solar powering my home!

My home has been using solar power since June 2013 and the power system has proven its reliability.
I am a proud owner of an off-grid solar power generation system.
I decided to post this Instructure to let my colleagues know the basics of designing and installing systems like mine.
If you decide to go this way, don\'t expect an exact copy of my system.
You need to know your home layout, load requirements, budget constraints and future power requirements.
In this note, I will use basic electrical terms.
Precautions to be remembered in this manual: 1.
Grid is not allowed in my country.
I am unable to provide technical assistance on grid connection issues. 2.
The whole design and installation I completed myself.
In your case, you will either need the ability to install electrical equipment or hire experienced electrical professionals to install it. 3.
I have finished the code (NFPA 70, TTS-171 Part 1)
And power facilities requirements. 4.
Having a power collection system means you are responsible for it.
If something goes wrong during the operation, you can\'t expect to always call someone. Take control! 5.
This is only a technical statement.
I don\'t answer financial questions.
Now, let\'s go ahead and discuss how I can implement my off-grid power system.
Remember, when it comes to solar power, the bigger the better!
Cable: cable size (AC and DC)
The voltage drop as low as possible is very important.
For my home, I used the 2% maximum voltage drop from any power breaker to the farthest load.
You can use stricter requirements, which is no problem;
Your cable must be bigger.
The attached chart is an example of my use, but keep in mind that the current of the PVC insulated cable is not as high as the XLPE.
In addition, there are other types of insulators and their temperature ratings.
Please check your cable data sheet or simply use the worst case chart.
Please also adhere to the copper wire.
For simplicity, I refer to the AC load flow chart to indicate what wire size to use.
Please note that due to the fact that there is no skin effect on DC, the DC current carrying capacity of the same cable is higher.
Take the lines in the car as an example.
Headlights, alternator, starter, etc.
Please note the cross-sectional area difference of the equivalent current on the AC system.
Using the AC chart to adjust the size of the DC cable means that the voltage drop will be lower, which is good.
A basic guide I have used over the years is 5 amps per mmsq copper cable.
My cable is less than 100ft in length and this estimate is good.
For example, if I need to go through the 50amp dc then I will use the 10 mmsq copper conductor.
For longer run times, Cable charts are recommended.
Circuit breaker: usually allows the Molded Case Circuit breaker to operate the maximum continuous current with a nameplate rating of 80% (
Unless it is a 100% rated circuit breaker).
The rated power of the DC circuit breaker is different from that of the AC circuit breaker.
If you wish to use AC rated circuit breakers in DC service, the general rule is that the maximum DC voltage is 1/5 of the AC voltage rating of the circuit breaker.
Exceeding this limit means that the circuit breaker does not properly extinguish the arc during the opening operation.
Always check the cut sheet of the circuit breaker of your choice to verify the DC operation.
Don\'t make your vandals too big, or you will break your protection (eg.
15A circuit breaker with 2 amps load).
Solar panels: I used the rule of the available sun for 4 hours to adjust the size of the panel.
Energy needs need to be identified within 24 hours.
You can use the public electric energy meter and use it on average for a week, or you can use a separate meter.
Electricity meters are the easiest way.
For example, if you use 1000 watts-
24 hours of energy, then the panel you need will be (1000/4 =)
Panel of 250 W.
You can assume the available sunlight for 6 hours or more to reduce your cost, but I prefer to provide more power to meet my needs.
Battery: Watt-
The hourly demand during the 24 hour period is the minimum size that the battery pack should reach.
X amps for battery hours-hours.
Larger battery pack means better voltage regulation at the input of the DC load
Inverter, DC lighting, DC fan, etc.
I installed my panel on the roof of my house.
There are OEM mounting kits or you can make them yourself in metal or hard PVC.
I actually did both.
I have a total of 8 panels with a rated power of 225 watts per panel.
The best angles for installation around the world vary.
For me, it\'s 15 degrees away from the level, so it\'s great for me to install directly on the roof.
I have panels facing the east and west to capture the sun from dawn to dusk.
It is a good idea to install panels where you can reach them for cleaning, but for the most part they are maintained for free and have a long service life (20+ years).
An interesting side effect of the panels on top of my house is that the shadows they provide actually make the house cooler.
Please note that I have a three bedroom house (
Not very big but this is my home).
You have a lot of tree shadows, then you need to fix this first or have an alternative position from dawn to dusk to harvest the sun.
I did penetration on the sheets on the roof and put the power cord through.
I put strain relief and a lot of silicone on the penetration.
The panels are actually mounted on penetration, so the water intake is not a problem.
You can install a Sun tracker to get the most if you want.
These are expensive and should not be installed on the roof. Why?
Strong enough wind to blow, if the roof is not yet affected by the weight of the tracker and panel, it is affected.
The tracker needs maintenance as well, so you need to keep these pointers in mind.
I originally had a maximum power tracking 60 amp controller for the Morning Star but failed after using it for a month.
I just threw it in the trash angrily and the warranty was cursed.
I have been serving since mid-2013, an inland max power tracking fm80.
I firmly believe in this controller and will recommend it at any time.
To put more energy into the battery pack, I would also recommend using the maximum power point tracking type instead of PWM.
