Key takeaways:
Huasun highlighted that falling midday electricity prices in mature solar markets are weakening revenues for conventional south-facing PV systems
System topology strongly affects both generation profiles and revenues, with vertical and tracker systems better aligned to higher-price hours
Vertical PV and trackers deliver higher net returns than fixed-tilt layouts, while batteries add limited incremental benefit
Electricity prices in the market, especially during the peak hours when a conventional solar system (fixed-tilt south) generates maximum energy, have been falling over the years. There are examples of Spain and California recording almost zero price for hours during the day.
In his presentation at the TaiyangNews Advanced Solar Module Applications 2025, Christian Comes from Huasun shared a practical comparison of different PV plant topologies, focusing on how system design affects the profitability of PV plant. His message was that developers need new topologies, such as vertical PV or PV with trackers, to protect project revenues against the low mid-day power prices.
Comes began by showing how mature markets such as California and Germany are already experiencing deep price drops during the central hours of the day, driven by high solar generation. In these markets, maximum solar electricity is often produced exactly when prices are lowest. This creates a mismatch between generation profiles and revenue potential, particularly for conventional fixed-tilt, south-facing systems. This trend makes it harder to justify investments as future spot prices pose a risk of falling below the project’s levelized cost of electricity (LCOE), especially for projects that sell in the free market (without feed-in tariffs).
To address this, Christian compared 4 different PV topologies: south-facing fixed tilt, single-axis trackers, east-west ‘dome’ layouts, and vertical PV with Huasun’s Kunlun HJT module. He evaluated each topology both with and without battery storage, using utility-scale simulations with identical system sizes and realistic assumptions for CapEx, OpEx, and energy yield.
The results indicate that fixed-tilt systems have the lowest upfront cost, closely followed by dome layouts. Trackers and vertical PV showed higher CapEx, with vertical systems currently being more expensive, mainly due to mounting structures and, to some extent, the use of Huasun’s heterojunction modules. Batteries were modeled separately using an aggressive all-inclusive cost assumption of around €140/kWh. The batteries were considered to be half the size of the installed DC, in kWh, to allow roughly 300 cycles per year, ensuring they were not underutilized.
On the operating side, Comes assigned higher OpEx to both trackers and vertical PV. For vertical systems, this was largely due to increased land requirements rather than cleaning or maintenance. Batteries added another layer of operating costs, including inspections, safety systems, and ongoing servicing, for which long-term data is still limited.
In terms of energy yield, simulations for the Munich region in Germany showed that trackers delivered roughly 20% more than fixed-tilt systems, which themselves produced 10-12% more than dome systems. Vertical PV, using Huasun’s 95% bifaciality HJT modules, showed surprisingly strong results. With a row spacing of about 11 meters, vertical installations in the simulation produced more energy than south-facing systems, owing to strong morning and evening generation and substantial rear-side contribution.
But yield alone was not the main point. Comes shifted the focus to when energy is produced and how that aligns with electricity prices. Vertical PV generates 2 distinct peaks, one in the morning and one in the late afternoon, precisely when market prices tend to be higher. In contrast, south-facing systems concentrate production around midday, when prices are increasingly depressed. This time-shifted generation profile is what gives vertical PV its financial advantage. He illustrated this with hourly revenue curves, showing that vertical systems generate significantly higher revenue in the morning and evening than south-facing plants, and less during midday. Importantly, those midday hours are exactly where future price erosion is expected to be strongest. Batteries do help shift some energy into evening hours, improving revenue by roughly 13-15%, but much of that gain is offset by higher CapEx and OpEx.
When all costs and revenues were combined, Comes showed that trackers and vertical PV deliver similar profitability, both clearly outperforming fixed-tilt and dome systems. Battery-equipped systems improved income, but the additional investment and operating expenses reduced the overall advantage, particularly for south-facing plants, where adding batteries barely improved returns.
To make this tangible, he translated the results into annual net returns before taxes as a percentage of total investment. Vertical PV and trackers emerged as the most attractive options, returning approximately 13% of invested capital per year, compared with around 11% for fixed-tilt. Adding batteries increased gross income but did not always improve net profitability.
Beyond the numbers, Comes highlighted risk considerations. Vertical PV is a fixed, well-understood PV configuration. Trackers introduce mechanical failure risk, while batteries add a new layer of technological and safety complexity. From his perspective, vertical PV offers a simpler way to hedge against low midday electricity prices without taking on the operational uncertainty associated with storage or moving structures.
Comes also addressed land-use concerns. While vertical PV requires wider spacing, roughly doubling the land area compared to dense south-facing installations, the actual impact on project OpEx is around 10%. More importantly, vertical systems allow genuine dual land use. He cited examples where agricultural machinery operates normally between vertical rows, enabling real agri-PV rather than symbolic grazing arrangements often seen under conventional arrays.
In closing, Comes summarized that vertical PV already provides better protection against spot-market price volatility than batteries in high-solar markets today. While installation costs are slightly higher, the revenue profile aligns much better with future electricity pricing trends. For developers concerned about declining midday prices, vertical PV offers a compelling alternative that combines predictable technology with improved financial resilience.
You can access Christian Comes’ full presentation titled, Vertical PV and Batteries – Maximizing the Market Value of PV in the Next Decade, here.