https://docs.google.com/spreadsheets/d/178-lrcqUqP5BmLZgmcYzc8IfY...

https://docs.google.com/spreadsheets/d/178-lrcqUqP5BmLZgmcYzc8IfYcrI_iQH3OdyLrFPaaA/edit?usp=sharing

All you have to do is put in the profit you expect Gibio to make per lettuce, the percentage of Gibio that RGI owns, and the profit that RGI makes for every 8' RotoGro machine that they sell to Gibio.
There are a number of assumptions made in this calculator. I have assumed that there will be 1 facility going up every 6 months for the next 5 years (10 facilities over 5 years as announced) and that each facility will produce 36,000 lettuce's per day as announced in the most recent market update.

For example, let's put in $0.9 profit for a single lettuce, the current 9% stake, and a profit of $4000 per machine.
We can see that RGI will earn $532k from the lettuce every 6 months from every facility as well as $1.68m profit from the sales of machines.
With these figures, over the next 5 years, RGI stands to make $46m from their 9% stake.
However, if we bump our stake up at 49% (as we have the option to do) then things get even juicier. Go ahead and try that!

Hope this helps! If you have any suggestions, want me to add anything or notice any errors then let me know.

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This is a public shreadsheet which anyone can edit. I believe I have set it so that you guys can only edit row 2, which is where you enter in the price of coal and the costs to mine the coal. If you can edit other rows let me know because I'll have to change.... something. This is the first spreadsheet I've tried to make.

Because it is public and can be edited at anytime by anyone LIVE, I recommend you:
Click 'File' 
Click 'Make a copy...' or 'Download'

This way you should get your own copy which no one else can edit it while you're trying to do your own working out.
I think it's unlikely that after tonight anyone will be using it at the same time as you are anyway though