Greetings!
You do a good job of explaining the difference between hydrogen electric motors and internal combustion electric motors. Very interesting!
One thing that might help with your punctuation is to read your essay aloud to someone. Come to a complete stop at every period, and only pause slightly at a comma. In this way, you (or your friend who is listening) should be able to hear if the periods and commas are in the right places for your words to make sense.
Also, make sure that when you ask a question, you end your sentence with a question mark. "Right now our cars run on gas, so how can we convert to hydrogen?" and "It doesn't make it very far, does it?" (There were a number of errors in that sentence; compare my version with yours.) However, normally, one does not address questions to the reader in an essay like this. If you are presenting it orally to the class, though, that's probably fine.
You have a few misspellings of the sort that spell check won't catch, because they are also real words -- just not the right words. :-) "Witch" should be "which" ... and it should come after a comma, not a period; you have a sentence fragment.
Go through your essay very carefully and make sure that all your sentences end with
the appropriate punctuation mark and start with a capital letter. Do not capitalize nouns that are not proper nouns, like hydrogen and performance.
You have quite a few sentence fragments like this: 'Now that we have looked over hydrogen in internal combustion engine and in fuel cells running electric motors." -- Now that we have looked them over ... what happens? It will make sense if you take out "that" and connect your two fragments, like this: "Now we have looked over hydrogen in internal combustion engines and in fuel cells running electric motors, and on the basis of cost, performance, and implementation, the hydrogen internal combustion engine is the preferable solution."
You have a bit more editing to do, but stick with it and you'll have a fine essay!
Thanks,
Sarah, EssayForum.com