And so ends the 100th day of the inquiry...

We're happy to report that the Hansard staff didn't forget us and we've been tucking into a slice or two of their famous RHI anniversary cake - thanks!

We'll be back on Tuesday for the 101st edition, when Department of Finance official Emer Morelli returns to the Senate chamber - she last gave evidence back in sunny June.

See you then and have a brilliant weekend.

BBC News NI

The head of the body that administered the RHI scheme was asked about its apparent failings.

Inquiry chair Sir Patrick Coghlin said that Ofgem was much better placed to smell the "odour of gaming" in the initiative but did not pass it on to the Stormont department that had set it up.

Image source, Pacemaker

The so-called "gaming" of the scheme refers to the way in which claimants could exploit the rules by having multiple boilers installed in order to maximise their subsidy payments.

Ofgem's chief executive Dermot Nolan accepted that Stormont's economy department could not have spotted gaming without his organisation's help.

Ofgem had a fraud prevention strategy for the RHI scheme but it had a fundamental problem.

It listed that the tiering of subsidies on offer through the scheme was a way that the wasteful use of heat by claimants was being prevented.

Tiering works by reducing the subsidy on offer once a claimant has used their boiler for a certain amount of time.

Image source, RHI Inquiry

But crucially, tiering wasn't included in the Northern Ireland scheme - the fraud prevention strategy was therefore flawed and one Ofgem told the inquiry that it was a "cut-and-paste job" of the document for the Great Britain initiative, which did have tiering.

Inquiry chair Sir Patrick Coghlin is critical of Ofgem, saying its staff "hadn't bothered to look to see if there was a this distinction" between the NI and GB schemes.

Asked what that says about the attention to detail that Ofgem gave to the NI scheme, Dermot Nolan admits that Ofgem didn't draw up a bespoke fraud prevention plan.

RHI scheme claimants were being given advance notice by Ofgem that their boilers would be inspected.

It's not hard to see the problem with that, especially when the intention of the inspections was to spot improper use of the scheme.

Inquiry barrister Joseph Aiken observes: "If you tell someone three weeks in advance that you're coming by the time you arrive the problem won't be there for you to find."

Ofgem boss Dermot Nolan says he doesn't know of any unannounced audits having taken place in Northern Ireland until 2016.

But he says - hoping his answer isn't "too glib" - that if any claimants had a need to cover something up they probably couldn't do that "in three weeks".

As part of its work in administrating the RHI scheme for DETI, Ofgem contracted auditors to inspect biomass boilers to check that they were being used in compliance with the initiative's rules.

But the amount of audits carried out was far lower than should've been the case - the inquiry's heard that there were just 31 audits across the first three years of the scheme's operation.

In that time there'd been 2,120 applications - the 31 audits amounted to 1.46% of those applications, well below the intended level of at least 7.5%.

Image source, Getty Images

Not only that but the few audits that did take place weren't shared with DETI, and Ofgem boss Dermot Nolan says the department didn't want them and didn't ask for them.

Inquiry panellist Dame Una O'Brien points out that from the outset Ofgem and DETI had agreed to "keep each other informed of any significant issues... and highlight abuse, misuse and irregularities".

She asks whether Ofgem could've been more proactive in giving DETI information about the scheme instead of taking a stance of: "If they don't ask they don't get."

Mr Nolan says the information he's been shown by the inquiry is "sobering" and he admits Ofgem was "far from perfect" in its work.

A farmer in Scotland "sold his entire herd of cows and was turning all his cow sheds over" to biomass boilers on the Great Britain RHI scheme, he told an Ofgem official.

The official had a conversation with the farmer at an event and reported back to her colleagues, telling them that he "didn't seem at all interested in finding a use" for the heat his boilers would generate.

Image source, Getty Images

At the same event, a boiler installer said he'd noticed that the scheme was proving to be a "massive boost for the farming community in Scotland".

But he was worried that it didn't always seem that there was a need for the heat that the boilers were producing "other than to harvest the RHI".

Like the material discussed before the lunch break, it never made it was from Ofgem to DETI.

Sir Patrick Coghlin begins the afternoon session by noting that it's the inquiry's 100th day.

"Amazing how time passes so quickly when you're enjoying yourself," he quips.

And it seems that one of those lovely cakes in our previous post was devoured - at least in part - by the inquiry team.

The inquiry chair makes a public tribute to the Hansard staff for the "delightful cake which would easily meet any of the criteria of Bake Off"!

In the absence of anything happening in the Northern Ireland Assembly chamber, the Hansard team at Stormont has been working hard since last November, transcribing every word said at the RHI Inquiry.

And they certainly know how to celebrate - not one but FOUR cakes to mark the 100th day of RHI Inquiry hearings!

The inquiry takes a break and will return at 13:50 - rejoin us then.

Ofgem was told of another example of "literally public money going up in smoke", says inquiry barrister Joseph Aiken.

A north England-based woodchip fuel supplier wrote to Ofgem's chief executive to say that it had spotted activities that were "primarily designed to game" the RHI scheme in Great Britain.

It was aware of a "growing number" of poultry farmers installing multiple smaller boilers instead of a single, larger, more efficient one - it had heard of "one owner ordering 33 boilers... to maximise their benefit".

The firm understood that such activity was "perfectly allowable" under the scheme's rules and told Ofgem that it should "close these loopholes" to stop the scheme being "manipulated".

The letter was passed to a government minister at DECC but again it wasn't provided to DETI - Dermot Nolan admits that it should've been.

Asked if that example and the other cases of Ofgem not sharing crucial information with the department point to a "major systems failure" by the administrator, he says: "I'd like to reflect on that."

