Make Sure Your Solar Panels Are Accessible
Lastly, solar panels need to be clean and cool to work a maximum efficiency, and have a nice long life. Dust, dirt, and snow will naturally accumulate on solar panels, which need to be cleaned off periodically. Snow accumulation on your solar panels will reduce their life. Placing your panels closer to the ground where they are easier to access can go along way towards making routine solar panel maintenance actually get done in a timely manner.
Determine Your Power Needs For An Off
For any type of DIY solar project, you must determine your power needs as previously discussed. With off-grid, you take that value and figure out the number of batteries youll need to store it in. If youd prefer to have a supply that lasts for several days or weeks, you must take that into account, too.
This gets complicated with batteries since theyre rated to be stored at room temperature or slightly above. This means their storage capacity is significantly reduced if youre in freezing conditions. So, when youre in a cold location or season, you may need to increase your battery bank size significantly for this reason alone.
Battery voltage
The voltage of your battery bank whether 12V, 24V, or 48V matters, too. It affects the thickness of the connecting wires between them and the cable going to the inverter.
To determine the voltage, consider how many watts you need to power all your appliances. A 12V battery bank may be adequate for a cellphone and a few 12V DC appliances. But if youre looking at generating 2,000 watts or more, a 24V or 48V battery pack makes more sense.
Sun hours
Yet another important consideration is the number of sun hours that your panels will receive every day. This number does not equal the length of daylight and varies with the seasons.
It depends on the angle of the sun in relation to your panels orientation. Maps of sun hours for the U.S. are available through the National Renewable Energy Laboratory .
Charge controller
Make Sure Your Panel Location Has The Proper Angles
I have written a whole separate article on the proper angle to place your solar panels, and what happens when you dont put it in the right spot. But, suffice it to say, you lose a lot of the potential power you could be producing when your solar panels are not facing due south and when theyre not properly angled. Because many homes do not have a roof lines that face directly south, it can be expensive, difficult, or impossible to face your solar panels in the right direction when they are on the roof.
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Sizing Of Fuses / Breakers
Fuses and circuit breakers are primarily used to protect the system wiring from catching fire or getting damaged if a short circuit occurs. They are not necessary for the system to run properly, but it is recommended for safety purposes only.
There are three different locations where fuses or breakers must be installed:
1. Between the charge controller and solar panel
2.Between the charge controller and battery bank
3.Between the battery bank and inverter
You can add one more breaker at the inverter output.
DC Breaker / Fuses:
As per NEC, the DC fuse or breaker size can be determined as per the following equation:
Circuit ampacity = Short Circuit Current X 1.56
Example-1:
A 315 Watt module with an Isc rating of 9.12A.
To calculate the fuse size required between the string and the charge controller, you take 9.12 x 1.56 = 14.7 and round up to the next trade size of 15A.
Example-2:
Main Types Of Solar Power Systems
You have three choices for solar energy systems to power your homes and property:
During the research and planning phase of your DIY solar project, youll have to ask yourself:
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Bottom Line For Diy Off
Despite their advantages, batteries and generators can provide a finite amount of electrical power. Hence, power conservation is necessary to make an off-grid system perform as expected. Power conservation becomes achievable by choosing the right appliances and adopting energy-efficient habits such as proper sizing of energy demands, adequate wiring, etc.
You need to design and implement your DIY off-grid system effectively and correctly. By doing so, the result will be a fully functioning renewable power system that you can be proud of.
Achievement unlocked!
How Does An Off
Ideally, the loads will be powered by solar panels during the day. When the sun goes down, the batteries will take over and supply electricity to the home appliances. The battery system should be large enough to provide power throughout the night. Solar panels will then charge them during the day while supplying power to the loads. This is how an off-grid solar power system is expected to work.
The system generates DC electricity from the solar panels during the day. This process involves the photovoltaic effect within solar panels and rays of light coming from the Sun.
As sunlight hits the surface of solar cells, electrons become free and excited. This allows them to flow through the solar panels cables as direct current electricity.
Depending on the system setup, the direct current can directly go to an inverter where the electricity is converted to AC or alternating current. This will then become the electricity that the appliances use.
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How To Build An Off Grid Solar System In Just 6 Steps
An off-grid solar system allows users to satisfy all their energy requirements using the suns power without an electrical grid. Essentially, to make this possible, you must set up a solar power system linked with an energy storage system, such as a solar-powered battery.
Are you wondering how to build an off grid solar system for your home? In this guide, well help you learn more about an off-grid solar system before buying one. Likewise, well help you determine the materials and steps needed to get started in your solar energy journey.
