Installation of solar panels for homes is becoming a widely interesting topic nowadays. This matter of discussion is really timely — considering the cost for electricity bills is increasing almost every year. Thus, finding ways to reduce electric energy consumption from the utility is a must-do thing.
Without a doubt, installing solar panels for your home will definitely offer a huge help. Especially now, materials and labor costs of solar PV system installation have dramatically dropped — as compared to previous years. This means, the return of investment for solar homes sees a really great improvement. Indeed, going solar is a worthy pursuit if you’re serious in cutting down your monthly electric bill cost.
Why should I consider installing solar panels?
Aside from the obvious reason of saving money, powering your home with solar energy has more advantages than you can imagine.
Firstly, you begin to tap on the most abundant power source in the planet; which is the sunlight! The Sun produces its energy by nuclear fusion of hydrogen nuclei to helium (source). Powering your homes with solar panels means harvesting energy that the sun generates and converting it into electricity. Indeed, it is possible to power your home appliances using sun rays, which is awesome!
Secondly, it reduces your carbon footprints. So, what does it mean? It simply means that you are helping the environment because you reduce the release of carbon dioxide into the air. Now, you might ask how it works. By simply using solar energy, you reduce the demand for power plants in burning fossil fuels. In effect, these power plants produce lesser greenhouse gases to the environment. Meanwhile, some highly developed countries like Germany and the Netherlands plan to eliminate CO2 emission from non-renewable power sources by using more solar and other renewable types of energy.
Additionally, installing solar panels for homes is a great investment to make. It will pay for it self in an average of 6 years. For the rest of its 25-year or more life span, you will enjoy free electricity. It also increases the value of your property.
If you want to learn more about the advantages of solar energy, start reading our previous post
What do I need to know about solar panels?
Before you buy solar panels for your home, make sure you know the basic things about them. Actually, they come in various shapes, sizes, power capacities, types and other characteristics. It is important to note as well that they come in many different brands. Thus, the solar panel cost also varies.
You will find more of the details on the solar module data sheet that manufacturers provide. Indeed, it is a good idea to know your solar panels first before buying and installing them.
Solar Panel Types
There are a few types of solar panels that are available in the market. However, we will just introduce the top 3 solar cell types which most solar homes use.
Monocrystalline Solar Panels (Mono-SI)
High-performance solar modules utilizes monocrystalline silicon. We call them Monocrystalline Solar Panels (Mono-SI). Process of creating it involves melting high-purity, semiconductor-grade silicon. This produces least amount of impurities. Thus, forming continuous single crystal, making it the most efficient type of solar panel in the market.
Mono solar panel efficiency ranges from 18-22%. We base the calculations on the amount of solar energy it will produce within its total surface area.
This will be the best option if you want higher capacity of solar power in a small area.
Polycrystalline Solar Panels (p-Si)
Polycrystalline Solar Panels (p-Si) is made up of polycrystalline silicon or polysilicon. A chemical purification process produces this is also a high purity form of silicon. Unlike the mono crystalline variety, multiple small silicon crystals makes up a polycrystalline solar cell.
Its efficiency ranges from 15-19% as of the moment. And, It is quite cheaper than the mono crystalline solar modules.
Thin-Film: Amorphous Silicon Solar Panels (A-SI)
Thirdly, the thin-film module is another type of solar panel being used for homes. This consists of thin layers of photovoltaic materials. Usually, it has glass layers on the back and front of the panel to enclose and protect the light absorbing materials. Solar cells on thin-film modules uses several technologies including:
– cadmium telluride (CdTe),
– amorphous thin-film silicon (a-Si, TF-Si) and, –
– copper indium gallium diselenide (CIGS).
In terms of efficiency, it ranges from 7-15% as of the moment.
Solar Panel Physical Attributes
In basic terms, a solar panel is a group of solar cells connected together within a rectangular frame.
Solar Cell Dimension. In average, each solar cell has a 156.75 mm x 156.75 mm surface area (6.17 in x 6.17 in). And, the most common configurations of a solar panel are in 60-cell (6 by 10 cells) or 72-cell (6 by 12 cells) arrangements.
Thus, this gives us the solar panel dimensions of 992 mm x 1953 mm (37.8 in x 76.89 in) for 72-cell module. It usually comes in 300 to 390 Watt-peak in solar capacity.
