It is not atypical for particularly cold or hot climates to require greater energy consumption in homes and workplaces for heating (furnaces, or electric heaters) or cooling (air conditioning, fans, refrigeration).
Thus, a nation that is highly economically productive, with mild and temperate weather, demographic patterns of work places close to home, and uses fuel efficient vehicles, supports carpools, mass transportation or walks or rides bicycles, will have a far lower energy intensity than a nation that is economically unproductive, with extreme weather conditions requiring heating or cooling, long commutes, and extensive use of generally poor fuel economy vehicles.
Therefore, some small-scale but frequently used energy sources like firewood, charcoal peat, water wheels, and wind mills are not counted.
Several countries, like Sweden, Norway, France, and Canada, have made the transition to operating on low-carbon utilities.
It is not directly causal that a high GDP per capita must have lower economic energy efficiencies.