These are the steps, which are described in detail below: devise a system according to your requirements, select the installation spot, order components, construct the battery housing, assemble the panels, and wire everything.
Sizing An Mppt Charge Controller
When sizing a a MPPT charge controller you need to consider the following:
- Current
- Temperature
1. Current
MPPT charge controllers often reduce a DIY solar arrays voltage to the charging voltage of the solar batteries.
Remember, the power into the charge controller is equal to the power flowing out of it, this results in a rise in the output current.
Therefore, by dividing your solar arrays power output by the battery voltage you can determine its amperage.
Once you have this number, always multiply it by 1.25 .
2. Voltage
MPPT charge controllers are able to handle higher nominal voltages than batteries. However, the Voc is the limiting factor here.
For example, a 24-volt solar panel has a Voc of about 44 volts.
Therefore when deciding on which charge controller to go with for your DIY solar system, make sure to select a controller that can handle he open circuit voltage of the string.
3. Temperature
Temperature fluctuations can affect the amount of voltage solar panels produce.
In colder temperatures for example, the Voc can increase in each string by approximately 0.03% per each degree Celsius below freezing.
While higher temperatures above 25°C has no affect on sizing a solar charge controller.
We recommend you to keep this information in mind should you plan on setting up your solar system in freezing conditions.
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What Type Of Roof Does Your Home Have
A DIY solar system can be installed on almost any type of roof. However, some roof types require much more effort than others, resulting in extra costs.
For example, it is very hard to install solar panels on a regular wood-shingled rooftop. If you happen to live in a home with this sort of roof, we would highly recommend that you call an experienced, professional roof-top mounting contractor.
Some of the best roofs for solar panel installations are:
Asphalt Shingle Roof
Solar panels may be attached with a clamp, so no drilling is needed.
Flat
These roofs require either ballasted racking or a standard penetrating mount. Usually, tilt-up brackets are used to keep the panels at a 30-degree angle to the sun.
Choosing The Right Place For Your Panels Is Essential
Next, we take care to find and plan for the right site. Often, the top of the house is not the most efficient place for an off grid solar array. Choosing the right spot to prevent excessive shading and to ensure proper access and passive cooling for your solar panel can more than double the efficiency of your solar panels over their lifetime.
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What Permits Will You Need
It is important that you acquire all of the necessary permits before installing your own solar panels.
These are the permits you will need for your DIY solar system build:
- Electrical permit
- Structural or building permit
- Dedicated solar photovoltaic permit
Regarding permits, it is best for you to consult with local professionals who know all about the legal issues and zoning laws within your city/country.
Information pertaining to building permits is very important as skipping this step may result in you having to rebuild your entire solar system, or being subject to a hefty fine.
Building permits are issued at the local level. Therefore, each state will have its own set of rules and regulations.
For more information on permits, give this article from EIA a read.
Overview Of Building An Off Grid Solar System
Designing your own self-sufficient solar power system must start with your end users needs in mind. Making the effort to follow a proper design process saves you money, time, and makes the process of going off the grid a pleasant one.
Here is an overiew of the steps Ill take you through over the course of this three part guide.
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Calculating Your Daily Usage
Now, add up all of the energy measurements that you took all of the devices that you plan to use in a given day. This is your daily energy usage.
Its important to realize I your energy usage fluctuate throughout the year. You may use lights much longer in the winter when its darker, yet the refrigerators will run less. I recommend you take a power measurement both in the winter and the summer, or at least attempt to adjust number of hours used by each device to account for the differences.
Knowing how your power usage varies session ally is extremely important for off grid solar, because solar power production also changes throughout the year. So, it is easy to over or under size your system if you only use a yearly average to plan for your system.
Mounting The Solar Panel
After design the solar system. Buy all the components with an appropriate rating as per the previous steps.
Now it is time to mount the solar panel. First, choose a suitable location on the rooftop where there is no obstruction sunlight.
Prepare the mounting stand: You can make it on your own or it is better to buy one from any store. In my case, I have taken the drawing from the solar panel company and made it at a nearby welding shop. The tilt of the stand is nearly equal to the latitude angle of your location.
I made a small wooden mounting stand for my 10 Watt solar panel. I have attached the pictures so that anyone can make it easy.
Tilting: To get the most from solar panels, you need to point them in the direction that captures the maximum sunlight. Use one of these formulas to find the best angle from the horizontal at which the panel should be tilted:
> > If your latitude is below 25°, use the latitude times 0.87.
