Trackers in solar parks: what single-axis tracking adds in electricity and revenue and what it may cost

A fixed solar array faces the same direction all day, usually south. A tracker turns the module rows with the sun: towards the east in the morning, flat at midday, towards the west in the evening. That sounds like simple arithmetic: more light, more electricity. For investors the question is a different one. What is the extra electricity worth on the market, and is it enough to pay for mechanics, motors and maintenance over 25 years?

The question has become a practical one. Tracking systems were long a niche in Germany because fixed racks were cheaper and the extra yield disappeared into the midday surplus. Now that solar power is worth less and less at midday and new plants receive no money at all at negative prices, the calculation is shifting. Trackers now show up in offer documents, above all in agrivoltaics.

What does a tracker do in a solar park?

A tracker is a mounting structure that turns the modules to follow the sun. In solar parks the term almost always means a single-axis tracker: the module rows sit on an axis running north to south, and a motor turns them from east to west over the day, controlled by the calculated position of the sun. Dual-axis trackers also follow the sun's elevation; they yield more per module but need a lot of spacing and are rare in large parks.

Two functions are standard today. With so-called backtracking, the rows deliberately turn flatter than the sun in the morning and evening so that they do not shade each other. In a storm the system moves into a safety position, usually flat, to reduce wind load. Both cost some yield, and both only work as long as drives, controls and sensors are running.

For the investor this changes the nature of the asset. A fixed ground-mounted array has hardly any moving parts apart from its inverters. A tracker park has hundreds of drives, gearboxes and controllers that work outdoors for 25 years. More yield and more technology come together.

How much more electricity does a tracker produce in Germany?

Around a fifth more than a fixed south-facing array, slightly more in the north and slightly less in the south. We used PVGIS, the European Commission's tool, to calculate hourly generation profiles for three locations: Kiel, a point in central Germany and Munich. Each was modelled as a fixed south-facing array tilted at 25 degrees, an east-west array at 15 degrees and a single-axis tracker with a north-south axis. The weather year is 2023 and system losses are set at 14 percent.

The north gains more because of its long summer days. In June the sun rises far in the north-east in Kiel and sets far in the north-west. A fixed south-facing array sees it from the side or even from behind in those hours; a tracker turns towards it. The north thereby makes up part of the gap described in Is a solar park in northern Germany worth it? Location, yield and the price per kilowatt-hour but does not catch up with the south. In our calculation a tracker in Kiel produces slightly more electricity than a fixed south-facing array in Munich, but 9 percent less than a tracker there.

An east-west array sits at the other end: it produces 13 percent less per kilowatt-peak than the south-facing array but fits considerably more capacity onto the same hectare. A tracker, by contrast, tends to need more land than a fixed south-facing rack, because the rows must not shade each other as they turn. Anyone comparing designs should therefore always look at capacity per hectare and price per kilowatt-hour, not just yield per kilowatt-peak.

Our figures are an upper bound. PVGIS models neither mutual shading between rows nor backtracking nor downtime in storms or after defects. In practice the extra yield is therefore a few percentage points lower. Fraunhofer ISE puts the extra yield of single- or dual-axis tracking at 15 to 30 percent; our figures sit in the lower part of that range. A yield assessment for a specific park should calculate the extra yield with row spacing, backtracking and availability, as Reading a yield assessment: what P50 and P90 mean for a solar park direct investment explains.

Why is a tracker's electricity worth more than that of a fixed array?

Because it is produced at different times of day. A tracker's extra yield does not come from the midday sun but from the morning and evening hours. In our calculation for central Germany, 55 percent of the extra yield arrives before 10 a.m. and 63 percent from 4 p.m. onwards. Between 10 a.m. and 4 p.m. the tracker actually produces less than the fixed array, because it lies almost flat while the south-facing array at 25 degrees faces the midday sun ideally. The share of output between 11 a.m. and 2 p.m. falls from 50 to 38 percent.

