Velog News

Photovoltaic expansion: Fill it up, please - the roof, not the open spaces!

The expansion of photovoltaics continues to gain momentum, and that is good. But: Both in photovoltaics and in solar thermal energy, a new trend towards large ground-mounted systems has recently emerged in Austria. The old farmer's wisdom "plate - trough - tank" for the priorities in the use of valuable farmland this unfortunately seems to be forgotten at the moment - for the time being!

Photovoltaic open spaces - do we really need them?

The discussion sprouted this spring in Burgenland, Austria. If the red state government and the energy provider Energie Burgenland have their way,

new photovoltaic plants are to be built on an area of 1,300 hectares in 17 municipalities.

Much to the displeasure of the opposition there.

The Greens are critical of Energie Burgenland's expansion plans

. Among other things, they fear a massive encroachment on the landscape and accuse the energy provider of putting commercial interests above ecology. In any case, the Spatial Planning Act stipulates that PV plants are to be erected primarily on existing roof areas. The Greens have the support of the Austrian People's Party (ÖVP). The Turquoise Energy Spokesperson of Burgenland calls on the provincial government to "leave valuable farmland for food and to give priority to PV systems on public and private roofs".

The Upper Austrian Agriculture Provincial Councillor, also from the Austrian People's Party (ÖVP), takes a similarly objective view.

In contrast to Burgenland, however, his party is currently in government in the province above the Enns: "Domestic agriculture is committed to the energy transition and the expansion of photovoltaics, but this should not be at the expense of agricultural land". In a plea for the protection of the soil and against further sealing, it is also pointed out that in the course of climate change, a 19 percent reduction in agricultural yield capacity is to be expected throughout Austria by 2065. For food sovereignty, it would therefore have to be in one's own interest to keep agricultural land for food production and instead use "dead land" such as roofs or land that has already been built on for solar power generation. An opinion that, according to a survey, is also shared by 94 percent of the population. Moreover, Austria is currently the negative leader in Europe in terms of land consumption. Every day, an area the size of 20 football pitches is built in this country.

Expanding photovoltaics: maximising the use of roof space

As early as 2019, my-PV therefore called for all roof surfaces in new construction, especially commercial properties, to be inherently sized for use in solar power production and for building codes to be adapted accordingly. It is a sad fact that even lightweight photovoltaic modules are often too heavy to be installed on large roof areas.

Advocates of ground-mounted PV systems do point out that only 1 percent of the soil is sealed during construction if foundations are dispensed with. Nevertheless, from that moment on, the soil is no longer available as arable land and

concepts such as "agrophotovoltaics"

, which promise a dual use of the land, are currently still in the experimental stage.

Solar thermal open spaces - The last glimmer of hope for an outdated technology

Solar thermal energy still has a few spirits left in it. In residential buildings, photovoltaic heat generation has almost completely overtaken it in recent years due to drastically simplified system technology. Moreover, a technology-independent heat generation system is the basic prerequisite for so-called sector coupling. This is the only way to combine the energy sectors of electricity, heat and mobility in our homes, because it enables the transit of renewable energy from one sector to the other.

From a technical point of view, there is also the fact that photovoltaic modules, due to their significantly lower weight, are more in line with the static load-bearing capacity of roofs than heavy collectors and pipelines. In addition, the price of solar thermal energy has hardly changed for years. The reason for this is raw materials such as copper and aluminium, which are still used in large quantities in production. In contrast, there has been a veritable price crash in photovoltaics.

Kostenvergleich ENG

Photovoltaic expansion: significantly cheaper than solar thermal energy

It has now succeeded in becoming the most

cost-efficient energy source

of all. No other type of power plant can generate electricity so cheaply.

Large-scale systems are therefore being propagated as the last remaining field of application for solar thermal energy. But without life-support measures in the form of government subsidies, the technology is not financially viable even on this scale. Thus, at the beginning of May 2021, the Austrian Climate and Energy Fund launched a

45 million euro subsidy budget for systems with a collector area of 5,000 square metres or more


For more than ten years, since 2010, attempts have been made to help large-scale thermal systems achieve a breakthrough in this country. For smaller systems, however, there have been subsidy programmes at the federal and state levels for much longer. This is why these subsidies have been called "zombie subsidies", because if a technology does not show any further development despite financial support, i.e. it has to be subsidised forever, one can basically stop right there.

Even the Indians were wise enough to dismount when they realised that the horse they wanted to ride was already dead, and in times of billion-dollar Corona aid packages, taxpayers' money would probably be less wasted elsewhere.

It has now succeeded in becoming the most cost-efficient energy source of all. No other type of power plant can generate electricity so cheaply.

But why this wrong focus on open spaces in the expansion of photovoltaics?

In the Photovoltaic Industry Association "PV-Austria", 6 out of 12 board members are now either directly employed by an energy supplier, are former managers, work for a subsidiary of an energy supplier or their own company has a stake in one. The direction of travel in the sector is thus set. It is a matter of preserving one's own monopoly position and keeping consumers dependent.

But it is not only electricity providers who have recognised the opportunities offered by

free-field photovoltaics for their own market domination

. With the approaching end of the fossil fuel era, mineral oil companies have also set their sights on a new business field here. For example, solar power is to be used to produce "green" hydrogen. In this case, too, consumers would remain dependent on a central supply system.

Because if our energy continues to come from central power plants in the future, then the restructuring of the supply system can perhaps be delayed a little longer. Fortunately, it cannot be prevented!

Where the journey will go instead

Only a few would profit from building on the ground, but at the expense of society as a whole. At the same time, Austria's roofs have a huge potential for photovoltaics, most of which is completely untapped. In Burgenland there is agreement on this between the Greens and the ÖVP.

The Turks also have the support of their party colleagues in Upper and Lower Austria.

In order to counter climate change, the switch to renewables must be made.

But this must not be at the expense of domestic soils, our own sovereignty in food supply or ecology as a whole.

Currently, there is a little more than 2 GWp of photovoltaic capacity installed in Austria. To reach the expansion target of 15 GWp in 2030, more than a sevenfold increase is needed. 10,000 hectares are needed for this. According to an EU study, however, we have about 15,000 hectares of roof space available for photovoltaics in Austria, primarily on private roofs.

This spares precious farmland and shifts the market power of the energy suppliers to the consumers, who will then be "prosumers" but also energy producers at the same time. Hermann Scheer, one of the authors of the Renewable Energy Sources Act in Germany, once put it this way in the

documentary film

"The 4th Revolution": "We are facing the greatest structural change in the economy since the beginning of the industrial age. [...] Instead of a few owners, we suddenly have hundreds of thousands or even millions of owners. Energy supply is getting democratised."

More articles


Next Step from my-PV: The DC Power Manager SOL•THOR for Photovoltaic Heating

On June 13, in front of over 1,100 participants, we unveiled our Next Step: a DC Power Manager called SOL•THOR.



my-PV at the InstallerSHOW 2024 in the UK

my-PV is participating for the first time at InstallerSHOW 2024 in Birmingham.



my-PV Device Trio Enables 98% Self-Consumption of PV Energy

By integrating an AC ELWA 2 and two AC ELWA-E devices, a homeowner in Estonia achieved a self-consumption rate of 98%.