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The Size Of Solar PV
Once you've determined whether or not your home or business is a suitable candidate for solar power, your next question is, of course; what size solar system setup do I require to power it? With the rising interest in ecologically friendly energy solutions worldwide, demand for solar systems has skyrocketed.
According to surveys, Australia's typical solar panel system size is a 5kW system with around 14 panels. So, which solar system should you buy for your property? What should the price be? Where will it be set? What are some of the trustworthy brands to purchase your system from?
How big should it be? Who does the installation? These and other questions have most certainly entered your thoughts on several occasions. This article will teach you more about the different solar system sizing available on the market and their distinct capabilities, so you can make an informed decision when looking for an appropriate-sized solar system capacity for your house or business in Australia.
Also, remember that households that generate their power using renewable technology, like solar panels or wind turbines, are eligible for cash incentives under the feed-in tariff (FIT) program, which is an added advantage.
Pre-Purchase Solar System Size Considerations
As far as the capacity of solar systems is concerned, there are many factors to consider prior to deciding on the ideal model for your needs. If you are unsure about any of the tips listed below or have other concerns or questions about solar systems, contact a competent solar installation and maintenance company now.
We cannot emphasise how vital it is to speak with a professional; their duty is to understand solar systems, so make full use of their skills and knowledge. Here are some elements to consider when determining the right size of a solar system for your home or business:
What percentage of power usage happens during the day?
It is essential to consider what percentage of power your property uses during the day to gauge the size of the solar system required. According to Solar Quotes, the typical Australian family uses 18kWh of power per day. To generate this amount of power in a given residence, a 5kW solar system would be required.
However, having such a massive system is pointless if your property only uses around 40% of its power throughout the day. In this case, a system generating an average of 7.2kW (calculated by multiplying the percentage consumed by the average kilowatts of power consumed by a typical family in Australia, i.e., 40 per cent x 18 kW) of power per day would suffice. As a result, a 7.2kW solar unit is likely to provide you with the most cost-effective option and the highest financial payback.
Do you intend to live off the grid?
You will have to install a more extensive solar system than most if you intend to live off the grid. This is because your solar system will serve as your sole source of electricity, along with whatever backup plans you may have in place, and you will be entirely dependent on it.
These systems, sometimes referred to as Stand-Alone Power Systems (SAPS), provide independence and sustainability by harnessing solar energy to produce electricity that is then used to power a solar battery through the use of a charger controller.
It is advised that beforehand you should consult a specialist to determine whether this type of system is appropriate for you and your environment and whether you have the necessary room to keep it.
How much will you save overall if you use solar energy?
One of the most prevalent queries is how much you're genuinely saving by switching to solar energy. Depending on the solar system configuration and where you live, it might take anywhere from around two to seven years for your solar system to finally pay for itself. Once that duration is over, you may start thinking about calculating your savings.
What is your financial situation?
Regarding solar energy, the initial expenses might be significant, but the long-term advantages are enormous. Having said that, the amount of money you can afford to offer for the initial cost will impact the size of the solar system you can acquire.
Therefore, you need to do your maths and plan your finances from the get-go to guarantee that you get the most advanced system to meet all your energy needs. Comparing rates for entire systems rather than individual panels is best since you will most likely receive more bang for your buck.
How will your solar system be used?
If you are considering the solar system size to purchase, any quotation or estimate you receive will be based on your property's typical solar generating potential. Remember that if you rely on the solar system to provide specific quantities of electricity in both summers and winters, your system needs to be adjusted.
Calculating The Solar System Size You Need
What is your energy consumption?
Most individuals start by making a list of all their electrical gadgets and devices which will be used in their specific house or location, as well as an estimation of how long each device will be switched on and utilising energy each day. After that, multiply each gadget's power usage (in watts) by the number of hours it is turned on to get the daily electricity consumption in watt-hours.
What are the daily sun hours in your geographical location?
Because solar energy is generated through the incidence of sunlight on solar PV panels instead of heat, it is vital to determine the approximate number of hours of direct sunlight your panel will be exposed to during the day. The quantity of energy that can be obtained from the solar system at an off-grid property is determined by its location and also the time of year.
