Power Logging

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I don't know how many other off-grid folks keep track of their monthly power production, but I have records going back 5 years. The Classic controllers make it really easy to log power production of your off-grid system (I used to use Doc Wattsons with external shunts).

At any rate, even though the month isn't over, for the first 30 days of January we had the best energy producing January ever, and the third best month ever in my 5 years of records. Our wind turbines produced 499.1 kWh, the solar 166.2 kWh, and an estimated 350 kWh from the generator for peak load running and occasional battery charging. Our fuel bill in the generator was $176.32, which for 1,015 kWh puts our out-of-pocket expense at just over 17 cents/kWh for the month.

Now, for the grid-tie folks that might not seem too impressive. But off-grid up here in the dark, overcast, snowy and cold north I'm pretty happy with it. :D
--
Chris

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    Re: Power Logging

    Chris, you are one of the few people I have ever talked with here that actually logs wind turbine and backup generator power generated (and fuel used).

    I am very impressed. It makes it much easier to understand where to put your efforts (and $$$) to get the best bang for you buck.

    Personally, I like to add capital and maintenance/battery bank replacement every X years too which does push the price up.

    But for pure fuel out of pocket expenditures, that is really good in this era of high fuel costs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Sun Dog
    Sun Dog Solar Expert Posts: 115 ✭✭
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    Re: Power Logging

    PVWatts says March is your best month for solar ( I used Eau Claire), does your data support that? Our 2.8kW of PV only generated 38 kWh in December :cry:
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
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    Re: Power Logging

    I've only just started logging this month and only been off-grid for 1 year- but this January is definitely better than the last and we're only solar + gen. Daily solar energy produced is logged here: https://cosm.com/feeds/75889

    On most days we make 7.5kWh from a 2.8kW array. Had to run the generator once this month for 2 hours, so about 3 litres of fuel = 4.2 Euros :D Our worst month was October, with lots of rain, had to run the gen for a total of 10 hours for the month.
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
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    Re: Power Logging

    One thing I want to add is a kWh meter on the generator output. As utilities have gone to the so-called "smart meters" I've seen the old flywheel type analog meters for sale, with the socket, for pretty cheap. Right now I estimate generator output based on hours of operation and estimated average load. My estimate is probably close enough but for the $25 I've seen those used utility meters for, it would be nice to have one.

    Eau Claire is way further south from us and they get much better solar insolation than we do in the winter time. But generally I would say that once March gets here that the solar panels start to work again pretty good, and they work well all thru the summer and fall. From about November to the middle of February it is very hard to get much power from them and mid-December to mid-January is the worst. This year we had surprisingly good solar insolation after the winter solstice with some really cold bright clear days. So we got more power from the solar panels than we have gotten in previous years.

    Once we get into the "dog days" of summer the wind turbines do not produce much, except when storms come along. But in the winter, with the cold dense air that has no turbulence from daytime solar heating of the land, the wind turbines work awesome.

    I'm pretty happy with our balance of power between solar and wind, as the wind works better in the winter and the solar works better in the summer. Our goal is not to eliminate generator run time because we use it for the peak loads, and those peak loads are some of the things that we have that usually only people with grid power have. No matter how much solar or wind turbines we put in, the cost in batteries to run the peak load stuff would make it not practical. And that's what we use the generator for. To have the stuff we have (all electric home, including range, water heating, clothes dryer and my shop) for only $176 out-of-pocket for generator fuel for the month, I don't think is too bad, to have an off-grid home that uses over 30 kWh/day.
    --
    Chris
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
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    Re: Power Logging

    Using that much power per day pushes the upper tier billing for my electricity plan (Time o use, seasonal) to around $0.30 per kWH in winter and around $0.50 per kWH (peak; ~$0.29 per kWH off peak) in summer.

