In Western Washington, the two most common choices for fuel type are electricity and natural gas. While some factors affecting which one to choose are relatively straight forward and obvious- cost, availability, compatibility with heating system, efficiency- one factor requires some number crunching and investigation- the effects of the fuel type on the environment. For many, the other factors may preclude which fuel type is eventually chosen. However, it is important to understand the impacts of the fuel choice on the environment.

The largest single effect of the fuel choice on the environment is the amount of greenhouses gases- most notably, carbon dioxide and methane- that are released into the environment for every unit of energy used. Natural Gas is mined, processed, and delivered to your house without emitting any greenhouse gases. Only after combustion in a furnace, stove, or water heater does it release Carbon Dioxide, and this amount is minimal when compared to electricity.

In order to produce and deliver electricy, significant greenhouse gases are released before the energy arrives at your home. This is because electricity is a secondary energy. It is produced by converting other forms of energy into electricity: hydroelectric, coal, natural gas, oil, nuclear. With Puget Sound Energy, 37% of its electricity is derived from coal, while 19% comes from natural gas. The process to convert these fossil fuel feedstocks into electricity is very inefficient. A fossil fueled electric plant converts only about 33% of its original feedstock into electricity as 67% of it is wasted in the process. Another 9% is lost as it travels through power lines to your home. Considering about half of all PSE electricity is derived from fossil fuel origins, this means that it takes about 80% more fossil fuels to produce , deliver, and use a unit of electricity as it does to produce , deliver, and use the equivalent of natural gas. This also means that electricity production releases more greenhouse gases than does Natural Gas combustion. According to the EPA, 0.90 lbs of Carbon Dioxide are emmitted for every kWh of electricity when using PSE, compared to .39 lbs for natural gas. All of this would suggest that natural gas is more beneficial from an emissions standpoint.

But like most issues in green building, the issue of gas vs. electricity is not cut-and-dry and other facts must be accounted for and then weighed against each other. Here are a few:



1.) What is your utility's fuel mix?
Compared to other states, Washington utilities rank 47th in the amount of fossil fuels used to produce electricity, as we rely mostly on hydroelectric power. Other states rely more on coal, making natural gas that much more attractive.

2.) What appliances will the fuel feed?
The more efficient the appliance is at using electricity vs. natural gas, the less attractive gas becomes from an environmental standpoint. For example, a mini-split heat pump produces four to six times more heat than the electricity it consumes. If you compare this to a natural gas furnace that converts 90% of the incoming energy into heat, then the electric air heat pump is more attractive, from both an emissions and a cost of energy standpoint.

3.) Does your utility offer green power?
PSE currently offers the option to buy green power from renewable sources (wind, solar, biomass, geothermal) at a rate of $0.0125 per kWh, potentially negating the greenhouse gas aspect of electricity production.

4.) Cost.
Currently, with PSE, the price of natural gas is about 45% less than the cost of electricity, making natural gas even more desirable. However, this is expected to rise and eventually surpass the price of electricity.