How much will solar panels produce in Philadelphia?

A 8 kWp system facing south at 35° tilt in Philadelphia produces about 11,444 kWh a year. In a weak year that is 9,569 kWh, in a good one 13,318 kWh — 1,431 kWh per kWp.

That’s about 109% of a typical home’s yearly use (10,500 kWh).

Calculate for my roof

Based on 2014–2023 satellite weather data

Production by month

05001,0001,500JanJanuary: 8 kWp 764 kWh, range 595–934FebFebruary: 8 kWp 824 kWh, range 606–1,042MarMarch: 8 kWp 1,055 kWh, range 862–1,248AprApril: 8 kWp 1,097 kWh, range 904–1,290MayMay: 8 kWp 1,073 kWh, range 828–1,319JunJune: 8 kWp 1,098 kWh, range 909–1,288JulJuly: 8 kWp 1,124 kWh, range 939–1,309AugAugust: 8 kWp 1,089 kWh, range 888–1,291SepSeptember: 8 kWp 1,018 kWh, range 819–1,218OctOctober: 8 kWp 871 kWh, range 693–1,050NovNovember: 8 kWp 827 kWh, range 665–989DecDecember: 8 kWp 650 kWh, range 518–782

kWh per month

A typical day in July

The sunniest month in Philadelphia. Output peaks around 11:00 solar time, at about 4.8 kWh in the best hour.

0:006:0012:0018:0023:00 4.8 0

Month by month

Month Weak year, kWh Typical year, kWh Good year, kWh
January 595 764 934
February 606 824 1,042
March 862 1,055 1,248
April 904 1,097 1,290
May 828 1,073 1,319
June 909 1,098 1,288
July 939 1,124 1,309
August 888 1,089 1,291
September 819 1,018 1,218
October 693 871 1,050
November 665 827 989
December 518 650 782
Year 9,569 11,444 13,318

The months don’t add up exactly to the yearly figure, because each one is the typical value across many years.

Common questions

How much do solar panels produce in winter in Philadelphia?

From November to February the system produces about 3,066 kWh, which is 27% of the year. The weakest month (December) gives roughly 650 kWh.

Is an east-west roof worth it in Philadelphia?

An east-west system typically produces 10–25% less per kWp than one facing south, but spreads production more evenly through the day. The exact difference depends on tilt and shading.

Compare an east-west roof for Philadelphia

Ground mount or roof in Philadelphia?

A ground mount can be tilted and aimed freely, which can add some yield, but it costs more and needs space. Compare both for your own plot.

Check a ground-mounted system in Philadelphia

Your roof is not an average roof

Set your own tilt, direction, shading and inverter limit and get a range for your address.

Calculate for my roof

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Climate data: Photovoltaic Geographical Information System (PVGIS) — European Commission, Joint Research Centre