Poll

How much electricity (in kWh) per day does your home use when you are away traveling (on average throughout the year)?

Less than 0.5 kWh
0 (0%)
0.5 kWh to 1 kWh
3 (25%)
1 kWh to 3 kWh
5 (41.7%)
3 kWh to 5 kWh
1 (8.3%)
5+ kWh
3 (25%)

Total Members Voted: 12

Author Topic: How many kWh per day does your home use when you are away traveling?  (Read 10828 times)

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jlsoaz

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[2016-06-05 addendum/edit - When I first set this poll up, I was unclear if it should include all household energy use (including propane and nat gas) or just electric energy.  Having received some input on the matter, I have modified the poll back after a day or so to be clear that it is just about electric energy - gas is ignored.  However, I do think that it would be well worth it for some of us to do a whole-house energy calculation... perhaps a separate poll in the future.]

Hi -

I'm wondering what results others see as to their home's energy use when it is largely not in use other than awaiting the return of denizens.  Just to be clear: solar harvesting doesn't count here.  This is just about your home's energy use, not about its net-energy-harvesting-minus-use equation.

It was pointed out to me that the answer for some may well depend on time of year.  For now my compromise is to ask if a person can provide an overall average.  I suppose it's possible other compromises would be to set up separate polls for time of year, or perhaps allow more than one answer.

Background - this is similar to a poll I set up here last year:

http://forum.theenergydetective.com/index.php/topic,3265.0.html

Then I got to thinking that fieldlines might be a very interesting place to ask the question, especially if there are folks here who are entirely or partially off-grid and possibly very conserving of their energy.
« Last Edit: June 05, 2016, 11:58:14 AM by jlsoaz »

bigrockcandymountain

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #1 on: June 04, 2016, 09:35:24 PM »
I am in the process of building right now in a passive house style.  16" thick walls with lots of solar gain windows.  It should be zero heat in the dead of winter to stay above freezing.  This is based on others that have built this way so I won't promise anything.  I'm near Maple Creek SK Canada. That leaves the fridge and freezer so maybe 1kwh/day. 

The off grid system is in already.  3000w solar array.  428ah @48v batteries.  Magnum 4400w inverter.  Wind turbine to be built when I get done the house.

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #2 on: June 04, 2016, 10:03:58 PM »
I am in the process of building right now in a passive house style.  16" thick walls with lots of solar gain windows.  It should be zero heat in the dead of winter to stay above freezing.  This is based on others that have built this way so I won't promise anything.  I'm near Maple Creek SK Canada. That leaves the fridge and freezer so maybe 1kwh/day. 

The off grid system is in already.  3000w solar array.  428ah @48v batteries.  Magnum 4400w inverter.  Wind turbine to be built when I get done the house.

Very ambitious.  Overall I'm hopeful this poll and topic will prove a bit of a toe-hold for folks to mention some of their individual measures.

Upon reading your points, one thing I'd want to mention about my own numbers - a few years ago I put in batteries and a new inverter:

http://outbackpower.com/outback-products/make-the-power/radian-series-inverter-chargers/item/radian-series-gs8048?category_id=529

Under "Idle consumption (Invert Mode, No Load)" it says 30W.

In effect, I may have raised the 24x7x365 energy consumption of my house by about 30 W (though it's hard to know, for example, maybe it could use less when there is a load).

For your inverter, it seems to indicate 25 W when under no load:
http://www.invertersrus.com/magnum-ms4448ae.html

I also replaced my old hot somewhat primitive (and very broken) solar hot water heater with a new one that included a motorized pump for getting the glycol to the roof and then I guess there is a heat exchange process.  While the overall solar hot water heater functions wonderfully to help me save energy (it works so well that basically I can leave my conventional electric hot water heater circuit turned off at the panel much of the time) it still does add a small amount of energy use in that the motor has to be working.  In fact, there is a vacation mode so if I am really away for a long period of time, and there is no hot water use, then the motor will cycle at night and reduce the overall temperature, but that means a bit more energy use.

