Monitoring Electricity Use...

[maple1]

Since the other thread got locked and I can't update there...


...my E-Matic whole-house energy monitor showed in the mail today (same as the Efergy, I'd say - even see the word Efergy in the manual in a few places). Just got done setting it up. I got out our last power bill, divided our total bill $ amount by kwh used and input that into the monitor for $/kwh. It's now saying I'm using $0.15/hour of electricity. I get the bill out again and divide the total amount of the bill by hours in the billing period, and get $0.16/hour. So it appears to be working.

It will be interesting keeping an eye on this thing as the boiler runs (it's not now), the fridge & freezer cycle on & off, the TV gets used, etc. etc.. Now I'm waiting on a cheap Ebay Kill-A-Watt device to arrive from China to check out a couple more things in more detail. It would maybe be nicer if this thing sampled more often than 10 seconds (real nice if it was constant real time) - but I can make do with this.

It also has temp & humidity levels displayed, which is a nice unexpected touch - I almost bought a second humidistat the other day but didn't at the last second for some reason. Which is a bit spooky...

 

[Highbeam]

I don't want to monitor cost per hour, not very important. I would suggest you monitor watts as a more direct measure of what is turning on and off. Even makes sense when you see a 4500 load come on and realize that is is your water heater with a 4500 watt element.

What is your base load with everything supposedly turned off but all the breakers still on. No fridge, no lights, etc.? In other words, how low can you go? I've gotten down to 160 watts.

 

[maple1]

Not sure yet, need more play time. I also don't really plan to monitor by $ either, I was just playing with the numbers while setting it up to see if it made sense compared to what my power bill was telling me I was using. Already got one shocker when my laser printer spooled up- mentioned that one in the diy printer thread.

 

[woodgeek]

I put my efergy e2 up a couple days ago. Even with everything I know of idle, I am at 360W.

 

[semipro]

Highbeam, woodgeek;
Are you establishing base load by unplugging everything you can and turning off everything else or are you leaving things plugged in but turned off?

 

[maple1]

It's not even been a day yet, but watching this thing is already becoming addictive.

When I got up a couple hours ago, it was around 450 watts - that's the quietest time for power use here. We've got 2 satellite receivers that are on all the time, my computer monitor was on (box went to sleep), and there's a lot of stuff plugged into the power bar at the entertainment unit. Also a couple of UPSs that are plugged in all the time.

Found my first target though. Have two 'standard' 48" double flourescent fixtures in my office. Never thought about them before because, well, they're flourescent. So far I'm seeing they're showing around 200 watts when on, and they're on a lot. Like, at least 12 hours a day most days. I got a few LED bulbs a couple months ago @ $3.99 when there was a big push on them here, I think I'll find a couple fixtures to put them in & take the tubes down. That should be a $10/month cut on the bill just there. Also, I usually leave my computer on 24/7 leaving the power saving stuff in the software to shut it down when I'm away from it for a while. It doesn't always shut it down, and when it doesn't there's another 240 watts or so.

 

[semipro]

maple1,
I'd be really interested in knowing whether removing a bulb from a fluorescent fixture with multiple bulbs actually decreases power consumption and by how much.
At work most offices seem overly bright and many occupants remove bulbs to decrease light levels.
Of course, if you have the older T12 fixtures with magnetic ballasts then the results might not transfer to the newer electronic t-8 fixtures.

 

[maple1]

Couldn't resist trying that, since you mentioned it & they're right above my head.

I think these are T12's - they're almost 20 years old. When I take one bulb out, it does cut it down by 25% (one out of 4 bulbs total), but the other bulb in the fixture barely lights up. So can't do that, with these ones at least.

The bulbs are 40 watt bulbs, but they seem to be using at least 50 watts each according to the monitor.

 

[Redbarn]

Thanks for the info guys. I just ordered an efegy e2.
Our electric use has climbed over the last year and I need to find out why.

 

[semipro]

Couldn't resist trying that, since you mentioned it & they're right above my head.

I think these are T12's - they're almost 20 years old. When I take one bulb out, it does cut it down by 25% (one out of 4 bulbs total), but the other bulb in the fixture barely lights up. So can't do that, with these ones at least.