When a solar PV panel faces incident sunlight directly, the sun's rays beam directly down onto its surface, producing the highest electricity. Solar insolation is a measurement of the power of sunlight striking the Earth at your position, and you'll need to have the peak sun-hour value for your specific location.
It is critical to have a suitable place to guarantee that the PV panels are exposed to strong sunshine every day of the year. It also ensures that you are gathering solar energy more effectively. This can be as low as four hours during the winter season and as much as seven hours during the summer season.
Power backup storage system
Unfortunately, the sun doesn't shine throughout, particularly at night; thus, some backup storage system to store excess solar energy is essential. Solar panels can generate lots of electrical power on a bright sunny day. Therefore, to utilise solar energy at night, during the winter, or during times of low insolation, you will require batteries with good storage capacity to store and access electricity after the sun goes down.
Determine the number of solar panels you require
Once you have an exact estimate of your solar insolation for your specific location, all that is left is to determine the number and type of photovoltaic panels that will generate the necessary power for your home or business. There are hundreds of various types of solar panels to pick from, each with its own unique kind, shape, size, and voltage rating.
In most circumstances, the size of a solar panel relates to its ability to generate power. Solar panels' voltage ratings can also vary depending on their manufacture and size. Off-grid applications often employ those with output voltages ranging from around 12 to 48 volts. Maximum power (Pmax) supplied by a single panel in full sun is calculated as Maximum Power Voltage (Vmp) multiplied by Maximum Power Current.
Your solar panels' orientation and angle will be determined by the direction and pitch of your roof. Both parameters, particularly the direction, could significantly influence solar energy output. A solar panel installation facing west or east will produce around 15% less power than the one facing south. Therefore, if your installation can only be positioned on a west or east-facing roof, your solar system size must be increased to account for this.
All solar power systems encounter system losses, so you won't be able to access the entire DC output of your solar panels. There are generally wiring losses of around two per cent during transmission of DC electrical energy to the solar inverter. Then there are also conversion losses that occur when your inverter transforms the energy from DC to AC electricity, accounting for a further three per cent of electricity produced.
That implies that with a traditional grid-tied solar system, you may expect to have just about 95 per cent of the power produced by your solar panels available for use in your household. Actual values will vary based on your solar system design and equipment. For instance, you could indeed reduce power losses by minimising your wiring.
Every time energy enters or exits a battery, a certain amount of energy is lost. Depending on your chosen battery system, you should expect a wide range in overall losses. The typical round-trip efficiency of DC-coupled battery systems is about 95%. The round-trip efficiency of AC-coupled batteries is lower, hovering at around 90%. You will need to appropriately size your solar panel system to compensate for these losses.
Increase Your Solar Power Systems Battery Life
Investments like solar power systems need to be protected; thus, keeping your batteries in good condition is crucial. Follow these recommendations to increase the battery life of your solar system to get the most out of your batteries.
Never leave your batteries uncharged for long
You should never leave your solar system's batteries uncharged for a lengthy period. Be careful to keep your charging device on so the batteries can keep charging. Batteries can become damaged if they are not charged. AGM batteries have a high self-discharge rate; therefore, you need to periodically recharge them (every two to three months).
However, you should only charge them when they are not used to prevent deep drain, which may be highly harmful to lead-acid batteries. Also, keep them dry, cold, and aired when storing them.
Allow partial discharges but refrain from complete ones
Unlike NiCad batteries, lithium-ion batteries don't have a charge memory. As a result, deep-discharge cycles are thus not necessary. Utilising partial-discharge cycles is healthier for the battery. One thing stands out. Solar battery storage experts recommend that you let lithium-ion batteries drain almost entirely after 30 charges.
The precision of the device's power gauge is lowered by a situation known as digital memory, which is brought on by constant partial discharges. Allow the battery to completely drain before recharging it. Recalibrating the power gauge is planned.
Interconnect your solar system batteries using large wires
Large connecting wires between batteries lower resistance and enable uniform charging. For 12V and 24V systems, use a 4/0 size cable and a 2/0 size cable for 48V systems.
Permit boiling or gassing
Battery gassing or boiling is standard and an essential component of good charging. Gassing is frequently caused by self-discharge or electrolysis of water inside the electrolyte while charging.
