Dividend stocks have historically been powerful investments. Since 1973, dividend stocks outperformed the S&P 500 (9.6% average annual total return versus 8.2%), according to a study from Ned Davis Research and Hartford Funds. Among that dividend group, dividend growers performed even better and delivered a 10.7% average annual total return. 

There are plenty of dividend stocks to choose from these days, but not all of them outperform. Three solid ones our Fool.com contributors believe are great buys this month are A. O. Smith (AOS 0.72%), Brookfield Renewable Partners (BEP -1.09%) (BEPC -1.36%), and Enbridge (ENB -0.32%). Here's why they think these are great dividend stocks to buy and hold for the long haul. 

It will make you feel good (honest!)

Reuben Gregg Brewer (A. O. Smith): During a recent hurricane, I had to take a cold shower. It was awful and reminded me of the business of A. O. Smith, which makes water heaters. The company is dealing with headwinds today, including inflation and housing slowdowns in the United States and China, a key foreign market. Adjusted earnings per share were down 15% year over year in the third quarter. However, this company's products are not falling out of style. Take a cold shower yourself, and you'll quickly agree.

Confirmation of this fact can be found by looking at sales in India (another key market) which rose 16% in the quarter. Basically, as this emerging nation's population moves up the socioeconomic ladder, the demand for hot water increases. And once customers have hot water, they want to keep it, which is why North American markets are largely sustained by replacement demand. This is a stable business, even if short-term headwinds cause some temporary turbulence.

As for A. O. Smith's dividend, it has increased annually every year for over 25 years, making the stock a Dividend Aristocrat. The dividend yield, meanwhile, is around 2.1%. While that's not huge on an absolute basis, it is toward the high side of the company's yield range over the past 10 years, suggesting the shares are attractively priced.

Note, too, that the dividend has increased at a rapid 20% clip over that span. The dividend growth rate slowed of late, which isn't shocking given the business backdrop. However, if you are a dividend growth investor, A. O. Smith is a buy-and-hold gem.

Earn more dividends every year with this stock

Neha Chamaria (Brookfield Renewable Partners): Some stocks consistently pay out dividends and even commit to growing them regularly over time, underpinned by earnings and cash-flow growth. But they still don't get much love from the market.

Brookfield Renewable Partners is one such dividend stock that lost more than 20% of its value this year. Yet if you look at how steadily the company grows, you'd want to consider buying this dividend now and holding for the long term to reap the rich returns.

Brookfield Renewable just reported its third-quarter numbers, and it grew its funds from operations (FFO) per share by 15% year over year during the quarter. The company is aggressively growing its renewables pipeline and supplementing that growth with acquisitions, which is driving its FFO higher. Recent growth moves include a partnership with uranium giant Cameco to acquire Westinghouse Electric, the world's largest nuclear energy equipment and services provider. Brookfield Renewable will invest $750 million in Westinghouse and, together with its institutional partners, own a 51% stake in the nuclear company.

In another notable move, Brookfield Renewable and its institutional partners have just proposed to acquire Origin Energy's power generation and gas retailing businesses. Origin Energy is among Australia's largest electricity and gas providers.

Brookfield Renewable is clearly on a roll, and with the world transitioning to clean energy, this company has tremendous growth opportunities. As its FFO grows, so should dividends. Brookfield is already targeting an average annual dividend growth of 5% to 9% in the long term, which, when combined with its dividend yield of 4.3%, makes for a solid dividend stock to buy and hold.

Built for the long term

Matt DiLallo (Enbridge): Enbridge is an exceptional dividend stock. The Canadian energy infrastructure giant offers a high yield (currently 6.1%) that it consistently grows. The company delivered its 27th consecutive year of dividend growth in 2022. 

Enbridge's high-yielding payout is on rock-solid ground. The company's four core franchises -- liquids pipelines, natural gas transmission, natural gas distribution, and renewable energy -- produce very stable cash flow, backed by long-term contracts and government-regulated rate structures. Its pipelines and utilities are crucial to supporting energy demand across North America.

Meanwhile, it has a conservative dividend payout ratio for a pipeline/utility company -- 60% to 70% of its cash flow -- giving it a cushion while allowing it to retain earnings to help fund expansions. Enbridge also has a strong investment-grade credit rating with a relatively low leverage ratio. That gives it billions of dollars of annual financial flexibility to fund expansion projects and acquisitions.

Enbridge has billions of dollars of expansion projects underway across its four franchises. It's investing to meet current energy needs as well as the lower-carbon energy sources we'll need in the future. It's building several offshore wind farms in Europe and recently bought a large onshore renewable energy project developer in North America. Enbridge is investing in emerging lower-carbon energy sources like renewable natural gas and green hydrogen. Those lower carbon fuels could eventually replace natural gas in its pipelines and utilities, extending the life of those legacy assets.   

The company expects to grow its cash flow per share at a 5% to 7% annual rate through at least 2024. Meanwhile, given its growing focus on investing in lower-carbon fuels, Enbridge should have plenty of power to continue growing its high-yielding dividend for years to come.