Two days in and so far, so good


#1

We moved into our new home last summer and I’ve since noticed that our electricity bills have been very high. Our average consumption is around 1,800 kWh over the past 10 months!

Some background. The home is a bit over 5,000 sf, is around 50 years old, and has been renovated several times over the years. There are two subpanels, a fourth panel hidden in a closet that I just noticed was active tonight and hooked to gadgetry that looks like it’s from the cold war, a 47 kW generator, a PowerwoRx e3 (look it up, it’s suppose to reduce power consumption on certain types of loads), a Venmar HEPA ERV, and a few other odds and ends. Suffice it to say, it’s not going to be a case where I swap out a few incandescent bulbs and the problem is solved.

I received my Sense two nights ago and installed it myself on the main breaker. It took about 10 minutes to install, and I assumed it would be a long wait to start seeing individual devices. As of tonight, though, it’s already discovered a dehumidifier (which it thought was an AC unit), the engine block heater for the generator (which it simply called Heat 1), a garage door opener, an Always On load, and an Other load. I’m very impressed so far with what it’s found, and will share more details in the coming weeks. So far, so good on the install and initial impressions.


#2

1800kwh in a month? For a 5ksqft home that’s 50y old? Unless you’re in Hawaii or coastal California, that doesn’t sound too bad!

For reference, we’re in a 2.1ksqft ranch, about 20y old and we use about 1000kwh a month. May - November we’re using +/-1500, the rest of the year it’s more like 5-600.

Everything here is on dimmable leds, and our water heater is on a 2x daily timer so it runs for <2hrs a day. Those two things go further than you think :slight_smile: We’re also using an ecobee thermostat, which has really helped dial in comfort levels and save money. They’re on sale lately and our power company even gave us a retroactive $75 credit for it!


#3

1800 KWh average is pretty darn good for a 50 year old, 5000 sq ft house.

I have 4700 sq ft heated with a 3300 sq ft unheated basement. Insulation is spray foam including the roof so the house Is very air tight. My average over the last 12 months is 2582 KWh with a max of 4311 KWh in September and min of 1358 KWh in February. The 4311 was due to a refrigerant leak in my heat pump upstairs I didn’t realize for about a month of the unit running continuously until my kids complained about it being hot. I usually average about 3500 in the summer months.

I started going around the house with a Kill-O-Watt meter in January trying to figure out where to lower my consumption before I know about Sense. I turned off my server lab, switched from xbox 360s for media center extenders to Linksys DMA2100s. Switched out 6 60 watt incandescent bulbs in the kitchen that were on constantly to LED bulbs. I’ve been slowly switching over my 100+ can lights from 65 Watt to 9.5 watt LEDs. That project is almost complete.

So far I’ve been able to lower my consumption about 800 watts over the same months going back a few years.

I’m still averaging about 1200 watts always on at night and I’m hoping sense will help me identify what’s going on. I know by my kill-o-watt meter that about half of that is my media center PC, home automation system, cable modem, two 24 port switches and a few other small devices. I’m still trying to track down the other 600 or so watts.


#4

Thanks for the posts. It’s reassuring to hear that my power consumption isn’t too bad! I’m interested in seeing what happens over the summer. Since the home was remodeled and added to over the years, there are three discrete forced-air HVAC systems. I added ecobee thermostats to all three zones and will try to tune them as much as possible.

Curious what your always on consumption looks like? It’s showing 553 watts right now, though there still is an ever-present 991 watt “other” bucket right now. Since I’m only on the third day of using the Sense, I’ll give it time to sort things out.


#5

I can’t tell you my always on because I’m only monitoring one of my panels. I’m waiting on sense to add support for multiple panels from one logon before I buy a second device. The half I do monitor is usually in the 160 watt range. This does not capture my basement, second garage, upstairs or my three HVAC systems.

I monitor whole house usage by ir pulse counting of my meter, raspberry pi and emoncms. I also have a custom emontx I sometimes hook up and play around with.


#6

Between always on and unknown, we’ll run about 200-250w overnight. That covers a fridge, a couple fans, and our modem/etc. bank in the office.

We’ve got a pretty simple and small house, so my use case was a bit different than yours :slight_smile: I’m mostly trying to keep track of usage and solar production, the appliance identification is just gravy as far as I am concerned.


#7

Our always on is a little over 1000W because I have an office in the house and we have computers, servers, switches, etc. always running. Although I just checked and it’s at 861 so now I’m wondering what isn’t running…Hm.


#8

@jamey_a: My Sense just reported that our average weekly usage is 394.0 kWh, or about 1,700 kWh/month. Also a 5,000 sf house circa 1973, so we’re about the same. However, the Sense has been running for only about a month and we haven’t gotten into A/C season yet (Illinois) when I’m sure it will spike.


