Investors looking for stocks in the Utility - Electric Power sector might want to consider either NRG Energy (NRG) or NextEra Energy (NEE). But which of these two stocks offers value investors a better bang for their buck right now? We'll need to take a closer look.The best way to find great value stocks is to pair a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system. The proven Zacks Rank emphasizes companies with positive estimate revision trends, and our Style Scores highlight stocks with specific traits.Currently, NRG Energy has a Zacks Rank of #2 (Buy), while NextEra Energy has a Zacks Rank of #3 (Hold). Investors should feel comfortable knowing that NRG likely has seen a stronger improvement to its earnings outlook than NEE has recently. However, value investors will care about much more than just this.Value investors analyze a variety of traditional, tried-and-true metrics to help find companies that they believe are undervalued at their current share price levels.The Value category of the Style Scores system identifies undervalued companies by looking at a number of key metrics. These include the long-favored P/E ratio, P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that help us determine a company's fair value.NRG currently has a forward P/E ratio of 3.67, while NEE has a forward P/E of 29.33. We also note that NRG has a PEG ratio of 0.30. This metric is used similarly to the famous P/E ratio, but the PEG ratio also takes into account the stock's expected earnings growth rate. NEE currently has a PEG ratio of 3.04.Another notable valuation metric for NRG is its P/B ratio of 1.95. Investors use the P/B ratio to look at a stock's market value versus its book value, which is defined as total assets minus total liabilities. By comparison, NEE has a P/B of 3.61.These metrics, and several others, help NRG earn a Value grade of A, while NEE has been given a Value grade of D.NRG is currently sporting an improving earnings outlook, which makes it stick out in our Zacks Rank model. And, based on the above valuation metrics, we feel that NRG is likely the superior value option right now. Zacks Names "Single Best Pick to Double" From thousands of stocks, 5 Zacks experts each have chosen their favorite to skyrocket +100% or more in months to come. From those 5, Director of Research Sheraz Mian hand-picks one to have the most explosive upside of all. It’s a little-known chemical company that’s up 65% over last year, yet still dirt cheap. With unrelenting demand, soaring 2022 earnings estimates, and $1.5 billion for repurchasing shares, retail investors could jump in at any time. This company could rival or surpass other recent Zacks’ Stocks Set to Double like Boston Beer Company which shot up +143.0% in little more than 9 months and NVIDIA which boomed +175.9% in one year.Free: See Our Top Stock and 4 Runners Up >>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 NRG Energy, Inc. (NRG): Free Stock Analysis Report NextEra Energy, Inc. (NEE): Free Stock Analysis ReportTo read this article on Zacks.com click here.Zacks Investment Research