How does solar power work?
By definition, solar power works by converting energy from the sun into trapped heat. That heat is then used to generate electricity.
This can happen either with PV (photovoltaic) solar panels or concentrated solar-thermal power, which stores the heat until it’s needed. At the moment, we utilise solar power to heat water, buildings and to power various devices.
When photovoltaic cells are used to collect this solar power, the cells convert sunlight into electricity, being capable of powering anything from small garden lights to whole neighbourhoods.
Using rooftop panels can power homes, whereas solar farms and community projects that use mirrors to collect concentrated sunlight can generate bigger supplies.
It’s truly renewable
Among the many advantages of solar panels, the biggest is that solar is a true source of renewable energy. It can be used anywhere in the world and it’s available every day, even on cloudy days.
Solar energy can’t run out, unlike other energy sources. We’ll be able to use solar as long as the sun exists, with sunlight being available for at least another 5 billion years.
Reduced electricity bills
Because you’ll be meeting part of your energy needs with solar power, you’ll find that your energy bills will decrease. How much money you save will depend on the size of your solar system and how much heat and electricity you use.
For example, if you have a business that has commercial solar panels, this can provide some significant benefits because a large system like this can cover huge parts of your energy bills
You can use solar power for many different purposes as it can create electricity or heat. Solar energy can be utilised to create electricity in places with no access to the energy grid, to power space satellites, or to distil water in areas with limited access to clean water.
You can also integrate solar into building materials. For example, manufacturing company Sharp introduced transparent solar-powered windows.
Technology in the solar energy sector is always advancing and the improvements will only get better in the future. Innovations in nanotechnology could potentially improve the effectiveness of solar panels and the electrical input of solar-powered systems.
Can be expensive
The initial cost of buying solar systems can be high. This includes purchasing a solar panel, batteries, wiring, and the installation process. However, solar technology is always being improved so there’s every chance that the cost will be reduced in the future.
Their effectiveness depends on the weather
Although a solar system can still be used during rainy or cloudy days, it does become less effective. A solar panel depends on sunlight to effectively collect solar energy, so cloudy days can affect how well the system works.
Remember, solar can’t be gathered overnight. But, if you do need to heat water at night or in the winter, thermodynamic panels may be a good option.
Storing solar energy is costly
Usually, solar energy has to be used immediately. If you need to store it you can do so by using large batteries. These batteries are often used in off-the-grid systems and can be charged all day so the energy can be used overnight.
Although this is an ideal solution for using the energy 24/7, it’s quite expensive. It’s usually better to use up the solar energy in the daytime and use energy from the grid overnight – but you could only do this if you have a system connected to the grid.
How does wind power work?
Wind power works similarly to old-fashioned windmills by utilising the power of the wind to rotate the blades. Originally, the motion of the turning blades would cause the millstones to grind against each other, to make flour.
But today’s wind turbines power generators, creating electricity. When wind turbines are installed, they should be placed in high wind areas such as open fields or on the tops of hills.
Offshore wind farms have been developed for years, providing a good solution for generating energy without being noisy or unsightly.
Fuel is free
Because turbines run exclusively on wind power, fuel isn’t needed. When the turbines have been installed, they don’t need to be connected to a power source or fuelled to be able to carry on working.
This will also reduce the general cost of running a large scale wind farm compared to other renewable energy resources.
It’s one of the cleanest energy sources
Because wind energy doesn’t need to rely on fossil fuels to power turbines, it won’t add to global warming as it does not emit greenhouse gas emissions during the production of energy.
Wind energy will only indirectly release greenhouse emissions when they’re manufactured and transported, and during the installation process.
It won’t disrupt farm operations
Wind farms can be built by energy suppliers on pre-existing farmlands and pay farmers to be able to build on their properties using leases or contracts.
This is great for farmers who need extra income, plus the turbines’ footprints don’t take up much ground-level space. They also won’t affect or disrupt farm productions.
Wind energy is sporadic
A wind turbine’s ability to generate electricity largely depends on the weather conditions. Because of this, it can be challenging to predict how much energy a wind turbine will be able to generate. If wind speeds aren’t high enough, the turbine’s blades won’t turn.
Because of this, wind energy won’t always be available when electricity demands are at their peak. For wind power to be used on its own, turbines will have to be paired with an energy storage technology.
It can be noisy and unsightly
One of the biggest drawbacks of wind power is visual and noise pollution. Turbines can be loud when they’re in operation because of the wind vortex and mechanical operation that’s produced when the rotors are turning.
As well as this, wind turbines have to be installed high enough to catch the right amount of wind, which means they can disturb otherwise peaceful landscapes.
Turbines can negatively affect surrounding environments
The blades of a turbine are extremely large and can turn at high speeds. Sadly, these blades can harm or kill animals that fly near to them such as bats or birds. When wind farms are constructed, natural habitats can be disrupted if it’s not done sustainably.
But, turbines are constantly being improved and these issues can be solved with advancements in technology and suitably-placed farms.
