Valero Energy Corporation VLO reported second-quarter 2021 adjusted earnings of 48 cents per share, turning around from a loss of $1.25 in the year-ago quarter. The bottom line beat the Zacks Consensus Estimate of 15 cents.Total revenues jumped from $10,397 million in the prior-year period to $27,748 million. The top line surpassed the Zacks Consensus Estimate of $22,657 million.The strong quarterly results were supported by increased refinery throughput and higher renewable diesel sales volumes.Valero Energy Corporation Price, Consensus and EPS Surprise Valero Energy Corporation price-consensus-eps-surprise-chart | Valero Energy Corporation QuoteSegmental PerformanceAdjusted operating income at the Refining segment was reported at $361 million, turning around from a loss of $383 million in the year-ago quarter. Higher refinery throughput volumes aided the segment.In the Ethanol segment, it reported adjusted operating profit of $99 million, turning around from a loss of $20 million in the year-ago quarter. Higher ethanol production volumes favored the segment.Operating income at the Renewable Diesel segment increased to $248 million from $129 million in the year-ago period owing to higher renewable diesel sales volumes.Cost of SalesTotal cost of sales surged to $27,039 million from the year-ago figure of $8,424 million.Throughput VolumesFor the quarter, refining throughput volumes were 2,835 thousand barrels per day (Mbpd), up from the prior-year quarter’s 2,321 Mbpd.In terms of feedstock composition, sweet crude, medium/light sour crude and heavy sour crude accounted for 50.1%, 11.6% and 13.7%, respectively, of its total volume. The remaining volumes came from residuals, other feedstock, and blendstocks and others.The Gulf Coast contributed approximately 61.1% to total throughput volume. Mid-Continent, North Atlantic and West Coast regions accounted for 16.7%, 12.6% and 9.6%, respectively, of the total throughput volume.Throughput MarginsRefining margin per barrel of throughput increased to $7.64 from the year-ago level of $5.10. Refining operating expense per barrel of throughput was $4.13 compared with $4.39 in the year-ago quarter. Depreciation and amortization expenses decreased to $2.11 a barrel from $2.53 in the prior-year quarter. As such, adjusted refining operating income was recorded at $1.40 per barrel of throughput against the year-ago loss of $1.82.Capital Investment & Balance SheetSecond-quarter capital investment totaled $548 million. Of the total amount, $252 million was allotted for sustaining the business. Through the June quarter, the leading independent refiner and marketer of petroleum products returned $401 million to stockholders as dividend payments.At quarter-end, Valero had cash and cash equivalents of $3,572 million. As of Jun 30, 2021, it had a total debt and finance lease obligations of $14,680 million, signifying a debt to capitalization of 45.4%.GuidanceThe company is planning to invest capital of $2 billion in this year. Of the total amount, the company is likely to allocate 60% toward sustaining the business. The remaining proportion is expected to get allocated for growth projects.Zacks Rank & Stocks to ConsiderThe company currently has a Zacks Rank #4 (Sell). Meanwhile, a few better-ranked players in the energy space include Whiting Petroleum Corporation WLL, Continental Resources, Inc. CLR and PDC Energy, Inc. PDCE. All the stocks sport a Zacks Rank #1 (Strong Buy). You can see the complete list of today’s Zacks #1 Rank stocks here.Whiting Petroleum has witnessed upward earnings estimate revisions for 2021 in the past 30 days.Continental is expected to witness earnings growth of 256% in 2021.PDC Energy is likely to see earnings growth of 111.8% in 2021. 5 Stocks Set to Double Each was hand-picked by a Zacks expert as the #1 favorite stock to gain +100% or more in 2021. Each comes from a different sector and has unique qualities and catalysts that could fuel exceptional growth. Most of the stocks in this report are flying under Wall Street radar, which provides a great opportunity to get in on the ground floor. Today, See These 5 Potential Home Runs >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Valero Energy Corporation (VLO): Free Stock Analysis Report Continental Resources, Inc. (CLR): Free Stock Analysis Report PDC Energy, Inc. (PDCE): Free Stock Analysis Report Whiting Petroleum Corporation (WLL): Free Stock Analysis Report To read this article on Zacks.com click here.