For some people, aesthetics are everything. They could care less how something works, just so long as it looks good. Others tend to be more practical minded, opting for function over presentation.
When it comes to solar panels, sometimes it can be difficult to have both.
A multitude of variables are always at play, with each location presenting its own unique challenges. And with solar panels being the sizable features that they are, the desire to place them according to personal preference, can be pretty substantial.
However, there is one underlying rule that should never be ignored. Solar panels work best with direct sunlight.
For those of us living in the northern hemisphere, this means that solar panels should always be oriented for true south. Doing so, allows for the maximum exposure to direct sunlight, thereby producing the highest amount of power.
East And West Facing Solar Panels
How many times have you heard the phrase, “in a perfect world…”
I, for one, am glad that I don’t live in a perfect world. Where would be the challenges if things were already perfect?
As not every residence in the northern hemisphere is orientated identically, there will be locations where having a solar array face true south is not possible.
Let’s be honest, houses are generally orientated according to spatial constraints rather than solar alignment. This means that creative compromises will sometimes have to be embraced when choosing to go solar.
For some homeowners, east and west facing solar arrays are the only feasible option. And while this is less than ideal, it can work – to some degree – if proper homework is done ahead of time.
In the video, Productive Daylight Hours, we learn that total production time for solar panels is generally from sunrise to sunset, minus roughly 90 minutes of ramp up/down time. This is only true for panels facing due south. For panels facing east/west, this production time is shortened considerably.
Just how much?
Depending on your situation, maximum output could be cut as much as half. And while that sounds horrible, it does not make it unfeasible.
Take for example, our home.
Our ground mounted array of 7.8kW is orientated true south. With our house being off-grid, our panels are limited in production to the constraints of our battery bank. In other words, once the batteries are full, the panels are throttled back.
In the summer, when sunrise is early and the skies are clear, our batteries are typically topped off by lunch (even with the A/C running) and for the remainder of the day, the panels really only engage when household demand requires them to.
This means that for more than half of the day – during prime summer months – our panels are sitting idle.
Should you live in an area blessed with lots of sunshine, having an east or west facing array can still provide you with adequate power – providing your array is sized appropriately.
East/West Panels And The Grid
In the previous example, we discussed an off-grid scenario where the panels are not able to sell any extra power back to the electric utility. However, the majority of today’s solar homes are connected to the electric grid. So how does that work with east and west facing arrays?
To reiterate, photovoltaics work best with direct sunlight.
For east facing panels, you should find that power production comes on very strong first thing in the morning and then drops off dramatically shortly after solar noon, as the sun moves past the peak of the array to shine on the other side.
In contrast, for west facing panels, you should see a lower scale power production first thing in morning as the direct sunlight is hitting the back side of the array. But then, power should come on very strong sometime after solar noon as the sun has finally moved past the peak of the your array, to now shine directly on the power producing cells.
(To find out what time solar noon is for your exact location, check out the NOAA Solar Calculator.)
Solar Panels And The Southern Hemisphere
For those of you living in the southern hemisphere, your panels should be facing due north in order to maximize exposure to the sun. Places that are below the equator, like Australia, New Zealand and Africa, see the sun from a different angle and consequently should align their solar panels accordingly.
However, the same rule of direct sunlight still applies. Facing the panels directly north allows your panels to access the early morning sunlight as the sun rises in the east, and then track it across the sky until it sets in the west.