Power from peat—more polluting than coal—is on its way out in Ireland
|sciencemag.org 12 Dec 2018 at 14:55|
On a cold, gray morning in November, the Cornaveagh Bog in central Ireland is a scene of industrial harvest. Like other Irish bogs, it has been drained and stripped of its moss and heather to reveal the rich, black soil beneath: peat. The peat is scored with tread marks left by the machines that shaved off a crumbly layer and turned it over to dry. A long mound of peat, stripped and dried earlier in the season, is covered in plastic, waiting to be piled into rail cars and taken to a nearby power plant. There, the carbon-rich soil will be burned to generate electricity.
But not for much longer, says Barry O Loughlin, an ecologist employed by Bord na Mna, a state-owned peat harvesting and energy company based in Newbridge that owns Cornaveagh Bog. Bord na Mna, which means "Peat Board," will soon retire dozens of bogs like Cornaveagh from energy production. Its team of four ecologists will rehabilitate many of them by blocking drains, soaking the ground, and reestablishing plant life, O Loughlin says as his boots crunch through the frosty soil. "We bring life back into the bog again."
In Ireland, peat has been used for centuries to warm homes and fire whiskey distilleries. For a country with little coal, oil, and gas, peatdeep layers of partially decayed moss and other plant matteris also a ready fuel for power plants. Peat power peaked in the 1960s, providing 40% of Ireland s electricity. But peat is particularly polluting. Burning it for electricity emits more carbon dioxide than coal, and nearly twice as much as natural gas. In 2016, peat generated nearly 8% of Ireland s electricity, but was responsible for 20% of that sector s carbon emissions. "The ceasing of burning peat is a no-brainer," says Tony Lowes, a founder of Friends of the Irish Environment in Eyeries.
That is now beginning to happen. By the end of 2019, the Irish government will eliminate all of the roughly 100 million in annual industry subsidies it now pays for peat-generated electricity. Bord na Mna, which supplies peat to the three remaining power stations burning it for electricity, announced in October that it would cut its peat supply for electricity by a third by 2020 and end it completely by 2027. Ireland will need to find alternative, lower carbon sources of electricity. And approximately 60 bogs no longer needed for fuel will be converted back to wetlands or put to commercial uses such as land for wind farms.
Behind the phaseout is Ireland s promise to the European Union to reduce greenhouse gas emissions by 20% in 2020, compared with 2005 levels. "The country s decarbonization agenda is driving Bord na Mna s step down from peat," says Joe Lane, the company s chief operating officer. Even so, Ireland will miss its goal. Despite rapid growth in wind power and increasingly energy efficient homes and vehicles, it will struggle to reduce emissions by even 1%, says Phillip O Brien, scientific officer for the Irish Environmental Protection Agency in Dublin.
Like any energy transition, this one comes with a human cost. Up to 430 jobs will be lost, Lane says. "Most of the people who will lose their jobs are people who have worked for Bord na Mna for a long timepeople whose fathers, grandfathers, and villages are all tied to the company."
And replacing peat with biomass, as the power companies plan to do, is not a panacea. A decade ago, Bord na Mna began to cofuel a peat-burning station with mixtures of biomass including a grass called miscanthus, olive pits, almond shells, palm kernel shells, and beet pulp, much of it imported from all over the world. Because biomass takes up carbon from the atmosphere as it grows, the European Union counts it as a carbon-neutral, renewable resourceeven though transportation, processing, and land-use costs make it less so. "The unregulated or unfettered use of biomass would lead to serious problems," says Robert Matthews, a scientist at Forest Research in Surrey, U.K. In 2021, European legislation will tighten biomass standards, reducing the advantages of burning it from a carbon accounting standpoint.
Rehabilitating the harvested peatlands, however, is a clear plus for climate. When bogs are drained to harvest peat, or for any other use, such as agriculture, grazing, or forestry, exposure to oxygen jump-starts the decomposition of the stored organic matter, releasing carbon into the atmosphere. A 2013 study of Irish peatland carbon emissions, published in Irish Geography, found that each hectare of industrially drained and stripped peatland emits 2.1 tons of carbon per yearthe equivalent of driving a car 30,000 kilometers. And that s before the harvested peat is burned.
Those emissions cease as soon as drains are blocked and the water table rises to resaturate the peat, cutting off oxygen. As a result, ecologists say, conserving peatlands has a triple benefit: reducing emissions from both power plants and exposed fields and, with restored plant life, sequestering more carbon in future peat deposits. "Peatlands are our rainforest, our carbon sink," Lowes says.
Moreover, healthy peatlands improve water quality and provide needed habitat for threatened species such as curlews and marsh fritillary butterflies. "Our goal is to make things as wet as we can, where we can," says Catherine Farrell, an ecologist at Bord na Mna. She says that of the 80,000 hectares of peatland under company management, 18,000 hectares have been rehabilitated.
But in a country where peat smoke rises from chimneys every day, that s just a start. People cut peat to burn in their houses from another 600,000 hectares of peatlands, and there are few plans for rehabilitating these degraded bogs. Catherine O Connell, director of the Irish Peatland Conservation Council in Lullymore, would like to see more action to heal the bogs. "There s a lot of bare peat around," she says. "There s a lot of hemorrhaging carbon."