[{"data":1,"prerenderedAt":366},["ShallowReactive",2],{"example-monthly-yield-en":3,"faq-monthly-yield-en":136,"sources-monthly-yield-en":161,"location-compare-52.52,13.405":167,"city-yield-table":222},{"input":4,"output":10},{"location":5,"systemKwp":6,"tiltDeg":7,"azimuthDeg":8,"mounting":9},"52.52,13.405",8,35,0,"roof",{"monthlyKwh":11,"annualKwh":24,"specificYieldKwhPerKwp":25,"computedPerformanceRatio":26,"monthlyKwhSimple":27,"annualKwhSimple":40,"stageDifferencePercent":41,"p50MonthlyKwh":42,"p90MonthlyKwh":55,"p50AnnualKwh":68,"p90AnnualKwh":69,"monthlyPoaKwhM2":70,"bestMonthIndex":83,"bestMonthKwh":17,"worstMonthIndex":84,"worstMonthKwh":23,"bestToWorstRatio":85,"winterSharePercent":86,"mountingPenaltyPercent":87,"horizonApplied":88,"calibrationFactorAnnual":89,"steps":90,"warnings":115},[12,13,14,15,16,17,18,19,20,21,22,23],225.36486631642398,400.4913503349443,667.9156669402167,913.9775585801254,1025.4464418018754,1041.2469987872712,974.2150268832627,922.2974311661474,776.4539079918882,524.396907177155,282.4914378978374,204.34805807666854,7958.645651953817,994.8307064942271,0.7606679009273364,[28,29,30,31,32,33,34,35,36,37,38,39],228.34526315789472,394.7957894736843,681.6336842105263,953.7616842105263,1069.1671578947369,1097.8694736842106,1075.0416842105265,1005.2277894736843,826.4892631578947,544.6905263157895,288.05052631578945,205.09305263157896,8370.165894736843,5.170732066479178,[43,44,45,46,47,48,49,50,51,52,53,54],209.58034964331026,359.93478843805025,629.0639407317107,898.1833725214827,1040.1331064031667,1021.082082834934,941.1259100915843,929.8321419570042,762.6915058226347,530.8178952493281,281.75147318884933,198.06192289547056,[56,57,58,59,60,61,62,63,64,65,66,67],189.8224432634346,264.4326106255733,508.1803147567884,743.2137756838398,868.8257311685867,954.3129536518151,846.8683252588461,799.5205859462066,638.4001474594853,374.04330991300884,208.16594697664013,160.1202473890942,7928.8447558520575,7332.911935520004,[71,72,73,74,75,76,77,78,79,80,81,82],35.67894736842105,61.68684210526317,106.50526315789473,149.02526315789473,167.05736842105264,171.5421052631579,167.97526315789474,157.06684210526316,129.13894736842104,85.10789473684211,45.0078947368421,32.04578947368421,5,11,5.095458251903769,10.43147679937509,3.4648981644467614,true,0.9218157139195722,[91,97,100,104,108,111],{"label":92,"expression":93,"value":94,"unit":95,"provenance":96},"tmyEnergySimulation","Σ_8760h P_STC · G_POA\u002F1000 · η_rel(Huld) · η_sys, T_m Faiman(roof)",8633.66238151176,"kWh","measured",{"label":98,"expression":99,"value":24,"unit":95,"provenance":96},"climateCalibration","E_m × mean(2005–2023)\u002FTMY @ 35° S (× 0.922)",{"label":101,"expression":102,"value":26,"unit":103,"provenance":96},"computedPr","PR = E_a \u002F (P_STC · H_POA,a)","",{"label":105,"expression":106,"value":40,"unit":95,"provenance":107},"stage2Comparison","E_m = P_kWp · PSH_m · d_m · PR(0.80)","assumed",{"label":109,"expression":110,"value":69,"unit":95,"provenance":96},"exceedanceBands","P50\u002FP90(n = 19, ref 35°)",{"label":112,"expression":113,"value":86,"unit":114,"provenance":96},"winterShare","Σ(Dez..Feb) \u002F E_a","%",[116,124,130],{"level":117,"code":118,"params":119,"anchors":122},"warning","MOUNTING_HEAT_PENALTY",{"delta":120,"loss":121},12.9,3.5,[123],"mounting",{"level":117,"code":125,"params":126,"anchors":128},"SNOW_NOT_MODELLED",{"months":127},"1",[129],"tiltDeg",{"level":131,"code":132,"params":133,"anchors":135},"info","WINTER_SUMMER_RATIO_EXTREME",{"ratio":134},5.1,[129],[137,140,143,146,149,152,155,158],{"q":138,"a":139},"How