That's MY Solar Energy System (mixed panels) Powering my House AND Directly Charging my Electric Car!
*This post is meant to benefit the community. Win win for all. Giving free information is not a crime, nor is self promotion.*
Solar Energy FREE Tips and Tricks: Mixing Solar Panels (Below)
You CAN start building your own Solar Energy System right now, no matter where you are. All you need is a willingness to get started. You can build small and expand later, or plan out and build a large system, or build a system onto a vehicle or a trailer.
You don't have to be "off-grid" to start building your own Off-Grid Solar Energy System. You can build it in your garage or in your back yard or onto a vehicle or trailer. Being Off-Grid simply means you will not connect it to your existing house / electrical system. BUT, you can set it up to run independently, and use it to run a refrigerator or a freezer - or some power tools!
Learn by doing, practice your skills, and gain knowledge of how Solar Energy Systems work, so that you can control your own energy source and harness the power of the sun!
Let's say you want to take your first step towards Energy Independence, and start building an Off-Grid Solar Energy System.
However, you want to start small with the ability to expand as you go....
Can you do this? YES
You must be smart about it, but YES YOU CAN.
TIPS AND TRICKS
For example: Is it possible to mix and match different solar panels (different sizes or different Mfr.'s) in the same system? YES it is.
You may want to start by purchasing a few panels you found on CL.... but what about adding more panels in the future? What if you cannot find more of the same panels you started with?
Here's how you do it:
You CAN mix solar panels of different sizes and from different Mfr's but you must be smart about it. You cannot simply mix ANY panel with any other panel. You must match their electrical properties for the way you want to mix them.
There are two properties that must be matched smartly. Number of Cells (voltage) and Size of Cell (Amperage).
If you look at the back of a solar panel, on the Label, you will see several electrical specifications.... such as:
Open Circuit Voltage (Voc)
Short Circuit Amperage (Isc)
Maximum Power Voltage (Vmp)
Maximum Power Amperage (Imp)
For mixing panels, let us consider the Open Circuit Voltage (Voc) and the Short Circuit Amperage (Isc)
Open Circuit Voltage is the voltage you would measure if you point the panel at the sun, and measure the volts between the two electrical leads on the back of the panel.
Open Circuit Amperage is the Amps that you would measure if you connect the two leads of a solar panel together, and measure the amps flowing through them (i.e. with a Clamp Meter) while the panel is pointed towards the sun.
Mixing Panels in SERIES (where you connect the POS of one panel to the NEG of the other):
If you have two solar panels, and they each have a different number of cells, the Voc will be dramatically different. Each cell produces about 0.5x volts. So, a typical 36 cell panel will produce about 18 - 21 volts. Let's say for example the Voc for a 36 cell panel is about 21v.
Now, you may have another panel (different Mfr. even) that has 72 cells. This panel would likely have a Voc of about 42 volts.
Now, suppose these two panels BOTH have a Short Circuit Amps (Isc) of about 5.2x Amps (must be very close but does not need to be exactly the same). You can combine these two panels in SERIES, essentially creating one larger panel of 42 +21 = 63 Volts Open Circuit (Voc) running at 5.2x Amps. You could then connect this set of panels to a MPPT charge controller and use it to charge some batteries.
What you must understand is this: When combining panels in SERIES, the Short Circuit Amps (Isc) must be the same (or very close - ideally within roughly 0.2 amps), because if they are not the same, then the smaller of the two will restrict the larger (like a bottleneck) and you will only get the smaller amount of Amps. Also, if the difference is too great, you may risk damage to the smaller panel as the larger panel tries to overrun the smaller.
Mixing Panels in PARALLEL (where you connect the POS of one solar panel to the POS of the other, and likewise NEG to NEG)
When comibing panels in Parallel, the Open Circuit Voltage (Voc) must be the same, but the Amps (Isc) can be different.
For example, let's say you have two 72 cell panels (42 Voc). But one is a 9 Amp (Isc) and the other is only 5 Amp (Isc). You CANNOT put these two in SERIES (because the Amps are much too different).
BUT YOU CAN put these two in PARALLEL (because the Voc is the same - and they need only be close to be effective - like within 2 volts). If you connect them in parallel, you will essentially have one big panel running at 42 Voc, and 9+5 = 14 Amps (Isc).
Is it clear???
If you have questions about this and / or would like to learn more about how you can build your own Solar Energy System, starting small or starting big, combining parts and components from various sources, please contact me for a FREE ~20 minute Q&A session.
I also offer several Solar Energy Coaching packages (via Phone or Skype) at very reasonable rates if you would like more assistance in building your own Solar Energy System and taking some real steps towards Energy Independence... Like running a Refrigerator or Freezer on Solar, or some power tools. Rock ON!!!
But what about Batteries? What about Lithium Ion Batteries? What about Inverters and Charge Controllers??? What about wires? Which ones should I use???
Contact me through the CL Email and let's get started with your FREE 20 minute Q&A Session. I won't put my number here because I'm not looking to answer hundreds of random Text Messages about Solar. If you are serious, contact me through email. List some of your questions (so I can get prepared), and I will then give you my phone number, or you can give me yours, and we can arrange a call for the Free session with no obligation. Either way, as far as I am concerned, any step towards energy independence is a step in the right direction for all of us.
do NOT contact me with unsolicited services or offers