Cabinet has approved a plan by Minister Eamon Ryan to buy an additional 450 megawatts of electricity next year at a cost of 350 million euros.
Eirgrid will buy temporary generators to do the job, although it's unclear whether the generators will be fired from oil and gas or renewable energy.
The $350 million bill will be recovered from customers over three years, but the minister said the cost would be more than offset by a reduction in public service duty tax.
Under the National Energy Security Framework announced in April last year, the PSO has been reduced to zero and will come into effect in October this year.
Under this latest plan, PSO could go negative -- allowing customers to be reimbursed on a bill.
The Utilities Regulatory Commission will make a final decision on rates next month.In September last year, Eirgrid predicted Ireland could experience a power shortage for five consecutive winters, partly due to the closure of some peat power stations.
There have been "eight system alerts" on the system in the past 18 months.
Russia's invasion of Ukraine has led to instability in energy markets, which has greatly exacerbated the problem.
It is unclear what additional measures are being actively considered, such as extending the life of the coal-fired Moneypoint power station, to ensure supply security.
