Material Demands for Storage Technologies in a Hydrogen Economy

Table 3

DOE hydrogen storage targets for light-duty vehicles [41].

Storage parameter	Units	2010	2015	Ultimate target
Gravimetric system density	kWh kg^−1	1.5	1.8	2.5
	MJ kg^−1	5.4	6.48	9
	wt.%	4.5	5.5	7.5
Volumetric system density	kWh l^−1	0.9	1.3	2.3
	MJ m^−3	3.24	4.68	8.28
	gH2 l^−1	28	40	70
Fuel cost at pump	$ GGE^−1a	3–7	2–6	2-3
System filling time for 5 kg H2	min	4.2	3.3	2.5
	kgH2 min^−1	1.2	1.5	2
Maximum loss of useable H2	g (h kgH2)^−1	0.1	0.05	0.05

a1 gasoline gallon equivalent (GGE) ≈ 1 kg hydrogen [43].