With smart connections between current and future forms of energy production, integrated energy systems can help society make time, cost and space savings and reduce CO2 emissions. Hydrogen is an alternative to the use of natural gas in industrial processes, which currently produce a large amount of CO2 emissions. Marine energy and offshore wind can generate electricity that can be converted to hydrogen via the electrolysis of seawater and transported via existing gas pipelines. Transporting these hydrogen gas molecules through existing pipelines is much cheaper than transporting electrons via new electricity cables from wind farms on the North Sea to land.