A Department for Energy and Climate Change (DECC) policy document regarding the domestic RHI scheme in Great Britain was shared with DETI in June 2013 ahead of its publication.

Mr Aiken says that DETI was now "formally on notice" that the GB domestic scheme would have a digression mechanism - a cost control method - built in.

Image source, RHI Inquiry

Inquiry chair Sir Patrick Coghlin notes that DETI knew this in the context that "they have no emergency cost controls (and) they have no digression".

And the GB non-domestic scheme already had digression.

The biomass fuel prices prices in the third CEPA report were unchanged from its original 2012 report.

It confirms the cost of fuel pellets at between 3.5p and 4.5p per kWh.

The inquiry's heard many times already that the setting of the subsidy at 5.9p in comparison with the lower cost of fuel was the cause of the overcompensation of scheme participants and led to the budget being burst.

Mr Aiken suggests that the report is "a further potential opportunity for CEPA to recognise its own error over tiering" of the scheme's tariffs and for DETI's energy division "to do likewise".

Yesterday we heard from Joseph Aiken about the next part of the RHI scheme's lifetime that the inquiry is dealing with.

Today, he begins by looking at a report on the development of the RHI scheme that was provided to the Department of Enterprise, Trade and Investment (DETI) by energy consultants.

Image source, RHI Inquiry

The department engaged the same consultancy firm - Cambridge Economic Policy Associates (CEPA) - as it did when the scheme was first being set up.

CEPA delivered its third report for DETI - concerning how to add extra technologies to the RHI scheme and how a similar initiative for domestic users could be put in place - in June 2013.

This referred to by Mr Aiken as CEPA 3.

Conor Macauley
BBC News NI Agriculture and Environment Correspondent

A County Tyrone poultry farmer says he feels conned by the government over the RHI scheme.

Colin Watt borrowed £380,000 to invest in renewable heat technology through the initiative.

He says he did it on the strength of promises and encouragement from Stormont departments.

With eight years left to go on the loan, he says tariff changes have left him "paying the price" of mistakes made by others.

BBC News Northern Ireland

A letter sent by Arlene Foster to banks was the subject of "media speculation" and "innuendo",the inquiry was told.

Image source, Press Eye

It heard that in fact it had been written by one of her officials and was sent to banks without amendment by the then DETI minister Mrs Foster.

The letter was intended to encourage banks to lend to businesses who wanted to invest in renewable technologies but were facing resistance from the lenders.

BBC News Northern Ireland

An independent inquiry into the RHI scandal was established in January last year by the then finance minister Máirtín Ó Muilleoir.

He ordered it in the wake of the huge public concernand what was then a developing political crisis surrounding the scheme.

The RHI Inquiry began in November and Sir Patrick Coghlin (below), a retired Court of Appeal judge, is its chair and has been given full control over how it will operate.

Image source, Pacemaker

It will look at:

• the design and introduction of the RHI scheme
• the scheme's initial operation, administration, promotion and supervision
• the introduction of revised subsidies and a usage cap for new scheme claimants in 2015
• the scheme's closure

For more information on the RHI Inquiry,you can read our handy Q&A.

When the scale of the overspend emerged, public and political concern rocketed.

As the minister in charge of the Stormont department that set up the RHI scheme, the Democratic Unionist Party (DUP) leader Arlene Foster faced calls to resign from her role as Northern Ireland's first minister in December 2016.

Image source, PA

She resisted, and Sinn Féin's Martin McGuinness then quit as deputy first minister in protest at the DUP's handling of what had by then become a full-blown political crisis.

That move brought about the collapse of the Northern Ireland Executive. Now, more than a year on from that, Northern Ireland remains without a devolved administration.

You can find much more detail on the RHI scheme in our need-to-know guide.

The budget of the RHI scheme ran out of control because of critical flaws in the way it was set up.

Claimants could effectively earn more money the more fuel they burned because the subsidies on offer for renewable fuels were far greater than the cost of the fuels themselves

Image source, Getty Images

The most recent estimate for the overspend was set at £700m, if permanent cost controls aren't introduced.

The massive overspend bill will have to be picked up by the Northern Ireland taxpayer.

The Renewable Heat Incentive scheme - or RHI for short - came to the fore of the Northern Ireland public's knowledge in autumn last year... and the fallout from the scandal attached to it is still being felt in the region's politics today.

Image source, Getty Images

The scheme was set up by the Northern Ireland Executive in 2012, as a way of encouraging businesses to switch from using fossil fuels to renewable sources for generating their heat.

Those who signed up were offered financial incentives to buy new heating systems and the fuel to run them.

Stormont hill is dusted with snow this morning, so let's get inside the Senate chamber in Parliament Buildings and get a seat beside a radiator.

Image source, Press Eye

We're back with more from the opening statement of the RHI Inquiry's second phase - the initial operation of the RHI scheme.

Stick with us throughout the day for the live video stream and text commentary on proceedings.