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Simple energy meter


SuperJohnG

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A smart meter would do - however despite having a smart meter they can't connect to it because of the house/ where we are. 

 

Hence I'm looking for a basic item to tell me current power consumption (electricity only) I have seen the Shelky and the Emon unit from the openenergy guys in Wales. 

 

I want to do zero messing around or logging etc.  I just want to get a unit and get a display that'll tell me current consumption for the whole house. The display could be one on the unit or a nice to have would be an app I could look at on my phone. 

 

Any recommendations for the Shelly/ Emon units? Or alternatives.  

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  • 4 months later...

I think I'm going to order the shelly unit, I love the look of the open energy interface but it's 250 quid vs 80 and in reality I really only want to measure the main incomer and our ASHP.

 

The reason I've picked this up now, as I done a meter reading g the other day and for the 80 days we averaged around 47kWh each day which seems ALOT? the other day we were 70 kWh for a day which seems madness! 

 

But my ASHP is a vaillant running a cop of 4.1 for the heating, 3.4 for the DHW so it's not that but I really have to figure out where the energy is going. We do have a borehole but can't imagine it's those pumps as they run for very short periods,there is a UV bulb which runs 24 hrs a day but even at that I can't imagine the bulb is larger than 40W at most. 

 

I'll likely now order a PV system and some batteries but that's the next thing on the list. Likely this be a Giv energy unit has anyone used that along with a Shelley? 

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20 minutes ago, SuperJohnG said:

7kW unit, yesterday it said 80kW energy yield but I assume that is then divided by the COP. I can't be using 2kW every hour, I can't see it. 

Right.

Need to get the language sorted out.

kWh is energy, kW is power.

 

So if you used 47 kWh in 24 hours, that is mean of 1.9583 kW.

 

47 [kWh] / 24 [h]  = 1.9583 kW.  The hours [h] cancel each other out leaving just the kW, the power.

 

Now if your heat pump delivered 80 kWh of thermal energy in 24 hours, then that is a mean power delivery of 3.33 kW.

 

80 [kWh] / 24 [h] = 3.33 kW

 

Say you used 4 kWh for other things i.e. TV, cooking, massage machine, with the remaining 43 kWh going to the heat pump, then your CoP is 1.86.

 

80 [kWh] / 43 [kWh] = 1.86, which is not very good.

 

I am assuming that you meant 47 kWh of electricity a day, not 7 kW units, which basically means nothing.

Edited by SteamyTea
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7kW ASHP unit. 80kWh energy yield delivered it said (that specific day was 70kWh power consumed for the whole house), the COP its showing is around 4.1 for heating but you have dhw at 3.5 COP (roughly 9kWh was dhw) so let's say it's all at 4 as a round number. 

Edited by SuperJohnG
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Immersor was turned on...but its faulty, sparks were here today and while waiting for my Shelly  EM to arrive in the next few days we quickly checked the current draw, the immersor albeit for some reason isn't heating water, has been on for around two weeks, pulling 2.7kW the whole time. An expensive two weeks..but glad we found it quickly. 

Edited by SuperJohnG
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6 hours ago, SuperJohnG said:

Immersor was turned on...but its faulty, sparks were here today and while waiting for my Shelly  EM to arrive in the next few days we quickly checked the current draw, the immersor albeit for some reason isn't heating water, has been on for around two weeks, pulling 2.7kW the whole time. An expensive two weeks..but glad we found it quickly. 

Pleased you have found the problem, I having been using the Shelley EM with ct clamps for just over a year now, excellent product and app.

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On 13/02/2024 at 00:20, SuperJohnG said:

Immersor was turned on...but its faulty, sparks were here today and while waiting for my Shelly  EM to arrive in the next few days we quickly checked the current draw, the immersor albeit for some reason isn't heating water, has been on for around two weeks, pulling 2.7kW the whole time. An expensive two weeks..but glad we found it quickly. 

 

I don't understand how an immersion can pull 2.7kw and not generate any heat - that makes no sense in my head - it's using power it's generating heat somewhere even if not in the tank.

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On 13/02/2024 at 00:20, SuperJohnG said:

the immersor albeit for some reason isn't heating water, has been on for around two weeks, pulling 2.7kW the whole time

Does your heat pump use that heater to defrost?  The energy could just have been blown out the unit.

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>>> I don't understand how an immersion can pull 2.7kw and not generate any heat

 

it can’t without breaking the laws of thermodynamics. Either not switched on / bad connection / faulty thermostat / or duff element. Easy to diagnose in 2 minutes with a multimeter. 

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12 hours ago, SteamyTea said:

Does your heat pump use that heater to defrost?  The energy could just have been blown out the unit.

No, it draws heat from the UFH.

 

9 hours ago, Alan Ambrose said:

>>> I don't understand how an immersion can pull 2.7kw and not generate any heat

 

it can’t without breaking the laws of thermodynamics. Either not switched on / bad connection / faulty thermostat / or duff element. Easy to diagnose in 2 minutes with a multimeter. 

I don't know either, but if it was working it would keep heating the water between my heat pump setting (52 degrees) and the stat on the immersor then turn off, but it doesn't seem that has been happening. 

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