Two PV modules on a test frame beside a board of handheld meters.
Sun Safe LLC

SOLAR RESEARCH AND DEVELOPMENT — Rutland, VT

Balcony Solar or Plug-in Photovoltaics (PiPV)

Plug-in solar looks simple: a solar module or two, a small inverter, a plug. What trips people up is everything around it. Is it allowed where you live? Are the module and the microinverter compatible? How much sun does your spot really get? And maybe most importantly, does it make financial sense for you? Plug-in doesn’t mean just plug in: it still has to meet your electrical code. The good news: a few careful choices up front are what make balcony solar work for you, safely, and these tools walk you through them.

The tools below answer those questions in order. They run in your browser or your phone. Save it for later use or share it with friends. Print it out and give it to your local electrician for review. Most importantly, learn a little about PiPV!

  1. 1

    Check your state

    • Is plug-in solar legal where you live?
    • How big you can go
    • Who to contact: landlord, utility or electrician
    • The law’s own words, linked to the bill
    Check your state →
  2. 2

    Design your system

    • Pick your module and microinverter, and your location
    • Checks voltage on the coldest morning and hottest afternoon
    • Maps your sun hours and when it pays for itself
    • Flags problems before you buy
    Design your system →

Have these handy before you start

  • Your Solar Module’s information: On the back of your module. It lists Voc, Vmp, Isc, Imp and watts. If you have a datasheet, even better! If you don’t know what module to use yet, there are a variety of pre-loaded modules to choose from as examples.
  • Your microinverter’s make and model, or the kit you bought.
  • A recent electric bill, for the total, the kWh used and $/kWh.
  • The location of the proposed system. Full address preferred, but “City, ST” will suffice.
  • Optional: a panorama photo from where the panel will go, for a detailed shading analysis.
    What the photo is for

    a panorama taken where the panel will go, with the middle of the sweep pointed the way the panel faces. Sweeping as if capturing the path of the sun will allow a Solar-Eye like overlay that can be applied to the sun path chart. This will allow the user to then trace the shade patterns to determine energy loss due to shade for their particular setup. If not selected the tool will default to a “no shade” analysis and give full unobstructed sun hours and energy harvest predictions for the given location.

    Example: a traced skyline with the sun’s path drawn over a panorama in Rutland, VT
    Example: traced skyline (blue) and the sun’s path. Hours below the line are shaded.

See a finished example: the Rutland test stand

2 pagesQuick report: diagram, checks, state rules and sun hours 5 pagesAdds sun, production, payback and offsets 6 pagesAdds the shading profile from a site photo

Tap one to open it. Every part is labeled with what it means.

Our position on installation

Plug-in solar may be something an average person can and will set up. However, we still recommend having a practicing electrician install it or check it, and everything here is held to the electrical code. These tools help you plan and ask better questions. They don’t replace an electrician or your local inspector, and they can’t make an installation meet code. Where the rules aren’t settled yet, like UL 3700, the tools say so.

Start with step 1 →

Plug-in photovoltaics (PiPV) are arriving fast, and balcony-solar laws are spreading from state to state. These free tools help you set it up safely.

Solar is about to be more accessible than ever, and that freedom still needs some checks and balances. My hope is to make it safer, easier to understand and easier to design.

All of this is free. It’s been field-tested by just one guy in Vermont, so some things will be wrong. Find something? Reach out and I’ll fix it. That’s how it will get better!