What could be the connection between coal plants and tomato plants?

Well, if you are going to do vertical farming, you going to need a lot of CO2.
Here is an example of what I mean:
"Once the plants are placed on the final growing media, the air temperatures are maintained at 20°C day and night, with a relative humidity of 75% (VPD of 3.5 to 5 g/m3) and liquid CO2 supplementation to 800 to 1000 ppm. "
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/opp7957

Now, I have very roughly calculated:
A 100' by 100'- 10,000 sq ft- lighted with LEDs would take 100 kwh [10 watts per sq].
And if charged $.05 per kw/h would cost $5 per hour in electrical costs.

In 3-4 months could produce about 3 million lb of tomatoes or around +3 million dollars per year.

And if include the sugar in tomatoes, and the roots and stems of tomato plants- it's probably somewhere around
1 million lbs of carbon per year.

But as 5.5 lb of gasoline makes about 20 lb of CO2, the plants will be making more weight in Oxygen then their weight in carbon. So it will using up about 4 times the weight of CO2 as compared to weight of plants. So, it will need about 3-4 million lbs of CO2 per year- around 1000 tonnes per year.

And if one has 100' sq building which 10 stories, you need about 10,000 tonnes of CO2 per year- which if truckloads of CO2 is a fair amount. The 10 story vertical farm would also need 1 megawatt.

Now, on list of:
List of least carbon efficient power stations
Edwardsport IGCC is US is listed has second worse powerplant in terms of electrical power compared to CO2.
http://en.wikipedia.org/wiki/List_of_least_carbon_efficient_power_stations
I don't why [btw] since it says:
"Edwardsport is a 120-MW coal-fired electrical power plant, and also a site where an integrated gasification combined cycle power plant
...
The existing Units 1 and 2, rated at 45 and 75 MW respectively, were launched into service in 1949 and 1951.[1] They will be retired as the new 600-MW plant comes online. The new plant is slated to be a base-load station, capable of supplying Indiana with additional capacity as it is needed in the future. The plant will also be carbon capture-ready."

Anyhow, Edwardsport has CO2 intensity

(Mt/TWh) of 1.56

So, I suppose that is 1.56 million tonnes of CO2 per Terawatt-hour [1,000,000 MWh]

So this 10 story vertical farm needs 1 megawatts or 8760 MWh per year and consumes about 1000 tonnes of CO2 per year.
So for Edwardsport to make 8760 MWh of electricity it makes 13,665 tonnes of CO2.

So, the the vertical farm would only use about 1/10th the CO2 that would be made to generate the power to keep the lights on. At least in terms of the worse efficient coal plant in the US- and second in the world according to this list.
Hmm.