Ground Mounts for Solar Collectors

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Although almost all urban installations opt for roof-mounted arrays, ground mounting is a popular alternative because it is much more flexible. The biggest advantage is that the installation location can be chosen for optimum solar output rather than relying on which way the roof happens to point.

If you decide to ground-mount your collectors you should be aware of the following factors:

  • Ground mounts are almost exclusively used for pressurized antifreeze systems – they do not often lend themselves to efficient use for other setups.
  • Solar collectors are large, so you'll need a fair bit of space.
  • Ground mounts are open to abuse and damage from vandals, animals and inquisitive children.
  • The mounting rack can be built out of wood or metal.
  • The array should be mounted as close to the building as possible, to reduce pipe length.
  • The pipes will almost certainly be buried, so be aware of any possible obstructions (driveways, underground pipes, power lines, etc.)
  • The bottom of the rack must be twice as far off the ground as the region's deepest snowfall in an average winter, to allow for snow to slide off and pile up.
  • The rack must be able to resist the strongest winds in the region. You may need to lay concrete footings to anchor the rack in coastal or mountainous areas.

The rack itself is often made of angle iron, galvanized pipe or painted wood, all of which work well provided they are strongly built, with adequate cross-bracing. If you mix and match metals, remember to isolate any that will galvanize with rubber or neoprene. You can also paint galvanized metal – especially the cut ends – and wood constructions to extend their life. The rack will be in place for decades, so plan accordingly and don't cut corners just to save a few dollars!

The rack must be sized to support the collector model of choice. Each manufacturer has their own mounting systems, so you'll need to design your rack to suit. In most circumstances, this means building a rack that consists of two parallel rails at the correct tilt angle and attaching the collectors with the same mounting gear that you would use if they were going on a flat roof.

An alternative is to build a small outbuilding or shed based on the collector rack. Use the collector array as one side of the A-frame roof, throw up a few basic wooden walls and you have a garden shed, a children's playhouse, a firewood store, a craft room or even a very small office! The options are only limited by your imagination and budget.

Ground-mount rack footings

In most areas, wooden footings work fine with ground-mounted solar collector arrays. Simply sink wooden piers into the ground below the average frost depth – treated two-by-fours are great for this purpose.

If you live in an area with very strong winds, you will need concrete footings for your collector array rack. These should be laid on undisturbed soil and should be made of concrete. The footings should extend below the frost line and