Each of these files corresponds to one of the input arrays required by PyPower or MatPower. 
These have their own documentation, however, of the inputs required, those utilised are also described in the paper.



"baseMVA.txt" contains just one value; the base MVA used (100). 



"branch.txt" contains the values required to define the branches. 
Where each branch is a row, the columns denoting their specifications are:
Bus1	Bus2	R	X	B	RateA	RateB	RateC	ratio	angle	status	angmin	angmax



"bus.txt" contains the values required to define the buses. 
Where each bus is a row, the columns denoting their specifications are:



"gen.txt" contains the values required to define the generators. 
Where each generator is a row, the columns denoting their specifications are:
Bus	Pg	Qg	Qmax	Qmin	Vg	mBase	status	Pmax	Pmin	Pc1	Pc2	Qc1min	Qc1max	Qc2min	Qc2max	ramp_agc	ramp_10	ramp_30	ramp_q	apf



"genCost##.txt" contains the values required to define the costs generators. 
Where each generator is a row, 
(thus there will be equal rows to "gen.txt", with each row referring to the same generator), 
the columns denoting their specifications are:
Type	Startup	Shutdown	number of coefficients	a	b	c

It should be further noted that the values of generator cost vary based on the carbon tax rate, 
as described in the equations presented in the paper. 
Therefore, for convenience, a number of "genCost##.txt" files exist, 
where "##" is the tax rate (GBP/tCO2). 
This model optimises generator output, subject to different tax rates. 
Regardless of the tax rate, current infrastructure remains the same, 
but the cost of running generators, inclusive of the carbon tax on their pollution, 
does change. This is why there are multiple cost function files, but only one of each other type of file. 



To run the model at different tax rates use: 
"baseMVA.txt", "branch.txt", "bus.txt", "gen.txt", and one of the "genCost##.txt" files. 

For example:
To run the model at a carbon tax rate of 0 GBP per tCO2 use: "baseMVA.txt", "branch.txt", "bus.txt", "gen.txt", and one of the "genCost00.txt",
To run the model at a carbon tax rate of 30 GBP per tCO2 use: "baseMVA.txt", "branch.txt", "bus.txt", "gen.txt", and one of the "genCost00.txt",
To run the model at a carbon tax rate of 35 GBP per tCO2 use: "baseMVA.txt", "branch.txt", "bus.txt", "gen.txt", and one of the "genCost00.txt",
... and so on for the selected key tax rate levels. 



The Supplementary Material, part 1 (SM1) provides information on the formulation of the above files. 
In most cases this data is taken directly from the noted sources in the paper and methodology, 
such as for the Generator and Bus data, 
while the Generator Cost data is calculated as described from the combination of the base data and carbon output (subject to the carbon tax), 
finally, the branch data uses the base data, averages the longest distance OHLs' specifications, and applies these to the simplified branches described in the supplementary material. 



For further information of PyPower (what was used) / MatPower (same methodology) modelling, refer to the below sources (also linked in the paper):
PyPower: https://pandapower.readthedocs.io/en/v2.0.0/converter/pypower.html
MatPower: https://matpower.org/docs/MATPOWER-manual.pdf