EirGrid publishes a Generation Capacity Statement every year and this year's report sets out very clearly the potential shortfall in supply over the coming years.

There are many reasons for this.

One reason is that the electricity system is in the middle of a transition. Currently, over the course of a year, around 40% or more of our electricity is generated from renewable means. This is mostly wind power.

The Government's Climate Action Plan envisages a system where 70% of our power is generated from renewables by 2030.

In the meantime, older plants which burned peat or coal are being phased out. And gas fired plants have been gradually made to work in ways older plants were not designed. They are expected to be more "flexible" which means ramping up and down generation in response to fluctuating levels of wind power.

This has led to more wear and tear in existing plants and the direction from the CRU for new, modern flexible gas plants to be built and for extra capacity to allow for smoother maintenance schedules.

Before this happens, the concerns over supply have prompted the CRU to extend generation at the coal-fired Moneypoint and oil-fired Tarbert for a temporary period. These plants had been slated to be phased out due to their emissions.

In the future, there is an expectation that more offshore wind farms will generate a more reliable supply of wind power.

However, the MaREI Centre for Marine and Renewable stated in a report last year that even if we hit all of our renewable targets by 2030, we'll still be reliant on burning 80% of the gas we burn today because demand will have risen over that time and other technologies like battery power may not be sufficiently advanced to replace gas.

In the meantime, EirGrid's report identifies other factors that have exacerbated the supply problems as the system makes the transition to more renewables.

Recent auctions to supply power to the grid here did not deliver the amount required.

And then there's the growing demand for power, which hit historic peaks last December. The rate of increase in electricity demand ranges from 28%-43% between now and 2030.

EirGrid estimates that data centres will represent 28% of grid capacity by the end of the decade

It has also identified data centres as the primary factor behind growing demand.

It has also flagged that Government policy to encourage more electric vehicles and for homes to use electric heat pumps will add to demand.

There's a separate public consultation on data centres being conducted by the CRU and it's expected to be completed by the end of next month. EirGrid expects data centres to use 27% of electricity supplies by 2030.

EirGrid also warns that we will face more "system alerts". This is when the margin between demand and supply falls to a point where there would not be enough electricity to cover the loss of a large power plant or some other unforeseen event.

There have been eight such alerts since January 2020.