Financial Information of Continuing Operations by Business Segment (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Disclosure [Line Items]
Total revenue	$ 4,407,257	$ 5,905,304
Operating Income (Loss)	(3,879,726)	(4,035,335)
Net product sales	3,505,095	3,545,741
Cost of product sales	(2,603,876)	(2,506,879)
Capital Expenditures	592,677	82,855
Depreciation	254,602	259,156
Fuel Storage & Vehicle Systems
Segment Reporting Disclosure [Line Items]
Total revenue	4,407,257	5,905,304
Operating Income (Loss)	(1,918,880)	(1,578,174)
Net product sales	3,505,095	3,545,741
Cost of product sales	(2,603,876)	(2,506,879)
Gross profit	901,219	1,038,862
Capital Expenditures	592,677	82,273
Depreciation	244,287	253,827
Corporate
Segment Reporting Disclosure [Line Items]
Operating Income (Loss)	(1,960,846)	(2,457,161)
Capital Expenditures	0	582
Depreciation	$ 10,315	$ 5,329