This week, we have all of your renewable energy questions, answered. Here are your top 10 questions about renewable energy!
1. What is renewable energy?
Renewable energy, often referred to as clean energy, comes from natural sources or processes that are constantly replenished. For example, sunlight or wind keep shining and blowing, even if their availability depends on time and weather. While renewable energy is often thought of as a new technology, harnessing nature’s power has long been used for heating, transportation, lighting, and more.1
Non-renewable, or “dirty,” energy includes fossil fuels such as oil, gas, and coal. Non-renewable sources of energy are only available in limited amounts and take a long time to replenish. When we pump gas at the station, we’re using a finite resource refined from crude oil that’s been around since prehistoric times. Non-renewable energy sources are also typically found in specific parts of the world, making them more plentiful in some nations than others. By contrast, every country has access to sunshine and wind. Prioritizing non-renewable energy can also improve national security by reducing a country’s reliance on exports from fossil fuel–rich nations.1
2. How many different types of renewable energy are there?
The two main sources of renewable energy – or the ones you’ve most likely heard of before – are solar and wind power.
We use solar energy every day, from growing crops on farms to staying warm. Photovoltaic (PV) solar panels are made of solar cells. A cell is a small disk of a semiconductor like silicon. They are attached by wire to a circuit. As light strikes the semiconductor, light is converted into electricity that flows through the circuit. As soon as the light is removed, the solar cell stops producing power2.
We can also produce electricity through wind power. A wind turbine turns energy in the wind into electricity using the aerodynamic force created by the rotor blades, which work similarly to an airplane wing or helicopter rotor blade. When the wind flows across the blade, the air pressure on one side of the blade decreases. The difference in air pressure across the two sides of the blade creates both lift and drag. The force of the lift is stronger than the drag and this causes the rotor to spin. The rotor is connected to the generator, either directly (if it’s a direct drive turbine) or through a shaft and a series of gears (a gearbox) that speed up the rotation and allow for a physically smaller generator. This translation of aerodynamic force to rotation of a generator creates electricity.3
Hydropower, Biomass, Geothermal, and Tidal Energy
Other less ‘mainstream’ sources of renewable energy are hydroelectric power, biomass energy, geothermal energy, and tidal energy.
Like other forms of electricity generation, hydropower uses a turbine to help generate electricity; using the energy of falling or flowing water to turn the blades. The rotating blades spin a generator that converts the mechanical energy of the spinning turbine into electrical energy.4
Biomass contains stored energy from the sun. Biomass is organic material that comes from plants and animals. When biomass is burned, the chemical energy in biomass is released as heat. It can be burned directly or converted to liquid biofuels or biogas.5
According to the Geothermal Research Council, geothermal Energy is heat (thermal) derived from the earth (geo). It is the thermal energy contained in the rock and fluid that fills the fractures and pores within the rock of the earth’s crust. Deep wells are drilled into underground reservoirs to tap steam and very hot water. The steam and hot water are then brought to the surface for use in a variety of applications, including electricity generation, direct use, and heating and cooling.6
Tidal energy is produced by the surge of ocean waters during the rise and fall of tides. For most tidal energy generators, turbines are placed in tidal streams. A tidal stream is a fast-flowing body of water created by tides. A turbine is a machine that takes energy from a flow of fluid. That fluid can be air (wind) or liquid (water). Because water is much more dense than air, tidal energy is more powerful than wind energy. Unlike wind, tides are predictable and stable. Where tidal generators are used, they produce a steady, reliable stream of electricity.7
3. Which renewable energy source is the best?
Although all of the different forms of renewable energy can be used, the most efficient forms of renewable energy are geothermal, solar, wind, hydroelectricity, and biomass. In the US in 2015, renewable energy accounted for a tenth of the total US energy consumption. Half of this was in the form of electricity. Biomass had the biggest contribution with 50%, followed by hydroelectricity at 26% and wind power at 18%.8 However, these statistics may show the most efficient forms as such because of the availability and popularity of certain types of renewable energy. The more mainstream renewable energy becomes, and the more it is utilized globally, these statistics will change.
