About the data
First, definitions of the energies shown above.
- “Electricity” is Hourly Ontario grid electricity demand.
- “Transport” means road transportation, i.e. cars and trucks.
- “Heat” means space heating.
Explanations of the figures are given below.
Road transportation energy demand is estimated based on annual gasoline and diesel consumption in Ontario.
Annual consumption was estimated from retail sales in litres. Energy was derived from the energy content of gasoline (approximately 9.4 kilowatt-hours per litre) and diesel (approximately 10.2 kWh per litre).
Hourly road transportation energy consumption is derived from annual retail fuel sales in litres, according to a formula that assumes vehicular traffic volume according to time of day and day of week (holidays are assigned a similar aggregate driving pattern as Sundays).
Combustion of one litre of gasoline produces approximately 2,300 grams of CO₂; one litre of diesel produces 2,600 grams.
The number of litres of gasoline and diesel are therefore given per-kilowatt-hour CO₂ emission factors of 245 grams and 255 grams, respectively.
The cost rate for road transportation energy is based on gasoline prices in Ottawa Ontario, from the website Ottawa Gas prices.
Heat refers to that portion of space heating energy demand that is supplied by combustible fuels such as natural gas, oil, propane, and wood. Heat energy demand is based on current outdoor temperatures in 46 Ontario communities representing 99 percent of the private dwellings in the province.
This estimate of residential heating demand is then used to estimate demand by Industrial, Commercial, and Institutional (ICI) buildings.
It is assumed here that ten percent of Ontario’s space heating energy is provided with electricity. Therefore, the energy represented in the Electricity kWh bar includes that ten percent.
Heat CO₂ is based on the blanket assumption that all non-electrical heat is provided by high efficiency natural gas. The CIPK for this fuel technology is estimated to be 200 grams. One cubic meter of natural gas contains roughly 10 kilowatt-hours of energy, and when burned will emit 1,878 grams of CO₂. Factoring in conversion efficiencies (assuming a high-efficiency furnace) gives a gas-fired heat CIPK of 200 grams. This is of course a highly conservative assumption, which will soon be replaced with one that more precisely accounts for actual fuel use and heating technology in Ontario communities.
The cost of heat is based also on the assumption that all combustible-fuel heat is from natural gas, which to repeat is representative only of those Ontario communities that are served with natural gas. The cost is derived from a recent Enbridge residential bill.
Electricity kilowatt-hour data is current Ontario demand, published on the Ontario Independent Electricity System Operator’s Power Data web page.
Electricity CO₂ is based on EmissionTrak CIPK estimates for various fuel types and power conversion technologies. These are shown here.
The electricity cost rate shown here is based on the all-in per-kilowatt-hour rate derived from a recent Hydro Ottawa residential bill. This generally represents the rate for major urban areas in Ontario. Rural residential rates including those in which Hydro One is the provider are roughly 45 cents per kWh, more than double the urban residential rate. The rate for industrial, institutional, and commercial customers whose peak demand is greater than 50 kilowatts is much less than the urban residential rate.
Electricity and energy
Most of the artificial bulk energy we use falls into the following three broad categories:
- Electricity, for numerous things.
- Gasoline and diesel, almost all for road transportation.
- Natural gas, mostly for heating and cooling.
As you can see in the chart above, electricity is only one type of artificial bulk energy we use.
You can view electricity as a super category of energy. In addition to its numerous other uses, we use it for transportation—for example, Toronto’s subways and streetcars are electric powered.
But almost all cars and trucks are powered with gasoline or diesel. Ontario’s government wants more cars and trucks to be powered with electricity. This is because Ontario electricity is much cleaner than any of the other energy sources.
We also use electricity for heating and cooling. Electric heaters are widely available. Much of our air conditioning is electric powered.
All of the heating and cooling we currently get from natural gas could be provided with electricity. Again, when you compare CO₂ emissions, you can see that electricity is much cleaner than natural gas.
The importance of CIPK
The importance of CIPK
When we know the CIPK of electricity or other energy, then we can compare electricity from different grids, and we can compare electricity with the other energy we use.
Similarly, if we are able to compare prices of electricity or other energy, we can add a further valuable dimension to our comparison.
Knowing how the CIPK of our electricity compares with that of other grids, and how it compares with price of the electricity from other grids, can help us evaluate the relative success of policies aimed at reducing the carbon related to electricity generation.
The chart above allows us to instantly compare the effectiveness of carbon reduction during a period when policies were introduced in the United Kingdom, Germany, and Ontario to do just that.
© 2016, Stephen E. Aplin
CIPK stands for Carbon Intensity per Kilowatt-hour. It is a measure of the carbon dioxide emission content, in grams, of a kilowatt-hour (3.6 million joules) of energy. It is a function of the carbon content of the fuel being used to produce the energy. If the fuel contains no carbon, or if carbon does not participate in the process that produces the energy, then the CIPK is zero.