writes "This article offers an in depth but readable review of the current state of fusion research, along with a timetable for the future, a description of what still needs to be figured out and a fascinating look at what it'd take to scale up to worldwide commercial generation levels. Executive summary, by 2100 if all goes according to plan fusion might be able to generate 30% of Europes present day demand. The delay is largely due to tightly limited tritium supplies. Whilst a sustainable fusion reactor will produce tritium, it would do so only in small amounts so a reactor would take 2-3 years to produce enough tritium to "give birth" and start another one. It looks like even with the most optimistic assumptions, by the time Tokamak based fusion can meaningfully contribute we will likely be deep in the midsts of an energy crisis."