4. Can renewable energy replace fossil fuels?
Michael Klare, PhD, Professor of Peace and World Security Studies at Hampshire College, stated the following in his Apr. 22, 2015 article titled “The Age of Wind and Solar Is Closer Than You Think” available at the Scientific American website:
“That day will come: the life-changing moment when renewable energy—wind, solar, geothermal and others still in development—replace fossil fuels as the principal source of world energy…
The transition to renewables will be hastened by dramatic improvements in the pricing and performance of such systems. Due to steady increases in the efficiency of wind and solar systems, coupled with the savings achieved through large-scale manufacture, the price of renewables is falling globally…
The transition from fossil fuels to renewable energy will not occur overnight, and it will not escape recurring setbacks. Nevertheless, renewables are likely to replace fossil fuels as the dominant source of electrical power well before mid-century as well as make giant strides in other areas such as transportation.”13
The short answer is: yes. Renewable energy can and will replace fossil fuels in the future, but it will take time for the world to adjust to reducing their reliance on fossil fuels.
5. How can renewable energy benefit the environment?
This is a fairly straight-forward answer. Unlike fossil fuels such as oil and diesel, renewable energy sources produce no greenhouse gases and do not produce any toxic substances or pollutants that could harm us or the environment. In addition, renewable energy sources are – as the name states – renewable. For example, wind power or solar power cannot be depleted. We can’t run out of wind or sunshine. The same goes for hydropower.
However, there are some disadvantages to certain sources of renewable energy. Wind and solar power require large masses of land to erect wind turbines or solar panels. There are some ways to combat this issue, such as using farmland. Researchers from Oregon State University estimate that installing photovoltaic panels on just one percent of croplands worldwide would be enough to meet allof humanity’s global electricity needs9.
6. How does renewable energy save money?
There are a number of ways that renewable energy will save you money. For one, your electricity bill could be lower. Businesses that install solar panels, wind turbines and other forms of renewable energy on their properties and use them to power their operations can meet a significant portion or all of their energy needs. They would also be protected from fluctuations in electricity prices, and could potentially sell their energy back to the grid. When a power outage happens on the main grid, homes and businesses that have renewable energy will not be affected. Renewable energy is also becoming less expensive upfront to buy and install. In the long term, utilizing renewable energy sources either in your home or as a business will save money and reduce the risk of outages.10
7. Will renewable energy create jobs?
In 2016, the renewable energy sector employed about 9.8 million people, which is a 1.1% increase compared to 2015. Moreover, the solar power industry alone generated twice more workplaces than the coal or oil industry combined. Most of the fossil fuel jobs in extraction or other supportive activities have been declining since 2012 when gas and oil industry reached their peak. Therefore, people are looking for new opportunities and along comes renewable energy registering a 12% faster growth than the US economy.
Today, jobs in clean energy become more available and well-paid because, according to European Defence Fund (EDF), solar energy supply companies are able to offer more jobs per dollar invested. It develops 12 times faster than the whole US economy. The main reason for such growth is the economic indicators. Businesses have realised that sustainable development is key to success, long-term performance, and investment. Besides that, the prices on solar and wind products have dropped—making it more affordable. The Great Powers such as US, China, and Germany are pushing for renewables, which made them launch a plan to reduce the global gas emissions by 40%. It will include building factories generating clean energy that would require creating 430,000 additional jobs.
The increasing investments in the renewable energy sector has the potential to provide more jobs than any other fossil fuel industry. Local businesses and renewable industries will benefit from this change as their income will increase significantly. The benefits of shifting to renewable energy are clear-cut and for this reason the governments should react positively towards the transition to clean energy.14
8. Will renewable energy sources stop global warming?
Many people disagree over whether or not global warming is real. We are not here to debate that fact; however, we are here to discuss the significant impacts that fossil fuel use has on the environment, and how renewable energy will reduce those harmful effects. Carbon dioxide and other greenhouse gas emissions act like a blanket, trapping heat, which results in frequent storms, drought, sea level rise, and even extinction of animal species. In the US, 29% of emissions come from the electricity sector. Replacing these fossil fuels with renewable energy sources will reduce the amount of harmful emissions in the atmosphere, and will reduce the risks associated with global warming. Renewable energy sources produce little to no emissions during the manufacturing, installation, operation, and decommission. For example, burning natural gas for electricity releases between 0.6 and 2 pounds of carbon dioxide equivalent per kilowatt-hour; coal emits between 1.4 and 3.5 pounds of CO2E/kWh. On the other hand, wind produces only 0.02 to 0.04 pounds of CO2E/kWh during a life cycle, and solar produces 0.07 to 0.2; geothermal 0.1 to 0.2; and hydroelectric between 0.1 and 0.5.11
9. What happens if the sun isn’t shining or the wind isn’t blowing?
The answer to this question is: batteries. When the sun IS shining and the wind IS blowing, solar panels and wind turbines (as well as other renewable sources such as hydropower) produce electricity, and this electricity is stored in large batteries. When solar panels or wind turbines produce more power than we are demanding, the energy gets stored in batteries for later use.
