Any more references here? It looks like you just mean the price for natural gas futures is $0.03/kWh. I am hesitant to believe that includes production and transport. In addition, are you including the efficiency at which natural gas is converted to electricity?

I'm dividing by 0.3 to account for the efficiency of natural gas turbines. (In reality they're higher at around 35-45%)

If you assume a 100% efficient natural gas plant the cost is $0.00983/kWh (100% efficiency is of course nonsense though).

At 30% efficiency the marginal cost is $0.0327/kWh, distribution usually costs around $0.01-0.02/kWh.

This leads to a grand total margin cost of $0.0427-0.0527/kWh.

DoE estimates from 2012 show $0.0189/kWh in fixed costs.

So a combined grand total of $0.06-0.07/kWh.

Your marginal cost is about what I'm paying for electricity.

What about capital costs?

"DoE estimates from 2012 show $0.0189/kWh in fixed costs."

That includes capital costs.

Fixed costs =/= capital costs.

Fixed costs are the reoccurring costs that arise regardless of production. You can build a plant with free money, but you still have fixed costs.

Sorry I meant to say that the metric I called fixed costs is actually fixed and capital costs.

Fixed costs alone are ~$0.002/kWh...