Sources of passive income can help put you on the road to financial independence. As your earnings from those passive sources grow to exceed your expenses, you'll no longer have to work to make ends meet, and you won't have to sell assets either.

While it takes a lot of time (and money) to reach financial independence, everyone needs to start somewhere. Here are two stocks that can turn $1,000 investments into at least $50 worth of annual dividend income.

Your pipeline to passive income

The energy sector is a great place to find stocks that offer you passive income. The average energy stock in the S&P 500 currently has a dividend yield of around 4%, more than double that index's average yield. But many offer dividend yields that are even higher. For example, at its current share price, natural gas pipeline giant Kinder Morgan (KMI 0.40%) provides a 5.9% payout. So a $1,000 investment in the stock would produce about $59 in annual passive income.

Kinder Morgan's high-yielding dividend is on rock-solid ground. The midstream energy company generates stable cash flows backed by long-term contracts and government-regulated rates. It also pays out slightly more than half of that steady cash flow to investors via its dividend. It retains the rest to fund expansion projects, repurchase shares, and strengthen its already-solid balance sheet.

Kinder Morgan has several natural gas pipeline expansions underway and is investing in a few renewable natural gas projects as well. These investments should lead to increases in its cash flow that should in turn enable it to continue increasing its dividend, which it has done annually for the last five straight years.

Kinder Morgan is one of several pipeline stocks with yields of 5% or more. Other solid options include Williams and ONEOK. They also generate lots of steady cash flow and have reasonable dividend payout ratios. That gives them the funds to pay attractive dividends and invest in expansion projects that should provide them with the fuel to continue growing their payouts.

Passive income from real estate

The real estate sector is also known for offering high dividend yields. The real estate players in the S&P 500 currently average a yield of around 4%, putting the category in second place behind energy for the highest average dividend yield in the index.

Many real estate investment trusts (REITs) offer even higher yields, as those businesses are obligated to pay out 90% of their taxable income in dividends every year. One great option is W. P. Carey (WPC 0.36%). That diversified REIT's dividend yield currently clocks in at 5.4%, so a $1,000 investment in it would deliver about $54 in annual passive income. The company generates stable rental income from its portfolio of warehouses, industrial buildings, offices, retail properties, and self-storage facilities. W. P. Carey has increased its payout every year since 1998, thanks to steadily rising rental rates and a growing portfolio of income-producing real estate.

Several other REITs offer dividend yields over 5%, among them Innovative Industrial Properties (IIPR -0.92%) and EPR Properties Trust (EPR 0.73%). Innovative Industrial owns a rapidly growing portfolio of properties leased by companies in the regulated cannabis industry. It has expanded its dividend -- which currently yields 6.5% -- at a blistering 64% compound annual rate over the last five years by steadily acquiring cannabis-related facilities from operators in sales-leaseback transactions. 

Meanwhile, EPR Properties focuses on owning experiential real estate like movie theaters, eat-and-play venues, attractions, ski resorts, and experiential lodging properties. It leases these properties back to operating companies. Those leases provide relatively steady rental income, supporting a dividend that yields 8.5% at the current share price. The REIT should be able to grow its dividend in the future as it acquires additional experiential real estate. 

Many ways to start collecting passive income

If you have money to invest, there are many assets you can choose that will generate passive income. That's especially true in the energy and real estate sectors. Steadily building a portfolio of solid dividend-paying stocks could eventually help you become financially independent.