A majority of EU countries have significant levels of energy poverty, especially prevalent in Southeast Europe (SEE), and are unable to keep all their citizens warm this winter, the European Right to Energy coalition said on Wednesday.

“Bulgaria far outstrips other countries for prevalence of four key indicators – damp and leaky homes, high energy costs for households, inability to keep homes warm against winter, and inability to keep homes cool in summer,” the Right to Energy coalition said citing data from a new research by Paris based think-tank OpenExp.

The ranking, which covers all 28 EU member states, uses a composite index of four indicators, based on Eurostat data, according to Seenews.com.

Of all EU member states in SEE, Romania has the highest score, ranking 13th. Croatia is ranked 16th and Slovenia is 20th.

According to the research, a majority of EU countries (17) have significant levels of energy poverty, whereas the share of household expenditure spent on energy is rising in Europe, with increases more prominent in low-income families – whose expenditure increased 33% between 2000 and 2014.

“A clear divide exists between northern/western and southern/eastern European countries,” the report notes, adding that socio-economic factors play a bigger role in high energy poverty levels than weather.

Countries with strong building regulations and higher gross domestic product (GDP) per capita show lower levels of energy poverty, the statement said, adding that worst performing countries face both winter and summer energy poverty.

“To avoid low-income households falling victim to the fluctuations of energy prices and stagnating wages, governments must ensure buildings occupied by low-income families are positive energy. In other words, buildings must produce more energy than they consume to reduce low-income families’ energy bills to zero euros,” Yamina Saheb, senior policy analyst for Open Exp, who led the research, said.

Sweden and Finland rank as best performing countries.