Investors interested in Utility - Electric Power stocks are likely familiar with Atlantica Yield (AY Quick QuoteAY - Free Report) and Unitil (UTL Quick QuoteUTL - Free Report) . But which of these two stocks presents investors with the better value opportunity right now? Let's 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 puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.

Atlantica Yield and Unitil are sporting Zacks Ranks of #2 (Buy) and #3 (Hold), respectively, right now. This means that AY's earnings estimate revision activity has been more impressive, so investors should feel comfortable with its improving analyst outlook. 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 Style Score Value grade factors in a variety of key fundamental metrics, including the popular P/E ratio, P/S ratio, earnings yield, cash flow per share, and a number of other key stats that are commonly used by value investors.

AY currently has a forward P/E ratio of 22.56, while UTL has a forward P/E of 23.21. We also note that AY has a PEG ratio of 0.44. 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. UTL currently has a PEG ratio of 6.27.

Another notable valuation metric for AY is its P/B ratio of 0.95. The P/B ratio pits a stock's market value against its book value, which is defined as total assets minus total liabilities. For comparison, UTL has a P/B of 2.26.

These are just a few of the metrics contributing to AY's Value grade of A and UTL's Value grade of C.

AY sticks out from UTL in both our Zacks Rank and Style Scores models, so value investors will likely feel that AY is the better option right now.