So, while there are many things I could try to do to get my energy use under control, I think it's interesting that these two modern energy devices I've installed add a bit to the overall day-to-day energy use, even as they may provide convenience or reduce overall energy use in other strong ways.

DamonHD

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #3 on: June 04, 2016, 10:15:16 PM »
Background gross electricity consumption of house (on-grid, ignoring PV): ~1.5kWh/d of which most is the fridge/freezer.

Natural gas for hot water is 0 when we're away.  Space heating is also 0 at this time of year.  Mid-winter with no one one here and system only on frost protect with OpenTRV given temperatures are rarely sustained below zero C here would probably only be a few kWh/d at most.  Note that if/when we get a heat pump the kWh figure would be reduced ~2.5 by the CoP.  We have a fair amount of internal wall insulation (aerogel), triple glazing, etc.

Note that I have a small off-grid system which runs my Internet-facing servers (eg www.earth.org.uk) year-round 24x7, and can optionally take the networking gear off-grid too if feeling full of beans, which comes to a total of ~400Wh/d.

Rgds

Damon

bigrockcandymountain

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #4 on: June 05, 2016, 07:15:02 AM »
That is right on idle power consumption.  If I went away and turned off everything that has constant draw like clocks and such, the inverter has a power search feature that uses less than 10w.  I think 6w. The batteries also self discharge so there would be some. 

Yes, I know it is ambitious.  My goal is a less than $200 per year propane bill.  We will see how it goes. 

Hopefully some others chime in and give some ideas to further reduce power use.  I'm always interested. 


DamonHD

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #5 on: June 05, 2016, 07:18:39 AM »
Hi,

I have my incredibly boring list of things that we've done to reduce consumption (though I'm still not at all happy with night/vampire consumption right now, and I'm thinking hard about how to reduce it):

http://www.earth.org.uk/saving-electricity.html

The main things have been insulation, air-tightness, more efficient appliances when old ones are beyond repair or too old, and zoned heating that turns itself off when you're not around.  On that last one I'm very biased!

Rgds

Damon

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #6 on: June 05, 2016, 12:13:05 PM »
Background gross electricity consumption of house (on-grid, ignoring PV): ~1.5kWh/d of which most is the fridge/freezer. [...]

From another link you provided, I was reading your analysis of your fridge/freezer energy use and I guess you're saying under 1 kWh per day, but at first look I haven't yet found where you mention the volume? 

http://www.earth.org.uk/saving-electricity.html
http://gallery.hd.org/_virtual/ByCategory/mechanoids/fridge/freezer/upright/white/

Under 1 kWh per day does sound excellent.

I bought a SunFrost in 2004 from the same folks who sold me my first PV system, and while it was very expensive and only 12 cubic feet, it was on paper the lowest kWh per day AC unit I could find.  The cubic feet are laid out well (I think) and for a one-person household, the size was ok, but if it were for 2 people, it would start to raise questions of whether more energy is expended in more frequent trips to the grocery store.

I think there is other thinking that could make the fridge/freezer question even more complicated (for example, it could be split up into two units, and perhaps a freezer can be kept in garage in winter in some climates.... I have never known if this was a good idea.)

Mary B

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #7 on: June 05, 2016, 12:20:42 PM »
My freezer to fridge conversion uses 450 watt hours per day!

DamonHD

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #8 on: June 05, 2016, 12:27:19 PM »
Background gross electricity consumption of house (on-grid, ignoring PV): ~1.5kWh/d of which most is the fridge/freezer. [...]

From another link you provided, I was reading your analysis of your fridge/freezer energy use and I guess you're saying under 1 kWh per day, but at first look I haven't yet found where you mention the volume? 

http://www.earth.org.uk/saving-electricity.html
http://gallery.hd.org/_virtual/ByCategory/mechanoids/fridge/freezer/upright/white/

Under 1 kWh per day does sound excellent.

