Peatlands[1] account for 3% of the world’s land surface. As long as they are intact, they store large quantities of carbon dioxide (CO₂), one of the greenhouse gases (GHG) accelerating climate change. They even store twice as much CO₂ as all forests together. However, when drained or destroyed, they release great amounts of CO₂, hence turning from carbon sinks into emitters of GHG.
Credits: Henry Schneider | Unsplash, Public domain.
Many peatlands were drained or even destroyed to serve other purposes, such as peat extraction, infrastructure development and drainage by forestry or for agricultural use. Until the 1980s, funding instruments of the common agricultural policy (CAP) of the EU, for instance, were even designed to facilitate the use of drained peatlands. In Europe, about half of the peatlands are considered to be damaged. Currently, drained and damaged peatlands account for 4% of anthropogenic GHG emissions worldwide.
Extracted peat itself can be an energy resource, as a fuel for electricity or heat generation. However, the extraction process further destroys peatlands and the emission factor of peat is similar to fossil fuels – from a climate point of view, it is hence not a good idea to use it as a source of energy.
The opposite is a wonderful approach: drained peatlands can be restored – they can be “rewetted”. This way, they are returned to their original state and no longer emit CO₂, but instead absorb it again: from emitters back to carbon sinks. This is vital if peatlands are to contribute to mitigating climate change again instead of accelerating it. However, how can the rewetted surfaces be used as effectively and in as climate-friendly a way as possible?
One option, amongst others, is ‘the simultaneous utilisation of rewetted peatlands for climate protection and PV power generation’, also referred to as open-space photovoltaic (PV) systems on rewetted peatlands, or peatland PV. According to the Peatland Atlas, solar farms ‘are among the many promising ways of replacing previous land uses’ for peatlands after or in the course of their restoration process.
As available areas for solar parks are limited, repurposing former peat extraction sites and degraded peatlands ‘offers an environmentally responsible alternative to developing solar farms on undisturbed land, reducing unnecessary habitat destruction’. There is a double advantage, as open-space PV could be constructed without affecting intact and healthy ecosystems, fostering the energy transition whilst benefiting the climate.
The relatively new approach of peatland PV is to date primarily being explored in Europe. In Germany, for instance, the Renewable Energy Sources Act from 2023 subsidises the installation of PV systems on peatlands that had been drained and used for agricultural purposes, provided that these areas are permanently rewetted. This can be deemed an important step: oftentimes, peatlands belong to farmers or landowners and are used commercially, and in many cases provide the primary source of income for agricultural businesses.
Rewetting these lands is hence not necessarily attractive for the owners. Farmers who own and operate on drained peatlands need incentives to agree to a restoration process and compensation for loss of income as a result of the rewetting process and working on wet land. However, in combination with paludiculture (the agricultural and forestry use of wet peatlands), solar systems can constitute a second financial pillar for farmers. Furthermore, the market for paludiculture products is not yet large or predictable, and industry players in turn do not have the guarantee of a reliable supply of these products, which is why they are reluctant to invest in this kind of product segment. Peatland PV might prove the interim solution needed until the wet peatlands can be cultivated profitably. In addition, unlike agricultural or forestry alternatives, peatland PV does not require tilling or fertilisation – it could hence reduce the amount of work farmers have to do on part of their land and at the same time avoid ‘the mineralization of peat soils—a primary driver of greenhouse gas (GHG) emissions’.
The share of degraded peatlands in Europe is, compared to other continents, extremely high, which underlines the importance of new approaches to restore and use these fragile ecosystems. However, the approach should not be limited to Europe. Peatland destruction is also high in Southern Africa, India and Myanmar (between 70% and 90%), as well as in Western Africa and Southeast Asia (between 40% and 70%), for instance. If peatland PV proves to be a successful concept in Europe, the approach could also be applied in these regions of the world, where it could not only protect and restore peatlands, but also accelerate the energy transition.
According to the Global Peatland Hotspot Atlas, rapid infrastructure development, as well as industrial activities such as oil and gas exploration, amongst other businesses, result in peatland degradation worldwide. Currently, oil and gas development threatens peatland areas in, amongst others, South America, the West African Coast and Asia. Over 100,000 km² of the total area of tropical peatlands overlap with a buffer zone around oil and gas infrastructure, for example. In North America and Asia, there is ‘a high risk of peatland destruction’ by oil extraction in general.
The principle of solar plants on rewetted peatlands could also be transferred to peatlands worldwide that are still intact but under threat, and that might otherwise be used for other purposes. It would of course be a double benefit for the climate if solar plants were installed where peatlands would otherwise be destroyed for the extraction of fossil fuels.
To date, rewetting peatlands is only being practiced in a handful of countries. One of the few positive examples is Indonesia: the country is ‘a hotspot of peatland restoration and raising water levels over substantial peatland areas’. Hence, once peatland PV has proven successful and efficient, knowledge and assistance could be provided for countries already working on the restoration of peatlands.
As with any new concept, there are obstacles to peatland PV that need to be carefully assessed. The construction of peatland PV on permanently rewetted peatlands might be cost-intensive and associated with potentially lengthy planning processes. In addition, installing peatland PV comes with its own set of challenges, such as the risk of soil compaction due to the use of heavy machinery and ongoing drainage of the peat soil to facilitate construction, as well as maintenance of the solar panels. Also, there is little information on how the installation of solar panels might affect peatland vegetation – the fragile ecosystems might be disturbed by the reduction of sunlight. Areas that have both a high potential for rewetting and a high potential for nature conservation should not be used for the installation of PV. Instead, biodiversity protection should be prioritised here.
However, the expected benefits might outweigh the potential obstacles. Even if peatland PV is still in its early stages, it seems to be very promising and could support many countries in achieving their climate targets, all while contributing to the restoration of nature. Notwithstanding, it should be carefully examined and scientifically monitored, since to date, practical experience with PV systems on peatlands is limited.
[1] Used as a generic term for (amongst other things) peatlands, wetlands, bogs, mires, moors and fens.