The bulbs are 40 watt bulbs, but they seem to be using at least 50 watts each according to the monitor.

Thanks for doing that. I was hoping you would.
The ballasts are almost certainly sucking up some of that power. You can usually feel the heat being produced by them.
I'm not sure which T-12 fixtures you have but some can easily be retrofitted with T-8 ballasts and bulbs and this should pay off in energy savings. Depending on the fixture it may be easier to replace the whole thing though.

If you do the retrofit or replace the fixtures it would be great to know the effect of removing bulbs.

 

[maple1]

The fixtures are just the cheap 48" twin tubes. They're T-12s.

I just finished unwiring them at the feeds and cobbling up some temporary key fixtures so I could get some regular bulbs up there to see what the room would be like lit differently. I've got a '60w equivalent' 830 lumen LED in one, and a '100w equivalent' 1700 lumen CFL in the other - all I had to pick from on the shelf. Gotta say, so far, I miss the bright white light of those tubes in this room with those two bulbs up there - not sure I could get used to the yellower light but I'll give it a few days before I decide. The walls are brownish, might have something to do with it.

Time to investigate bulb choices I guess - including changing to T-8. I've got 9 of these tube fixtures in my basement, but those aren't on very much at all compared to this room.

The Tassimo really makes a big spike too - thought I saw something like 2500 watts when I looked quick at noon. Don't think I'll stop using that though - thing makes some darned good coffee.

 

[maple1]

We've also got a 24" twin tube T12 over the kitchen sink.

It has two 20w bulbs in it.

I was watching things & turning it off & on once in a while while doing supper a while ago - it uses almost the same amount of juice as the 48" ones do. I was actually seeing more use, like 150 watts - but my meter was jumping around some.

It won't be left on now as much as it used to be.

Would be interesting to see others observations of these things. I know some don't, but I really like the kind of light they throw in certain conditions & places.

 

[sloeffle]

Where did you purchase the energy monitor at ?

Thanks,
Scott

 

[maple1]

EBay.

 

[woodgeek]

Highbeam, woodgeek;
Are you establishing base load by unplugging everything you can and turning off everything else or are you leaving things plugged in but turned off?

My utility smart meter tells me my house uses 10 kWh/day when we are all away.

With the efergy, I was going to shut down the HVAC and DHW and then cycle circuits at the box.

 

[Highbeam]

Highbeam, woodgeek;
Are you establishing base load by unplugging everything you can and turning off everything else or are you leaving things plugged in but turned off?

So glad to see more folks doing this.

I thought that perhaps the monitors were inaccurate at low flows so I actually went to my panel with the display in hand and shut off each breaker one at a time. Then with a pencil wrote down the corresponding reduction in watts on the display. It adds up, we really do have these high baseloads.

Yes, I'm down to BL 160 but 58 of that is my electric range when totally off. Another culprit was all of the GFCI outlets, those buggers suck 6 watts each 24/7/365. I now turn them off using the "test" button.

 

[Highbeam]

Couldn't resist trying that, since you mentioned it & they're right above my head.

I think these are T12's - they're almost 20 years old. When I take one bulb out, it does cut it down by 25% (one out of 4 bulbs total), but the other bulb in the fixture barely lights up. So can't do that, with these ones at least.

The bulbs are 40 watt bulbs, but they seem to be using at least 50 watts each according to the monitor.

I removed a pair of 4 bulb t8 fixtures in my kitchen. Each ballast consumes .98 amps. This is how you determine the fixture draw, not by adding up the bulbs. Each 4' t8 tube made 2500 lumens. Pretty dang efficient really. I replaced those fixtures with 6 properly placed cans making 800 lumens and 15 watts each, leftover CFLs. This halved the electrical consumption and really dropped the lumens, however, properly placing the cans made the countertops just as bright. LED flood bulbs as I have in other rooms will cut the wattage way farther.

So consider placement of the light source as well as wattage and lumens.

 

[maple1]

I really like the white-light flood of the 48" tubes in my workspace. I'll be doing some bulb snooping, then figure out the fixtures from the bulbs. The wire boxes are in decent places for something like a couple of 2 or 3 light fixtures.

