STORMONT'S department in charge of the flawed Renewable Heat Incentive (RHI) set "unrealistic time frames" and had a "lack of understanding" of what was involved in setting up the scheme, an energy official has said.
Catherine McArthur worked from 2011 to 2014 for government energy regulator Ofgem, administrators of the RHI scheme.
She worked on an Ofgem feasibility study on RHI which was delivered to Stormont's enterprise department (Deti) in late 2011 before the scheme was launched.
Giving evidence at the public inquiry into the botched scheme, Ms McArthur yesterday described how there was a lack of clarity from Deti on its RHI policy.
She said Ofgem "asked a lot of questions", but Deti was "unable to give us any direction at all".
The RHI inquiry was set up after the initiative – aimed at encouraging the use of eco-friendly wood pellet boilers – ran significantly over budget.
It paid out more in subsidies than the cost of fuel due to a lack of cost controls, causing a potential overspend of £700m over 20 years.
The political fallout over the scandal led to the executive's collapse, a snap assembly election and the continued Stormont deadlock.
The inquiry heard how Ofgem had identified some "critical" weaknesses in Britain's RHI scheme and gave Deti options on how to address them.
Ms McArthur said there was "uncertainty" from Deti on what it would do.
The inquiry also heard from Keith Avis, who was the manager responsible for RHI from April 2012 to February 2013.
Mr Avis said Deti was "very keen to press forward as quickly as they were able" to launch the north's RHI scheme.
Asked where this came from, Mr Avis said he believed at times there was direction "right at the top at ministerial level that there was a need to move forward quickly".
Deti planned for its RHI scheme to be largely similar to the one in Britain, the inquiry heard.
But it decided to launch without amendments including cost controls being made to the scheme in Britain, and instead planned to revisit the issues later on.
In an email to colleagues in 2012, Ofgem's legal adviser Marcus Porter expressed concern over Deti "knowingly reproducing legislation" that had "considerable scope for improvement".
The inquiry continues.