> > If your latitude is between 25° and 50°, use the latitude, times 0.76, plus 3.1 degrees.
For more details on tilting click here
First place the stand in such a way that the face is directed towards the south.Mark the leg position over the roof.
To get the south direction use this android app compass
Then make a rough surface at each leg of the stand by using a sharp object. I made around 1Sq feet size rough surface over the roof at each leg. This is helpful for perfect bonding between the roof and concrete.
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Assemble The Solar Panels
The next step is building the solar panel support and setting up the solar array. Please note that solar panels are way more efficient when they face the sun directly, and they last longer when theyre well cooled and rigid. Choose quality solar panels here.
A solar support framework can be established in several methods, depending on the materials you have, and of course, your skill level. Establishing a south-facing A-frame framework using metal or wood is the best.
Its also beneficial if you can manually adjust the tilt of your solar panels during winter and summer. This way, you could bolster your power output by up to 40 percent with nearly no extra cost. Alternatively, you could make your DIY one-axis or two-axis tracking system.
Solar Pv Design Worksheet
I found a nicely documented worksheet on Solar PV Design from the Renewable Energy Innovation page.
This is a simple design worksheet for stand-alone solar PV systems. It explains the design process and explains some of the practicalities of building a system.
I hope it will be useful. The full credit goes to the authors of Re-Innovation
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Victron Color Control Gx & Vrm Portal
The Color Control GX is the communication center of you entire off-grid power system. It controls all products connected to it, gives live info at a glance, and even creates a Remote Management Portal so you can access you system from anywhere in the world.
Before you fire up your system for the first time, youll want to make sure everything is connected to this display.
Youve already connected the REC BMS via the VE.Can Bus, but in order for it to talk directly to everything youve got a few more cables to run.
To connect the Quattro Inverter, use a VE.Bus or Ethernet cable. And for the MPPT Solar Charge Controllers, use VE.Direct cables. The display also needs power, so connect its positive and negative wires to the positive and negative of the system.
You may need to put a Terminator Plug into your second VE.Can slot , and if you want to run the VRM portal full time, a USB WiFi adapter will allow you to connect the display to your network. Hardwiring ethernet is also an option. You can even get a USB GPS adapter if your system is on the move. Pretty cool!
What Are The Cons Of Solar
What are the drawbacks of going off grid?
If its so great, wouldnt everyone do it?
Here are some of the disadvantages.
High start-up cost: While batteries are increasing in efficiency and dropping in cost, going off grid is still expensive.
To do it, you need to install a large solar system that wont rely on any external grid power to keep the lights on.
This is generally a high start-up cost that most people cant afford.
Gas-powered generator required: People generally dont want to deal with the inconvenience of losing power at any point.
In the case of emergencies or system failure, most people will decide to purchase a backup generator for their homes.
This is yet another expense that can deter people from getting started.
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Which Solar Energy Equipment And Materials Do You Need
In a rapidly expanding renewable energy supplies market, you have many choices for every component you must integrate to make your DIY solar system work efficiently during its entire operational life. Heres a list of the major parts for most solar systems.
After all the headwork and logistics are done, you move on to the legwork: installation of PV panels on racks or poles somewhere on your property, then connecting them to your home electric panel. Depending on whether you opt for grid-tie, off-grid, or a hybrid system, further electrical connections may be needed to get everything up and running.
Series And Parallel Connection
After calculating the battery capacity and solar panel rating you have to wire them. In many cases, the calculated solar panel size or battery is not readily available in the form of a single unit in the market. So you have to add a small solar panel or batteries to match your system requirement. To match the required voltage and current rating we have to use series and parallel connection.
1. Series Connection :
To wire any device in series you must connect the positive terminal of one device to the negative terminal of the next device. The device in our case may be a solar panel or battery.
In series connection the individual voltages of each device are additive.
Example :
lets 4 12V batteries are connected in series, then the combination will produce 12 + 12 + 12 + 12 = 48 volts.
In a series combination, the current or amperage is the same.
So if these devices were batteries and each battery had a rating of 12 Volts and 100 Ah then the total value of this series circuit would be 48 Volt, 100Ah. If they were solar panels and each solar panel had a rating of 17 volts and were rated at 5 amps each then the total circuit value would be 68 volts, 5 amps.
2. Parallel Connection :
In a parallel connection, you must connect the positive terminal of the first device to the positive terminal of the next device and negative terminal of the first device to the negative terminal of the next device.
Example :
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