Is It Worth Removing Controlled Load Meter if You Have Solar?

Dr-StrangeLove on 20/01/2025 - 11:01

I have a seperate controlled load (CL) meter in my property which serves solely for the electric water heater. It runs only during non peak hours and consumes a lot of energy. However prices per kWH for CL is significantly less than normal rates. Since the appliance consumes so much power, end of the term the price of both meters are almost the same.

I am wondering if I can reduce my power bills by removing CL meter. I have a 6.6kW solar panels. Would that be sufficient to service water heating? Assuming it is running on full capacity in the middle of the day.

I have looked into switching to heat pump water heaters. But the noise is too much from it and also I recently replaced my old heater so don’t want to discard it now.

TIA

Home & Garden

Comments

  • killingtime on 20/01/2025 - 11:20
    +2

    Going to need some more numbers from you. What model got water cylinder? What's the usage pattern. Are you already using up all your solar now? What are the electricity prices?

  • wannagrababargain on 20/01/2025 - 11:24
    +1

    It takes about 5.25 kWh to raise 100 litres of water from 15 degrees to 60 degrees. Generously assuming 100L per day consumption of hot water. This is about 3 hours at 2 kW of excess solar output each day - in worst case scenario is this achievable in Winter? Although you have bills with actual kWh consumed of that one appliance so the maths should be pretty easy to work out. Regardless if you're feeding back a lot of solar to the grid it's generally better to try to self-consume it. The small number of days where you have to top up from the grid would likely end up costing a lot less than CL every day - assuming you have the solar generation to spare.

    • Dr-StrangeLove on 20/01/2025 - 12:02

      That calculation sounds about right. I have AGL app and as per the data there, consumption is less than 3kWH a
      during the time at night when it runs.

  • Baysew on 20/01/2025 - 11:34

    It runs only during non peak hours

    In situations where you run out of hot water during the day and need to heat water during the day, there may be a boost switch.

  • BOGOF on 20/01/2025 - 11:59
    +1

    I installed solar a couple of years ago and removed the CL meter at the same time.
    Got the sparky to install a timer on the H/W circuit to only heat during times when solar panels could possibly generate.
    Currently I have the water heater on a timer from 8:00 - 16:00. Never run out of hotwater.

    • Dr-StrangeLove on 20/01/2025 - 12:01

      Thanks, did it help reduce bill?

      • BOGOF on 20/01/2025 - 12:03

        Massively.

    • AB100 on 20/01/2025 - 12:23
      +1

      I did the same, but I also replaced the 3600w heating element in the H/W with a 1800w one. Takes longer to heat the water, but didn't overwhelm my solar system.

      • Lichen6420 on 20/01/2025 - 13:57

        This is actually more relevant. As above most largish electric hot water systems have a 3.6kw (3600w) heating element.

        Having only a small 6.6kw solar system this does not leave much left over for other loads, particularly in shoulder production times and winter months.

        Get a timer installed and a smaller element put in the HWS at the same time.

  • JIMB0 on 20/01/2025 - 12:12
    +1

    A solar diverter would dump any excess power into the hot water heater. A cheaper option would be using a lower power element and a timer.

  • Shame on 20/01/2025 - 13:29
    +1

    Depends what your controlled load tariff is. If you use 3kWh a day at 22 cents per kWh that is 66 cents per day or $240 per year. An electrician to remove the controlled load would cost $400 (guess?) so it would take 1 year 8 months for payback.

    I'd probably just wait until I need an electrician for another job and have them do it then or else just wait until the hot water tank dies.

    Do your own calculation

  • cashless on 20/01/2025 - 15:59

    I have solar panels but my hot water on CL like you OP.
    Difference for me is that the solar runs two pool pumps (one for filtration, one for a separate solar heating roof array), meaning that I don't generate a lot of excess power to heat hot water.
    Like you I've looked at heat pumps, but decided that coming off the CL and installing a heat pump was a lot of fussing and expense.
    I looked at running a heat pump on the CL, but that isn't an efficient option either.
    In the end my mind was made up when the old hot water tank blew up and I have to get a replacement in fast.
    What really p1sses me off is the way the energy providers have started to creep up the cost of the CL tariff, because the CL is really my only electrical expense.
    Have checked out all the providers in my area and they all seem to have increased the CL tariff over the last couple of years.
    Options are to fit more solar panels or move off the CL and use heat pump.
    But yeah, getting the decision right is tricky because you have to weigh up so many factors.
    And just when you think you've got things right the energy provider whacks you again.

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