been delving into Ng for years,CDH is the only one that has merit so far a couple of others are MEO and SLV the latter is shale gas connected to abandoned coal deposits,I also have some holdings in carburation switchover ie switching from gasoline to Ng,Cummins was interested but no more seems third world ie India converted some buses,the there's APF which is a batterey that charges 10x faster and last 5x longer than conventional,about two years ago I got involved with Solar Panels where the glaze is good enough to look through yet provide enough electricity for an Office tower.
Still my focus is in Oil with te Tar Sands (CLL) being my main stock,just see so much sustainability???