This is a policy decision by the government. More realistically it is a decision to not proactively do anything and instead rely on market prices to encourage new entrants to the market.
https://www.cso.ie/en/releasesandpublications/ep/p-dcmec/dat...
It’s a massive topic and I encourage everyone to go and dive into it. It’s endlessly fascinating and also one of the really positive stories in the world right now which can help balance your emotions in a sometimes depressing world. At least for me it does.
It's also just a rule of economics. The price is set at the cost of the most expensive production necessary to meet demand.
So if solar could fulfill 100% of energy demand, price would be the cost of solar, and any other more expensive generation would either lose money, shut down or idle.
But if we shut down or idle those today we wouldn't have enough electricity, so the price rises until the more expensive plants can stay open and demand is met.
This also demonstrated through most countries in Europe that citizens will vote to have government that fix the energy market. Citizens do not want a free energy market that can raise prices to any degree, and its their tax money that fund grid stability.
This all mean that the cheapest form of producing energy do not result automatically in reduced energy costs for consumers and companies. The product that people pay for is not energy in a pure form, it is energy produced at a given time and given location. Make the energy free but the time and location expensive, and the total cost will still be expensive.
Transmission can help Ireland, but it can also hurt it by linking it to a larger market that can create a even higher demand spikes than exist in the current local grid. If the linked grid has locations which has higher energy costs than Ireland, then Ireland will subsidize those people by linking the markets together. Rules like highest price regardless of source sets the price, and higher amount of transmissions, also tend to result in more companies getting paid to maintain operations and thus more parties getting paid that is not linked to the marginal cost of producing energy.
The people using carbon to create forcing functions to transition to renewables conveniently forget to mention that. Which sucks, as solar in particular is almost a miracle product, but at this point my delivery charges to get electricity exceed the electricity supply by 10%. 20 years ago, delivery was 30% of supply.
My state, New York, decided it would be smart to turn off the nuclear plant that supplies 20% of NYC electricity, and replace it over a decade with a rube goldberg arrangement of gas, offshore wind, solar, and Canadian imports. The solar is hampered by distribution capacity, gas was slowed down by corruption and is being limited by environmental activists, we elected a president that believes that windmills give you cancer, and of course we are picking fights with Canada now.
In a vast over simplfication, the most expensive producer that gets to supply sets the overall price. So even if you supply 99% from wind and hydro, the 1% of power that comes from gas sets the price for 100% of the electricity in the market.
When gas gets more expensive, electricity from gas gets more expensive. The more you have to rely on gas (because you don‘t have batteries, not enough solar, etc), the more you pay high prices.
There are different ways to address these issues. Demand side load management, batteries, etc.
The gas prices went up massively in 2022 with the war in Ukraine, and even though that subsided before the war in Iran a little, the existing supply companies are not going to give back an increase in the price they’ve gained because their prices dropped.
The tricky part here is that energy is an input to basically everything. It's a major (through fertiliser) input to food, and then all of transport and stocking of said food which tends to be how energy changes influence downstream inflation. So I think you'd probably need a deeper analysis to tease out these issues.