Sun2wheel and convoltas commercialize PV curtailment
Kriens/Küssnacht - Two Swiss companies, sun2wheel and convoltas, are making a business out of curtailing the output of photovoltaic (PV) installations during periods of surplus electricity generation by way of their Profit-Plus product. The compensation for this is far higher than the lost revenue from feeding solar energy into the grid.
The two companies sun2wheel AG from Kriens in the canton of Lucerne and convoltas AG from Küssnacht in the canton of Schwyz are showing that flexible PV systems can achieve many times the usual feed-in tariffs in the balancing energy market with a new marketing model. According to a statement published by sun2wheel, this move «opens a new chapter in the Swiss solar industry».
For this marketing model, which is being offered by convoltas under the name Profit-Plus, sun2wheel systematically bundles numerous PV systems throughout Switzerland into a large virtual power plant. To achieve this, the company, together with partners, has developed AI-based software that now also allows medium-sized systems to be integrated for marketing purposes. Swissanimate, an expert in the area of explanatory videos, has produced two short clips for the Profit-Plus model.
«When there is excess power in the grid, we curtail PV systems and turn it into a lucrative business model for system operators», comments Sandro Schopfer, CEO and co-founder of sun2wheel. In addition, plans are in place to open the solution also to small residential systems.
Since June 2025, the system has been operated as part of the PV4Balancing pilot project run by the national grid operator Swissgrid. Now, however, sun2wheel is the first provider that can offer PV systems outside of this pilot project.
While distribution network operators can curtail a plant by up to 3 percent per year without compensation to maintain grid stability, Profit Plus customers receive approximately 10 Swiss francs in additional compensation per installed kilowatt of capacity. To take a calculation example from 2024, this results in a net return of 4,725 Swiss francs for a plant with an output of 500 kilowatt peak and a total curtailment of 30 hours or 4,500 kilowatt hours per year.
«Given declining feed-in tariffs, our customers now earn more with flexibility than with pure grid feed-in», as Fabian Gloor, Sales Director at convoltas, explains in the statement. «So it’s not surprising that we already have more than 100 large-scale systems under contract».
