Introduction to ground mounted solar PV installation
Ground mount structures are designed to be located on the ground, supported by metal frames (generally of aluminum, steel or aluminum alloy) and fastened to the ground in different possible ways that we will explain below.
The best thing about ground mounted systems is the wide available range of options to design your solar system according to soil conditions, costs, weight to be supported, tracking system selection and array configuration.
Now, let’s take a look at some of the available options in ground-mounted systems.
Cast / Ballasted Concrete
When soil conditions are not right for making any penetration to the ground (rock, for example) then the best choice is to opt for a ballasted footing mount structure in which pre-cast concrete blocks are anchored to an evenly graded surface.
The best thing about this option is that no excavation is needed and it is a really simple installation among ground mounted options, although, if the system is big it may require a structural engineer to make the calculations for the concrete blocks.
The ground-mounted option par excellence. This structure consists of excavating the ground to install steel vertical driven or helical piles – screwed deep below the surface – or bored concrete piers which are poured into dug holes with steel pipes suspended in the middle of the concrete foundation.
The key consideration to select the correct option is the type of soil, which determines not only the type of foundation but also the length of the piles.
As a rule of thumb, the stronger the ground, the shorter the piles need to be. For this option, the types of soil material that can be considered are crystalline bedrock (strongest), sedimentary rock, gravel, sand and clay (weakest).
The elegant and cost-effective solution of the mounting systems.
These structures do not require the execution of complex foundations or surface levelling (as for ballasted options), as a simple rigid steel pole with a deep concrete anchor, is more than enough to sustain the solar panels.
Size and diameter of the pole will depend on the soil type and the expected total weight to withstand (panels’ weight, snow, wind, etc.).
Simpler configurations can be applied with the Side-Pole Mounts (SPM). Mostly used for lighting purposes and small load feeding solutions, these SPM are made with stainless-steel module hardware and a tamper-resistant hardware kit for installations with low maintenance.
When considering the bigger option – Top Pole Mounts (TPM) – you will be counting on heavy steel mounting sleeves, elevation pivots and strong backs coated with a durable outdoor paint, and if your installation site has severe environmental conditions, then you can opt for hot-dip galvanized steel.
These Pole Mount structures can carry from 1 to 18 solar modules, and allow you to change the tilt of the modules from 15° to 45°.
The preferred option for farms and other, wilder residential and industrial areas.
The concept is the same as Pole Mounts but instead of adding more panels on the vertical side, the idea is to add more panels on the horizontal axis by installing additional vertical steel supports.
Multi-Pole Mounts (MPM) allow you to install between two and four solar modules with the same tilt and orientation.
The great advantage of this system is the possibility of expansion of the PV array if it is needed in the future.
We know different types of PV mounting systems available in the market and their installation procedures as well.
Ground mounting systems have a wide variability of choices and are suitable for different customer needs: residential, commercial, industrial and the utility sector.
Roof-mounted options are available for residential, commercial and in some cases industrial installations.
To make the best decision on which mounting system to choose, consult with your solar installer and always remember to take into account these facts:
- Overall system costs with either one of them
- Roof condition
- Soil type
- Security constraints
- Shadow obstacles nearby
Balancing the results of these facts with the location of your PV array will give you an idea of which solar mounting system is best for you.