How many are there in a book? buy clomipramine uk HS2 may also encourage Birmingham to London commuting. And HS2's 250mph trains will use 50% more energy than the Eurostar trains, the HS2 Action Alliance says. The 2006 Eddington transport report predicted that the value of carbon saved over a 60-year period would be 脗拢3.2bn. The carbon saving of the line (at the time priced at 脗拢33bn) was a poor return on investment, according to Eddington.