1.   The cells will drive electric motors and use on-board hydrogen gas as fuel.

2.   The hydrogen gas would be collected within the galls and piped to a central storage system.

3.   Anhydrous caustic soda, hydrogen gas and phosgene, all well established product areas, are being developed to produce maximum returns.

4.   Another problem is finding a better source of hydrogen because pure hydrogen gas requires bulky onboard storage tanks and lacks a ready supply network.

5.   Automobile batteries produce hydrogen gas that accumulates in the battery case.

6.   Because its mass energy density is low, hydrogen gas needs to be significantly compressed to create useful energy levels.

7.   Because they are usually so far away, their light travels through and illuminates otherwise invisible clouds of intervening hydrogen gas.

8.   Because the quasar light passes through clouds of hydrogen gas before it reaches Earth, it serves as a probe of the cosmic environment out to great distances.

9.   Both lasers are passed through a tuning cell containing a small amount of hydrogen gas.