Most energy sources’ embodied energy is diminished by the time it is delivered to and consumed in your home. For example, the energy that is embodied in a piece of coal that is used in a coal-fired power plant to generate electricity is roughly diminished by up to 70% by the time it reaches an electrical outlet in your home through inefficiencies both in the production of electricity and in the transmitting power grid. It is important to take this into account when making choices for what energy source to consider for a building. In terms of electricity, I can recommend Xcel’s wind-source program for the TwinCities, as it’s production does not produce carbon emissions. Nevertheless, transmission losses are an issue here as well. On-site solar photo-voltaic systems can be a great option to eliminate high primary energy use. The best solution will depend on the location and solar exposure of your building.
In the Passive House calculations, primary energy is calculated using factors that describe inefficiencies and energy loss as opposed to just looking at the energy use in the building. Passive House standard limits this primary energy use to 31,700 BTUs per square foot of living space and year, or 120kWh per square meter and year in the metric system.