You can have multiple charging controllers in the same battery pack.
Each controller needs to have its own solar panel.
The Outback FM80 can accept up to 15vdc, so I have 4 panels in series.
I have a parallel connection of two strings which is entered inland.
In this configuration, My inland has reached the limit at present.
Always understand the maximum open voltage of your panel to understand how much voltage can be connected in series to your maximum power point charging controller.
Maximum input voltage not exceeding the maximum power point (
You know what will happen! ).
Using a maximum power tracking controller means that you can deliver power to the controller using a smaller cable.
Before entering inland, having a circuit breaker is important for protection and maintenance.
This is a free and eternal advice;
The circuit breaker of the battery pack needs to be turned off at last, and it is also the first to be turned on. Why?
If there is no battery control power supply and solar energy on the input, your expensive charging controller will see you again!
Believe me, I know!
I use lithium iron phosphate (Lifepo4)
Store the energy of harvest. It\'s a 25.
6 v hour bank.
The details of this bank are covered in my instructions below: once you can get a compatible inverter, the higher the battery bank voltage, the better.
There must be short circuit protection for each battery or battery pack.
Circuit breakers are a good way to do this.
Also, turning off the breaker will help with this in order to maintain or upgrade.
Don\'t connect the battery pack without protection!
No toxic ingredients, long service life (
More than 2000 cycles @ 100% mod, according to the manufacturer)
Do not discharge gas, provide 4 times the power density in the case of volume third, compared with lead acid.
Perfect for installation in the living area.
I personally charged a lithium-ion battery too much in 5 weeks, and the result was a brown electrolyte.
No burning, gas, irritating smell.
I really like this battery chemistry!
Also, please do not use the SLI battery.
These are shallow cycles that are only used to start the engine.
What you want is a deep cycle battery.
Lithium-ion batteries are actually suitable for both uses, but you can decide what your budget can offer.
Lead Acid is cheaper in front, but does not have good life, safety, environmental impact or emission properties like a4.
I use flexible cables to get the power to and from my battery pack.
These types of cables are easily available from electronics stores and even car audio stores.
Again, the bigger the cable, the better, but not too big, the wire can\'t be installed in the breaker or the connecting lugs.
The circuit breaker I use is the DIN rail mounting type.
The cost of Amazon is quite low.
All my DC circuit breakers are single-knife.
The negative pole of the DC power supply system is associated with the shared connection point.
Only the front is protected by the circuit breaker.
Whether it\'s 120 v or 240 v, the AC voltage is used for most household appliances and loads.
I highly recommend using only pure sine wave inverters to power these devices, especially those with motors.
120 v Inverter for transformer-
Fewer types are more efficient, but neutral outputs are not allowed to be connected to neutral outputs of your utility!
When measured to ground, there is always a voltage difference in the neutral output.
Utility neutral will connect to the ground and read 0 v between the ground.
Basically, when using a 120 v Inverter with a non-zero voltage neutral (
Relative to the ground)
You need to use a two-pole switch.
One pole is alive and the other is neutral.
If you don\'t have a utility power supply in your home, then you obviously don\'t need to switch the switch.
Don\'t be tempted (
Transformer-free inverter)
Connect the neutral line to the ground connection.
The inverter will fail because of this (
Yes, I know this first hand).
If you want to avoid all the hassle, just buy transformer-type inverters that will have a neutral output of zero volts.
Read the inverter manual carefully!
The output of my 120 v Inverter is connected to the panel I built with the auto-conversion switch.
Here\'s my note for the project: you can buy a panel with a switch if you want, but I prefer to build it for my needs.
The computer control of the automatic conversion switch ensures that if the voltage drop of the battery pack is too low, the load in my house will be powered on.
Here is my note for this automation project: proper protection will protect all and everything in the event of a failure.
This is a good message.
There are two ways to connect a backup power supply to the home. 1.
Circuit breaker interlocking kit.
This is basically a mechanical board that prevents both the main and sub-circuit breakers from opening at the same time.
This can be defeated and allows two non-step sources to be parallel!
Very dangerous and despite the low cost, I strongly recommend not to use this method. 2.
The conversion switch physically only allows one of the two power supplies to power the load.
There is no possibility of parallel connection here.
Very safe and robust.
All of my LED lighting is very helpful.
My standard fridge and washing machine are still there.
If these devices fail at some point in the future, I will definitely buy the inverter version of these devices for me to better save energy.
All TVs from off-grid families should be LED.
Computers should be low power types even for desktops.
The most important thing is the way humans think.
Use less of your energy.
Don\'t think there will always be energy available.
Wise and economical.
In most cases I live off-grid, although I have the ability to use utility power when needed, especially for large intermittent loads.
To make life simpler and more enjoyable, I automate the entire home to handle all solar loads.
Installation like this is a long-term investment that will pay off for itself.
Electricity is very cheap in my country, so the return period is very long, but I did this project out of love efforts and didn\'t really save money.
If you are a nomad and walk around, then this instruction may not be suitable for you unless you live in a RV or on a boat.
I recently installed a small wind generator to enhance my harvesting capacity. Check it out!
Green energy rules!