the cost of coffee?

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  • alterego
    Junior Member
    • Jul 2014
    • 20

    the cost of coffee?

    We make coffee every morning. Our programmable unit turns on at 5 15 and shuts off after two hours. And it gets left on that way. I leave before 6 and my wife before 7. So it is on for two hours. It is a 975 watt unit. So Damn near two kwh. So I pulled it's cord and I am using my percolator.

    It takes 15 minutes of propane on a burner to percolate coffee. At 3 dollars per gallon of propane.

    And electric at 15 cents per kilowatt. Or 2 kwh total.
    Which is cheaper on grid.

    And more importantly will it help me get down to a usage that makes off grid feasable?
  • russ
    Solar Fanatic
    • Jul 2009
    • 10360

    #2
    Try checking the actual consumption of the coffee maker - it is far less than you noted.
    [SIGPIC][/SIGPIC]

    Comment

    • pleppik
      Solar Fanatic
      • Feb 2014
      • 508

      #3
      Originally posted by alterego
      We make coffee every morning. Our programmable unit turns on at 5 15 and shuts off after two hours. And it gets left on that way. I leave before 6 and my wife before 7. So it is on for two hours. It is a 975 watt unit. So Damn near two kwh. So I pulled it's cord and I am using my percolator.

      It takes 15 minutes of propane on a burner to percolate coffee. At 3 dollars per gallon of propane.

      And electric at 15 cents per kilowatt. Or 2 kwh total.
      Which is cheaper on grid.

      And more importantly will it help me get down to a usage that makes off grid feasable?
      The coffee maker probably draws 975 watts only for the time it is actually making coffee. The rest of the time it's likely using a lot less.

      This is a good place for a power meter (like a Kill-a-Watt) to figure out the actual standby usage.

      I recently discovered that my coffee maker uses about 1KW when I'm brewing, and 50W in standby. It's a Bunn which keeps a reservoir of water hot all the time, which is why it's always pulling 50W. I reduced my daily power consumption by 8% (over 1 kWh/day) just by turning the darn thing completely off when I'm not making coffee.

      (It makes good coffee, though.)
      16x TenK 410W modules + 14x TenK 500W inverters

      Comment

      • Sunking
        Solar Fanatic
        • Feb 2010
        • 23301

        #4
        Originally posted by alterego
        And more importantly will it help me get down to a usage that makes off grid feasible?
        It is impossible to make off-grid feasible. Battery cost alone will be 60-cents per Kwh. So forget it.

        Your coffee pot does not use 2 Kwh. Just like your propane you do not turn it on for two hours as you would boil all water off and scorch your pot. In reality you likely use 500 watt hour or less. To calculate or compare cost between fuel source you have to find the common denominator which in this case is BTU's which is extremely hard to determine for your propane because you cannot tell us at what rate you burn propane. Is it a simmer or a torch? You cannot answer.

        However I can tell you exactly what 1 million BTU's is for both electricity and LPG based on the information you gave me.

        Electricity = 293 Kwh x $0.15 per Kwh = $43.95
        LPG = 11 gallons x $3 per gallon = $33

        LPG cost 25% less than electricity as a heat source.

        Take away here is if your electric coffee pot uses 500 watt hours cost you 7.5 cents, and if you use LPG cost 5.63 cents.

        Want to make that coffee on battery power will cost you 30 cents just for the battery. Add another 10 cents for the equipment and material and you are looking at 40-cents . So rush right out and get a solar system with batteries and start saving money today.
        MSEE, PE

        Comment

        • Wy_White_Wolf
          Solar Fanatic
          • Oct 2011
          • 1179

          #5
          That thing is also a phatom load. The timer and electronics draw for the whole day. It may only be a 5 or 10watt draw but it's still there. Add that into whatever the kill-a-watt reading is for the 2 hours you have it on.

