Comparison of least squares Monte Carlo methods with applications to energy real options.

•We apply regress-now/later least squares Monte Carlo (LSMN/L) to energy real options.•LSMN/L compute continuation/value function approximations (C/VFAs).•These C/VFAs yield tight lower and dual (upper) bounds (LBs and DBs).•Estimating the LSMN/L C/VFAs and associated LBs incurs similar computational effort.•Estimating DBs based on VFAs instead of CFAs takes seconds rather than minutes/hours.