Inspectors who'd carried out more than 230 audits of boiler installations on the Great Britain RHI scheme found "a number of unintended developments".

They told Ofgem in November 2013 that people were fitting multiple smaller boilers instead of a single, larger unit and said it could have serious financial consequences for the scheme.

Image source, RHI Inquiry

They even made practical suggestions for addressing the problem.

But again Ofgem didn't inform DETI - the administrator's boss Dermot Nolan accepts that the information should've been shared.

In an article about the Great Britain RHI scheme in the Farmers Weekly in May 2013, a poultry farmer who had 11 boilers stated that it was "crucial to ensure you're maximising the RHI tariff received for every boiler".

He'd decided against installing one large boiler for his heating needs, instead installing multiple smaller boilers to make the most of the top-rate subsidies on offer.

Sir Patrick Coghlin notes that the farmer was "quids in" because while he was paying 3.8p for the wood pellets to produce a kWh of heat he was getting an RHI payout of 8.6p for every kWh of heat produced.

Image source, PA

Ofgem spotted the article and worked out that the farmer was due to earn £11.6m in subsidies over 20 years but it didn't pass the information to DETI.

That's important because a similar loophole featured in DETI's RHI scheme, allowing the same thing to happen in Northern Ireland.

Asked why Ofgem didn't tell DETI about it, Dermot Nolan admits it should've been passed to the Stormont department.

Trying to explain the failure, he says: "People are imperfect, people make mistakes in good faith."

It's fair to say that DETI and its RHI scheme were not always spoken of in the most glowing terms in some emails between Ofgem staff.

Some of the correspondence suggests it was a "relatively low priority", while more blunt language is used in other emails.

Image source, Getty Images

But Dermot Nolan says he doesn't think you can "generalise from that that there was a cultural problem" in his organisation of a disregard for DETI.

He says the remarks were made by "someone who was clearly having a bad day" and was "letting off steam".

Inquiry panellist Dame Una O'Brien wants to know whether there was a "attitude" at the London-based Ofgem that because Northern Ireland was "geographically far away" and its RHI scheme was "small" it didn't need to "pay attention" to the same extent it did in its work for DECC.

DECC is based just down the road at Whitehall, a short dander from Ofgem's Millbank office.

Dermot Nolan acknowledges that there "is something to... the inherent closeness" of having DECC as a near neighbour.

Image source, RHI Inquiry

But he adds that he doesn't see any evidence from his organisation that there was a feeling that DETI "weren't interesting or competent".

"I don't think there was a sense from Ofgem that we don't like these guys, we're not interested in these guys - I don't think it was a cultural thing."

Sir Patrick Coghlin says that the inquiry has seen some emails from Ofgem staff that may suggest otherwise...

Ofgem had the ability to smell the "odour of gaming" in the RHI scheme but didn't refer it to DETI, says Sir Patrick Coghlin.

He points out that auditors had been contracted by Ofgem to inspect RHI-registered boimass boilers to check they were complying with the rules - the reports weren't sent to DETI.

Dermot Nolan says the inspectors were only to check for technical compliance, not to spot gaming.

But he accepts that DETI could not have spotted gaming without the help of Ofgem. "There would've had to have been a strong relationship between DETI and Ofgem."

He says it "would've been a reasonable thing" for Ofgem to have considered looking out for the gaming of the scheme but "it didn't happen and I find that hard to explain".

Ofgem warned DETI about the dangers of gaming in a 2011 legal feasibility study.

But the department didn't act on the legal warnings and the administrator didn't check if DETI had done so.

"I think both organisations are culpable there and I certainly include Ofgem in that," says Dermot Nolan.

He admits that was "a failing".

Conor Macauley
BBC News NI agriculture and environment correspondent

Inquiry barrister Joseph Aiken wants to know if it was right that the level of service that DECC received in how the GB RHI scheme was run "should've been broadly the same" as what DETI received in relation to the initiative in NI.

"Is there a reason for there being a distinction between them?"

Image source, AFP

Dermot Nolan says that given the way the question is posed it's "very hard to say anything other than yes".

But he feels it's a "slightly loaded question" and when Mr Aiken tries to intervene Mr Nolan stops him: "Sorry, if I may continue - I don't want to go all Judge Kavanaugh (above) on you."

He adds that "by and large" the service Ofgem provided to DETI was "roughly the equivalent" of what DECC received.

Ofgem didn't think it had a role to prevent the so-called gaming of the RHI scheme, says Dermot Nolan.

As Sir Patrick Coghlin puts it, gaming involves the "exploitation" of the rules of a scheme that was supposed to encourage "energy efficient expenditure of public money".

It was one of the biggest issues the led to the initiative's catastrophic overspend, which could hit hundreds of millions of pounds.

Basically, some claimants installed several smaller boilers rather than a single larger boiler in order to obtain a higher subsidy that was on offer for smaller installations.

The inquiry chair isn't one bit impressed that Ofgem didn't tell DETI to be more alert to the danger of the exploitation of the scheme.

"I just don't see how simple cooperation... couldn't say that: 'Gaming is a problem here, let's take a look at it.'"

Mr Nolan says that Ofgem and DETI didn't think about gaming and he adds: "I regret that."

Communication between Ofgem and DETI about the RHI scheme was far from ideal.

Dermot Nolan says that when it came to the problem of claimants exploiting the system for maximum profit, the administrator's contact with the Stormont department was not as effective as it was with the Department of Energy and Climate Change (DECC), which was running the GB scheme.

Image source, Getty Images

"That's interesting, isn't it?" observes inquiry chair Sir Patrick Coghlin.

Mr Nolan says the failure to have proper governance arrangements and a project board to oversee the scheme was a problem.