many kWh per kWp is normal — and what does a 10 kW system produce?","For the DACH region, guides quote 900–1,100 kWh per kWp per year; computed site by site (roof mount, 35° south) the German cities in the table below span roughly 950 (Hamburg) to 1,100 kWh\u002FkWp (Munich), with Alpine and western Swiss sites up to ~1,200. A 10 kWp system therefore delivers around 10,000 kWh per year on a good south roof — but only some 200–450 kWh of that in December (about 2–4% of the annual total; winter as a whole contributes 10–15%). If a heat pump or EV must run through winter, plan with the December figure and the P90 band, not the annual average.",{"q":141,"a":142},"How much does a solar system deliver in December?","In Berlin at 35° tilt, about one fifth of the June value: an 8 kWp roof system delivers a good 1,000 kWh in June and just over 200 kWh in December. That is exactly why this calculator computes every month individually instead of dividing the annual yield by twelve — the annual average exists in no real month, and off-grid systems are sized for December, not for the mean.",{"q":144,"a":145},"What sets this calculator apart from the usual rule of thumb?","The usual calculation is sun hours × system size × performance ratio — one flat factor for all losses. This calculator instead simulates each of the 8,760 hours with the PVGIS power chain: module temperature from air temperature, wind and irradiance (Faiman), the cell's low-light behaviour (Huld) and reflection loss at shallow incidence (Martin & Ruiz). The rule of thumb still runs as a comparison line — the 3–8% annual difference is itself an insight.",{"q":147,"a":148},"When is the rule of thumb most wrong?","Measured against the hourly model: in summer. A fixed performance ratio ignores that modules work worse in the heat — in June it overestimates Berlin's yield by around 8%. In December the errors nearly cancel: the missing temperature penalty offsets the low-light and reflection losses. The common belief that the simple formula fails mainly in the dull winter is not confirmed by the simulation.",{"q":150,"a":151},"What does the roof vs. free-standing distinction buy me?","A real 3–4% of annual yield — 3.4% measured in Berlin, identical to PVGIS's own calculation. A roof-mounted or integrated module runs about 13 Kelvin hotter in full sun than a ventilated one, because the back sheds hardly any heat. Almost no free calculator asks about mounting; here it is a visible input.",{"q":153,"a":154},"What does the P90 annual yield mean?","Your system reaches that value in 9 out of 10 years — computed from the 19 real weather years (2005–2023) in the dataset, scaled to your configuration. For sizing and financing, P90 is the conservative, dependable number; the mean (P50) is missed every other year.",{"q":156,"a":157},"Where do the numbers come from, and how accurate are they?","From the committed TMY hourly grid (PVGIS-SARAH3, 2005–2023, 1,155 grid points across the DACH region) with terrain horizon, calibrated to the multi-year mean. Cross-validated against PVGIS PVcalc at four reference sites, per month and for both mounting types: annual total within 1.7%, individual months within 6%. The remainder is explained — PVcalc adds a spectral correction whose underlying data is not freely available; our numbers are therefore deliberately slightly conservative.",{"q":159,"a":160},"Does this calculator work outside Germany, Austria and