Ravina Project guest blog #2 - Fugitive Methane

Fossil gas may be branded as “natural” but it’s even worse than coal when it comes to greenhouse gas emissions.

Susan and Gord Fraser have been experimenting with all things "green energy” for years, from solar panels to conservation, and have the data to prove it. This blog will make the geeky details of deep energy retrofits simple. Looking for an even deeper dive? Go to http://www.theravinaproject.org

Fuels have the greatest energy density we know about. We all know what a kilowatt-hour is … we all pay our Toronto Hydro invoices based upon the kilowatt-hours (kWh) of energy we use each month. So let’s look at the kWhs of energy in a kilogram (kg) of some common fuels. Wood has 4.5, sugar, 5.3; coal, 6.7; fat, 10.9; petrol, 12.9; natural gas (fossil gas), 15.4; hydrogen, 39.8; uranium U-235, 1,090,000. Except for uranium the energy in these fuels is released when their chemical bonds are rearranged when the fuel is burned. A lithium-ion battery also stores chemical energy but the storage is limited to about 0.20 kWh per kg. One can understand why chemical storage of a megawatt-hour (MWh) would require 5,000 kg of battery yet the same energy requires only 64.9 kg of fossil gas or 222 kg of wood.

We now know that fossil gas (natural gas) is one of our major enemies in the war against global climate disruption. Why? The reason is quite mundane actually … leaky pipes. The distribution pipes leak fossil gas which is almost pure methane into the atmosphere. The technical term is "fugitive methane." As we see in this academic paper, in New York State a leakage of 3.6% of the volume of fossil gas they use finds its way to the atmosphere through the 1000’s of km of pipes it traverses from well head to storage to our furnaces. But since New York State is larger both in terms of population and the number of users of fossil gas, let’s assume that the 3.6% leakage is twice as high as Ontario’s leakage. We will use 1.8% for our leakage number. When we burn a cubic meter of fossil gas we produce about 1.9 kg of CO2. When fugitive methane at 1.8% leakage is added, that total becomes 4.9 kg of CO2e. CO2e is a metric used to show the equivalent amount of CO2 that must be released in order to produce the same global warming as burning the same amount of fossil gas plus the leakage of fugitive methane. For the other data geeks like me who read this, I used the GWP20 calculation for Methane to calculate CO2e.

Many people have commented that fossil gas is a transition fuel away from coal. It’s clean and green. But is that true? Is fossil gas really a good deal for the planet when it comes to CO2e release? Let’s see. One kg of coal releases 2.4 kg of CO2 and produces 6.7 kWh for a ratio of 358 grams of CO2 per kWh. One cubic meter of fossil gas releases 4.9 kg of CO2e and produces 10.6 kWh for a ratio of 462 grams of CO2e per kWh. Coal emissions kill thousands every year though air pollution but fossil gas but releases more CO2e. This fact is a total gut punch to anyone who is serious about fighting the good fight against Global Warming. There is no way to dress this up or to spin it … it’s brutal and ugly.

Fossil gas is our mortal enemy.