Renewable energy is a fast-growing industry, and there are many opportunities for investors to get involved.

Exchange-traded funds offer a simple way to invest in a diversified portfolio of renewable energy stocks.

Some popular renewable energy ETFs include Invesco Solar ETF, iShares Global Clean Energy ETF, and First Trust NASDAQ Clean Edge Green Energy Index Fund.

Investing in individual renewable energy stocks can offer higher potential returns, but also comes with higher risk.

Some top renewable energy companies to consider include Tesla, First Solar, and NextEra Energy.

Mutual funds allow investors to pool their money together to invest in a portfolio of renewable energy stocks.

Some popular renewable energy mutual funds include Calvert Global Energy Solutions Fund.

Green bonds are issued by companies and governments to fund environmentally friendly projects, such as renewable energy infrastructure.