THE cost of wholesale gas is more than a third cheaper now than a year ago - and 14 per cent down over the past month alone.
According to the latest business energy report by Vayu Energy, wholesale gas prices in September were 36 per cent lower than the same month in 2015.
And compared to two years ago, prices have halved.
It said the losses were to "on-going healthy supply and decreased demand year on year".
Vayu added that a significant supply overhang pushed the "prompt market to lows not seen since 2009 during the first half of the month".
It said that to date in September, the average day-ahead price for gas, the contract for gas delivery tomorrow, is 26.28 pence per therm.
The fall will have significantly lowed energy costs for many businesses in Northern Ireland, particularly in the industrial and commercial sector.
Joanne Daly, senior energy analyst at Vayu said that on-going healthy supply and mild weather continue to put downward pressure on prices.
“Temperatures are expected to be above normal in the UK and throughout most of Europe during the last week of September," she said.
"Weather forecasts are also signalling strong winds for the same period. These point to a period of continued low gas demand for the remainder of the month, which could keep a cap on any potential gains due to supply issues.
“Storage levels across Europe are quickly filling up and are at 86 per cent capacity. This trend will continue until we see heating demand return.
"UK storage levels remain at 52 per cent and are unlikely to grow beyond that prior to winter due to the on-going restrictions on the Rough storage facility, which houses 70 per cent of the UK’s total storage capacity.
"Although withdrawals traditionally begin in early October, if the weather remains as mild as it has been recently, these withdrawals may not be necessary until later in the winter period, which may also be easing any concerns surrounding security of supply.”
The report also revealed an 11 per cent drop in day-time electricity prices in September compared to the same month last year.
This is again due to falling gas prices - the main energy source to produce electricity in the north.
Meanwhile, it found wind energy accounted for 16 per cent of overall electricity generation so far in September.
Total wind generation capacity across Ireland now stands at 3,169MW.
That gives it the potential to meet 56 per cent of total electricity demand on Ireland.
Some 20,942 gigawatt (GW) of wind energy has been generated since the start of the year, representing 21 per cent of total electricity demand during this period.
