Electricity supplied by fossil-fuel power plants will be flat over the short-term as any increase in demand will be met by rapidly growing renewable generation. Within this environment, coal and natural gas competition will be intense. This insight details the implications of a range of natural gas prices on North American coal markets from 2017 to 2021. In 2018 every one-cent change in Henry Hub will change coal demand by 1,390,000 short tons. This will increase in 2019 as every one-cent change in Henry Hub will change coal demand by 2,940,000 short tons. The increase is a result of less known contracts for coal delivery known in the prompt plus two years.