For centuries, men have used solar energy in various forms. The radiant energy of the sun was helpful in drying fish, fruits, and clothes. It was also an indicator for timekeeping. Today, solar energy can be harnessed, turned into electricity, and stored. The advances in Chemistry and technologies led to the discovery of solar panels that could generate renewable energy. In Australia, which receives a lot of sunlight, putting up solar panels has become a reliable source of energy.
How Does Solar Energy Work?
The sun is a natural nuclear reactor which is a million times bigger than the earth. Its radiant energy travels to Earth in about 8.5 minutes across a distance of 93 million miles. The stream of photons or light is enough to supply all of mankind’s energy needs. In order to harness this endless light energy stream, you will need solar panels made of silicon cells. How do solar panels work and how does solar energy work? Here’s how:
- When sunlight, which is made of photons or packets of energy, strikes the solar panel or photovoltaic cell, the photons knock out the electrons in the silicon. This results in a cascading flow of electrons; thus, initiating the photovoltaic (PV) effect. A solar panel is made up of a metal frame, silicon cell layer, wiring, glass casing, and metal frame which allows the direct current (DC) to flow from silicon cells.
- When the sunlight reaches the solar cell or photovoltaic cells, these PV cells generate DC (direct current) which is not useful at this moment, unless it is converted by an equipment called inverter.
- This inverter converts the DC into the useful AC or alternating current.
- The flowing electricity goes through the metre that measures the energy.
- This renewable and clean energy goes into the various loads such as light bulbs and appliances.
- The excess energy goes back to the energy grid.
Components of a Solar Panel
A solar panel comprises of a photovoltaic or solar cells that are made up of a wafer or stack of glass lens, an N type semiconductor, and P type semiconductor—all separated by a junction. This P and N all form the surface of the solar panel. Naturally, a solar panel is not a good electricity conductor, but when doped or added with impurities such as various minerals or chemicals, the solar panel turns conductive.
Types of solar cells
Amorphous silicon solar cells are used for small-scale devices such as flashlights and pocket calculators. The new process of stacking layers of this kind of cells increases the energy efficiency.
Cadmium telluride solar cells are cost-effective and provide energy efficiency of 9% to 11%.
Single crystal cells produce the highest-efficiency cells which are made up of long cylinders sliced into thin wafers. Single crystal cells generate up to 24% of electrical efficiency.
Polycrystalline cells are cheaper than single crystal cells and are made of molten silicon cast. This type offers lower efficiency than single crystal cells.
Thin film cells are made up of metal or glass films sprayed with metallic materials such as cadmium telluride, and amorphous silicon. This type is cheaper but has lower efficiency.
Devices that use solar energy
The advances in technology, an abundance of glass, and efficient production have made solar energy less expensive than decades ago. You can now find solar energy used in lawn night lights and street lamps.
How to determine your solar energy requirements:
1. Determine how much your battery can store. Convert the amps per hour indicated by the battery.
A (Battery Voltage) X B (Battery size in AH) = C (Power in watt per hours)
12 V X 30 AH battery = 360 WH ( C )
2. Calculate the appliance’s energy usage per hour.
- Choose which appliances, such as TV, fridge, or fan, you will run in an hour.
- Check the appliance’s power rating.
- Calculate the appliance’s watt per hour.
Power consumption (in watts) X hours = energy usage per hour (WH)
40 W laptop X 2 hours = 80 WH
- Do this to all appliances and add the results.
|Appliance||Watt per day|
|Heater 750W per 2 Hours||1500 W per day|
|Laptop 50W per 8 hours||400 W per day|
|Clothes Iron 1000W per 4 Hours||4000W per day|
|Total||5900 W per day|
- Calculate how much a solar panel generates. The number of hours exposed to sunshine also depends upon the weather. A winter season will reduce the sunlight exposure, whilst summer increases the amount of sunlight that reaches the ground. This calculation also depends on your location.
Wattage X Number hours exposed to sunshine = Wattage
Installation of Solar Panel
- Before installing a solar panel, ensure that you know your household energy needs. If you own a small house, you will need a few solar panels. Make sure that the solar panels are not obscured by vegetation or trees.
- Your roof should be strong enough to handle the mounting of solar panels. Install mount rails on flat roofs or brackets on sloped roofs. Use a roof sealant to secure the screws that hold the mount rails and keep rainwater from seeping into the holes of your roof.
- Measure the dimensions of your roof and check if it fits the solar panel roofing.
- Arrange the solar panels or arrays to face the direction of the sun as it rises for maximum exposure.
- Use meteorological data for the solar panel angle.
- Connect wires to the solar modules and join them in a fuse or junction connector box. Ensure that the modules are stripped in pairs before connecting to the fuse box and the underground conduit cables.
- After assembling the solar array, connect the interior control panels to the exterior wiring (angled and wired). Connect the solar breaker to the circuit breaker disconnect switch.
- Connect the control panels to the cables.
- Ground the solar panel system by inserting a rod in the soil near the solar array. Ensure that it extends above the ground.
