Solar parks – ground-mounted or floating – offer clean ways of energy. But what about the carbon emissions produced while constructing these parks? BayWa r.e. and its Dutch partner, GroenLeven, took on the responsibility to reduce CO2 while constructing large-scale solar parks.
Our recently built Floating-PV parks in the Netherlands were all built with their own generated electricity. This means, the solar park is literally self-supplying its energy need during construction time. That is our vision for all our future solar construction sites – only using the energy that is produced by the park itself, already during construction time. Another key aspect of a carbon-free construction process is recycling. Recycling plays a key role in our assignment to create a better, cleaner environment and a circular economy.
This could be observed during the construction of our latest project, Bomhofsplas with 27.4 MWp – the largest Floating-PV park outside of China.
On this construction site, a 600 kWh battery storage system got its power from a 'satellite' solar park of 600 floating solar panels, which is a smaller, temporary solar park that is, in first instance, solely used during construction time. After completion of construction, this mini solar park was ‘recycled’ by simply adding it to the total floating solar park as a missing puzzle piece.
All tools and appliances as well as vehicles on the construction site were electric. The power that was stored in the battery was enough to charge all tools and construction site facilities during nighttime.
Beside electric tools, we also tested electrical forklift trucks from the company Sijperda on the construction site. In addition, the solar battery system was put to the test by using it for rather harsh loads, like electric heating. The workers’ containers were kept nice and warm and wet clothes were dried by electric heaters, powered by the solar battery system.
The battery storage system used at Bomhofsplas was loaned. Meanwhile, BayWa r.e. is investing in three own battery systems.
More options through hybrid solar charging methods
At another construction site, we realized a hybrid solar charging system: The batteries were charged directly DC via solar modules, and AC via connected solar inverters at the same time. By doing so, we proofed that our battery system has a black start capability: when the battery is drawn empty overnight, one would usually need a start-up help from another power source, such as a diesel generator or an external grid. But not in this case, DC charging via solar modules enabled the system to black start. Thanks to a sophisticated monitoring system, the battery could also be monitored and operated remotely, which allows immediate interaction in case of any problem occurring.
With these actions, we are already a step closer on our way toward carbon-free construction sites and on the road to a "zero emission" way of working at all our construction sites worldwide. During the construction of our Sekdoorn site for example, we saved more than 4,000 liters of diesel or more than 10 tons of CO2 emissions. In addition, approximately €10,000 worth of diesel and renting costs of the emergency generators were saved with this approach.
An ambitious vision we finally realized, despite the fact that it posed a large challenge before! Stay tuned for more information on this topic.