One of the key principles of growth investing is finding companies with a large and expanding market opportunity. That's because a large-scale opportunity set should provide the company with ample running room to expand its operations. That growth should bolster its bottom line while also boosting its stock price.

One often-overlooked sector for growth-focused investors is energy. Many investors are missing out on two compelling growth opportunities: the Permian Basin and renewables. Our contributors don't want investors to miss this upside, which is why when we asked them for their top growth stocks to buy this month, they picked Permian Basin-focused driller Diamondback Energy (NASDAQ:FANG) and renewable energy companies NextEra Energy Partners (NYSE:NEP) and Brookfield Renewable Partners (NYSE:BEP).

Oil pumps under the setting sun with solar panels in the foreground.

Image source: Getty Images.

A high-octane oil stock

Matt DiLallo (Diamondback Energy): Oil driller Diamondback Energy has grown exponentially since its IPO in 2012. The Permian Basin-focused oil producer has increased its production by a jaw-dropping 900% on a debt-adjusted share basis, which takes into account both the new shares and debt it issued to help fund growth. Meanwhile, the company's underlying earnings per share have skyrocketed nearly 1,000% over that time frame. Diamondback Energy has delivered this high-octane growth thanks to a combination of needle-moving acquisitions and drilling high-return oil wells.

While the oil company likely won't grow quite as fast in the coming years, it has the resources to deliver peer-leading growth. In 2019, Diamondback Energy expects to increase its production 26%, with high-margin oil expanding at an even faster 30%. Further, the company can deliver this fast-paced growth while generating excess cash at current oil prices.

With Diamondback Energy producing more money than it needs to fuel its growth engine, the company has started returning cash to shareholders. The oil driller initiated a dividend last year -- which it boosted 50% in 2019 -- and recently authorized a $2 billion share repurchase program.

Diamondback Energy's fast-paced growth over the years has helped fuel big-time gains for its investors. Overall, its stock is up 500% since its IPO, which has crushed the roughly 100% return of the S&P 500. With plenty of fuel to continue expanding, Diamondback Energy is a top growth stock to buy this July.

A growth-oriented renewable energy play

Maxx Chatsko (NextEra Energy Partners): The S&P 500 has delivered a three-year return of 50% with dividends included -- pretty darn good. NextEra Energy Partners has rewarded investors with a total return of 84% in that span -- even better. Of course, it helps that the owner of power production assets and natural gas pipelines pays a 4% distribution yield, but it has solid growth potential backing up that income stream.

The business acquires, owns, and operates clean energy projects with stable long-term cash flows. As the name implies, it has a close relationship with NextEra Energy (NYSE:NEE) and its power generation subsidiary, NextEra Energy Resources (NEER). The latter is crucial to the partnership's success. Why?

NEER owns 17,000 megawatts of wind and solar power assets across the United States and boasts a backlog comprising another 29,000 megawatts. NextEra Energy Partners has access to that portfolio, which it has tapped multiple times in recent years to keep its growth engine humming along. The business has acquired 2,000 megawatts of wind and solar projects from the power generator in the last year alone. That's impressive considering the partnership owns a stake in 5,300 megawatts of total power capacity.

The ability to acquire cash-generating assets at great prices gives NextEra Energy Partners confidence it can grow its distribution 12% to 15% annually through 2022. A solid track record of execution should give investors confidence that management will maintain its financial discipline -- and that units will continue to thump the returns of the S&P 500 over the long run.

Killer combination of growth and income

Neha Chamaria (Brookfield Renewable Partners): Brookfield Renewable shares are on fire, gaining twice as much as the S&P 500, or nearly 44% so far including dividends. The stock's 10-year price chart further reveals what a consistent outperformer it has been.

BEP Total Return Price Chart

BEP Total Return Price data by YCharts.

Brookfield Renewable is, in fact, one of the few growth stocks that have been equally rewarding for income investors thanks to dividend growth. Management is presently aiming for a 5% to 9% increase in annual dividends in the long term, and the stock yields a hefty 5.8%. There's one big reason investors who buy the stock today could continue to enjoy dividend as well as capital appreciation: Brookfield Renewable's solid footing in a high-potential industry.

You see, Brookfield Renewable is one of the world's largest renewable energy companies, with a capacity of roughly 17,400 megawatts (MW) and more than 800 facilities spread across North America, South America, Asia, and Europe. Brookfield Renewable, however, stands out from the crowd because it generates 75% power from hydroelectric, also touted to be the largest source of clean energy globally in coming years. To add to the industry potential, Brookfield's business model of selling under long-term contracts ensures a steady flow of revenue and cash flows to back growth projects and dividend payout.

Through organic initiatives that include planned capacity expansion of 1,000 MW and cost reduction by $2 per MWh (megawatt-hour), Brookfield Renewable believes it should be able to grow per-share funds from operations by 6% to 11% annually over the next five years. If the company delivers -- which I believe it can, going by its past record -- the stock will have made you money multiple times over your investment today within the next few years.