Is it really renewable, for peat’s sake?

This blog, written by Lydia Cole, is being reposted with permission from the Energy Ethics research group at the University of St Andrews, after being published on The Energy Blog, on 26th November, 2020. 

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As part of Energy Ethics 2020, I joined three other panellists on Friday 13^th November to debate the question: Are renewable energy technologies a sustainable solution for meeting the world’s growing energy needs? It was a fascinating 90 minutes, filled with interesting and shocking facts about the dimensions of renewable energy in the 21^st Century. I learnt that if we wanted to rely on biofuels, we would have to plant crops on the whole of the world’s terrestrial surface in order to replace the 15 Empire State Buildings’ worth of crude oil that is currently extracted per day; that an average electric car uses three times more copper than a conventional car (where does this come from!?); and that many people in the Majority World lack access to sufficient energy to light up their homes for educational purposes or to cook without subjecting the household to air pollution, let alone have access to renewable energy sources. The challenges of powering the world on renewable technologies were as palpable as the need to overcome them in order to reduce our reliance on fossil fuels; and reducing this reliance is imperative if we are to limit the impacts of ongoing climate change.

I am an ecologist, who has studied landscapes in which bio-energy production has been one option for land use. Since energy use and sourcing is a topic that touches all of our lives, I have spent some time thinking about how we might produce renewable energy whilst ensuring we uphold the environmental pillar of sustainable practice. I remember being excited by palm oil, touted as the great solution to diesel-fuelled transport. After millions of hectares of Southeast Asia were converted into oil palm plantations, the critiques started to roll in: we are taking up precious agricultural land to fill our cars with biofuels whilst people starve; we are destroying miles upon miles of biodiverse tropical forest to plant a monoculture that provides limited habitat for wildlife; we are creating huge carbon emissions in the process of growing this ‘renewable’ fuel, amongst other condemnations. I remember getting excited about Jatropha, claimed to be a more renewable alternative, as a biomass crop that could be grown in areas that were already ecologically degraded. But Jatropha did not prove the golden ticket either: the crop requires significant inputs of fertilisers, pesticides and water (through irrigation systems) in order to be productive, and the process of converting Jatropha seed oil into biodiesel results in large greenhouse gas (GHG) emissions itself. There are large questions around the sustainability of these two biofuels (and many others). There is also enquiry to be made around whether they are actually truly ’renewable’.

According to Oxford’s online Lexico, a renewable resource is defined as one that is “not depleted by use”. The resource therefore has to regenerate at the same rate that it is harvested or otherwise consumed. For example, sufficient time must be left between the logging rotations in a tree plantation to ensure that the trees grow to reproductive age before they are harvested. If trees are harvested too early in their growth cycle for natural regeneration to take place, a key dimension of the renewability of the resource is undermined, along with the interdependent system in which it grows: the soil, with its finite stock of nutrients and growing material; the water supply to ecosystem; and the diversity of plants and animals involved in nutrient cycling and natural regeneration. If the context and condition of the whole ecosystem is considered, as the fundamental housing from which renewable resources are produced, many of our current ‘renewable’ resources would be axed from the list.

One resource that epitomises this renewability challenge is peat. Peat accumulates at an average rate of one millimetre per year, in waterlogged environments where the lack of oxygen slows down or entirely halts the process of decomposition. Burning one cubic meter of extracted peat is the equivalent to releasing one thousand years of accumulated carbon. It is produced through the natural process of harnessing the sun’s energy via photosynthesis, the same process as produces wood-fuel, but the slow regeneration time of peat demands that if we burn it, we must do so at an impractically slow rate.

Aside from the extensive time required to re-accumulate the equivalent carbon belowground that is extracted when peat is harvested, the process of extraction itself often leads to large carbon emissions. The equipment deployed uses fossil fuelled combustion engines and emits CO₂, but even greater volumes of GHGs result from the disruption of the waterlogged environment, which is an inevitable part of the extraction process. This prevents the ongoing ‘sinking’ of CO₂ from the atmosphere into the peat substrate. It also results in the release of carbon that was previously inaccessible to the forces of decomposition, which cycles the plant-derived organic carbon back into the atmospheric gas that we have come to dread. Rwanda, a country striving for domestic energy security and energy accessibility for all, has recently built a peat-fired power station. International financing and engineering assistance, primarily from Finland, has supported the development of this “sustainable electricity” infrastructure. But this strategy of burning peat for electricity generation is far from sustainable, and even further from a system harnessing a renewable resource, as I have touched on here.

Though the balancing of the three pillars of environment, society and economics to develop sustainable solutions to meet our energy needs is no trivial task, a sufficient understanding and consideration of the environment component is essential if the other two pillars are not to be undermined. But when has any big transition occurred without challenge? And it is challenge that drives innovation and positive change. To end the discussion, the panellists were asked for their final (ideally positive!) reflections in order to provide food for thought moving forward. Building decentralised, appropriate renewable energy systems at a community level was mentioned by several of us. One panellist emphasised the need to create macro-policies with micro-foundations. He also reflected on the need for a dimension of international cooperation and support, through knowledge transfer and financial assistance, to lend the opportunities of renewable energy to those countries less able to develop their own. Promisingly, finding the money for these initiatives now seems more possible than ever, with recent COVID-19 related budget decisions demonstrating to the population here in the UK that our national Government can deliver when it chooses to. There was further optimism in the recent election of a new leader in the United States of America, Joe Biden, who has both acknowledged the reality of climate change and will likely choose to provide national and international leadership on approaches to solve this challenge. But we were reminded, as conscious citizens, that we must hold our leaders to account and show them that we are willing to embrace equitable and truly sustainable solutions to one of the greatest challenges of our age.