Moor-PV

Background

The rewetting of peatlands is the most effective measure to reduce greenhouse gas emissions from drained peatlands. However, the previous forms of agricultural use will no longer be possible after rewetting. In addition to the site-adapted use of wet or rewetted peatlands (paludiculture), the construction of ground-mounted photovoltaic systems could also represent a new economically attractive utilization option. Since the Renewable Energy Sources Act 2023, peatland PV systems have already been eligible for funding as "special solar systems". The Federal Network Agency has drawn up more specific requirements for this, which also include compliance with minimum water levels.

However, there is still a considerable need for testing and research in order to be able to conclusively assess the impact of the construction of photovoltaic systems on peatland soils to be rewetted for this purpose, particularly with regard to peat conservation or climate balance, water balance and biodiversity. There is also a need to consider the economic incentive function of peatland PV systems to encourage more rewetting of previously drained, agriculturally used peatlands.

Project Aims

The aim of the project is to analyze the economical and ecological effects of the combination of peatland rewetting and photovoltaics:

• Investigation of the practical feasibility and economic viability of peatland photovoltaic systems
• Assessment of the development of biodiversity on peatland photovoltaic sites in comparison to drained, agriculturally used peatlands
• Determination of the greenhouse gas balance of rewetted peatlands with photovoltaic systems

The focus is on heavily degraded, agriculturally used, organic soils in northern Germany, whose water levels have been dammed up to a peat-retaining level at ground level for the construction of photovoltaic systems. In the research project, a main study area is to be closely examined and other areas are to be monitored in graduated intensities. The main study area is located in the north of Schleswig-Holstein and is kindly provided by Osterhof ökologisches Flächenmanagement GmbH & Co. KG.

Work packages

WP1: Economics

The plan is to examine established and planned peatland PV projects in Germany and to record the special economic features in comparison to ground-mounted photovoltaic systems on mineral substrates. Financial differences in the various process stages will be investigated and considerations regarding mixed financing will be made. In addition to the economic differences, political recommendations for action will also be derived. In addition, the stakeholder landscape will be examined. The perspectives of different stakeholders in the process of a peatland photovoltaic plant from the idea to implementation will be analyzed.

 

WP2: Biodiversity

As part of the peatland PV project, biodiversity will be compared between intensively managed, drained peatlands and those that have been rewetted and equipped with PV systems. A combination of passive acoustic monitoring, traditional arthropod traps and vegetation mapping will be used to collect data. Plants, ground beetles, spiders, amphibians, crickets, bats and birds will be studied as part of this project.

 

WP3: Greenhouse gases

The aim of the work package is to investigate the effect of solar panels on greenhouse gas emissions in a rewetted peatland. The three most important greenhouse gas emissions methane, carbon dioxide and nitrous oxide are to be measured under and next to the solar panels using canopy measurements. In addition, the influence of the water level will be investigated by measuring drier and wetter areas of a rewetted peatland. It is assumed that the panels minimize evaporation through their shading and thus have a positive effect on high water levels in the peat body. However, the shading could also have a negative effect on plant growth and thus CO₂ uptake. The greenhouse gas balancing is intended to create an initial knowledge base on the effect of photovoltaic systems on wet peat soils.

 

WP4: Coordination and integration

In addition to coordinating the research group, the research results will be summarized and incorporated into the ongoing discussion. In addition, the organization of a student peatland congress will be coordinated by the German scholarship holders. Students from various disciplines are to be supported in working on an overarching question on the sustainable use of peatlands with different professional perspectives and approaches and to present and discuss it with other students and experts from the scientific community at a self-organized congress.