In the United Kingdom, according to the first official definition (1991), which is still unofficially used in other countries, "a household is said to be fuel poor if it needs to spend more than 10% of its income on fuel to maintain an adequate level of warmth". Therefore, the share of households' expenditure covering their energy costs is another important indicator to point out energy poverty.
High energy costs and/or low household income often force people affected by energy poverty to fall behind on the payments of their utility bills. The indicator "arrears on utility bills" is monitored by Eurostat and refers to the percentage of persons from the total population who are in the state of arrears on utility bills, expressing the enforced inability to pay on time their utility bills due to financial difficulties.
Despite the fact that there is no common European definition, both the scale of the problem and the severe health impacts caused by energy poverty are widely recognised. Data from Eurostat can be used to estimate the scale of the problem, indicating the major threat for a significant proportion of the European population. Across MS, numbers and percentages of affected persons vary significantly. It is striking that energy poverty is less of an issue in various colder countries than in warmer ones.
As most European countries have no official definition for the term "energy poverty", this state is often described as the "inability to keep homes adequately warm". In France, this approach has been officially adopted and therefore, the "Grenelle II" Act defines energy poverty as a situation in which a person has difficulty obtaining the necessary energy in their home to meet their basic needs because of inadequate resources or living conditions.