Things you need to consider before buying your first Solar Panels for your home, RV or any other off-grid application
My first Solar panel was a 40Watt solar panel with a 7A solar charger included. Never mind, I will explain what all these things mean later. I bought my 40 Watt solar panel because my family and I were going from Canada to Kuje, a small city in Nigeria for to live for 3 or more years. The solar panels were on sale for 50% and I was sure it would help in many ways. To cut a long story short, it was useful but quite inadequate for the needs we had and still have. I have since upgraded to a 200Watt panel and I hope to expand this some more. Here are a few things I should have considered before buying my first solar panel or solar charger.
What do you need a Solar Panel For?
Solar Panels today are mostly installed to convert solar energy to electricity and fed back into the power grid for distribution, so that you can get a rebate. In off grid situation it is for charging batteries or powering devices that use direct current. If you are considering your Solar Panels for the purpose of feeding the power back into the grid, then you will be better off consulting companies who specialize in these. They are not only experts at installing and optimizing your panel, they will also inform you about all the government programs that are available in various states or provinces of your country.
Our focus for this site will be for those who are thinking of using Solar Energy for off grid applications such as charging the batteries of your RV, Your boat, Your solar generator, your water pumping machine and so on. The most common solar panels for the home are 100 Watt Solar Panels.
What is the Power Rating of your device or the Rating of your Batteries
Until after I got our first solar panel, I did not really take note of the ratings of batteries. Batteries are rated by the amount of current they can deliver for one hour. This is also the number of hours for which they can deliver one ampere of current. For example, theoretically, A 50AH battery can deliver one Ampere of current for 50 hours or 50Amperes of current for 1 hour. The problem with this rating for the regular user is that most devices are rated in watts, solar panels are also rated it watts. How then do you know how many watts of power a battery can deliver? You multiply the AH by the voltage to give you WattHour.
So a 12 volts, 50AH battery can deliver 50 x 12 = 600WH.
This means that this battery can power a 600watt load for one hour. Or a 60 watt device for 10 hours. This is the theoretical capacity of the battery. In practice however, this is not always so due to variations in connection, temperature and other variables. It is safer to use 80% of this capacity for planning. This means then that our 12 volts 50AH battery can deliver 600×0.8 = 480 Watts of power for one hour.
Where do you find the Rating of your Battery?
The Rating of your battery can be found on the battery itself. Even the small alkaline AA or AAA or D batteries have this ratings. You know I had always wondered why a set of AA batteries from the same manufacturer would have different costs, until I discovered that the higher the AH the battery has the more valuable it is and hence the higher it costs.
How Much Sunlight do you receive?
This will determine how many days it will take for your solar panel or solar charge to charge your batteries. Please a look at this video for more tips on what you need to know before installing solar panels
Do you have room to place your solar panels?
This will determine how efficient your solar panels will be. The panels are rated for direct sunlight. If you do not have access to direct sunlight, they will function but not as efficiently as they should or are rated. A 100 Watt panel may function at 50Watt level if it is only receiving 50% of the expected sunlight.
What is your budget?
For a solar powered system to function after sunset, you would need battery backup. It is important that you check how much you are willing to spend so that you can be properly prepared for the kind of system to purchase. These systems are usually expandable so you need to plan for expansion right from the first purchase.
Components you need with solar panels for your home
Solar panels do not usually stand alone. Most times, they are used to charge batteries or power DC components. They can be used to power DC water pumps, DC lighting points and other devices.
To set up an off grid solar power system you will need the following components. I give a non-technical explanation of each device below.
- Marine Batteries
- Power Inverter
- Solar Charge Controller
- Battery Rack (optional)
- Extra cables (optional)
As much as we know that the sun is always there, we also know that there are some cloudy days and that the sun, goes down at night. For an off-grid system (that is a system that is not connected to any other source of electricity from the city) you will need a way to power your appliances at night when there is no sunlight.
For your system, you will need enough batteries to power your appliances and lighting points through the night. The more devices you have the more battery power you need.
The power inverter is used to convert the direct current (DC) supplied by the batteries to alternating current (AC) required by most home appliances and devices. Without a power inverter, you cannot power your devices just with a bank of batteries.
Solar Charge Controller
This a device that is used to regulate the current that supplied by your solar panels to charge your batteries. The solar charge controller helps to prevent your batteries from being overcharged and destroyed.
Battery Rack and Extra cables
Depending on the distance between your panels and your batteries, you may need extra cables to connect them. You may also need some cables to connect your charge controller to your inverter. You may also need extra cables to connect your batteries together in series or parallel.
This blog is targeted to people who want to set up solar panels in their homes, cabins or RVs. If you are not technically experienced enough with such systems, you may simply get someone who knows about electrical systems to help with the installation. Even if they have never installed a solar power backup system, they will be able to follow the instructions for installation for an hourly pay.
Now you have an idea of what you need to set up your first solar power system. All you need to do is determine how many panels you need, how many batteries you need and what type of solar charge controller you should buy. Go ahead! Take the leap! You will become one of the “few” who are maximizing the constant supply of solar energy to our beloved planet.
I hope this has helped you. Please leave your questions and comments below.
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