22% of Welsh households were struggling to pay their energy bills in March 2013, which is 13% more than in June 2012.
They said in order to pay for their energy bills they had to cut back on essentials such as clothes, food and shoes, with 16% cutting back on groceries.
The report revealed that during the winter 2012/13, half of households in Wales had their heating on less or only in some rooms. Lower income familes and younger people were the most likely to resort to these measures.
Almost a quarter (23 per cent) of respondents said they had installed energy efficiency measures in their homes , but the figures revealed that almost twice the proportion of higher income households (AB rated) had taken this step compared to lower income households (DE rated).
Three quarters of households (76 per cent) also reported they were worried about being able to afford their energy bills if prices rose in the future, with this proportion increasing to 86 per cent for lower income households.