I stumbled upon this article from popular science. Enjoy!
http://books.google.com/books?id=tgEAAAAAMBAJ&pg=PA88&lpg=PA88&dq=lignite+pulse+popular+science&source=bl&ots=3NcnUDrwbk&sig=DJZPrb95mn7oTU57eDeOJ3R5Le0&hl=en&ei=hIvpTtDkNovQgAfIu5DuCA&sa=X&oi=book_result&ct=result&resnum=5&ved=0CD8Q6AEwBA