All here:

http://www.earth.org.uk/note-on-Siemens-KG34NA10GB-upright-fridge-freezer-REVIEW.html

[gross fridge and freezer capacities are 186l and 109l respectively (186l and 88l net)]

As far as I am concerned it never met spec, which was a claimed 0.75kWh/d, but it does work, and it is bigger than its predecessor which used 2kWh/d.

Rgds

Damon

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #9 on: June 05, 2016, 01:03:43 PM »
That is right on idle power consumption.  If I went away and turned off everything that has constant draw like clocks and such, the inverter has a power search feature that uses less than 10w.  I think 6w. The batteries also self discharge so there would be some. 

Yes, I know it is ambitious.  My goal is a less than $200 per year propane bill.  We will see how it goes. 

Hopefully some others chime in and give some ideas to further reduce power use.  I'm always interested.

In making my list of cool energy features which unfortunately have slightly negative side-effects on energy draw, I mentioned a couple, but the list is a bit longer.  This is not really a list of tips so much as a sub-category of areas to be aware where energy and resource savings are sought and attained, but there can be as well a negative energy cost to note:

1) inverter drawing energy 24x7x365
2) solar hot water pump drawing energy regularly
I forgot to mention:
3) energy meter drawing energy while plugged in - I have a TED 5000 which allows me to have a good idea of my home electric power use, but in order to have this idea, and I guess to maintain continuity of data, it has to use a small amount of energy.
3a) if I want to access this data, or home network stuff, while I am on the road, I think I would need to turn on my router while I am on the road (I don't presently do this, and am not set up for it.
4) I put in a motor to recirculate bathroom water so that I was not wasting a lot of water to take showers.  It saves a bit of water (which is a bit more important around here than in some other areas), but I'm not sure how much energy (if any) this really directly saves.  If I leave it turned on 24x7 I think it may draw a small amount of energy, so I have it on a power strip and tend to turn off the strip when not in use.

5 My limited understanding of heat and cooling heat pump systems is that for the heating they have some sort of "crank-case heater" that is on 24x7x365 and whose purpose is to keep the refrigerant heat-transfer material to remain in gaseous state rather than converting to liquid.  This heater uses energy and I'm told by several folks that it can be very damaging to turn off the power to the unit overall if one then turns the power back on and immediately restarts the unit (this would be if the gas has settled into a liquid and hasn't had enough time to regassify?.... not sure this is as much a concern during uniformly hot period where it might not turn to liquid form).  Years ago when I first bought an energy meter, I would often turn different circuits off and on, to try to isolate where the 24x7x365 energy use was particularly if it was on a 240 Volt circuit where I could not use a plug meter.  This heater energy use was perhaps the biggest in the house (16 watts?), however, I suspect that I did a lot of damage to my unit and buying a new one and having it installed was very expensive (though maybe that damage was not the only reason it wore out - it was fairly old.... and I did manage to get one that is more energy efficient).  I don't know all the ins and outs of this issue, but when I leave the house for lengthier periods of time, I have stopped my previous practice of turning off the circuit to the unit - even though I think there is a bit of energy used 24x7x365, I'm just not willing to risk any further needless damage.  I do think it points to a question of whether there are highly efficient modern heating and cooling technologies out there which do not have this issue built into them, but I have found it somewhat challenging to research.

So, the above are all my pet-topic sort of list of energy use that is tied in to measures that I take to save or monitor energy or water.

On more basic energy-saving tips that we might want to share with each other, it is I think a long and ongoing discussion, but to get the ball rolling slightly, whether on larger or small areas:

- reducing (or avoiding installing) too many cordless phones plugged in 24x7x365 is an area that I think has some potential.  I don't practice what I preach in this area.

