Building a $1 million retirement portfolio is probably easier than you think. For example, putting $300 a month into an investment earning 10% annually (about the average return of the S&P 500 over the last 30 years) would grow to $1 million in about 34 years. Increasing your investment or returns could make you a millionaire even faster. Enbridge (ENB 0.53%) and Brookfield Renewable (BEPC 0.61%) (BEP 0.35%) have demonstrated their abilities to deliver above-average returns over the years. That should conti ...