AMRC vs PESI vs ERII vs GEVO

For growth investors, Gevo, Inc.

(GEVO) is the stronger pick with 849. 3% revenue growth year-over-year, versus -7. 1% for Energy Recovery, Inc. (ERII). Energy Recovery, Inc. (ERII) offers the better valuation at 22. 5x trailing P/E (22. 9x forward), making it the more compelling value choice. Analysts rate Ameresco, Inc. (AMRC) a "Buy" — based on 23 analyst ratings — the highest consensus in this comparison. The "better buy" depends entirely on your goals: growth investors should weight revenue trajectory, value investors should weight P/E and PEG, and income investors should weight dividend yield and streak.

On trailing P/E, Energy Recovery, Inc.

(ERII) is the cheapest at 22. 5x versus Ameresco, Inc. at 35. 8x. On forward P/E, Energy Recovery, Inc. is actually cheaper at 22. 9x.

Over the past 5 years, Perma-Fix Environmental Services, Inc.

(PESI) delivered a total return of +45. 6%, compared to -65. 2% for Gevo, Inc. (GEVO). Over 10 years, the gap is even starker: AMRC returned +542. 4% versus GEVO's -98. 6%. Past returns do not guarantee future results, and the stock with the higher historical return may already have its best growth priced in.

By beta (market sensitivity over 5 years), Energy Recovery, Inc.

(ERII) is the lower-risk stock at 1. 53β versus Ameresco, Inc. 's 2. 03β — meaning AMRC is approximately 33% more volatile than ERII relative to the S&P 500. On balance sheet safety, Energy Recovery, Inc. (ERII) carries a lower debt/equity ratio of 5% versus 173% for Ameresco, Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Gevo, Inc.

(GEVO) is pulling ahead at 849. 3% versus -7. 1% for Energy Recovery, Inc. (ERII). On earnings-per-share growth, the picture is similar: Gevo, Inc. grew EPS 58. 8% year-over-year, compared to -22. 4% for Ameresco, Inc.. Over a 3-year CAGR, GEVO leads at 415. 1% annualised revenue growth. Higher growth typically commands a higher valuation multiple — check whether the premium P/E or P/S is justified by the growth rate using the PEG ratio.

Energy Recovery, Inc.

(ERII) is the more profitable company, earning 17. 0% net margin versus -22. 3% for Perma-Fix Environmental Services, Inc. — meaning it keeps 17. 0% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: ERII leads at 18. 2% versus -19. 0% for PESI. At the gross margin level — before operating expenses — ERII leads at 65. 2%, reflecting greater pricing power or product mix advantage. Stronger margins indicate durable pricing power, lower cost of revenue, or higher mix of software/services. They are one of the clearest signs of business quality.

On forward earnings alone, Energy Recovery, Inc.

(ERII) trades at 22. 9x forward P/E versus 25. 0x for Ameresco, Inc. — 2. 1x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for GEVO: 72. 4% to $3. 50.

None of the stocks in this comparison currently pay a material dividend.

All are effectively zero-yield and should be held for capital appreciation rather than income.

For long-horizon retirement investors, Energy Recovery, Inc.

(ERII) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding. Gevo, Inc. (GEVO) carries a higher beta of 1. 64 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (ERII: -11. 9%, GEVO: -98. 6%), confirming both are viable long-term holds — but the lower-volatility option typically results in less emotional selling during corrections. Retirement portfolios generally favour predictability over maximum returns. Consult a financial advisor before making allocation decisions.

These companies operate in different sectors (AMRC (Industrials) and PESI (Industrials) and ERII (Industrials) and GEVO (Basic Materials)), which means they face different economic cycles, regulatory environments, and macro sensitivities — making direct comparison nuanced.

In terms of investment character: AMRC is a small-cap quality compounder stock; PESI is a small-cap quality compounder stock; ERII is a small-cap quality compounder stock; GEVO is a small-cap high-growth stock. These fundamental differences mean investors should not choose between them on a single metric — the "better stock" depends entirely on which of these characteristics aligns with your investment strategy.