- I bought a good energy-saving refrigerator/freezer years ago and do not regret the basics of this decision.  I think the exact balance of money and energy savings is one that is a bit debatable, but the refrigerator/freezer percent of the overall daily energy use equation is pretty substantial for most of us, so it seems defensible to spend at least some money in this area, for an excellent energy-saving appliance (or in some cases, for a more complex strategy).
« Last Edit: June 05, 2016, 01:29:55 PM by jlsoaz »

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #10 on: June 05, 2016, 09:22:24 PM »
My freezer to fridge conversion uses 450 watt hours per day!

I don't know how big it is, but yes, that seems exceptionally low for a fridge.

DamonHD

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #11 on: June 06, 2016, 12:49:18 AM »
Thanks to improving energy standards you can buy an "A+++" fridge/freezer 'off the (rather large) shelf' that is in that sort of territory: here is one I picked at random from a UK retailer:

http://www.argos.co.uk/static/Product/partNumber/3656293.htm

Nominally ~470Wh/d.

Rgds

Damon

« Last Edit: June 06, 2016, 02:23:43 PM by DamonHD »

Mary B

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #12 on: June 06, 2016, 02:16:27 PM »
13cu foot chest freezer with an outboard temperature controller. Super efficient because your cold stays put when the door is opened.


My freezer to fridge conversion uses 450 watt hours per day!

I don't know how big it is, but yes, that seems exceptionally low for a fridge.

clockmanFRA

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #13 on: June 07, 2016, 02:27:51 AM »
Hi jlsoaz,

Your question...... I don't think I can give an honest answer....

Mrs says that I should get out more....

 ::)
Everything is possible, just give me time.

OzInverter man. Normandy France.

3off Hugh P's 3.7m Wind T's (9 years).  .. 5kW PV on 3 Trackers, (5 yrs) .. 9kW PV AC coupled Used/SH GTI's, on my OzInverter created Grid, and back charging with AC Coupling to the OzInverter to my 48v 1300ah batteries.

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #14 on: June 07, 2016, 09:26:52 PM »
Yes, you're right.  That particular example is physically not that big if I'm translating the net Liters correctly (206+98 L = 304 L = 10.73 cu ft), but still, there does seem to have been notable progress in fridge/freezer efficiencies.  I paid a very high amount for my 12 cubic foot Sunfrost back about 12 years ago.  I think it was advertised as using about 0.6 kWh per day and it seems to have held up (as far as I know) which is pretty darn good.  So, I'm glad I bought it and saved so much energy the last 12 years, but if I were going to buy now, it would be interesting to be able to spend much less and get great efficiency.

Thanks to improving energy standards you can buy an "A+++" fridge/freezer 'off the (rather large) shelf' that is in that sort of territory: here is one I picked at random from a UK retailer:

http://www.argos.co.uk/static/Product/partNumber/3656293.htm

Nominally ~470Wh/d.

Rgds

Damon

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #15 on: June 07, 2016, 09:29:57 PM »
I do like how the cold stays in when you open the door.  Makes sense.  There was one such competing option when I bought mine a long time ago, but I opted for the more conventional fridge/freezer side-opening combo.

13cu foot chest freezer with an outboard temperature controller. Super efficient because your cold stays put when the door is opened.


My freezer to fridge conversion uses 450 watt hours per day!

I don't know how big it is, but yes, that seems exceptionally low for a fridge.

DamonHD

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #16 on: June 08, 2016, 12:42:41 AM »
Yes, you're right.  That particular example is physically not that big if I'm translating the net Liters correctly (206+98 L = 304 L = 10.73 cu ft)...

That's quite large by UK standards.

Many people, eg renting, may have something more this size:

http://www.argos.co.uk/static/Product/partNumber/4871314.htm

Note that this is "A+" and similar consumption to the previous bigger one, but using smaller appliances generally helps Europeans save energy (and wastelines) compared to Americans, it seems.

Rgds

Damon

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #17 on: June 09, 2016, 10:12:12 AM »
Yes, you're right.  That particular example is physically not that big if I'm translating the net Liters correctly (206+98 L = 304 L = 10.73 cu ft)...

That's quite large by UK standards.