- Install the interior electrical connections. Connect the inverter panel disconnect to the array. Link the black wire to the negative terminal, positive terminal to the red wire, and green to the grounding terminal.
- The solar panels must be 16” from the eaves and no closer than 12” from the roof edge.
Benefits of Solar Panel
- Ubiquitous source of energy. You can easily set up a solar panel from a small and pocket device anytime and anywhere. For instance, you could use a solar panel to charge your phone when you venture to camp in the wild. Whenever there’s sunlight, there’s solar energy.
- Unlimited source of energy. The sun, the perpetual source of energy in the universe, gives solar panel a continuous energy supply, except during night time. You can mitigate this by using a battery that would store energy which is enough to cover your power requirements at night.
- Clean energy. Solar panel doesn’t give off smoke or any chemical residue, unlike petrol, coal, battery, and firewood. At the same time, the solar panel doesn’t pollute the environment.
- Safe energy. Solar energy is totally safe. You don’t have to worry about explosions from the nuclear power plant, obnoxious smoke billowing from burning coal, and flood from the collapsed hydro-electric dam.
- Easy maintenance. With solar panels, you don’t’ need expensive maintenance to fix broken machinery or moving parts. They don’t need frequent and tough maintenance to keep your energy flowing. They may need little maintenance, but it won’t require complex and risky processes. Most vendors and manufacturers offer 20 to 25 years of warranty. You could use an inverter for a long time within five to ten years.
- Flexible energy. You can embed solar panels in any device or machinery. Place a solar panel in your backpack or connect it to various devices. In fact, some solar panels are bendable that you can embed them to accommodate various sizes and shapes.
- Easy installation. Solar panels don’t need complex devices and highly technical installations, unlike batteries or generators.
- Reduced electricity bills. With solar panels and energy, you won’t mind the monthly recurring bills. Say goodbye to worries of unpaid bills to the energy company.
- Diverse applications. You could use solar energy to run various devices such as a fridge, laptop, mobile phones, power tools, HVAC, and lighting.
- Technological advances. The advances in physics, materials technology, and nanotechnology could double or triple the solar panel system’s output and reduce the needed solar panel’s surface area.
- Enhancement of home value. You might be thinking of selling your home and a good way to increase its value is to install a solar panel array.
- Job creation. The solar panel industry has created thousands of jobs in Australia through solar panel manufacturing, installation, marketing, and maintenance.
- Energy independence. Say goodbye to the company that put you at their mercy when you could not settle your bill and threatened to cut off your electricity connection.
- Improved Grid Security. Solar panels in homes can add grid security during natural disasters and overload.
- Amplified energy. During energy transmission, a huge amount of electricity is reduced because of the long distance. With solar panels, you can amplify or recoup that energy lost.
- Quiet energy. Unlike gas-powered generators, solar energy is quiet. You won’t hear any sound from the production of the electricity.
- Flexible installation. You can install one solar array on the rooftop and power your lighting or heating and place another one in the backyard to power your shed.
- Cost effective. Solar panels are inexpensive to install, unlike power plants using fossil fuels such as coal and gas. In a remote region where there’s no electricity, solar energy is considered the most reliable source.
Solar panels may appear expensive depending on type, dimensions, and availability, but in the long term, they can provide you with renewable, non-polluting, and energy-saving electricity without worrying about monthly utility bills. Technology has improved rapidly, and the cost of solar panel installation has significantly decreased over time.
Disadvantages of Solar Energy
- Weather dependent. Cloudy and rainy days reduce the efficiency of the solar panels. At night time, you cannot depend on a solar panel. To compensate for this, install a battery bank that could store the panel’s energy and use it after dusk.
- More energy means more space. Solar panels use a lot of space, as its output increases. Sometimes, the roof isn’t enough to house the solar panel array.
There is a misconception that a solar panel can be safe because it provides electricity from a battery. However, you have to treat a voltage as cautiously as the one found in AC outlets. Systems that are connected in series can produce higher and dangerous voltages.
Lead Acid Batteries
Another is the hazard posed by batteries. Lead acid batteries can release an explosive amount of energy in case of a short circuit. Another potential threat is arcing which is an extreme plasma temperature. During charging, lead-acid batteries can release hydrogen which can ignite with a spark. Sulfuric acid is corrosive and lead is highly poisonous.
The future of solar energy and cells
The continuing studies by companies and universities such as the University of Melbourne, Bosch, and Monash University have led to the mass production of solar cells that are thin, flexible, and inexpensive. By using a solar ink, a thin layer of solar cells could be printed onto the surface. This process makes solar energy more flexible. Advances in technology could further bring down the cost of solar cells, increase energy efficiency, and reduce the need for larger solar cells’ surface area.
The advantages of solar panels outweigh the disadvantages which can be mitigated by other means. Solar energy and panels are the way to energy independence because no one can monopolise the sun or its rays. By harnessing the sun’s perpetual energy, you can also help protect the environment.
Maxray helps you find good quality solar panels for your indoor or outdoor needs. With 25 years of experience in the solar industry, Maxray can provide you with foldable and top-quality solar panels. For more info, visit https://maxray.com.au.