          WWW

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          • alterego
            Junior Member
            • Jul 2014
            • 20

            #6
            Originally posted by Wy_White_Wolf
            That thing is also a phatom load. The timer and electronics draw for the whole day. It may only be a 5 or 10watt draw but it's still there. Add that into whatever the kill-a-watt reading is for the 2 hours you have it on.

            WWW
            I Went A Round THE House And Unplugged THE WI the treadmill the coffee maker two night lights a laptop cord that has not been plugged into a laptop but has a small light on its transformer and an alarm clock.

            I have the new consumers digital electric meter. In the nighttime hours between midnight and morning our average kwh went from .38 .47 per hour to .27 .37 or very close. I of corse do not know how much any one was suckling but they all add up. Oh yeah my daughters electric piano as well.

            Comment

            • bcroe
              Solar Fanatic
              • Jan 2012
              • 5198

              #7
              Originally posted by alterego
              I Went A Round THE House And Unplugged THE WI the treadmill the coffee maker two night lights a laptop cord that has not been plugged into a laptop but has a small light on its transformer and an alarm clock.

              I have the new consumers digital electric meter. In the nighttime hours between midnight and morning our average kwh went from .38 .47 per hour to .27 .37 or very close. I of corse do not know how much any one was suckling but they all add up. Oh yeah my daughters electric piano as well.
              So your phantom loads are around 300W? Each watt is adding 3/4 KWH to your monthly bill. You are on the
              right track, but have a long way to go. Get your KILL-A WATT meter and check everything, including stuff
              wired in, like furnace control trans, doorbell trans, etc. I had a hundred such things all adding up to 300W;
              with considerable effort reduced it to 50W. Some things I couldn't undue were motion detector lights, GFI
              outlets, garage door radios, and a couple clocks; some things were reworked for a 70% reduction. Bruce Roe

              Comment

              • Mike90250
                Moderator
                • May 2009
                • 16020

                #8
                I've got about 200w of "base loads" that are always on, including Ozone bubbler for water tank, aerator for filter tank, couple night lights, one of 3 fridges always running, laptops, water heater brain, garage door receiver.
                Some you just can't get rid of.
                Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                solar: http://tinyurl.com/LMR-Solar
                gen: http://tinyurl.com/LMR-Lister

                Comment

                • SunEagle
                  Super Moderator
                  • Oct 2012
                  • 15125

                  #9
                  Originally posted by Mike90250
                  I've got about 200w of "base loads" that are always on, including Ozone bubbler for water tank, aerator for filter tank, couple night lights, one of 3 fridges always running, laptops, water heater brain, garage door receiver.
                  Some you just can't get rid of.
                  I'm still working on my vampire hunting. I am down to about that 300 watts (~$32/month) and I know a few places I can reduce it.

                  I use to like those "instant on" capabilities but now understand what it is costing me not to wait a few minutes for something to "warm" up.

                  Comment

                  • bcroe
                    Solar Fanatic
                    • Jan 2012
                    • 5198

                    #10
                    Originally posted by SunEagle
                    I'm still working on my vampire hunting. I am down to about that 300 watts
                    (~$32/month) and I know a few places I can reduce it.
                    I use to like those "instant on" capabilities but now understand what it is costing me not to wait a few
                    minutes for something to "warm" up.
                    I put things that are actually working for me (refrigerator) in a different category, typically improved
                    by using the latest Energy Star stuff.

                    Phantom loads would be things that sit there doing nothing most of the time, but using power (garage
                    door opener/radio, doorbell transformer, battery maintainer, GFI, wall wart/in line power supply). The
                    doorbell transformer was eliminated by running it off the furnace transformer. Many surprisingly inefficient
                    older control transformers and wall wart supplies can be replaced with a big improvement. Bruce Roe

                    Comment

                    • SunEagle
                      Super Moderator
                      • Oct 2012
                      • 15125

                      #11
                      Originally posted by bcroe
                      I put things that are actually working for me (refrigerator) in a different category, typically improved
                      by using the latest Energy Star stuff.