For the 60-cell module, it usually has an area of 992 mm x 1637 mm (37.8 in x 64.45 in). Usually, it comes in 250 up to 340 Watt-peak capacity.
Solar Panel Average Weight. Solar panels weigh between 18 kg to 28 kg, depending on the types of materials used by manufacturers.
Knowing these numbers is very helpful. In fact, it makes it easy to estimate the quantity of solar panels you need to install in your home. You can then know what the total capacity of your solar power plant will be.
Note: To become 100% sure of their dimensions and weight, you can directly check it from the solar panel datasheet. Go to the manufacturer’s website and download the file. Or, contact them directly by email.
How do I calculate my solar plant size?
Do you really plan to install your solar panels on your home? Do you have enough space for solar on your roof? How much do you want to save from your electricity bills?
These are some of the questions you need to answer in order to calculate your solar plant size. Depending on the amount of space available, you will be able to know the total capacity of your solar home.
Estimate Your Solar Plant Size Quickly
Estimating the maximum solar plant size for your home is pretty straightforward. Basically, the average surface area of a solar panel is around 2m². We are talking about the commonly used 72-cell solar module here. As a rule of thumb, simply divide your allotted area by 2m². (Bear in mind though, the allotted area mentioned here should not include your space for maintenance access). Then, you will have the estimated number of solar panels for your home. Multiply that to the solar module capacity of your choosing. As a result, you will get your estimated solar plant capacity fairly quick.
For example, your roof area that is intended for solar is about 40 m². It means, you will be able to fit approximately 20 solar panels. But, make sure you have considered having maintenance access space as well. This means, you want to leave good amount of area for cleaning and maintenance purposes.
Let us say, you chose to buy 390 Watt-peak solar modules. Then, your total solar plant capacity will be 20pcs. x 390Wp or 7,800 Watt-peak or 7.8kWp.
This is good only if you just want to quickly assess your solar plant size.
Calculate Your Home Solar Plant Size Properly
Here, we will identify the steps on how to properly calculate your solar plant size. It is a very important thing to do at this stage. This will make your planning smooth and precise.
1. Measure Your Roof.
To be more accurate with your solar plant size, you need to measure up your roof. Measure it safely and accurately. Or, you can just refer to the scaled as-built drawings for your home if you have them.
2. Choose Your Solar Panel.
This step is both exciting and interesting. At this point, you need to consider a lot of things in choosing your solar panel model. You have to decide on the factors like module size, capacity and the cost. However, thousands of solar module manufacturers fill the market today. So, how do you know which model is right for you?
Let’s make this simple here. If you want to maximize your roof space, you will want to choose the one with the highest panel efficiency. It means, the one that has high wattage output with less surface area. But, this also comes in a hefty price per unit. Notable brands for this type are the likes of SunPower, LG, Panasonic and others.
Meanwhile, there are also the brands that give fair panel efficiency with competitive prices. Jinko Solar, Suntech Solar, Canadian Solar, JA Solar, Trina Solar and others belong to this group.
Undoubtedly, it is recommended that you take your time in choosing your solar panel model. Doing research and checking out more information about them will definitely help. In the end, what matters is the quality of the solar panels for your home.
3. Create Solar Panels' Layout.
Now, you have the roof measurements and specific solar panel model. The next step is to create the layout of the solar panels. In other words, you will need to finalize the arrangement of these modules on your roof. Through this, you will determine the number of solar modules you can install on your home.
It is recommended to use a computer aided drawing (CAD) to properly plan your solar rooftop system. You can hire someone to do this for you if you don’t have the time and skills for this task. Or if you want, you can still draw it manually with your pen, paper and ruler. Just make sure everything is scaled properly.
4. Calculate Your Solar Plant Size.
After following the first 3 steps, calculating your solar plant size is pretty simple. From the solar panel layout, you will have the total quantity of solar modules. Now, multiply that to the module wattage and you will have your total solar plant capacity.
For example, you have chosen a 390Watt-peak solar module. Upon creating the solar panel layout, it turned out you can fit 20 nos. of them.
20 x 390 Watt-peak = 7,800 Watt-peak or 7.8 kWp solar PV system.
From there, you will have the solar power plant’s peak power output.
What materials do I need to prepare for my home solar power plant?
Follow this blog to learn more.