Your batteries should be gassed often, ideally daily. At around 14.1 Vdc (12V nominal system), 28.2 Vdc (24V), or 56.4 Vdc, batteries will start to gas (48V). Since both hydrogen and water will be produced during this process, your battery bank must have sufficient ventilation to prevent hydrogen accumulation.
Utilise battery equalisation
Your batteries will be intentionally overcharged during equalisation. After being completely charged, flooded lead-acid batteries undergo an overcharge process known as equalisation. It stops the accumulation of harmful chemical phenomena like stratification, which occurs when the acid concentration is higher at the bottom of the battery than at the top.
Although overcharging may sound undesirable for your batteries, it may be highly beneficial since the normal cycling process might cause individual battery cells to charge unevenly over time. As a result, some cells cannot consistently attain full charge, which can cause sulfation to accumulate on the plates.
Equalisation offers the chance to charge all the cells fully once again. This allows gassing to remove part of the sulfation from the plates. Additionally, gassing can assist in blending your electrolyte to stop stratification.
Charge the batteries at the appropriate temperatures
Extreme outside temperatures may result in inconsistent battery charging during the charging procedure. When the battery's internal temperature reaches a certain level, it may no longer be able to absorb enough external power. Lead-acid batteries suffer from a partial charge as a result, which is bad. You should ideally charge AGM batteries at temperatures between 0°C (32°F) and 40°C (104°F).
Consider buying a lithium-ion battery with a large capacity
Whether they are being utilised or not, batteries degrade with time. When buying batteries, it's critical to keep in mind the aging feature. Ask for those with the latest production date if possible.
Does A Solar Panel's Size Matter?
There are several methods to assess the size, but the fact is that size is essential whenever it comes to panels. Solar panels come in various sizes, often measured in square feet or how much area they occupy on your roof. Power rating is another metric for determining size. One panel's power rating does not necessarily correspond to its physical size.
The size of a solar panel is measured in watts. There are solar panels of 100, 200, or 300 watts, much like there are 100, 200, and 300-watt light bulbs. Therefore, it would be simple to think that the larger the physical size of a solar panel, the more watts it produces. However, with batteries, this isn't always the case.
A smaller solar panel that generates more electricity than a physically bigger one is said to be more efficient, just like a smaller battery which produces more power. This means that a system composed of physically smaller panels might be equally as productive as a system consisting of physically bigger panels made up of less effective panels.
Since panel efficiency has significantly increased, homeowners can now buy fewer physically smaller panels that nonetheless generate even more power than prior systems composed of bigger panels. Naturally, this has several ramifications, but the most significant is that since the homeowner doesn't have to buy as many panels, the return on investment is considerably quicker.
Not only is it better for your return on investment to acquire fewer small-sized panels, but they also occupy less space on your roof. The additional room allows homeowners to add one or more panels, providing enough electricity to cover additional energy costs like your heated pool or electric vehicle. Some homeowners install an extra panel or two in preparation for future increased energy needs.
Benefits And Drawbacks Of Using Large Solar Panels
Benefits of large solar panels
- Because you have more solar cells and less aluminium frame, you obtain a somewhat better Watts per m2. In principle, a more dependable system should result from using fewer panels for a given system size because there are fewer electrical connections.
- A significantly speedier setup is possible with fewer large panels.
- Large panels often come from more recent production lines than earlier panels and are newer stock.
Drawbacks of large solar panels
- They may limit the possible setup locations in your system design.
- Because they individually output so many volts, the number of ways you can connect them might be limited.
- They are more challenging to install on your roof and could be more hazardous.
- It will cost extra to replace if one breaks after the warranty has expired.
What Size Solar System Do You Need?
The most straightforward approach to respond to this question is to determine the size of your solar system. To do this, multiply your daily energy needs in kWh by the number of peak sun hours to obtain the system's kW output. To get the approximate number of solar panels you'll need for your solar system, divide the kW output by the efficiency of your panels.
There are other additional criteria in addition to those mentioned in this article. Therefore, if you are not an expert solar service tech, it may be challenging to determine precisely what size you require. For further information and better advice that is specific to your house or place of business, please get in touch with a reputable solar installer and service provider.