Switzerland?","Not yet. The hourly grid currently covers the DACH region (1,155 grid points at 0.25°). For other regions the official tools are the best choice: NREL PVWatts for the United States, or PVGIS by the European Commission (worldwide except polar regions) — this calculator is cross-validated against PVGIS. A US grid built on NSRDB hourly data is in preparation, with the same monthly resolution and P50\u002FP90 bands.",[162],{"name":163,"url":164,"retrievedAt":165,"version":166},"JRC Photovoltaic Geographical Information System (PVGIS), European Commission — endpoints tmy, MRcalc, printhorizon","https:\u002F\u002Fre.jrc.ec.europa.eu\u002Fpvg_tools\u002F","2026-07-30","PVGIS API v5_3, solar radiation database PVGIS-SARAH3",[168,175,181,187,193,198,204,210,216],{"name":169,"slug":170,"distanceKm":171,"annualPsh":172,"p90KwhM2":173,"bestTiltDeg":174},"Berlin","de-berlin",1,3.5831189617880312,1207.886,40,{"name":176,"slug":177,"distanceKm":178,"annualPsh":179,"p90KwhM2":180,"bestTiltDeg":174},"Oranienburg","de-oranienburg",19,3.503000720980533,1193.894,{"name":182,"slug":183,"distanceKm":184,"annualPsh":185,"p90KwhM2":186,"bestTiltDeg":7},"Blankenfelde-Mahlow","de-blankenfelde-mahlow",20,3.5798803172314346,1197.9479999999999,{"name":188,"slug":189,"distanceKm":190,"annualPsh":191,"p90KwhM2":192,"bestTiltDeg":174},"Potsdam","de-potsdam",22,3.5934405191059837,1215.032,{"name":194,"slug":195,"distanceKm":190,"annualPsh":196,"p90KwhM2":197,"bestTiltDeg":7},"Bernau","de-bernau",3.520992069214132,1209.374,{"name":199,"slug":200,"distanceKm":201,"annualPsh":202,"p90KwhM2":203,"bestTiltDeg":174},"Ludwigsfelde","de-ludwigsfelde",26,3.642096611391492,1218.8539999999998,{"name":205,"slug":206,"distanceKm":207,"annualPsh":208,"p90KwhM2":209,"bestTiltDeg":174},"Königs Wusterhausen","de-koenigs-wusterhausen",29,3.569196827685653,1203.042,{"name":211,"slug":212,"distanceKm":213,"annualPsh":214,"p90KwhM2":215,"bestTiltDeg":174},"Strausberg","de-strausberg",33,3.62602451333814,1231.65,{"name":217,"slug":218,"distanceKm":219,"annualPsh":220,"p90KwhM2":221,"bestTiltDeg":174},"Eberswalde","de-eberswalde",45,3.5717015140591206,1227.4499999999998,[223,228,236,244,252,260,268,276,284,292,300,309,317,325,333,342,350,358],{"name":169,"slug":170,"country":224,"annualKwhPerKwp":25,"p90KwhPerKwp":225,"decemberKwhPerKwp":226,"bestMonthKwhPerKwp":227,"winterSharePercent":86},"DE",916.6139919400005,25.543507259583567,130.1558748484089,{"name":229,"slug":230,"country":224,"annualKwhPerKwp":231,"p90KwhPerKwp":232,"decemberKwhPerKwp":233,"bestMonthKwhPerKwp":234,"winterSharePercent":235},"Hamburg","de-hamburg",948.6832354051097,895.4567797393421,21.498275065355873,123.1154698520814,9.525955497297454,{"name":237,"slug":238,"country":224,"annualKwhPerKwp":239,"p90KwhPerKwp":240,"decemberKwhPerKwp":241,"bestMonthKwhPerKwp":242,"winterSharePercent":243},"München","de-muenchen",1090.9503197612748,1020.4684832969659,45.40840902319309,126.81709520164402,14.403227823972834,{"name":245,"slug":246,"country":224,"annualKwhPerKwp":247,"p90KwhPerKwp":248,"decemberKwhPerKwp":249,"bestMonthKwhPerKwp":250,"winterSharePercent":251},"Köln","de-koeln",970.7383370829548,920.13680954691,27.28083192797524,118.89639711484047,11.579021591931328,{"name":253,"slug":254,"country":224,"annualKwhPerKwp":255,"p90KwhPerKwp":256,"decemberKwhPerKwp":257,"bestMonthKwhPerKwp":258,"winterSharePercent":259},"Frankfurt am