Where should they go?

By 2032, 2 per cent of Germany’s land area – amounting to a good 700,000 hectares – must be designated for wind energy. By contrast, it would take just 0.3 per cent of the Federal Republic’s land area to meet the requirement for ground-mounted photovoltaics (PV) by 2030. Are enough sites available? Where are they located and how can user conflicts be addressed? And another question: how can renewable energies be distributed fairly across the regions? 

It's enough, the researcher says. What she means is that there are enough sites for the expansion of wind and solar energy. Enough to achieve their respective targets. “With ground-mounted photovoltaics, there are a great many sites that are not affected by major user conflicts and are perfect for hosting solar plants – alongside railway tracks or motorways, for example,” says Dr Marion Wingenbach, a Senior Researcher in the Oeko-Institut’s Energy and Climate Division. But there are also countless opportunities to site photovoltaics on agricultural land. This is revealed in the study on “Potential sites for agriphotovoltaics”, conducted by the Oeko-Institut as part of the EmPowerPlan project, which is funded by the German Federal Ministry for Economic Affairs and Energy. In the study, the Oeko-Institut, together with the Institute for Futures Studies and Technology Assessment (IZT) and the Reiner Lemoine Institute, explores how the expansion of renewable energies can be managed in a regionally just, systemically meaningful and socially compatible way. “Agri-PV is a good option for mitigating site usage conflicts with the agricultural sector as it allows shared use. The PV modules are installed above or between the cultivated areas.” In the study, the Oeko-Institut quantified the potential for expansion. “For example, we found that there is high potential in vine, fruit and vegetable growing. In fact, systems that are installed at height can protect the crops – from hail, for example – at the same time. In Germany, synergy effects such as these can be observed across a total area of more than 400,000 hectares.” What’s more, sites with low or intermediate soil quality are particularly suitable for agri-PV. “Here, we’re talking about a potential area of almost four million hectares.” 

Not conflict-free

Siting conflicts can still arise, of course. “On top of that, the sites are not yet being utilised to an optimal extent. As a rule, it is the project developers who offer landowners the opportunity to lease their sites. It would be much better for local authorities to manage site selection, because as things stand, what can happen, of course, is that highly fertile, high-yield land disappears under solar cells.” Clear guidelines enabling local authorities to prioritise sites for diverse forms of use – including renewable energies – would therefore make sense. “The guidelines should include criteria for dealing with issues such as user conflicts with agriculture, proximity to a grid connection and also the potential for dual use.”

What is fair?

Another key point of relevance to renewables expansion and site availability is fair distribution across Germany’s federal states and regions. What might a regionally just, systemically meaningful and socially compatible distribution of renewables in Germany look like? To facilitate debate about this issue, the Oeko-Institut is now providing baseline data with two studies on “Justice in renewables expansion”, also produced within the EmPowerPlan framework. Here, the researchers define various aspects of justice and propose a methodology for applying them and addressing diverse perspectives. “Part of this, for example, is that the expansion should be evenly distributed with regard to the available sites, that the focus is on regions with high electricity demand, and that the burdens on the public are evenly spread,” Marion Wingenbach explains. “Of course, there are different views on what fair distribution means. Our approach enables these various perspectives to be captured systematically and channelled into spatial planning. It takes both technical and social issues into account.” What’s more, using the datasets, “sites of consensus” can be identified where the various conceptions of justice overlap; these should be used first for the expansion. The project team’s work also enables low-conflict sites to be identified and planning priorities to be made visible. “In the case of wind energy, for example, system costs and import requirements differ considerably according to which distribution principle is selected – this shows that some forms of justice are systemically more advantageous. With ground-mounted PV, on the other hand, there is barely any difference, and this offers scope to give greater weight to aspects such as local participation or landscape conservation.” The datasets are publicly available and can be used for distribution analysis. 

High forests, old industries

The project “Planning transition through the transdisciplinary integration of regional and socio-cultural factors in the development of local energy transition measures” (PlanTieFEn) explores how energy transition measures can be implemented at the regional level. For the project, the Oeko-Institut is running participatory planning laboratories in three model regions in Baden-Württemberg, North Rhine-Westphalia and Mecklenburg-Western Pomerania. “The aim is to identify different local identities, regional planning cultures and renewable energy potential and, on this basis, to develop and test regionally adapted instruments,” says Marion Wingenbach. “We look at how regions would construct renewable energy plants themselves independently of regulatory frameworks, which specific needs they have and how the regions differ from each other.” 

The study found, for example, that perceptions of new projects are very strongly influenced by previous experiences of transformations and that regional identities in rural areas often centre on landscape features. “Early communication and participation are also important, with consideration of regional identity and genuine engagement with opportunities for co-creation.” For example, in the Black Forest Highlands (Hochschwarzwald) – Dr Marion Wingenbach’s home region – the natural and cultural landscape, such as forested mountains and open meadows, is highly significant. The Ruhr region, by contrast, is characterised by dense construction and high settlement pressure, as well as an industrial culture that has been shaped by fossil fuels. “Here, the challenge is to integrate this into a renewable future. The regions are highly diverse, and so too are their pathways towards renewable energies.” PlanTieFEn is conducted in cooperation with ILS Research gGmbH and the Institute for Climate Protection, Energy and Mobility (IKEM) together with numerous stakeholders from the planning sector and wider society and is funded by the German Federal Ministry for Economic Affairs and Energy. 

Renewables at home

Countless sites for renewable energies also exist on our rooftops and balconies. “Solar plays a key role in this context – around two-thirds of Germany’s photovoltaic capacity is installed here,” says Dr Marion Wingenbach. At the same time, the addition of new capacity is more difficult to steer here, which is why sites for ground-mounted photovoltaics are also required. “But I am optimistic that rooftop and balcony-mounted PV will remain a strong contender, not least because more and more of Germany’s regional states are introducing a solar energy requirement for new residential buildings.” 

--

How can renewable energies be integrated into the energy system? What is important for acceptance in the context of the transformation of the energy infrastructure? And how do socio-ecological factors influence the expansion of power plants? These are just some of the questions explored by Dr Marion Wingenbach in the Energy and Climate Division, which she joined in 2019. 

m.wingenbach@oeko.de