Apply another security clearance job while waiting

I have been waiting for 14 months for security clearance and I can not start this job without it to be cleared. This is a DOE L clearance. I was laid off 3 months ago and I am running out money. Another company is interested in me, it will be a long drive but manageable, it requires DOD security clearance but I can start without security to be cleared. . Will it pretty easy to transfer from DOE L level to DOD ? And if when it cleared, I still want to DOE job, ( 20 mins drive vs 70 mins) can it be easily transfer back?

DOE “L” investigation requirements are the same as for “Secret”. They are both done by OPM, so reciprocity works both ways. The problem you will have is that the T3 currently in progress will prevent any new investigation at the same level from being started. You would need your new company have DoD request that the DOE release jurisdiction on the current investigation in progress so that when it is done it would be sent to DoD for adjudication.