Hydroelectricity is the proper term for electricity generated by hydropower, which is the utilization of the gravitational force of falling water to produce electricity. Hydroelectricity accounted for approximately 17% of electricity produced in the world as of 2015 and is expected to increase by about 3% for the next two and a half decades. Below are the details of the top five hydroelectric power stocks.

Alterra Power Corp.

Alterra Power Corp. (OTC: MGMFX), based in Vancouver, British Columbia, Canada and formerly known as Magma Energy Corp., had approximately 120 employees as of August 2016. The company acquires, develops and operates various renewable energy power projects and facilities. Overall, it operates power plants totaling 757 megawatts of capacity, with approximately 31% of those being hydroelectric. The company had a market capitalization of $251 million as of Aug. 28, 2016. The company has a three-year annualized return of 22.5% and returned a whopping 65% year-to-date as of Aug. 28, 2016. The 52-week range on the stock is 29 cents to 59 cents.

Brookfield Renewable Partners LP

Brookfield Renewable Partners LP (NYSE: BEP) is a 1,500 employee-strong utilities firm headquartered in Toronto, Canada. The company owns a portfolio of hundreds of renewable power facilities. In total, Brookfield owns 207 hydroelectric power generating stations. Its next-largest type of holding is wind-power facilities, followed by biomass facilities. Overall, the company owns 7,284 megawatts of power generating capacity across the United States, Canada, Europe and Brazil. The company has a market capitalization of $9.2 billion and dividend yield of 5.57%. Through Aug. 28, 2016, the stock price's 52-week range was $20.36 to $31.64. Brookfield has a five-year annualized return of 10.9% and has realized a year-to-date return of 21.4%.

Innergex Renewable Energy Inc.

Innergex Renewable Energy Inc. (OTC: INGXF), a sustainable energy company located in Vancouver, Canada, has 817 megawatts of installed capacity. The company develops and operates hydroelectric, wind and solar power generators and facilities. In August 2016, the company began operating a new 41-megawatt hydroelectric facility. Based on company data, one megawatt of hydroelectricity is enough to meet the annual needs of approximately 400 households. Innergex had a market capitalization of $1.2 billion as of August 2016, and its 52-week stock range was $6.86 to $11.96. The company has a five-year annualized return of 8.7% and year-to-date return of 40.4%.

IdaCorp Inc.

IdaCorp Inc. (NYSE: IDA) is an electric company with over 2,000 employees based in Boise, Idaho. The company is involved in the generation, transmission, distribution and sale of electricity in the United States. As of August 2016, the company owned and operated 17 hydroelectric power facilities, mainly in Southern Idaho and Eastern Oregon. It also owns interest in natural gas and coal-based electric plants. The company had a dividend yield of 2.7% and a market capitalization of $3.8 billion as of August 2016. The company has an impressive five-year annualized rate of return of 18% and through Aug. 28, 2016, had returned approximately 30% year to date.

Portland General Electric Company

Portland General Electric Company (NYSE: POR) is a Portland-based electric company with about 2,650 employees. The company is a fully integrated electric utility company engaging in all aspects of the business from power generation to transmission, to direct sale. Portland General Electric operates seven hydroelectric plants, and thermal and wind plants. As such, it is the second-largest hydroelectric-focused power company in the United States. The company's yield was about 3% and its market capitalization was $3.7 billion as of August 2016. Year to date, the company has returned almost 16.5%, and it has maintained over a 15% annualized return on a five-year basis.