Hubitat Local Control Success Story


#1

All,

I want to share a success with the Community, which may lead others to appreciate the benefits of Local Control.

Yesterday, here in Northern Virginia, we had a rather fierce Thunderstorm. Not unusual in itself, but typically, my Provider NOVEC (Northern Virginia Electrical Cooperative) does a fairly good job of managing trees near power lines, and all things considered, power outages are rare. Even more rare (despite my provider being COMCAST) does my Internet connection go down.

Last night proved exceptional in both ways.

A tree fell "just so", and took out power to 173 homes, and Internet down for (presumably) a similar number. My home was one of the 173.

Since it was a mere 173 homes in a service area of 85K Homes, the restoration time was a mere ~ 2 hours.

So really, nothing to write home about. However, this outage allowed both my Tesla Battery system and Hubitat to prove themselves!

The Tesla picked up the load so smoothly, I only saw a brief flicker on the lights and didn't think much of it until my neighbor texted me to say I was the only one on the street with power!

Once I realized (and the Tesla alerted me very shortly after I switched my phone from the now Internetless WiFi to the 4G signal), I started my invented on the spot load shedding. I walked to the Nest Thermostats and turned them to "off", and then grabbed my tablet and started switching non-critical loads off.

The Hubitat performed with nary a glitch. All the lighting rules worked, the house continued to run without a problem. Once I switched the HVAC systems off, we turned off ceiling fans in unused rooms, and I switched all the exterior lights off. With just the pumps, fridge, freezer, dehumidifier, and Network up and running plus some LED lighting in the living room, and whatever vampiric load I have, I was pulling 900 Watts, so clearly I need to do some work.

But the key takeaway here, is that despite not having internet, my automations continued to work. My house ran perfectly, and once the power was restored, I was able to quickly resume normal operations.

In the future, intend to use a button to enable a "load shed" and perhaps implement a power outage protocol that lets me run my Freezer for a set period every couple of hours, and set the dehumidifier to a much higher moisture level. Once I replace the Nest units with something else, I should actually be able to monitor the Tesla system and Load Shed automatically when I got to Battery power.

In closing, I'd like to say "Thank You" to the Hubitat team. The Hubitat Elevation Hub performed admirably in a "perfect storm" set of conditions, and I couldn't be more happy to have moved here from "those other guys".

Scott


#2

Awesome! This type of case will only be more likely with our aging grid in the US so good to hear. The local aspect was a requirement for my HA needs.


#3

I have a large generator and once I got it set up with a transfer switch I have been reluctant to test it. Now if only I could get a test tree to fall on the power wires . . .


#4

Yeah, I know the feeling! I've had the batteries since December, and despite a boatload of storms, we haven't really had a test of the system.

This couldn't have worked out to be a better test though. I learned a lot, so it was a very good test!

Well worth knocking down a tree or two!

S.


#5

It is great when your investment actually works like your situation or leak sensors shutting off the water when water heater dies.


#6

Could always find a reasonable weekend and flip the main breaker. That should kick in the generator and you can check power usage and your plans for everything. Especially with a generator you can plan for "if it goes on for X hours..." because at some point (if it is not a hard connection) you will have to shut it down to refuel it at least.


#7

The last time we lost power, 8 years ago or so, and it lasted 5 days if I remember. The previous generator worked just fine. The new generator gets tested but I just hate finding and fixing all the things that crash when power is cut. The generator isn't enough to power the whole house. I could set aside a weekend but why spoil a weekend. I'm just waiting on a tree. :wink: This is tornado season and we just had local tornado warning. My tree may arrive soon enough.


#8

Gotta Love Trees!


#9

Our neighborhood is all underground power lines... but all the feeders into it are on poles through woods. First few years at this house we lost power any time there were strong winds. It must have knocked down all the deadwood (that and the couple actual wind storms we have had) because our power has been fairly stable the last couple years.