How does hydroelectric power work?
Hydroelectric power works similarly to wind power, in that it’s used to turn the blades of a generator to produce electricity. Hydropower uses water from rivers or waterfalls to turn the blades and is commonly used in some countries.
The majority of hydropower plants have water reservoirs, a valve or gate to control the amount of water that flows out, and an outlet where the water goes afterwards.
It’s clean and renewable energy
Unlike fossil fuels, using hydropower for generating electricity won’t produce harmful pollutants into the water or air. Some environmental worries come with creating big hydropower plants such as reservoirs and dams.
However, once they’re in operation, the power plants themselves don’t need to burn any fossil fuels. As well as this, hydroelectric plants won’t use water when they operate, making them a fully renewable source of electricity.
It works well with other renewable sources
Most hydroelectric plants are used as storage for large amounts of water from reservoirs. This means they’ll generally always have water in storage to use to create power. The reliance that hydroelectric power has on stored water means that it’s a reliable source of energy.
This is because hydro plants can be a dependable source of supportive energy for more sporadic sources such as solar and wind energy. Wind and solar rely on the availability of sunlight and wind.
Like energy storage systems, when there’s little to no wind or it’s nighttime and the sun isn’t shining, hydropower provides energy when wind and solar can’t. This makes it a more practical and economical source of electricity.
Some hydropower plant designs meet demands
A common drawback of renewable energy sources, such as natural gas, oil, and coal, is that they’re non-dispatchable. This means they can’t produce electricity 24/7. Instead, renewable sources like wind and solar will rely on the wind to turn turbine blades, and the sun to shine to create energy.
But pumped storage hydropower and storage hydropower facilities are capable of electricity generation on-demand. This makes hydro plants dispatchable sources which means that hydroelectric plants can replace dispatchable methods such as coal and gas plants.
Hydropower plants may negatively affect the surrounding environments
Although hydroelectric power is a renewable source of energy, there are a few environmental impacts that come with building the plants. As well as this, storage hydropower plants can interrupt a river system’s natural flow.
This can lead to animal departure paths being disrupted, as well as affecting water quality and wildlife displacement. These adverse environmental impacts of hydroelectric power are usually lower with tidal power, wave energy, or run-of-river setups.
Hydropower facilities are expensive to build
Hydropower plants are usually very large projects that require dams to be built as well as turbines that produce power and a reservoir, meaning a large financial investment is needed.
Although a hydropower facility is capable of providing affordable electricity for up to 100 years after it’s built, the initial building costs can be very expensive. As well as this, suitable locations for reservoirs are becoming harder to find, meaning that large hydroelectric plant construction costs could continue to inflate.
Hydroelectric facilities depend on local hydrology
Although hydropower is reliable, it’s still dependent on precipitation and the weather. Hydropower generally depends on river water, so if droughts occur, hydropower electricity generation can be affected by the low water flow.
Over the months and years, the water levels that are available for hydroelectric systems may vary, meaning the electricity generation at the facilities can vary too. No matter how energy is produced by water, it’s essential to think about the number of pros and cons of it.
Hydroelectric power, like all energy sources, also requires upfront costs and some changes in the environment to build important infrastructure.
How does biomass energy work?
Biomass energy works by using organic materials from animals and plants such as trees, crops, and wood. This biomass is then burned to generate heat, which provides power to a steam turbine and creates electricity.
Although biomass can result in renewable energy production if it’s responsibly sourced, there are some instances where it’s not a clean or green energy source. Unfortunately, no source of energy is perfect and this includes biomass.
Biomass is readily available because organic materials are all around us, from croplands and forests to landfills and waste sites.
Biomass uses energy from the sun, and thanks to photosynthesis, its resources can regrow quickly compared to fossil fuels that can take millions of years to regrow. Because of this, we can’t run out of biomass to utilise for energy generation.
Biomass can help to reduce waste
It’s no secret that landfills can negatively impact the environment, including contaminating the soil, water, and air nearby, as well as emitting greenhouse gases. Many materials that end up being dumped in landfills are also toxic and hazardous.
Depending on how these products are sorted, they could contaminate the land, water, and air which will eventually lead to devastating human health and environmental consequences. As well as this, landfills are a big contributor to greenhouse emissions being emitted into the atmosphere.
Putting waste into biomass energy plants rather than landfills will help in two ways. Firstly, it will help to reduce landfills and ease the risks of greenhouse gases. Secondly, it makes use of materials that would otherwise sit around doing nothing.
It’s a reliable electricity source
A lot of the time, biomass power plants are dispatchable, which means they can be easily turned on and off. This enables grid workers to take energy from these plants when demands are at their peak.
Bioenergy isn’t intermittent like other renewable energy sources such as wind or solar if the sun isn’t shining or there’s no wind. Without storage technology, solar and wind energy can’t always be used when they’re needed.
Although the availability of certain biomass resources might be seasonal, biomass plants can always be turned on to supply power, no matter what the weather is doing.
