Question

How many scientific years can a 6.6 W LED lamp shine with 0.781 kg deuterium if 26.2% of the released energy in each reaction becomes electrical energy? Assume here that the neutron mass is m_n = 1.01 u instead of the table value.

Answer 1

$$6.6(31556952)t\\=(0.262)\frac{(0.781)}{2(2.014\cdot1.66\cdot10^{-27})}(3.27\cdot1.6\cdot10^{-13})\\t=76875\ years$$