What is the version of the following sentence with correct punctuation?

For the past 25 years natural gas has played a significant role in Denmarks energy supply both with regard to reducing the dependence on oil and in promoting efficient smallscale combined heat and power plants
For the past 25 years, natural gas has played a significant role in Denmark's energy supply, both with regard to reducing the dependence on oil and in promoting efficient small-scale combined heat and power plants.