Many people, eg renting, may have something more this size:

http://www.argos.co.uk/static/Product/partNumber/4871314.htm

Note that this is "A+" and similar consumption to the previous bigger one, but using smaller appliances generally helps Europeans save energy (and wastelines) compared to Americans, it seems.

Rgds

Damon

Thanks, good points about general differences in fridge and freezer sizes.  I do think it's important when discussing the efficiency of fridge/freezers to note size and if necessary certain features (does it have water filtration), otherwise it seems to me hard to gauge the efficiency claim.

Also, as I have a small-ish fridge/freezer by US standards (about 12 cubic feet I think), it has sometimes made me wonder about the transportation energy use attributable to a fridge/freezer.  For a larger household, more trips to the grocery store would be needed and so energy use would go up.  Driving distances are (I am guessing) sometimes (on balance) greater here in the US and so maybe that also is a factor in why we may have bigger fridge/freezers though, yes, I'm probably just trying to side-step acknowledging a gluttony angle.


dbcollen

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #18 on: June 09, 2016, 10:45:49 AM »
We use around 10kwh/day regardless of if we are here or not, but we are completely off grid and have no reason to conserve, the solar is already there, use it or lose it. We run 4 freezers and a large fridge. 4.3Kw solar and up to 1.5Kw hydro seasonally, 50Kwh battery bank.

ChrisOlson

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #19 on: June 10, 2016, 02:39:44 PM »
I'll chime in on this one, but I should note our usage is kind of skewed when we are gone because our inverter is very inefficient at light loads less than about 1.5kW.  Without posting the efficiency curve, suffice it to say the inverter's power efficiency is ~30% at the normal 100-150 watt load that is on in our house when we are gone.  So while our actual consumption is about 3kWh/day with everything at idle - most of that being the fridge and freezer - the amount of DC input power to the system to cover that, with losses in the inverter and batteries, is about 11.7kWh.  We can increase our loads when we are there up to ~8 kWh day on the same 11.7 kWh input from DC sources.  So in my opinion, it doesn't really pay to to try to cut energy consumption that much in your home when you live off-grid, and it's better to run your inverter at 20% load or better 90% of the time, than it is to let it idle at 5-10% load 90% of the time.

As most are aware here, I've always been an advocate of using a smaller inverter to keep it loaded at peak efficiency (>20% rated continuous load) most of the time, and use a combustion generator for peak loads for off-grid power.

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #20 on: June 11, 2016, 01:13:24 PM »
We use around 10kwh/day regardless of if we are here or not, but we are completely off grid and have no reason to conserve, the solar is already there, use it or lose it. We run 4 freezers and a large fridge. 4.3Kw solar and up to 1.5Kw hydro seasonally, 50Kwh battery bank.

As clear as your point seems, I had never really thought about it prior to this.  I guess I haven't given that much thought to the totally off-grid point of view, will mull it over a bit more.

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #21 on: June 11, 2016, 01:59:54 PM »
Here again, an issue (or more than one) that I hadn't considered.

I think it's kind of off-to-the-side, but I do want to say that, technically, I did say for the poll "Just to be clear: solar harvesting doesn't count here.  This is just about your home's energy use, not about its net-energy-harvesting-minus-use equation."

So, in your poll vote, I don't know if you incorporated this principle (i.e.: just look at your end-use, and not at the low efficiency of the solar in getting it to the end-use).  However, regardless of your poll response, I'm glad you did spell out these solar/inverter low-load efficiency considerations, as I was not aware of them.

Very approximately, my house historically has been in that 100-150 watt load area when I am gone.  I guess since 125*24=3000, then if I could just get it to average a bit below 125, then I could fit back into the 1-3 bucket in the poll, where I was some years ago.  Mission creep, for my house, has included adding relatively new loads over the last few years:

- Home security system has been added to house; it is plugged in and has a small battery UPS that draws power.  Yes, in theory, if my whole house is on a battery, then this shouldn't be needed, and I have retired some of my other UPSs, but am reluctant to draw this one.  Part of the issue is that I never really dotted the i's and crossed the t's on my battery installation and really getting to understand it, so doing that next week with a consultant.  Even so, I am likely to leave that extra load in place.

