Investors interested in Alternative Energy - Other stocks are likely familiar with HF Sinclair (DINO) and Ameresco (AMRC). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great 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.HF Sinclair has a Zacks Rank of #1 (Strong Buy), while Ameresco has a Zacks Rank of #3 (Hold) right now. Investors should feel comfortable knowing that DINO likely has seen a stronger improvement to its earnings outlook than AMRC has recently. However, value investors will care about much more than just this.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.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.DINO currently has a forward P/E ratio of 3.97, while AMRC has a forward P/E of 35.73. We also note that DINO has a PEG ratio of 0.57. 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. AMRC currently has a PEG ratio of 1.42.Another notable valuation metric for DINO is its P/B ratio of 1.18. 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, AMRC has a P/B of 4.44.These metrics, and several others, help DINO earn a Value grade of A, while AMRC has been given a Value grade of D.DINO 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 DINO is likely the superior value option right now. Free: Top Stocks for the $30 Trillion Metaverse Boom The metaverse is a quantum leap for the internet as we currently know it - and it will make some investors rich. Just like the internet, the metaverse is expected to transform how we live, work and play. Zacks has put together a new special report to help readers like you target big profits. The Metaverse - What is it? And How to Profit with These 5 Pioneering Stocks reveals specific stocks set to skyrocket as this emerging technology develops and expands.Download Zacks’ Metaverse Report 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 HF Sinclair Corporation (DINO): Free Stock Analysis Report Ameresco, Inc. (AMRC): Free Stock Analysis Report To read this article on Zacks.com click here.