Main","de-frankfurt-am-main",1040.3126528753542,969.6535873791918,28.47431026020612,129.2546940055206,11.49122751353489,{"name":261,"slug":262,"country":224,"annualKwhPerKwp":263,"p90KwhPerKwp":264,"decemberKwhPerKwp":265,"bestMonthKwhPerKwp":266,"winterSharePercent":267},"Düsseldorf","de-duesseldorf",987.397317140589,934.1194501035031,28.0020661851064,121.81626878903856,11.366206836657657,{"name":269,"slug":270,"country":224,"annualKwhPerKwp":271,"p90KwhPerKwp":272,"decemberKwhPerKwp":273,"bestMonthKwhPerKwp":274,"winterSharePercent":275},"Stuttgart","de-stuttgart",1062.7822908203043,991.9299241405461,35.475721310510046,128.5702696500368,12.520471403693435,{"name":277,"slug":278,"country":224,"annualKwhPerKwp":279,"p90KwhPerKwp":280,"decemberKwhPerKwp":281,"bestMonthKwhPerKwp":282,"winterSharePercent":283},"Essen","de-essen",976.6827946754606,923.9150697141541,27.15156558301156,121.01370820845032,11.030994234993049,{"name":285,"slug":286,"country":224,"annualKwhPerKwp":287,"p90KwhPerKwp":288,"decemberKwhPerKwp":289,"bestMonthKwhPerKwp":290,"winterSharePercent":291},"Dortmund","de-dortmund",979.4774070232531,913.3019846229257,27.90284029138244,122.15385345141443,11.179980325328048,{"name":293,"slug":294,"country":224,"annualKwhPerKwp":295,"p90KwhPerKwp":296,"decemberKwhPerKwp":297,"bestMonthKwhPerKwp":298,"winterSharePercent":299},"Dresden","de-dresden",1015.7611696985762,947.3528361048261,33.71911538237504,125.99740738955283,12.1869637090282,{"name":301,"slug":302,"country":303,"annualKwhPerKwp":304,"p90KwhPerKwp":305,"decemberKwhPerKwp":306,"bestMonthKwhPerKwp":307,"winterSharePercent":308},"Wien","at-wien","AT",1087.3402074216917,1030.4839485743043,27.40495959460784,135.7973057483907,11.710613590803003,{"name":310,"slug":311,"country":303,"annualKwhPerKwp":312,"p90KwhPerKwp":313,"decemberKwhPerKwp":314,"bestMonthKwhPerKwp":315,"winterSharePercent":316},"Graz","at-graz",1152.133301307322,1059.5583969359207,47.46295906648014,133.61636958323933,15.446335128190885,{"name":318,"slug":319,"country":303,"annualKwhPerKwp":320,"p90KwhPerKwp":321,"decemberKwhPerKwp":322,"bestMonthKwhPerKwp":323,"winterSharePercent":324},"Linz","at-linz",1075.1127586389296,1026.7233793151531,34.91859896270787,129.66506743589616,12.850262541498203,{"name":326,"slug":327,"country":303,"annualKwhPerKwp":328,"p90KwhPerKwp":329,"decemberKwhPerKwp":330,"bestMonthKwhPerKwp":331,"winterSharePercent":332},"Salzburg","at-salzburg",991.0099208260672,919.7803521414971,11.603351180606088,116.07123905170461,11.68252110323441,{"name":334,"slug":335,"country":336,"annualKwhPerKwp":337,"p90KwhPerKwp":338,"decemberKwhPerKwp":339,"bestMonthKwhPerKwp":340,"winterSharePercent":341},"Zürich","ch-zuerich","CH",1107.6186232618697,1040.7990538421966,43.616185253799074,129.69329245114506,15.123299766633236,{"name":343,"slug":344,"country":336,"annualKwhPerKwp":345,"p90KwhPerKwp":346,"decemberKwhPerKwp":347,"bestMonthKwhPerKwp":348,"winterSharePercent":349},"Genf","ch-genf",1196.3842441767301,1129.3410587224964,51.02758300426332,138.29592823238463,16.0425525213502,{"name":351,"slug":352,"country":336,"annualKwhPerKwp":353,"p90KwhPerKwp":354,"decemberKwhPerKwp":355,"bestMonthKwhPerKwp":356,"winterSharePercent":357},"Basel","ch-basel",1089.3065273728344,987.7207636871576,43.68749851541315,130.02974142167034,14.374350298047531,{"name":359,"slug":360,"country":336,"annualKwhPerKwp":361,"p90KwhPerKwp":362,"decemberKwhPerKwp":363,"bestMonthKwhPerKwp":364,"winterSharePercent":365},"Lausanne","ch-lausanne",1180.5693085392252,1105.4463405798256,51.82135377849747,136.28303827518621,16.04971824115367,1786101737848]