- The new-ish solar hot water pump and heat exchanger is plugged in and cycles.  It does this even a bit more when I am not here so as to avoid heat/pressure build-up of unused hot water.

- I no longer turn off the Heating and Cooling circuit when I leave the house, and this means that some sort of 24x7x365 load is there.  This used to be maybe my most important trick for getting down below 100 watts (I think the old system used to draw 16 watts?  or was it 26?

- Replacing the new inverter with one that could handle my batteries and such has ended up I think adding a continuous load, but I'm not sure how much.  I didn't consider the old inverter when I used to do my calculations, but I am wondering if there is a sense in which the new one is plugged in and acting as an appliance.  I don't know. 

So, I guess these newer loads, and probably a few other older ones (leaving lights on for security for example) unfortunately for now put me up into the 3-5 kWh per day bucket.



I'll chime in on this one, but I should note our usage is kind of skewed when we are gone because our inverter is very inefficient at light loads less than about 1.5kW.  Without posting the efficiency curve, suffice it to say the inverter's power efficiency is ~30% at the normal 100-150 watt load that is on in our house when we are gone.  So while our actual consumption is about 3kWh/day with everything at idle - most of that being the fridge and freezer - the amount of DC input power to the system to cover that, with losses in the inverter and batteries, is about 11.7kWh.  We can increase our loads when we are there up to ~8 kWh day on the same 11.7 kWh input from DC sources.  So in my opinion, it doesn't really pay to to try to cut energy consumption that much in your home when you live off-grid, and it's better to run your inverter at 20% load or better 90% of the time, than it is to let it idle at 5-10% load 90% of the time.

As most are aware here, I've always been an advocate of using a smaller inverter to keep it loaded at peak efficiency (>20% rated continuous load) most of the time, and use a combustion generator for peak loads for off-grid power.

ChrisOlson

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #22 on: June 12, 2016, 09:58:47 PM »
So, in your poll vote, I don't know if you incorporated this principle (i.e.: just look at your end-use, and not at the low efficiency of the solar in getting it to the end-use).  However, regardless of your poll response, I'm glad you did spell out these solar/inverter low-load efficiency considerations, as I was not aware of them.

Just to be clear, I did use the actual usage on the load side of the inverter.  We have a system that can accurately measure that, where most that have off-grid power don't and will use the DC side which most solar controllers can tally quite well.

We don't run any less electrical equipment when we're gone than the average utility-connected home does.  We just have to think differently.  When we left to go sailing in the wintertime for 2 1/2 months we figured our system could take care of itself and manage the ~3kWh/day with no problem.  We were wrong.  We shut down the automatic start on the generators when we were gone, and came home to a system that was still operating but the batteries were in very poor condition, even though the energy produced by the solar panels was technically enough to meet the loads.  It all got ate up in battery and inverter losses.  The solar panels got covered up with snow and the batteries never got charged for the entire 2 1/2 months we were gone.  We ran the diesel generator around the clock for over a week to get the batteries happy again.

So when you put this type of poll on here, different people will look at it differently, depending on their experiences with it.  More here are off-grid than on, so the results may be a bit skewed.

jlsoaz

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #23 on: June 14, 2016, 11:24:12 PM »
[...]
So when you put this type of poll on here, different people will look at it differently, depending on their experiences with it.  More here are off-grid than on, so the results may be a bit skewed.

Thanks Chris, interesting story.

It does indeed seem true that the answers here are different than elsewhere.  So far though (with only a limited number of people responding) the kWh/day is lower than I've seen elsewhere, though the point is taken that some folks, when not at home, will leave their place using more than I might have realized.

kitestrings

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #24 on: June 16, 2016, 10:41:30 AM »
We're in the 1-2 kWh/d range.  Slightly different approach...