The costs can be quite high
Like other non-renewable and renewable resources, creating energy using biomass does have its drawbacks. Apart from the upfront expenses to get the biomass plants started, there are other costs to do with transporting, extracting, and storing the biomass before any electricity can be generated.
These are additional costs that other renewable energy technologies don’t have to consider, because they depend on free resources such as sunlight, wind, and the tides, to use as fuel.
A lot of space is needed
Bioenergy plants need a lot of space which limits where they can be set up. Also, companies usually have to choose plant sites that are close to the required biomass sources to cut down on storage and transportation expenses.
Extra space might also be needed so the organic materials themselves can grow. If crops and trees are being specially grown for bioenergy instead of agricultural waste being used, this can create a bigger land footprint for each unit of energy generated.
It can negatively affect the environment
Depending on which types of biomass are used to create electricity, unsustainable practices can cause deforestation after a while.
When forests are cut back to take materials for the biomass plants, the natural environment is harmed and the habitats of animals and plants are disrupted in the process. Clearing organic materials can also affect the health of nearby soils that need these compost materials.
How does geothermal energy work?
Geothermic energy works by using the heat that’s trapped in the core of the Earth. This is created by decaying radioactive particles that are present in rocks in the planet’s centre.
Drilling wells can bring heated water to the earth’s surface, which can be utilised as a hydrothermal resource to power turbines and generate electricity. This renewable energy source can be made even more green by pumping the hot water and steam back into the earth, keeping emissions to a minimum.
How much geothermal power is available depends on geographical location, with countries such as Iceland having an easily accessible and readily available supply of geothermic energy.
It’s very reliable
One of the biggest benefits of geothermal power is that it’s a very reliable and predictable energy source, especially when compared with other renewable sources such as solar or wind.
Solar and wind are more sporadic sources that need the energy to be stored for it to be used effectively in large amounts. Whereas geothermal plants have typically consistent power outputs in all seasons.
This has many advantages, including the fact that geothermal power is a suitable energy source for meeting energy demands.
Geothermal plants don’t have large land footprints
Another benefit of geothermal energy consumption is that the plants have relatively low footprints compared to other large wind, solar or hydroelectric plants. Unlike hydropower, solar, or wind, geothermic energy comes from inside the earth.
This means there’s no need to build collection setups over huge parts of land surface to use it. To put it in perspective, National Geographic evaluates that a geothermal plant with the ability to generate 1 GWh (gigawatt) of electricity, would measure roughly 404 square miles.
Whereas a wind farm with an equal amount of energy output would need around 1,335 square miles, with a solar farm needing approximately 2,340 square miles. That’s 88% less space needed for a geothermal plant in comparison to a solar plant, both producing 1 GWh.
Geothermal plants can be large or small-scale facilities
Geothermic energy isn’t just for large-scale plants. On the contrary, an efficient way of using heat from the earth is to collect it using a geothermal heat pump for commercial and residential buildings.
Unlike geothermal plants, heat pumps make full use of cool-temperature geothermic reservoirs, which are readily available almost everywhere.
The geothermal energy sector is rapidly expanding
Although the geothermal industry is still quite young, it’s quickly expanding with new renewable energy technologies, research, development, and many new projects.
These industry enhancements are making geothermic energy more efficient, accessible, and applicable to a broader range of uses.
Geothermal plants can only be constructed in certain places
Unfortunately, geothermal plants can’t just be built anywhere. Geothermal reservoirs that are above 100°C are typically needed for larger plants.
The problem is that these reservoirs can only be found in certain locations, usually near hot spots or tectonic plate boundaries.
Geothermal plants may cause earthquakes
Building a geothermal plant involves lots of drilling deep down inside the earth to release the hot water and steam that’s trapped in the rocks. Unfortunately, this process may cause the underground to become unstable.
This can cause earthquakes on the surface, potentially causing danger to humans and the environment.
How does tidal power work?
Tidal power provides a renewable energy source since tides are controlled by the constant gravitational pulling of the moon. The power that can potentially be created by the tide might not be constant but it’s very reliable, making it a great option.
However, care should be taken as tidal power can impact the environment. Tidal barrages and other similar constructions can harm the environment and wildlife.
No carbon emissions
Not only is it a renewable energy source, but tidal energy also doesn’t release greenhouse emissions while it’s creating electricity. Because these gases are one of the biggest causes of global warming, using zero-emissions sources of energy is of the highest priority.
Tide currents are easy to predict. Both high and low tides always follow cycles that are well known, making it easy to pinpoint when power will be available for the day.
This pattern also makes it easier to tell how much power the turbines will generate because the tidal power can be accurately forecasted.
Installation sites are limited
To build tidal plants, the installation site needs to meet specific criteria. This includes the fact that they need to be built on coastlines, which means that building sites are limited to areas with a coastline.
One of the biggest disadvantages of tidal energy is the expensive initial costs. Tide power turbines must be a lot stronger than turbines powered by wind because water has a higher density than wind.