Thursday 19 September 2019

Colm McCarthy: 'Choosing nuclear option may not be so far-fetched anymore'

Fossil fuels are being replaced in power generation. But the interruption to the UK's national grid highlights the pitfalls, says Colm McCarthy

Energy: Sceptics say sources dependent on weather are harder to manage
Energy: Sceptics say sources dependent on weather are harder to manage

Electricity systems in Europe are changing rapidly, more so in Ireland than in most other countries. Generation from carbon-emitting fossil fuels is being withdrawn and replaced with renewables such as wind and solar. Interest in nuclear power, which also has near-zero emissions, has revived as newer small-scale technologies become possible.

Demand will rise as electricity becomes more of a de-carbonised alternative to fossil fuels in transport and space heating. The changes are being resisted in some countries - Poland is insisting on building new coal plants, among the worst emitters - but most countries have accepted change must come and that it will be costly. Historic expenditures on stranded fossil fuel assets are being written off, the latest example being the early closure of peat-fired plants in the Irish midlands.

New generating plant costs money, as does extra investment in the grids which deliver power to users. The new electricity industry already involves extra costs for consumers, who pay for any subsidies to renewable generators and for consequent grid costs, and there will be more. Electricity could also become less reliable. On Friday week last, the United Kingdom's electricity grid experienced a sudden and severe interruption. One million homes, the electrified rail system around London and several hospitals and airports lost supply. The distribution of power was restored inside a few hours; the distribution of blame will take many months and multiple inquiries.

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The supply of electric power into national grids must match demand almost exactly, on a minute-by-minute basis. Should it fail to do so there are automatic control systems which summon additional generation should it be available. If not, they cut off supply to pre-selected users. On the afternoon of August 9, a gas-fired power station in Bedfordshire unexpectedly ceased production. Unplanned outages are common, and grid operators maintain spare capacity to deal with these regular occurrences. The power lost was less than 3pc of the national load at the time and there should have been no blackouts - spare capacity is meant to be several times larger. But a second unit of roughly similar size, a big offshore wind farm in the North Sea, cut out almost immediately and the system began to disconnect loads around the country. Had it not done so there would have been a drop in the frequency reading throughout the system, potentially damaging to the system itself and to electrical equipment being operated by users.

Candidates for blame include the national and regional grid operators (why were high-priority customers cut off first?) and the wind farm owner, whose switch-off may have been triggered by the sudden outage at the gas unit a few minutes earlier - it may not have been a one-in-a-million coincident technical failure. Whoever is blamed, a bigger question will concern policymakers beyond the UK. Are the emerging electricity systems likely to be less reliable than people have been used to? What happened was a sizeable blackout across a national system, not the occasional winter storm damage to local power lines, which cannot be engineered away, and which customers forgive.

Sceptics about renewables have been quick to point out that weather-dependent generation is inherently prone to interruption, since the wind may not blow, and the sun may not shine. It is not clear that this was a factor in the UK blackout, but any power system with a high reliance on weather-dependent units is necessarily harder to manage. The more wind and solar units in operation, the greater the spare capacity and backup needed to keep the system stable.

When renewable output falls, the substitute power must be available quickly from conventional plants, usually carbon-emitting gas plants. Keeping these plants available, although regularly idle, is part of the cost of renewables. These costs are particularly important in Ireland since the renewables share in generation, mainly wind, is already high and the Government's target for renewables, at 70pc, is one of the highest adopted by any government.

Electricity demand in Ireland is expected to rise rapidly in the years ahead. The main reason is the proliferation of data centres, which have heavy power requirements. If home heating and road transport move away from fossil fuels towards electric technologies, also part of government plans, this leads to even greater electricity use. While demand is expanding some of the conventional power plants, including the largest, the high-emission Moneypoint coal station in Co Clare, are due to close and something must replace them. Replacement plant, and provision for demand growth, must include units which are always available, as well as renewables, if a stable system is to be provided. There is not much choice as a practical matter - Ireland has a fleet of reasonably modern gas stations which have emissions much lower than the peat and coal stations which are to cease production.

As EirGrid, the State-owned transmission company, has acknowledged, there will have to be some new gas stations. These stations are best seen as an enabler of more renewables rather than an alternative, and security of gas supplies, domestic or imported, remains critical.

The other practical option for always-on generation could eventually turn out to be small-scale nuclear. Large nuclear plants of the type being constructed in several European countries are ballooning well over budget and engineers are sceptical anyway, saying they are just too big for the Irish system. But much smaller nuclear plants, even smaller than existing Irish gas units, are under development and could become available in due course. No one knows if they will prove to be commercial and their introduction is at least a decade away.

In its recent reports on generation adequacy, EirGrid has adopted a passive attitude to the extraordinary boom under way in the construction of data centres in Ireland. They expect that 31pc of total electricity demand will come from these energy-gobblers inside a decade. They employ few people and there will be heavy costs for EirGrid in the form of grid reinforcement, apparently to be borne by customers in general and not by the data centres.

There must be data centres somewhere in Europe, but it is a mystery why 25pc of European capacity is headed our way. Are more cautious countries, and grid operators, playing pass-the-parcel at Ireland's expense?

In any area of policy which is technically complex, there is scope for public relations executives to spread a little bewilderment. Energy policy fits the bill nicely and the subsidy-farmers in the renewables business have been congratulating themselves down the years, courtesy of a gullible media, for saving the planet at public expense. This is not an argument against renewables, it is an argument against misleading the public. The data centres have joined the virtue-signalling chorus, announcing that they will use only 'green' electricity, since they have collared a share of the output from renewable suppliers. Electricity is colourless, uniform and ignorant of its provenance. Grid-connected users cannot tell where it came from. They're having you on.

EirGrid will be updating the generation adequacy report shortly. This time they should address the implications of the 70pc renewables target, and all those new data centres, for system stability - and for your electricity bills.

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