How is Solar PV saving me money?

[Leighton Gill]

Hi All,

First post here, so hello there.
I'm not an electrician so please excuse my ignorance in the subject.
I recently installed a Smappee energy (and solar) monitor system, and I'm really pleased with how it works.
However, I have noticed that the load on my meter does not drop when my solar pv array is generating power.
Therefore, I am struggling to understand how this is saving me any money on my electricity bills, as they will calculated based on my meter readings.
I have attached a picture (from the Smappee website) of my configuration if this helps to clarify what I mean.

I hope you can clarify this for me!

Thanks in advance.

View attachment 35815

 

[yellowvanman]

check your clampmeters are installed correctly

 

[LeeH]

The CT's may be directional. Look for an arrow on them.

 

[LeeH]

They are. Did you watch the video?

Support - Smappee - http://www.smappee.com/be_en/support

 

[Leighton Gill]

Hi there and thanks for the replies.
I'm sure I installed them with the arrows facing the correct way, but I'll double-check tomorrow.

 

[LeeH]

Hang on a minute...

The load won't drop, as the load is constant if you're producing or not.

You are monitoring both and the unit might not give you a differential as a numeric value. Just maybe something telling you that you are using more then you are producing or vice versa.

 

[Leighton Gill]

Hi Lee,
So if the load doesn't drop, does that mean mt solar isn't saving me money? Or am I misunderstanding how it works?

 

[LeeH]

You are monitoring load and generation.

If you are using 1000w AND generating 500w you are saving 500w.

Your meter only tells you both and does not deduct what you generate off the load value.

My geosolo has graphical green and red bar that shows red when I'm using more then I'm generating, and green when I'm exporting excess generation. The latter is bad as you get paid wether you put it back onto the grid or not, so make sure you use all of what you generate. (Unless like me you have an old meter that goes backwards.)



Does that make sense?

 

[LeeH]

This is a screen grab of the online portal showing BOTH. The physical meter shows the same.

When I'm over generating the excess gets diverted into the hot water tanks immersion so my 2 bars always stay level until the tank is up to 80 degC approx.

View attachment 35837

 

[Leighton Gill]

Hi Lee,
Ok thanks - but I'm still not clear how my actual bill is lower.
To use your example, if I'm using 1000w and generating 500w, but the meter still registers 1000w of use, then that is surely how the energy company calculates my usage and bill?

 

[LeeH]

No, you are using 1000, but you are producing 500. So you are paying for 500 only.

Understand your new meter does not DEDUCT the generation from the load. It only shows what you are using AND producing. 2 separate figures.

 

[Leighton Gill]

Hi Lee,

So I thought that any solar generation energy would be used to power the house first, with any additional draw/requirement coming via the mains.
Therefore I was expecting the electricity meter to register less usage while generating, and therefore reduce my electric bill.

 

[LeeH]

It is being used, the meter just doesn't display it that way.

Your meter that the distribution company supplies (the one you have always had) will show less energy being used. It will spin slower, stop or blink less if it's a newer digital meter.

The 'evergy monitor' you have just installed will only monitor load and generation. It will not calculate the difference between the 2 and display the difference. Only what you are currently using and what you are currently making. It 'may' give you some indication if you are using all that you are producing like mine.

You can be assured that you are saving on your bill. Wether you are turning a profit is a very different question.

Does that make sense?

 

[LeeH]

Think of it this way...

Your new 'meter' gives you real time information only at a glance. The savings will be seen on your old meter when the little man in a van turns up and records a lower number.

 

[Leighton Gill]

Ahh, ok I think I the penny has dropped now!
So, I won't see the reduced mains electricity usage directly through the Smappee monitor (compared to pre-solar), just the two values, generation and consumption.

 

[LeeH]

Simple as that.

That Smappe looks a nice bit of kit.

 

[Leighton Gill]

Crikey, I got there in the end! Thanks for your perseverance!
Yes, so far the Smappee is working really well. It's starting to distinguish between devices as well which will be really useful.