[[!meta date="2023-06-11 13:27:13 +0800"]]
[[!opengraph2 ogimage="https://www.vanrenterghem.biz/blog/pics/solarExposure.png"]]
[[!tag R analysis weather visualisation]]

Perth, Western Australia is a sunny place, as any local will
confirm. Combined with subsidised buyback tariffs for electricity
returned into the grid, this has resulted in many local households now
having an array of solar panels on their roof.

What most will intuitively understand is the production of these
panels varying over the year. That's a combination of the differences
in average cloud cover on the one hand, and on the other hand the
amount of energy that falls down on the panel from the sun varying
over the year due to the tilted axis of the earth.

Combined, this results in significantly different levels of energy
available on our roofs throughout the year.

[[!img /pics/solarExposure.png alt = "Perth solar exposure variation" class="img-fluid"]]

__Table:__ Average solar exposure per m<sup>2</sup> in Kings Park, Perth Jan 2017
to Jun 2023.

[[!table header="row" data="""
__Month__|Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec
---|---|---|---|---|---|---|---|---|---|---|---|---
__MJ/m<sup>2</sup>__|949,152|741,432|642,187|484,428|362,085|280,690|297,863|411,215|548,154|718,831|831,845|958,651
"""]]

Right now in June, we're at the low point for the year in expected
yield from a solar panel, with just about a third of the energy being
generated that we can expect to get in Dec.