OpenEnergyMonitor Community

Storage Battery potential on the Solar app

Tags: #<Tag:0x00007fc9af265928>

I was wondering how difficult it would be to modify the Solar app so that it has an option to show how much energy you could have offset if you’d used a Storage Battery (and the size of battery you’d need).

Any easy way to do that within EmonCMS at the moment? You need to accumulate the solar export and then subtract the import as it happens marking in a different colour until the accumulator hits zero. Then someway of displaying the maximum value of the energy stored in kWh.

Anybody had a go at this?

Hi @NeilW,

Rather than creating/ updating an app, had you thought about setting up different feeds and graphing module to give you an equivalent?

For my local install I have a feed which shows the kWh/d for an Input/ Output delta. With the idea that I can understand my daily net import/ export, with the same idea of seeing how much of a difference a battery could make.

I’ve setup one input (taken from the CT clamp around the meter tail) as follows:

Order 	Process 	Arg
1	Log to feed	Node emontx3: grid
2	Allow positive
3	Log to feed	Node emontx3: import
4	Power to kWh	Node emontx3: import_kwh
5	Power to kWh/d	Node emontx3: import_kwhd
6	Reset to Original
7	Allow negative
8	x	        -1
9	Log to feed	Node emontx3: export
10	Power to kWh	Node emontx3: export_kwh
11	Power to kWh/d	Node emontx3: export_kwhd

I multiplied the export by -1 to give a positive figure as I wanted the stats to show what it was, rather than a direction.

I then setup a “virtual feed” with the following processes, you choose a feed name when you create the virtual feed:

Order 	Process 	Arg
1	Source Feed	Node emontx3: import_kwhd	
2	- source feed	Node emontx3: export_kwhd

From there you can graph this alongside your import_kwhd ane export_kwhd to compare the 3 and see what you’d need and be able to actually refill during a day.

You could always use the “display CSV” in the graph setup module to then place into your favourite spreadsheet and tinker with it further.