#9

I hear you. We’re right up the road from you in Minneapolis, so we too are waiting to see what summer will bring for electricity usage. The silver lining is the $500/month gas bills will start to go down…

Our first major observation is with the engine block heater for the generator. It runs 3-4 times per hour for about 5-6 minutes each time. It draws nearly 1500W so that’s about 8 kWh/day. I’m going to shut this off. My car seems to start fine without a block heater and the generator is just a Ford V6 engine in a Cummins metal enclosure, so it can live without a block heater IMO.

I’m also noticing one dehumidifier running 4-5 times/hour but for 10-12 minutes each time. We’re going to dial back relative humidity to 50% and see if that helps. As much as I want a dry basement, I can live with an extra 10% humidity. We’ll see if that does anything.

My goal is to try for a 12-month return on investment for the Sense. I tell my employees that if they can show me an ROI of less than a year on a project, I’ll usually go for it. I’m applying the same logic here.


#10

My basement fluctuates between 45% and 55% and it’s always completely dry. It’s 10 feet deep poured concrete sealed with an elastomeric spray coating that’s not tar based. I have no cracks but it I did, the membrane will stretch and keep the cracks covered. If you have a block or rock wall with an unsealed or tar based damp proofer applied, I can see the basement being and feeling wet even if humidity is low.

My beach house dehumidifier was cycling way to much when using the auto on/off feature. I ended up getting a Belkin WeMo insight switch so I could monitor energy usage. I also use a Wireless tag to detect humidity in the house and trigger a komodo script to turn the dehumidifier on and off. This helped a whole lot with keeping energy usage low as I found that the internal sensor in the dehumidifier wasn’t turning it off at the preset level plus it had to come on and air sample way more than needed.


#11

A 12 month ROI is certainly a worthy goal for any investment. And then there is what I call the non-monetary benefit of the Sense. Learning about how we use energy has a value even if we don’t change a thing, particularly if we discover its because we’ve already maximized our energy efficiency. And the peace of mind that knowing that we’ve done everything that we can, whether we made a change or not, also has a value. At $300, even if I didn’t change a thing (although I have) the expense would be worth it the knowledge I’ve gained.

That said, I suspect that every Sense user has discovered some energy sucking device or changed their habit(s) in some way that saved energy and thus money. So there’s a good chance everyone will save at least something. Whether it pays for itself over a period of time all depends on how energy conscious you were before and what effort you put into changes after installing the Sense.


#12

If you’d be willing to share the Komodo script you wrote, I’d be keen on seeing it, or at least give me an idea on how you set up the trigger and relay. I agree that the humidity sensors in most humidifiers I’ve used are not very accurate. Mine is sitting less than five feet from an AcuRite humidity monitor and one of the two of them is lying… and I don’t think it’s the AcuRite.


#13

Check out wirelesstags.net I have a tag manager and temp and humidity tags from them. Their scripting interface is called Kumo. Not sure how I typed komodo. I forgot that I use IFTTT now, not Kumo. You can use Kumo to directly interface with the WeMo devices but it was causing problems originally with being able to access them with the WeMo app.

My IFTTT to turn on the dehumidifier is “If LivingRoom became too wet, then turn on Dehumidifier”. To turn it off, it’s “If LivingRoom returns to normal humidity range, then turn off Dehumidifier”. “Dehumidifier” is what I named my WeMo insight switch. These IFTTT applets are triggered by what you have configure for humidity too high detection for a particular wireless tag.

I got these tags for two reasons. One was because our ancient refrigerator had been slowly leaking coolant and stopped cooling so we were rudely surprised with a non functioning fridge when we went down for a week long family vacation. I bought a new fridge because I was paying more per month for the old one than the new one costs to run all year. Also because the previous winter was particularly wet causing the humidity to get so high that hold had grown on everything in our house and other houses in the area that weren’t cooled/heated year round. The dehumidifier was costing me almost $30 per month to run. By controlling it with the tags and IFTTT, it only costs about $10 per month since it’s not running way longer than needed.


#14

A little over three weeks in, and I have around 22 devices detected. Latest were a laser printer and some appliance lights. One interesting “find” is that the engine block heater for our generator has the same power signature as the Keurig coffee maker. I ended up turning off the block heater, but have since noticed it shows up every morning exactly at 5:55am. That’s when the coffee maker is set to pre-heat the water. If that’s the biggest anomaly so far, I think Sense is doing pretty well. I’ve already started making changes to our power consumption, and that’s really all that matters for me.


#15

Thanks for sharing, Jamey! I’m glad to hear that you’re having a good experience and have already been able to make use of Sense’s data.