Investors interested in stocks from the Utility - Electric Power sector have probably already heard of Avangrid (AGR) and WEC Energy Group (WEC). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.Everyone has their own methods for finding great value opportunities, but our model includes pairing an impressive grade in the Value category of our Style Scores system with a strong Zacks Rank. The proven Zacks Rank emphasizes companies with positive estimate revision trends, and our Style Scores highlight stocks with specific traits.Avangrid and WEC Energy Group are sporting Zacks Ranks of #2 (Buy) and #3 (Hold), respectively, right now. This means that AGR's earnings estimate revision activity has been more impressive, so investors should feel comfortable with its improving analyst outlook. But this is only part of the picture for value investors.Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.Our Value category highlights undervalued companies by looking at a variety of key metrics, including the popular P/E ratio, as well as the P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that have been used by value investors for years.AGR currently has a forward P/E ratio of 18.25, while WEC has a forward P/E of 23.44. We also note that AGR has a PEG ratio of 3.32. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. WEC currently has a PEG ratio of 3.96.Another notable valuation metric for AGR is its P/B ratio of 0.79. 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, WEC has a P/B of 2.63.These metrics, and several others, help AGR earn a Value grade of B, while WEC has been given a Value grade of D.AGR sticks out from WEC in both our Zacks Rank and Style Scores models, so value investors will likely feel that AGR is the better option right now.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 Avangrid, Inc. (AGR): Free Stock Analysis Report WEC Energy Group, Inc. (WEC): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research