of green power that can replace the fossil-fuel-based generation facilities. But is it feasible? There are over 2.7 million  single family homes in Ontario. 12,500 homes could generate 2,500 mWh to compensate for the power currently generated by natural gas (my calculation here is based on November production of 0.2 mWh per house and peak demand for gas of 2,385 mWh).