STORMONT departments have spent more than half a billion pounds on energy bills in five years.
It means that on average each of the twelve departments - based in locations across Northern Ireland - are spending around £7.5m a year on heat and lighting for their offices and buildings.
A previous Assembly report showed that the cost of heat and lighting for the Stormont building was just over £400,000 a year.
The latest figures were disclosed in response to a series of Assembly questions by Sinn Féin Newry and Armagh MLA Conor Murphy.
The largest amount was at the Department of Health, which spent £206 million, including costs for the five health trusts.
The Department for Regional Development spent £240m, although most of this was for street lighting and costs for NI Water, with the actual energy expenditure for offices around £3m a year.
The Department of Education ran up costs of £159m, but the department itself spent just £133,000 and the remainder of the expenditure was incurred by arms-lengths bodies.
The bills for other departments ranged wildly in cost from just under £2m for OFMDFM to £66m for the Department of Justice.
The overall total, around £556m, covers the period from 2010-11 to last year.
The Irish News reported in 2014 that more than £1.2 million of taxpayers' money had been spent on heat and power at Parliament Buildings at Stormont in the preceding three years.
It meant that the annual electricity bill alone for the 'big house' was equivalent to the cost of heating 500 homes.
The 12 Executive departments are due to be reduced to nine later this year.