#10

Yeah, for the most part ours are underground too...one year the tree fell on the Transformer directly. That was pretty. But, as in your case, all our feeder lines are in the woods on poles. Go figure!


#11

Have you got a sense of how long you will be able to power the house from the Powerwall? I love the idea. We didn't get hit so bad here. I am just East of you by a few miles (Falls Church).


#12

I'm not sure. We spec'd a couple of days when we set it up, but that's probably not going to happen.

At my base load of ~1 kW, I'm looking at no more than 26 hours. I have 2 Powerwals, and without checking, I think they are rated at 13.2 kWh each....so 26.4 kWh.

I have ~6kW of Solar as well, so it seems reasonable that I could extend it a day or so if we were frugal. There's a good chance the bulk of that base load was actually a dehumidifier in the basement. If I control that during a load shed situation....and it's not 100F outside, I might be able to extend it to three days.

Having said that...everything in my house is pumped. SUMPS, Sewer, Well....so if its wet out or I use a lot of water...all bets are off!

Truth be told, the most common outage I have out here is sub 4 hours, so I could probably roll through an entire outage on just my 26kW!

Whole house UPS...

S


#13

Thanks. I wish I could do some PV panels but I have some huge trees. It does make for good passive solar as the shade keeps the house cooler in the summer. The way we're getting rain everyone may be using pumps soon. We're probably similar on outages - most are probably 4-5 hours. The derecho was, hopefully, an exception.
Eric


#14

Mine aren't optimal, but they don't do too bad. My biggest quibble, is that I really needed about twice as many, and I don't have either the $ or roof space for that. I cut down a lot (most) of the trees on my property, as they were too large and very much too close to the house in addition to being ancient. Now, I have little shade, but the Solar panels sure work! lol

S.


#15

I did learn through judicious relocation of a Zooz Zen15, that my Dehumidifier is pulling 500-600 watts far too many hours a day. So my base-load could probably be a lot lower during power outages.

I think I'm going to have to break down and learn the InfluxDB->Grafana thing so I can get a better handle on some of the heavy power users in my house!

S


#16

Awesome case use example! I would figure a great addition to your solution would be integrated motion sensing to turn lights out In unoccupied rooms and turn on minimum/emergency lighting (small lamps and such) on as you enter or off as you leave a room.


#17

Good suggestion!

I use a lot of motion sensing, and lighting automations. Not so many room presence automations, but I don't really have a problem with left on lights and the like (just me & the Mrs live here full time). And, in truth, the amount of energy my lights use is trivial compared to all the pumps, and other devices...and, I do wonder about my TV's vampire power usage.....

However in line with what you suggest, I'm (at some point) going to set a Global Variable (Boolean Loadshed) that is checked in pretty much every automation.

Basically, if Loadshed is TRUE, then a lot of routine automations won't run, and certain Loadshedding operations will run. Basically, where I can cut out known loads without affecting the basic operation of the house, I will.

First thing I'll do that to, is the automated lights, so my neighbors don't notice me being a conspicuous consumer during power outages...:innocent:

The big users though, are the HVAC units, and since NEST automation is still unknown, post the Google announcement, it may mean I'll have to move to some other thermostat solution.

I also need to write an app, or a Script on a PI to monitor my Tesla system, so I "know" when I'm on battery. Right now, I don't "know", unless my phone tells me, or I happen to notice my neighbors have no power.

Several moving parts for sure...but the great thing is I can write such automations because Hubitat doesn't require the cloud to make them work!

S.


#18

Perhaps a power monitor device? I know nothing about the Tesla system. Does it have any IOT type interface?


#19

Interestingly the SolarEdge controller has a Zigbee interface, but I haven't dug into the internets to see if it is usable for anything.

And the Tesla Gateway serves some JSON data through a Semi-Documented API. I expect that for what I want to do a pretty Simple Groovy app that runs on Hubitat could be implemented that monitored the JSON for state changes...or, I can probably do something on a Pi with NodeJS or even some Bash Scripts. It's on the list....

S.