    Your power bill would not have been much different here in California when on grid. :cry:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
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    Re: Power Logging

    I would have to stop eating if I paid those California rates.

    last year we consumed :
    House annual usage = 17713 kWh
    Office/Shop = 3675 kWh
    Volt Charging = 3309 kWh for 2 Volts
    Total consumption = 24697 kWh

    Solar production = 20514 kWh

    so a 4183 kWh purchased @ about $0.055 a kWh off peak. Roughly $230, well down from our peak annual bills of $5000-$5500.
  • mtdoc
    mtdoc Solar Expert Posts: 600 ✭✭
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    Re: Power Logging
    ChrisOlson wrote: »
    At any rate, even though the month isn't over, for the first 30 days of January we had the best energy producing January ever, and the third best month ever in my 5 years of records. Our wind turbines produced 499.1 kWh, the solar 166.2 kWh
    Chris

    166.2 kWh solar / 30 days = 5.4 kWh per day. With 3.5 kW of solar panel, in January, in Norther Wisconsin!!!!!!

    Wow Chris I'm impressed- what happened to the snow covered panels you had talked about??:confused:

    Did you get your panels mounted vertically to catch some snow reflected photons?
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
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    Re: Power Logging
    mtdoc wrote: »
    166.2 kWh solar / 30 days = 5.4 kWh per day. With 3.5 kW of solar panel, in January, in Norther Wisconsin!!!!!!

    Wow Chris I'm impressed- what happened to the snow covered panels you had talked about??:confused:

    Did you get your panels mounted vertically to catch some snow reflected photons?

    No, I left them right where they are and we had a pretty good month for once in the dead of winter. We have had some really cold clear days with not a cloud in the sky and they have worked good this year. It is the normal for us to not see the sun even once from about Christmas to the middle of February. So far it has been shining a couple days a week at least, which is fine with me :D
    --
    Chris
  • unicornio
    unicornio Solar Expert Posts: 217 ✭✭
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    Re: Power Logging

    yeah! ... Cris, you are admirable!!! .... hehehehe

    we are taking the accounts since 2007, but we have only the better power data since we installed the mate3, this January has rained a lot (which we most needed than the sun), you can see our data here:
    monitor solar on-line from jepefe

    too, we have meteorological data since 2011, that are online here:
    taller ecologico "los unicornios" weather data

    we also carry the accounts about the fuel we consume, both the generator, and the three vehicles we have, (land cruiser lj70, wolkswagen polo y yamaha grizzly) monthly in liters and also the water we waste and the water we recycle, monthly in m3 ...

    We should also keep accounts about the food we eat, and 4 Samoyeds, and 4 cats, but here we have not yet organized ...

    in our mind is to have everything posted on our website, but still do not have a practically method to do so ... but we're at it ... ;-)

    we're doing an experiment, I do not think normal people this taking so rigorously accounts!...
    but as I always say, since we have no money to keep any relevant accouting data, we entertain acounting other things! .... hahahaha
  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
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    Re: Power Logging

    Finally found this thread again!

    My solar production for Jan 2013 was 87kwhrs. Historically solar production for January is from 115 to a high of 175kwhrs. Wind production was 88kwhrs. That was the best ever January for wind in 9 years, but also the worst solar January. 2012 was the least productive solar year ever for me...1928kwhrs, but maybe 2013 will beat 2012. Other years ranged from 2033 up to 2359kwhrs. I haven't yet read the utility meter to see what the consumption was there, but probably 250kwhrs for January. A yearly total for utility is usually 600 to 900kwhrs (2012 was 1250, lower solar year).

    Every year I tell myself I'll get the monthly figures on an Excel spreadsheet so I can massage the numbers and display them coherently ( instead of scribbled on a sheet of paper), but as you can tell, I don't listen to myself too well. Someday.

    Ralph
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
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    Re: Power Logging
    Ralph Day wrote: »
    Finally found this thread again!

    2012 was the least productive solar year ever for me...1928kwhrs

    For us the first part of 2012 produced very terrible solar conditions thru the middle of June. In July and August we had day after day of 100+ degree heat with cloudless skies. And even though it was hot the solar panels here ran our air conditioning unit with no problem for those two months. The latter part of 2012 produced slightly above average solar conditions for us, and even December was above average solar output this year.
    --
    Chris
  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
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    Re: Power Logging

    Chris
    very off subject but what type of air conditioner were you running?
    Thanks
    gww
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
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    Re: Power Logging

    We have a window unit. It pulls about 10 amps on 120 volt.
    --
    Chris
  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
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    Re: Power Logging

    Chris
    Thank you
    gww