So we're pretty old-school, but when we started putting our system together it was small and back then you really couldn't depend on an inverter to cover the critical things.  We're off-grid since about 1984-85 IIRC.  Most all of our lighting is DC.  Our refrigeration is DC.  Our water pumping and refrigeration is DC.  The new inverter has about a 23 watt stand-by loss; it is about 6w if left in search mode.  I've sweat it less as our system and family has grown, but I hate phantom loads; even if the power is free.  And, in our case we have some winter production days that are 0-.5 kWh for several days.  We try to use search mode at least in the winter period.

We have plug strips on entertainment things (TV, satellite box, etc.).  We have three OH door operators.  I put them on a DC motion switch (and timers from inside) so they are only active when needed.  I have one load, our water softener, that is on its own small 100+w sine wave inverter.

Most folks, with a family of any size, would likely hate our refrigeration, but we have two small units.  An old 8 CF fridge/freezer with a Danfoss compressor - its over 30-YO., and a Steca 24V freezer.  Small, but very efficient.

We've focused more and more on diverting opportunity loads to water heating, so our overall "harvest" has grown.  This has worked well especially on days we're away at work/school, and it has helped reduce our LPG use.

Batteries pretty much suck from every perspective, so in the past we have looked to reduce what we needed to the extent possible.  Springing for new ones this summer, and it will be the most robust system we've had.  Still always some trade-offs.

~ks

ChrisOlson

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #25 on: June 16, 2016, 11:51:17 AM »
Yeah, anybody with batteries and a primarily DC system will have more difficulty figuring out daily usage because of unknown losses in the batteries.  Our batteries are starting to show signs of their age - get hotter than they used during absorb and take more water than they used to.  With fuel prices down we've just gone to diesel power more and take the load off the batteries so they don't have to cycle as much and try to stretch their life out to 15 years.  Using the diesel generator we've gotten a cycle stretched out to 10 days in the winter.  But our total input into our power system is still quite a bit more than we normally get out when running on batteries.  The diesel generator, for us, is much more efficient and about 60% of the cost/kWh of charging batteries with solar and wind.  It seems to me that the best return on investment with solar or wind is to grid-tie it and use it offset your loads and not necessarily sell back to the utility.  Once you put batteries into the equation its practicality is questionable, to my way of thinking.

In the summer our usage goes up because the fridge and freezer runs more.  And the only time we will run the generator in the summer is if we want to run our central A/C system at night when it's hot and muggy.

So I think the OP's poll is somewhat interesting from the standpoint that many people will use a 'gut feeling' figure instead of actual long-term power system logging to come up with real numbers.

Frank S

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Re: How many kWh per day does your home use when you are away traveling?
« Reply #26 on: June 27, 2016, 12:45:47 AM »
Chris is absolutely spot on in his analysis.
 At the house we have been repairing to move into  I now have a 10 month energy usage total. On the months where we were only there 3 to 8 days of the month,ranging from last Aug. through Dec. the average usage was 69.8 Kwh no fridge or anything other than lighting and power tools.1 month we did not go there the total for the month was only 4 kwh.
 Interestingly since January t here has been the inclusion of a Fridge and Freezer as well as a television and using the Air-conditioner or the furnace as needed,(this is a heat pump system) since January the totals have been 166.5 per month average. Jan being the highest 10 days there with 750 Kwh used. Feb the lowest only 2 days with 70 kwh used.
  It would be next to impossible at this point to know just how much or how little we actually use while not there since we are there at least 3 to 6 days per month 4
 I know our current primary residence the motor coach with its bank of 12 3 to 5 year old golf cart batteries a 1.1KW PV and currently only a 6.5 KW diesel generator uses a lot more in Dollar cost per month due to the batteries having had over 1500 charge discharge cycles on them means we are using at least 100 gallons of diesel per month.
I live so far outside of the box, when I die they will stretch my carcass over the coffin