Glare Questions

Yes. Due to how PV panels are designed, substantial amounts of sunlight can be reflected by the panel cover. This reflection may be hazardous for motorists, observers or even pilots. The panel absorptivity does not negate this reflection since it is caused by the glass cover on the panels and occurs before light even reaches the cells.

Panel glare largely depends on the position of the sun relative to the panels (the incidence angle). At high incidence angles, 20-30% of incoming sunlight may be reflected[1].

[1] See page 36 of the SGHAT User Manual for more details.

Mostly No. Research by the Sandia National Labs[1] found that almost all PV panel materials, with or without ARC, reflect enough sunlight to be potentially hazardous. Most of the specular reflection occurs before sunlight even reaches the panel cells, so absorption does not matter. The only exception was deeply-textured glass, which is rarely used.

[1] See page 36 of the SGHAT User Manual for more details.

There have been several instances of solar glare causing project delays, costly reconfigurations or even neghborhood issues.

In 2012 the Manchester Boston Airport had to tarp and then re-configure its 530 kW array after flight controllers began experiencing hours of blinding glare each morning. The changes delayed the project and reportedly cost millions of dollars.

The same article (linked below) includes an image of discomforting glare reflecting off a residential PV system.

Further reading and references:

Please read the FAA Interim Policy on glare, FAA Review of Solar Energy System Projects on Federally Obligated Airports.

According to the Interim Policy (78 FR 63276), solar installations being reviewed by the FAA must:

  • cause no "yellow" or "red" glare for nearby flight paths.
  • cause no glare whatsoever for nearby Air Traffic Control Towers.

Please contact the FAA for up-to-date, accurate details. The above information is preliminary guidance only - Sims Industries does not speak for the FAA and cannot approve or deny projects.

General Questions

One of our Partners and co-founders, Cianan Sims, co-invented the Solar Glare Hazard Analysis Tool technology alongside the Principal Investigator of the original project, Dr. Clifford K. Ho. Cianan was the lead software engineer on the SGHAT project since it's inception.

We have since licensed the SGHAT technology from Sandia National Laboratories to provide an advanced, sustainable glare analysis application for years to come.

We are currently a key team member alongside Sandia Labs on a related DOE project aimed at developing novel new features and enhancements for the SGHAT technology.

The Sandia SGHAT page now allows users to download their existing component data. We are working on an import tool so you can import and use your data on this site. Stay tuned.

Not at all! You can skip the subscription step during registration. As a free user, you'll have access to enough basic features to accurately judge the impact of potential glare from a home PV installation.

The key difference between paid tiers is quantity: as a Professional user you'll be able to create more of everything: projects, site configurations, components per analysis, and even automatic optimizations.

If you're needing glare analyses on a frequent basis or your site configurations contain numerous components like PV arrays and flight paths, the Professional level might be for you.

You can read more about the differences on our Pricing page.

ForgeSolar has been updated with new organization tools to keep your analyses orderly. Brief definitions of terms:

'Component' is a catch-all term encompassing the different pieces of a site. PV arrays, observation points, flight paths, vertical surfaces are all components.

Site Configuration
A site configuration (or 'config' for short) is a single set of components at a specified configuration. For example, a set of two PV arrays, each with a tilt and orientation, and a few nearby flight paths. Another site config might include the same components (PV arrays and flight paths), but with different tilts and orientations.

Projects are simply a way of organizing related site configurations. If you're working on a proposed set of arrays near an airport, you would create one Project (maybe named after the airport) which would include every possible site config (different tilts, etc.). Think of Projects like folders holding similar or related site configs.

Account & Subscription Questions

All paid subscriptions renew automatically at the end of the selected billing period. A courtesy email is sent three days before the renewal occurs.

If you do not want to renew your paid subscription, you can cancel at any time in the Account page. Your paid features will remain active until the end of your billing period (31 days for a monthly sub).

No data is deleted or destroyed when switching or canceling plans. You will still be able to view all created projects and configurations. Note that if you cancel, your subscription will be downgraded to the free tier. If you have more than one project while on a Free sub, you will have to delete existing projects before you can create a new one.

Editor & Analysis Questions

The Vertical Surface tool enables the analysis of reflective surfaces like billboards and glass buildings. These are separate from solar panel installations.

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