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Connection Options for Backup Power

A spate of recent storms over the past month has much of Houston once again thinking about strategies for backup power. The crazy derecho weather event on May 16th had parts of the city without power for up to 6 days. This particular event was our first time actually using the backup power strategy we put in place after Winter Storm Uri in 2021.

Unlike a hurricane, this storm was very short-lived. Largely a wind event, it raged past just after 6pm and was truly gone by 9pm. We were fortunate. Our pecan tree took a beating, but we only lost power for about 10 hours. Even before the rain stopped, I had the Predator 9500 invertor running, just as I had planned.

Predator 9500 Inverter Getting some exercise on a dry day in March

As detailed previously, the Predator 9500 inverter powers the entire house, including our 4T central air conditioner. So, we were comfortable overnight. Only in the morning did we see the carnage the storm wrought upon all the trees in the neighborhood.

The Shelly 3EM in our breaker panel continuously reads the power drawn by the house from the utility. This data is aggregated in our Home Assistant server. That combination provides the following chart that illustrates the outage nicely. The power went out around 7pm, and returned around 4am the next morning.

Power Drawn May16-17

In the aftermath of the storm, both online and in-person, backup power has resurfaced as a topic of conversation. Since Uri, many people have opted to install a standby generator from the likes of Briggs & Stratton, Cummins, Generac, or Kohler. For a variety of reasons, that may not be practical for some people. For people like us, using a portable generator is the approach that remains.

Once our power was restored I loaned our Predator to friends who were not so lucky. It served them well for a few days. Their experience reminded me that it’s not enough to have a generator. You have to be able to connect it to the important things that need power. There are several ways to go about that. What follows is an overview of several approaches have come up in recent discussions.

1. Extension Cords ($)

In 2021, faced with Winter Storm Uri, we had our old Predator 8750, a traditional, synchronous generator. Beyond having this old beast tucked away in the garage, we had made no specific preparations. On that basis, I consider this an ad hoc approach.

The old Predator 8750 Generator we used during Winter Storm Uri in 2021.

We setup the generator at the back of the driveway where it’s exhaust would not enter the house. Also, where it’s considerable noise would be least irritating to ourselves and neighbors.

We have a long-established habit of significant displays of holiday lights. As a result, we have a considerable collection of long extension cords. We used the heavier of these, and some good outlet strips, to deliver power to places where it was required.

  • One to the kitchen for a lamp and the refrigerator.
  • Another to the living room for lights, laptops & chargers.
  • A third up into the attic where I rigged the furnace to have normal plug.
  • A fourth to the garage apartment to power a small space heater and our network core.

Running the cords and getting everything plugged in was relatively simple, but certainly not effortless. It was all we could do at the time.

“Do what you can, where you are, with what you’ve got.” – Theodore Roosevelt

2. Inlet & Interlock ($$)

We began implementation of our formal backup power strategy in the spring of 2021. We had the vintage 60A breaker panel replaced with a new 200A panel. That meant lots of room for expansion. We also added a 30A inlet and mechanical interlock.

30A Inlet

The inlet (pictured above) provides a direct connection between the breaker panel and the generator. That means no more extension cords! Connected directly to the breaker panel, the generator is able to run the entire house.

Well, up to the limits of the generator. In our case, we know that our Predator 9500 will run the whole home as long as we’re a little careful. We can’t run the AC while also doing laundry, washing dishes, microwaving popcorn and making coffee…all at the same time.

A mechanical interlock is legally required to ensure that the house is disconnected from utility power before it can be connected to generator power. This is to protect utility linemen who might be working to restore power. You really don’t want to back feed generator power in their direction.

The interlock requires that a breaker panel have two empty spaces available to receive a breaker for the generator. Since we had a large, new breaker panel, this was no problem.

We opted for a 30A inlet since that’s what our generator supported. It cost $400 from a local company called Backup Electric. It only took them about 2 hours to install.

3. Manual Transfer Switch ($$$)

Another approach would be to have an electrician install a manual transfer switch. It’s a special kind of supplemental breaker panel that isolates a handful of selected circuits to have backup power available. When utility power goes out, the generator connects to the transfer switch. You then switch some or all of the circuits in the transfer switch to use generator power.

50A Transfer Switch with inlet

My impression is that this is perhaps more appropriate for a larger home where it’s just not practical to power the entire home from a portable generator. It requires you to decide in advance what will/will not have backup power available.

Since installation is more involved, I’d guess that it’s also more costly to install than the simple inlet & interlock.

4. Generlink ($$$)

A neighbor nearby is considering a solution for their home. Like ours, theirs is an older home. It has a small breaker panel that’s already completely full. No space available for the extra double-pole breaker required for an interlock. They could consider a manual transfer switch, but given the old panel, I suspect an electrician may well insist upon a costly breaker panel replacement.

Happily, there is another approach to be considered. Generlink is a transfer switch that’s designed as a collar that fits between the electric meter and its mount. It provides both a connection for the generator and a way of safely switching the whole house between utility and generator power.

Generlink inlet + transfer switch

Quickly and easily installed by an electrician, it requires no change to the breaker panel. In some parts of the country you can have it installed by your utility company. Not so in Texas. Listed on Amazon for around $1100, the device itself is quite expensive, but still much less costly than replacing an old breaker panel. Very possibly comparable to a traditional manual transfer switch.

If this is the route you choose, be sure to check that your generator is compatible with Generlink. Apparently, it’s not compatible with some implementations of ground fault protection.


There you have it. Four ways to deliver backup power from a portable generator to your home.

When I was a kid I was a cub scout. That wee, paramilitary organization leaned hard on the notion of being prepared. As an adult, I have been a desk jockey. I find these rare instances when scout-style preparation pays off very gratifying. To quote George Peppard from The A Team, “I love it when a plan comes together.”

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