According to GE12, a battery energy storage solution offers new application flexibility and unlocks new business value across the energy value chain, from conventional power generation, transmission & distribution, and renewable power, to industrial and commercial sectors. Energy storage supports diverse applications including firming renewable production, stabilizing the electrical grid, controlling energy flow, optimizing asset operation and creating new revenue. Energy storage can help you increase the dispatchability and predictability of renewables, helping to meet strict code and connection permits.12
10. How can I use renewable energy?
The following are some top green alternative energy tips that will help you get an idea of how you as an individual can incorporate more renewable energy into your life:15
- Switch to green power. An increasing number of electricity providers offer renewable alternatives, such as wind and solar power.
- Use solar power. Active solar power is captured through solar cells and can be stored for later or used immediately to provide heat or electricity. You could also use solar power to heat the water for your showers, dishwasher, and laundry by installing a solar hot water system.
- Use geothermal energy. Ground source heat pumps are a way to reduce electricity use for heating and cooling, so its easier to go 100% renewable.
- Replace fossil fuels with biomass/biofuels. You can heat your home using biofuels. You can also use a woodstove or pellet stove.
- Use wind power. It is more expensive up front, but a wind turbine is a 20-year investment that will save you money in the long run.
- Use small-scale hydropower. Micro hydropower can be used, like pumping water to power a generator.
- Start smart. When buying a home, make sure it is well insulated and energy-efficient so you use less electricity.
1Shinn, Lora. (June 15, 2018). Renewable Energy: The clean facts. Retrieved from nrdc.org: https://www.nrdc.org/stories/renewable-energy-clean-facts
2Northwestern University. (2019). What are solar panels? Retrieved from qrg.northwestern.edu: http://www.qrg.northwestern.edu/projects/vss/docs/power/1-what-are-solar-panels.html
3Wind Energy Technologies Office. (2019). How Do Wind Turbines Work? Retrieved from energy.gov: https://www.energy.gov/eere/wind/how-do-wind-turbines-work
4Origin Energy Limited. (August 14, 2018). What is hydropower? Retrieved from originenergy.com: https://www.originenergy.com.au/blog/about-energy/what-is-hydropower.html
5U.S. Energy Information Administration. (2019). Biomass explained. Retrieved from eia.gov: https://www.eia.gov/energyexplained/biomass/
6Enbridge Inc. (2019). Geothermal Energy: What is it, where is it, and how do we capture it? Retrieved from enbridge.com: https://www.enbridge.com/energy-matters/energy-school/geothermal
7National Geographic. (2019). Tidal energy. Retrieved from nationalgeographic.org: https://www.nationalgeographic.org/encyclopedia/tidal-energy/
8New Jersey Institute of Technology’s Online Master of Science in Electrical Engineering program. (August 2017). The Most Efficient Form of Renewable Energy. Retrieved from borntoengineer.com: https://www.borntoengineer.com/efficient-form-renewable-energy
9Bard, Susanne. (September 5, 2019). Farmland Is Also Optimal for Solar Power. Retrieved from scientificamerican.com: https://www.scientificamerican.com/podcast/episode/farmland-is-also-optimal-for-solar-power/
10Folk, Emily. (February 8, 2019). 10 Ways Renewable Energy Can Save Businesses Money. Retrieved from https://www.renewableenergymagazine.com/emily-folk/10-ways-renewable-energy-can-save-businesses-20190208
11Union of Concerned Scientists. (December 20, 2017). Benefits of Renewable Energy Use. Retrieved from ucsusa.org: https://www.ucsusa.org/resources/benefits-renewable-energy-use
12GE Renewable Energy. (2019). Why energy storage? Retrieved from ge.com: https://www.ge.com/renewableenergy/hybrid/battery-energy-storage
13Klare, Michael. (April 22, 2015). The Age of Wind and Solar is Closer Than You Think. Retrieved from alternativeenergy.procon.org: https://alternativeenergy.procon.org/view.answers.php?questionID=001244
14Greenmatch Co. (January 3, 2019). Does Renewable Energy Create Jobs? Retrieved from greenmatch.co.uk: https://www.greenmatch.co.uk/blog/2017/07/does-renewable-energy-create-jobs
15Copeland, Blythe. (August 1, 2014). Clean power to the people. Retrieved from treehugger.com: https://www.treehugger.com/htgg/how-to-go-green-alternative-energy.html