Use cumulative sum in Excel, ( linked in loops) , need help .

Dear all I need some support in a complicated excel function , which I was trying hard since a week .

its simply a function to calculate electricity power consumption, including generated power from solar systems I will try to explain it in her and will be happy if someone can help me knocking it out. (prefer in excel not VB) .

So
column A ..Is Value " B" = monthly Net power consumption
column B ..Is Value "MC" = Monthly power consumption from Grid ( consumed from the Grid)
column C ..Is Value " MI" = monthly power feed into the Grid ( generated from the solar system)
column D ..Is Value "R" = total power reserve ( cumulated from extra generated power month by month)

SO simply

B = MC - MI + R
in words ( Net power consumption = monthly power consumed - generated power + reserve which was generated and not used from previous months)

if B is positive then its need to be paid
if B if negative (which means we generate more than consumed) , then the new R = old R + the new B

it looks simple , but the problem that if I use if statement I will have a loop , where I can cumulate the R and use it again in the next month.

how can I get this don !!!

thanks all

If we have 1st month's data in row 2 in columns A:D

B MC MI R
-20 100 130 10
40 160 110 -10
x x x 30


in D3 and copy down

=D2+A2

This gives R for next month to be entered in row 3

In example above we have entered months 1 and 2

and R for month 3 is 30.

"x" indicates data to entered for month 3

Originally Posted by abedoo

Dear Friends

Shull I start a separate dissection regarding the title ?
where someone (like johny) help me to solved the main topic instead of getting confused.

Thanks

Glenn .. don't worry .. I never take things personal .. I speak 5 langues .. so I am fine if its not perfect as mother Tung people ..its just to communicate and understand each other. )

No, it would break another rule
It's fine now, and I can delete discussion.

It's about being more descriptive so other people that will search for simillar problem, can also get benefits from the answers.


Also I forgot to answer JohnTopley

Originally Posted by JohnTopley

If the OP does not know which formula to use, what is he/she supposed to say?

As rule say: describe a problem, not anticipated solution.
Sometimes users use some function while other is better to his solution. So formula he use is irrelevant.
It's a problem that we put focus on.
And "excel function help" doesn't give ANY information about a problem.