9 Best Green Energy Penny Stocks to Invest In

7. Montauk Renewables Inc (NASDAQ:MNTK)

Stock Price: $1.41

Number of Hedge Fund Holders: 10

Upside Potential: 47.26%

Montauk Renewables Inc (NASDAQ:MNTK) is one of the best green energy penny stocks to invest in. The stock has gained more than 20% in the past month, and Street predictions indicate it has more room to rise.

Montauk Renewables Inc (NASDAQ:MNTK) reported its Q1 2026 results on May 6. The report showed revenue grew 9% YoY to $46.4 million. This topline growth was supported by biofuel credits called RINs. The company said its RINs sold during the quarter increased 25.5% YoY to 12.4 million.

The biogas fuels and electricity company said its renewable natural gas production was flat year-over-year at 1.4 million MMBtu. However, Montauk made a profit in the quarter, reporting a net income of $5 thousand, compared to a net loss of $0.5 million in the same period a year ago.

Looking ahead, Montauk expects to produce 5.8 million to 6 million MMBtu of renewable natural gas (RNG) in 2026. It anticipates RNG revenue between $175 million and $190 million for the year. In its renewable electricity generation (REG) business, the company expects to produce 195,000 to 207,000 in 2026. It projects REG revenue between $33 million and $37 million.

Pennsylvania-based Montauk Renewables Inc (NASDAQ:MNTK) is in the business of producing fuels and electricity from biogas. It produces renewable natural gas and generates renewable electricity by capturing methane from landfills and agricultural waste.