Choosing a solar tracker or fixed solar mount

What to consider when choosing between a fixed-angle solar mount or one that tracks the sun all day.

Dual axis solar tracker
dual-axis solar systems © C-TEC Solar

The first step when considering home solar power is to get your demand down as low as possible before sizing and pricing a system so that you can get the smallest system possible to meet your demand. 

To be factored when determining the size and location of a panel array:

  • Average daily power consumption
  • Geographical location - hours of sun exposure in a day
  • Potential shade from nearby buildings or trees
  • Typical local weather - average days of cloud coverage
  • Whether the panel mount is fixed or operable

Which direction should solar panels face?

The most common answer is ‘south’, but there are variables to consider. Depending on how much you rely on solar panels to meet your demand and whether or not you have batteries to store power will determine the optimum orientation for your panels, and the best direction for you is not necessarily due south.

If you are not storing solar power but count on your system as a means to reduce your bills by supplementing grid power, you might be better to orient them more towards the west. Panels facing a bit more to the west will generate more power at the end of the day when the average household consumption spikes, along with the rates.

Choosing a solar panel mounting system:

The price tag for fixed solar panel mounting stands is unquestionably lower than moveable ones; They can free standing, attached to a roof, you can even build your own stand if you choose, like the timber framed panel mount in the image below.

Timber framed solar panel stand
Timber framed solar panel stand © Bala structures

The downside of a fixed panel system is that you need to pick the one orientation and angle that will bear the most fruit in the times you need it. Given that the angle will almost always be less than optimum, there is only one fleeting moment where they are directly facing the sun and harnessing all the available energy; the rest of the time they are not operating at full capacity.

Those who use panels seasonally (cottages for example), often choose a more horizontal angle to accommodate the high position of the sun, or a steeper angle if your use is predominantly in the winter months.

solar tracker stand
© 123 Zero Energy

Manually operable solar panel stands are a bit more expensive and many of them don't offer a great range of position, many only allow you to change the angle, not the axis. They are normally adjusted twice a year (or a few more times if you're more ambitious) to maximize its direct exposure to the sun.

Some are dually-adjustable, which adds another element of cost that you may not get a lot of benefit from unless you are out there adjusting it every hour, which no one would do.  

Solar trackers move continuously throughout the day, constantly adjusting to maximize their exposure and power output. As a safety feature, they can go into a vertical  'sleep' position at night with an orientation that can protect them from life's unknowns, such as drivers who find parking without hitting something to be a bit of a challenge.

Solar tracker
Solar tracker © Ecohome

So, the question now comes, which one is the best value for your money? While a tracker stand will cost more to install than a fixed stand, you will always collect 100% of the system’s possible capacity since it is always pointing in the perfect direction. That means you can get away with installing less panels and still have the same yield as a larger fixed array, which most of the time (if not all) is pointing in a less than ideal direction.

Solar tracker
Solar tracker © Ecohome

An additional benefit but quite a valuable one, is that you also avoid having to factor in the durability of roofing materials and the cost of removing and replacing panels to access a roof that needs repair.

Picking the best way to mount your panels is a conversation worth having with a solar installer, and there is no 'right' answer. To find the best return on investment, your installer would need to calculate how many panels you would require with a fixed mounting system, and how many with a tracker. 

Solar tracker
Solar tracker © Ecohome

You'd need fewer panels to meet demand with a tracker, so along with determining convenience, the question is whether or not the savings of buying fewer panels offsets the greater cost of the tracker stand in the long run. As prices vary greatly by region, this is not something we can calculate for you, but a solar installer worth their salt should be willing to look into that for you.

Below is a tracker installed by Goggin Energy of Portland Maine; in this case, the roof orientation and limited space and shade from nearby trees made a tracker the most sensible option.  And given that calculating demand is at best an educated guess, there is always the possibility that the needs will increase in the future. The system shown in these photos provides 20% over the total estimated household demand, but should additional power be needed in the future there is room for 8 more panels and no additional stand would be needed.  

Solar tracker
Solar tracker © Ecohome

 

Related topics: