19.2 kW Roof-Mount – with SUNLIGHT BACKUP! 🌞

Going solar does NOT mean you will have power if the grid goes down. The typical grid-tied solar PV system (that sells excess generation back to the utility) turns off when the grid goes down – an important safety feature to prevent injuring or killing a lineworker repairing transmission lines.

A typical home energy storage system (ESS), a.k.a. batteries, might cost $15,000 and up, after tax credits. With NYS’s low electric rates and stable grid infrastructure, it’s hard to justify batteries on cost effectiveness alone.

So what’s a homeowner to do when they want just a little backup in the case of a power outage?

Enter Enphase Sunlight Backup. Their IQ8 microinverters are capable of creating a micro-grid, isolating the house and powering select essential loads directly from the solar, no need for on-site storage.

Enphase IQ8 microinverter

During the day, if the grid goes down, the Sunlight Backup system will start. It powers on essential loads in sequence, waiting to ensure that there is enough solar power to support the load before adding the next. If any load draws more power than the solar can provide, the system shuts down and tries again.

Without on-site energy storage, Sunlight Backup is roughly a third of the cost of a battery-backed system.

This summer, we installed our first Sunlight Backup system!

The homeowners are on a well, and with little kids in the house, they really wanted to maintain running water during a blackout. They also didn’t want to lose the contents of their fridge.

Even though the load sequence is pre-set, the homeowners can manage it in real time using the Enphase homeowner app.

image source: https://enphase.com/homeowners/sunlight-backup-user-guide

A typical microinverter-based solar PV system doesn’t require many (or any!) additional components in the house, but Sunlight Backup does. Here’s an overview of the additional “balance of system” (BOS) components in the homeowner’s basement:

  1. IQ Combiner Panel
  2. IQ System Controller
  3. Backed-up Loads Panel
  4. IQ Load Controllers
  5. House Main Service Panel
  6. AC Junction Box

In the future, adding on-site energy storage (batteries) will require very little system reconfiguration – most of the cost will be the batteries themselves. So Sunlight Backup is a reasonable stepping stone to get a little backup now in preparation for full backup later.

This homeowner had some shading on their roof and wanted to invest in the system with the best long term economic return, so we recommended REC modules. These modules are so awesome they deserve their own blog post!


The homeowner described her experience:

“10/10… We are very happy with the finished product but the entire process was informative and efficient. Sungineer Solar was the only company to ask what our goals were for this project… Our favorite thing was how we never felt like we were being sold on a product but rather educated and exposed to options.”

J.C, homeowner

Speaking personally, I love to homeowners to find out what they REALLY need and want (believe it or not, sometimes it’s not rooftop solar – and that’s a-ok!). So, it’s a special joy to work with engaged yet chill homeowners who are interested in learning something new.