This shift is exactly what the market pays for. At midday, Germany's entire solar fleet pushes prices down, on sunny days often below zero. In the morning and evening electricity is scarcer and more expensive. How strongly this effect depresses the value of solar power is described in Solar market value: why solar power is worth less and less on the exchange. On top of that comes § 51 EEG: in hours with a negative price a new plant receives no market premium and is usually curtailed. A tracker produces a smaller share of its electricity in precisely those hours.

So 20 percent more electricity turns into 31 percent more revenue in 2023, 38 percent in 2024 and 41 percent in 2025. The gap widens with every year in which more solar capacity is connected and midday prices fall further. In Kiel the revenue advantage in 2025 was 50 percent, in Munich 34 percent. The market premium plays almost no role here: the annual market value for solar was only just below the award value of 4.79 cents per kilowatt-hour in 2024 and 2025, so the premium amounted to fractions of a cent. The difference comes almost entirely from the market price in each hour. The EWI analysis from January 2026 points the same way for 2024: 29 percent more yield and 43 percent more market revenue for a park in Brandenburg, though with generation profiles supplied by the commissioning manufacturer.

One limitation applies here too: we lay the weather of one year over the prices of another. That shows how the generation profiles perform on the market, not what a particular park would have earned in a particular year. It is enough to show the direction, not to value a project.

How much more may a tracker cost?

As much as the extra revenue is worth over the lifetime, minus the higher operating cost. We discounted the extra revenue over the fixed south-facing array over 25 years at 5 percent. Because PVGIS flatters the tracker, we deduct 3 percent from its yield. For additional maintenance, spare parts and insurance we assume 4 euros per kilowatt-peak per year. Both are our own assumptions; a project should document its own values.

Across all three price years, all locations and haircuts between 0 and 5 percent, the supportable premium lies between 228 and 366 euros per kilowatt-peak without extra operating cost and between 171 and 310 euros with 4 euros per kilowatt-peak per year. That is the figure a tracker project has to be measured against. If the premium over a comparable fixed park is lower, the investor earns from the tracking. If it is higher, the extra yield is bought too dearly.

What a tracker actually costs extra in Germany is poorly documented; we found no European primary source with figures. The cost study of the US National Renewable Energy Laboratory assumes 6 US cents per watt more for a 100 megawatt park with single-axis tracking than with fixed racking, a little over 7 percent of system cost, and around 10 percent more for operation and maintenance. The analysis by the Institute of Energy Economics at the University of Cologne (EWI), commissioned by a tracker manufacturer, assumes 380 instead of 365 euros per kilowatt of investment, 1 euro more maintenance and 1.30 euros more land lease per kilowatt per year; the cost data there come from the manufacturer. Both premiums are far below the supportable premium from our calculation, and our assumption for extra operating cost is above both. That explains why trackers are standard elsewhere: in the US, according to Lawrence Berkeley National Laboratory, 96 percent of new solar capacity in 2025 ran on trackers, and the cost premium there has fluctuated over the years and at times even reversed. In Germany, wind and snow loads, smaller parks and high agrivoltaic mounting can raise the premium considerably. Ask for the premium of the specific project rather than calculating with figures from other markets.

For tax purposes tracking does not change the basic principle. A higher purchase price increases the acquisition cost and with it the base for depreciation and the investment deduction, as The Investitionsabzugsbetrag explained simply: how the IAB works shows. That is no reason to pay more: the tax effect shifts payments in time, the premium has to be earned through electricity revenue.

What can go wrong with a tracker in operation?

Mainly what a fixed array does not have: moving parts. Five points matter to investors.

• Drives and controls: motors, gearboxes, bearings and controllers fail, usually one at a time. A row stuck in the flat position keeps producing electricity but loses the extra yield. What counts is the availability guarantee, the response time of the maintenance provider and a spare-parts stock.
• Wind and storms: in strong wind the system moves into its safety position. That costs yield and requires the wind measurement and drives to work. Whether the structure is designed for the wind zone of the site belongs in the technical review.
• Snow and hail: snow and hail also require a suitable module position. That only works with weather forecasts or sensors that trigger in time.
• Terrain: single-axis trackers tolerate only limited slope in the north-south direction. On uneven land, earthworks and costs rise.
• Manufacturer and lifetime: a tracker is a specialist product with its own control software. If the manufacturer fails, spare parts and updates become difficult. How long the warranties on drives and controls run is set out in the supply contract and should match the operating life of the park.