                      Phantom loads would be things that sit there doing nothing most of the time, but using power (garage
                      door opener/radio, doorbell transformer, battery maintainer, GFI, wall wart/in line power supply). The
                      doorbell transformer was eliminated by running it off the furnace transformer. Many surprisingly inefficient
                      older control transformers and wall wart supplies can be replaced with a big improvement. Bruce Roe
                      I understand just about 98% of my vampire loads. The issue is getting them turned off.

                      The biggest barrier is convincing the other members of the household to wait a couple of minutes to get their TV working or not to plug the hand vacuum or leaf blower into its charger every day. I at least got them to go to a 2 watt LED night light instead of those 12watt incandescent ones.

                      Comment

                      • pleppik
                        Solar Fanatic
                        • Feb 2014
                        • 508

                        #12
                        Originally posted by bcroe
                        The doorbell transformer was eliminated by running it off the furnace transformer. Many surprisingly inefficient older control transformers and wall wart supplies can be replaced with a big improvement. Bruce Roe
                        That's brilliant....

                        Too bad my doorbell transformer is hardwired and I can't plug it in to a Kill-a-Watt. I'd be curious to know how much of a phantom load that is.

                        I think my doorbell gets rung about once every two weeks (I live in a quiet neighborhood). If the transformer pulls just 1W in standby, that's 0.336 kWh for each time the doorbell rings. Enough to make a full pot of coffee.

                        Maybe I could just replace it with a pull-cord, like on the Addams Family.
                        16x TenK 410W modules + 14x TenK 500W inverters

                        Comment

                        • bcroe
                          Solar Fanatic
                          • Jan 2012
                          • 5198

                          #13
                          Originally posted by pleppik

                          Too bad my doorbell transformer is hardwired and I can't plug it in to a Kill-a-Watt. I'd be curious to
                          know how much of a phantom load that is.

                          I think my doorbell gets rung about once every two weeks (I live in a quiet neighborhood). If the transformer pulls
                          just 1W in standby, that's 0.336 kWh for each time the doorbell rings. Enough to make a full pot of coffee.
                          If you're as serious as me, you'll unwire it and take a measurement. I'll bet its a lot closer to 3 watts than one.
                          I actually measured nearly 60 120 VAC circuits, by opening the breaker with a KILL-A-WATT connected across it.

                          1 watt was my threshold; I'd try to get it down to 0.1 W. Just eliminating waste; none of this involved retraining
                          personal or loss of service. Bruce Roe

                          Comment

                          • alterego
                            Junior Member
                            • Jul 2014
                            • 20

                            #14
                            My wife brought the percolator in last Thursday night.
                            So Friday Monday and Tuesday I have data chart from my consumers smart meter to compare from the last several days before Thursday.
                            It is really quite remarkable how consistent our usage spikes in the morning up above a kilowatt between 1 and 2 from 5 am to 7 am and then down to .5 at 8 am and floats in the .27 to .43 for several hours while people are not using things.

                            So with out the coffee pot the peaking for two hours is down below .75 kwh. So the coffee pot was eating more in the tune of .6 to .75 kwh.

                            I took pics of the charts but can not get them to upload.

                            Comment

                            • bcroe
                              Solar Fanatic
                              • Jan 2012
                              • 5198

                              #15
                              Originally posted by SunEagle
                              I understand just about 98% of my vampire loads. The issue is getting them turned off.

                              The biggest barrier is convincing the other members of the household to wait a couple of minutes to get their TV working or not to plug the hand vacuum or leaf blower into its charger every day.
                              Very small battery chargers seem to all be very inefficient. They draw a lot of current on
                              standby or when the battery is floating; the power about doubles when delivering maximum
                              charge current. That current typically is only a small percentage of the time. I did design
                              one 12V FLA maintainer with a very low standby drain, but there are others. Bruce Roe

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