Note: The information contained in this periodical weblog may be outdated. This was my personal weblog published before January 1, 2015. Since then I have been the co-owner and Principal Solar Designer at Florida Solar Design Group.

Solar Energy in New Construction

New housing starts are picking up, and I am starting to get more requests to fit solar energy products onto new home plans. Typically this works great because we can make provisions during the construction stage to make the job easier and the installation better. However, it would be nice to get in on the “ground floor” and be consulted about the roof ahead of the construction start. Ideally I would get involved at the design stage and discuss requirements with the architect.

Since the “solar guy” is not often consulted in advance, here are the top 10 requirements that make for a better solar installation:

  1. A south facing roof with lots of space, preferably a 5:12 or 6:12 pitch in Southwest Florida. Gable roofs provide more space for solar products, but understanding that is not in vogue today, a south roof with no dormers or other protrusions works fine.
  2. Route vents to other roofs. This is typically not a big problem. Even if we get involved at the construction stage, we can have other trades reroute vents to adjacent roof surfaces with a simple plans change.
  3. Provide access to the underside of the roof. Sometimes we need to install blocking between rafters to make suitable attachment points. Ducts, pipes, air handlers, and other obstructions can make this difficult or impossible. We also like to get in the attic and do our work prior to spray foam insulation work.
  4. If a standing seam metal roof is anticipated, make sure the profile is compatible with S-5 Clamps to minimize roof penetration requirements, and require extra screws to increase uplift potential. Consider a standing seam metal roof over a 5V or other metal roof profile.
  5. If planning a barrel tile roof, let us get in there after the roof is dried in but before tile is installed. It’s easier for the roofer to flash around our attachments than for us to remove roof tiles after installed.
  6. Shingle roofs are the easiest and most cost effective for solar installations.
  7. If considering solar on a flat roof surface or as a shade structure, definitely consult a solar dealer first.
  8. Ensure there are no shading issues from the building and landscaping plan. Roof hatches, chimneys, and even electrical service entrances can cast shadows that are detrimental or even devastating to solar production.
  9. Most modern trusses will be more than capable of handling the weight and wind uplift of solar products. If in doubt about the requirements, ask me!
  10. If considering solar electricity, make interconnection provisions by providing appropriate lugs for supply side connections (see NEC 690.64(A)) or circuit breakers for load side connections (see NEC 690.64(B)).
  11. Bonus Tip! Check out the National Renewable Energy Labs Technical Report NREL/TP-7A2-46078, December 2009, Solar Ready Buildings Planning Guide by L. Lisell, T. Tetreault, and A. Watson.

These tips will put you on the right track for designing and building a solar ready building when planning a new construction project in Southwest Florida. When in doubt, don’t hesitate to get a solar professional involved in the early stages.

 

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