Found another little item last night. We've got a halogen floor lamp in the corner of the living room that is on most evenings. Somewhere around 300 watts on low. That will be swapped with a regular incandescent tri-light floor lamp from the kitchen that rarely gets used.

This is laundry day, and laundry is a killer - glanced over at the meter once & thought it didn't look quite right. The decimal point was shifted one place to the right. Washer, dryer & water pump really chew up the watts when they're all going at once. And that's with wood heating the water. Our appliances are almost 20 years old, and I'm pretty sure a new fridge, and front load washer would help - but have a feeling throwing out perfectly good working units would be just asking for trouble. I'm superstitious that way I guess.

 

[woodgeek]

There are now many fluorescent-based replacements for those halogen torchieres...many also have dimming or three-way settings

 

[TradEddie]

Another culprit was all of the GFCI outlets, those buggers suck 6 watts each 24/7/365. I now turn them off using the "test" button.

Do you know if the GFCI's which are in the breaker box are better or worse? When I moved in here, I had some outlets with local AND breaker GFCIs, my inspector recommended removing the outlet GFCIs in case the redundancy affected operation, but I don't ever remember doing it!
Another project, thanks for nothin'.

TE

 

[Highbeam]

I have only used one breaker GFCI and that was for a hot tub install. On my current hot tub install I used the separate "hot tub panel" which includes a GFCI breaker for the 60 amp circuit. That same circuit has an additional GFCI outlet on it for the required outdoor 120 volt service outlet so I couldn't determine which GFCI was parasitic.

I would always avoid using breaker GFCIs when an outlet GFCI can do the job. I don't want that junk in my panel and the GFCI breakers are quite expensive. I would also avoid using double GFCI protection. Not sure if it is even allowed.

In your case with the double protection it is easier to replace the breaker in the panel than it is to replace an outlet but then you need to be certain that there are no standard outlets on that circuit that still need GFCI protection.

One other thing, these monitors are likely not accurate to the one watt. It is possible that just the presence of voltage in the monitored lines is causing some base load to appear. I tried to eliminate that possibility by shutting off individual breakers and closing the base load with success but at some point we have to consider that these instruments are fairly crude.

 

[TradEddie]

Looks like I have some detective work ahead of me. My inspector believed that doubling up wasn't allowed, he wasn't sure, but recommended removing them, so the sellers had to discount the cost of an electrician coming to perform the work, and I intended to get around to it myself. I have a vague memory of doing something, but ten years later, I still have outlet GFCIs near all sinks, and one in the breaker panel. Perhaps I removed other ones from the breaker panel, the remaining one might be for the outdoor outlet. A job to keep the kids busy with walkie-talkies some weekend.

I might jury-rig a GFCI outlet to the kill-a-watt, see what it measures... Each wasted watt draining 24/7 is $1 per year at 12c/kwh, might save a whopping $6.

TE

 

[maple1]

Anybody know how much electricity their fridge uses in a month?

My Kill-a-Watt thingie hasn't gotten here yet, and that's where it's going when it does get here, but ours seems to spend a lot of time running now that I'm paying more attention to things electrical. Think it's around 18 cu.ft., standard top mount frost free, 18 years old. Label says should be using 639kwh/yr. Will be interesting to see...

 

[sloeffle]

We just bought a Frigidaire 20.5 cubic foot refrigerator / freezer that is energy star rated. It is rated at 408kwh/yr. This is a standard top mount freezer also.

(broken link removed)

Not to take this too far off topic. The reason we bought the above refrigerator is because our fancy dancy new Kitchen Aid refrigerator is a pile of crap and breaks down every few months. From talking to the appliance repairman, he said the new ones are made so cheap he wouldn't buy one. He said he would find something older. IMHO I would keep yours until it dies. The extra 20$ a year it costs you to run it is not worth the hassle of loosing hundreds of dollars worth of food.

Scott

 

[Highbeam]

I was surpised at how little the fridge used. I forget the exact number but hardly anything and this is another one of those energy hog myths. I wouldn't replace a fridge until it breaks or is needed for some other reason than energy efficiency.