How to measure whole house load?

ligwyd
ligwyd Registered Users Posts: 212 ✭✭
I have been told that a device from Efergy is a cost effective way of measuring your total power consumption over a period of time for the purposes of sizing a system.
What is the consensus here for doing just that? Any recommendations? Have a generator running everything right now but would like to know how much power is actually being used to start accurately sizing a system build.'



Comments

  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    For under $100 you can buy a used utility meter, either pointer or digital, along with a meter base.  Wire it in, read the KWH.  Want to record genny & PV?  Wire two.  All pretty simple

    there are also CT metering schemes that would work as well, but probably not as inexpensive yet, but may be easier to install?

    Tony
  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,167 ✭✭✭✭
    Tony, I agree - using Current Transformers will be waaaaaay easier to install. Get split core CT and the exposure to heavy power will be a few minutes.
    I just use the metering data provided by my local utility - including hourly.
    I always have more questions than answers. That's the nature of life.
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    For ~$50 I used a power recorder to log energy useage over a month, this one is rated for 3750W which is greater than the output of my inverter so doing whole house loads were possible in my case.
    https://youtu.be/qZ5FoI6qoXI
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,617 admin
    TED has been around for a long time... And they have different models that can measure more than one circuit (main, water heater, A/C, etc.).

    http://www.theenergydetective.com/

    Just of an example of what is out there...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Tony, I agree - using Current Transformers will be waaaaaay easier to install. Get split core CT and the exposure to heavy power will be a few minutes.
    I just use the metering data provided by my local utility - including hourly.
    Mark,  do you have a brand/model you use?  Ihave a client that I need to do an analysis for with 15 water heaters and 15 clothes dryers.  The client has no idea of how much load these draw on a annual basis used seasonally.  As part of a broad audit I want to meter/log each device for a year.  I have not seen a CT system that is really affordable in quantity.  I have found some 240 vac pass through meters but that is a wiring issue, each one needs to be hard wired (and enclosed).  Failing that, I can buy cheap meter bases and cheap utilities meters for ~$35 USD for the pair.  That comes with an install headache and cost as well.  I might consider doing the water heaters one season, the dryers a second, so the hardware could be moved.

    Thanks,

    Tony