Nuclear
Nuclear is a proven clean energy. But it has some lingering issues that must be corrected before wider expansion. These issues include resilience of station during a lost of Off-station Power (LOOP event). In many cases, if cooling water is not put back on a facility before the emergency systems run out of resources (7 days by regulation), the reactors and spent fuel rods will not be able to cool. This could lead to a loss of containment.