None of these points speaks against trackers. But they belong in the calculation: as a haircut on yield, as operating cost and as a question for the provider. How the other components age is described in Module degradation and inverter replacement: what ages in a solar park and what it means for returns.

Does a tracker lose more electricity at the planned 70 percent cap?

No, rather less. Under the government draft of Germany's grid package, new ground-mounted plants from 2027 would be allowed to feed in at most 70 percent of their module capacity. One might expect a tracker with its higher yield to hit that limit more often. The opposite is true: its output is spread more widely across the day, and its strongest hour in our profile is 0.80 kilowatts per kilowatt-peak, against 0.85 for the south-facing array.

At a 70 percent cap the fixed south-facing array in central Germany loses around 1.0 percent of its yield, the tracker 0.7 percent. In revenue terms both lose less than 1 percent, because the clipped midday hours are the cheapest ones. The tracker's revenue advantage stays practically unchanged. The mechanics and the legal position of the feed-in cap are explained in Overbuilding the grid connection: what more module capacity than connection capacity means for yield and investors; the 70 percent cap has not yet been adopted.

Why are trackers so common in agrivoltaics?

Because they solve two agrivoltaic problems at once. The module rows are spaced far apart anyway so that machinery can drive between them; the larger row spacing a tracker needs costs hardly any additional land there. And the rotation can be used for the crops too: in heat or hail the modules can provide shade or protection, and at harvest they can stand vertically. What this looks like in fruit growing is described in Agrivoltaics over orchards from an investor's perspective: support, cost per hectare and what the trial plants show.

Tracking has nothing to do with remuneration. The bonus of 0.5 cents per kilowatt-hour that agrivoltaic plants with an award from 2026 can currently receive applies only to high-mounted installations with at least 2.10 metres of clearance; whether the modules turn plays no role. A tracking park between crop rows is therefore an ordinary agrivoltaic plant as far as remuneration is concerned. The design types are set out in Investing in agrivoltaics: dual land use, revenues and tax leverage at a glance.

Which questions should investors ask about a tracker project?

• What extra yield over a fixed array does the yield assessment show? Is it calculated with row spacing, backtracking, wind stow and availability?
• What tracker availability does the assessment assume? Who guarantees it and what happens if it is not met?
• How high is the premium per kilowatt-peak over a comparable fixed park? Is it below the present value of the extra revenue?
• Does the revenue model calculate the extra yield with hourly prices and with the loss in hours with negative prices? Or only with an average price?
• Which maintenance costs are assumed for the tracker? Is there a maintenance contract with response times and a spare-parts stock?
• How long do the warranties on drives, controls and structure run? What applies if the manufacturer fails?
• Which wind zone and snow load is the structure designed for? How and when does the system move into its safety position?
• Does the insurance cover storm damage to the mechanics and the loss of revenue during a repair?

General checks that apply to any provider are listed in How to tell a trustworthy provider of energy direct investments.

How we check tracker projects

Several of the parks we currently present to investors are agrivoltaic plants with single-axis trackers. For each of them we recalculate the extra yield with our own hourly model against a fixed south-facing array at the same site and compare it with the yield assessment. If the assessment is clearly higher, we ask for the assumptions on backtracking, availability and row spacing. We calculate revenue with hourly prices and without feed-in during negative hours. We set the premium for tracking against the present value of the extra revenue, including the maintenance costs and the warranty periods from the contracts.

We do not promise returns. We show which figure rests on which assumption. What a solar park as a direct investment involves overall is set out in Investing in solar parks: revenues, costs and tax leverage at a glance. That is exactly what we check with you in a free initial consultation, ideally using a specific offer document.