The multi-trillion-dollar electricity market is being restructured by the renewable energy sector. In a few years, it will be obsolete. On a cost basis, wind and solar energy beat coal, nuclear and natural gas, and electric vehicles could be the dominant transportation option by the middle of this century. This is a huge runway to expand into disruptive renewable energy stocks.Three of our energy contributors were asked to share their top picks for long-term renewable energy. NextEra Energy (NYSE :NEE), Bloom Energy (NYSE :BE) and Seimens Energy(OTC:SMEG.F), all rose to the top and are sure to continue to prosper for at least the next decade.The hydrogen energy giantTravis Hoium (Bloom Energy),: Hydrogen is a segment of renewable energy that's just starting to take off. Hydrogen can be used to replace fossil fuels in a wide range of applications, including transportation, power plants, and local backup power. Electrolysis is a process that creates hydrogen from water and electricity. When wind, solar or any other renewable energy is used, it's possible to create "green hydrogen" which will enable us to build a clean energy system.Bloom Energy, a pioneer in hydrogen technology, has been producing fuel cells for utilities and businesses for over a decade. Long-term, solid-state fuel cells technology from the company should be less expensive than comparable proton-exchange technology. It allows fuel cells to run backwards to create hydrogen and then consume it to make electricity.Bloom Energy's financial performance has been steadily improving. Below you can see that revenue has increased slowly but steadily from the beginning of 2019, and that margins and losses have improved. Revenue growth can be slow and subdued in times of rapid cost fall. This is because price drops cannot overcome installation growth. The company installed 40.2% more fuel cells in the first quarter 2021 than the previous year, but the revenue was only 23.8% higher. This is a significant challenge for the top line, but the falling cost trend should make it possible to adopt fuel cells and hydrogen over the long-term, which will eventually lead to revenue growth.There are many options in hydrogen and fuel cell technology. It can be used to store energy for the grid or businesses, as well as fuel for shipping and carbon capture. Bloom Energy, an industry leader in improving financial finances, is poised to prosper for the foreseeable future.A growth sector offers long-term securityHoward Smith (NextEra Energy). NextEra Energy offers investors the opportunity to have a variety of stock holdings. It is the parent company of electric utilities Florida Power & Light, Gulf Power and NextEra Energy Resources. The future looks bright for renewable energy. According to the International Energy Agency, renewables were the only source of energy for which the global demand grew in 2020 even during the pandemic.NextEra Energy Resources is a leader for wind and solar power. It has a backlog that is even larger than its current portfolio. This portfolio is expanding and should allow for more growth. According to a report by Wood Mackenzie and the Solar Energy Industries Association, the U.S. has more than 100 gigawatts of generating power. This is more than twice the capacity of solar generating plants that were available three and a quarter years ago.Any growth industry has risks that investors must consider. It is difficult to predict whether a company will thrive in the future. NextEra Energy's utility company is a hedge. Because it has a steady cash flow, it offers shareholders a reliable dividend. The stock price has risen over the last three years as has the company's value.NextEra informed investors in its fourth-quarter earnings release, that it intends to increase the annual dividend by approximately 10% through next year. It also expects between 6% to 8% annual earnings growth with the help of its growing renewables business through 2023.NextEra Energy is a well-run business that looks poised to continue its success. Although it isn't a typical utility, income investors shouldn't expect a higher dividend yield than most regulated utilities. NextEra Energy can be a great name for investors who have the right expectations.A new renewable giantDaniel Foelber, Siemens Energy: When investors think of long-term investments in renewable energy, the first thing that comes to their minds is German integrated industrial giant Siemens. Siemens's renewable investments are often dwarfed by other ventures, despite being so diverse.Siemens holds a minority share in the new independent Siemens Energy. Siemens Gamesa Renewable Energy has 67%. Siemens Energy, which combines a strong portfolio of power transmission and gas turbines with renewable investments, is a perfect fit for investors in renewables.Siemens Energy owns approximately 80% of Siemens Energy's value, but its stake in Siemens Gamesa accounts for roughly two-thirds Siemens Energy's second quarter 2021 revenue. This is due to the fact that the vast majority Siemens Gamesa projects are still in progress. Siemens Gamesa's order queue now stands at 33.7 billion euros. Orders increased 150% in Q2 by Siemens Gamesa compared to the same quarter of 2020. Siemens Energy expects a nominal growth rate of 2% to 6 percent in its gas- and power businesses, with an adjusted EBITDA margin between 3.5% to 5.5%. Siemens Gamesa expects nominal revenue growth rates of 8%-11% and adjusted EBITDA margins of 3%-5%.These numbers aren't very impressive, in all honesty. Both the adjusted EBITDA guidance and revenue for these segments were lower than those provided by Siemens Energy. The company's short-term performance is not as good as it could be due to the size and scope its renewable investments. These projects will take some time to scale up and develop. Siemens Energy could still be a successful industrial and wind energy company in five to ten years.There are many ways to participate in renewable energy growthAlthough these stocks are very different, they offer a great way to get involved in the rapidly growing renewable energy sector. They will all pay dividends for investors in the coming 10 to 20 years.
