Plug-in solar yield 2026: what 900 Wp deliver per year and month
Upright on a south-facing railing, 900 Wp produce 656 kWh a year on the German average, or 949 kWh tilted at 35°. In June that is 82 kWh, in December only 17 kWh.
Checked by Radif Partners · Editorial policy · How we calculate
Your balcony system’s output per year and month
Output per year (German average)
656 kWh
| best month: June | 82 kWh |
| December | 17 kWh |
| April to September | 459 kWh |
The yield (Ertrag) of a German balcony power plant depends on three things: panel output, mounting angle and location. A 900 Wp kit hung upright facing south on the railing produces 656 kWh a year on the German average, about 1.8 kWh a day. The same panels tilted at 35° deliver 949 kWh. Yield is very unevenly spread over the year: April to September brings 459 kWh, or 70 % of the year, December only 17 kWh. There is a clear north-south gradient. Upright facing south, a 900 Wp device reaches 635 kWh in Flensburg, 680 kWh in Berlin and 727 kWh in Munich, 14 % more than on the Baltic coast. The values come from the European Commission's PVGIS for each postcode, with 14 per cent system losses and the terrain horizon, converted by this site's engine.
Annual yield: the three levers
The panels' rated output sets how much area catches light. The mounting angle decides how much of it strikes squarely. And the location determines how much sun arrives at all. The data come from PVGIS, the irradiation service of the European Commission's Joint Research Centre, queried through its non-interactive interface for every grid point in Germany. Each postcode is assigned a point via the municipality register. Yield is stated after 14 per cent system losses, meaning what comes out of the socket.
Month by month on the German average
| Month | 900 Wp upright | 900 Wp, 35° tilt |
|---|---|---|
| January | 20 kWh | 30 kWh |
| February | 34 kWh | 49 kWh |
| March | 59 kWh | 85 kWh |
| April | 76 kWh | 110 kWh |
| May | 80 kWh | 116 kWh |
| June | 82 kWh | 118 kWh |
| July | 82 kWh | 118 kWh |
| August | 75 kWh | 109 kWh |
| September | 64 kWh | 93 kWh |
| October | 44 kWh | 63 kWh |
| November | 23 kWh | 34 kWh |
| December | 17 kWh | 25 kWh |
The curve is a flat bell peaking in June. The six months from April to September deliver 70 % of annual yield. In December, the weakest month, it is 17 kWh, a fraction of June. For a specific month and a different panel output, set both in the mini calculator above.
From the Baltic coast to the edge of the Alps
| City | upright | 35° tilt | June | December |
|---|---|---|---|---|
| Flensburg | 635 kWh | 871 kWh | 85 kWh | 12 kWh |
| Hamburg | 633 kWh | 877 kWh | 83 kWh | 14 kWh |
| Berlin | 680 kWh | 941 kWh | 85 kWh | 19 kWh |
| Köln | 674 kWh | 932 kWh | 83 kWh | 19 kWh |
| Dresden | 687 kWh | 962 kWh | 83 kWh | 21 kWh |
| Frankfurt am Main | 670 kWh | 969 kWh | 83 kWh | 17 kWh |
| Stuttgart | 709 kWh | 1,009 kWh | 85 kWh | 21 kWh |
| Freiburg im Breisgau | 712 kWh | 1,004 kWh | 83 kWh | 25 kWh |
| München | 727 kWh | 1,016 kWh | 83 kWh | 27 kWh |
The gradient runs roughly north to south, but not evenly. Berlin and Dresden, though further north, come close to Frankfurt, because the continental climate in the east brings more clear days than the maritime one in the west. Cologne on the Lower Rhine sits a little below. Munich has the highest value in the list at 727 kWh upright, Flensburg the lowest at 635 kWh. There are detailed pages for Berlin and Munich; any other postcode is covered by yield by postcode.
Upright or tilted: what the angle does
On the German average the same kit yields 949 kWh at 35° and 656 kWh upright, 31 % less. The loss arises almost entirely in summer, when the sun stands high at midday. In December the two are close, 17 against 25 kWh. The angle, together with direction, is covered in more detail in the guide on orientation.
Yield per kWp: the number for comparisons
Offers and data sheets often state the specific yield in kilowatt-hours per kilowatt peak. For a balcony kit it is 729 kWh per kWp upright facing south on the German average, and 1,054 kWh per kWp at a 35° tilt. Rooftop systems are usually advertised with the second value; a railing gets the first. When comparing figures found online, check first which angle they refer to. Above about 1,000 Wp of panels the value per kWp falls further, because the 800 VA inverter clips on bright middays.
Why no two years are alike
The values on this page are long-term averages from satellite data. A single year can come in above or below, depending on how sunny spring and summer turn out. A rainy July weighs more than a dull January, because July produces many times as much. If you read your own yield on the inverter or a metering plug, compare whole years, not single weeks. If your result stays well below the table, shade is almost always the reason: a roof overhang, the balcony above or a tree in full summer leaf.
Produced is not saved
Yield is what the device delivers. You only save what the household uses at the same moment. Of the 656 kWh in the example, a household using 2,500 kWh a year consumes 420 kWh itself, based on the metered load profiles from HTW Berlin. Higher yield in the south therefore does not translate one to one into a higher saving: in Munich it is 444 kWh, in Flensburg 412 kWh. What that means in euros and years is worked out under is plug-in solar worth it?.