How to Build a 48V Off-Grid Solar System

Building an off-grid solar system is a great way to make your home more energy-efficient and self-reliant. The components of the system are relatively inexpensive, but the installation process can be time-consuming. This guide will show you how to build a 48 V off-grid system that will provide enough electricity for most homes.

Before reading any further, please understand that this project should only be attempted by those who have experience making electrical connections and working with power tools such as drills and saws safely. If you do not feel comfortable performing these tasks independently, it would be best to hire a professional solar contractor to help you complete this project properly. 

What is a 48V off-grid solar system?

A 48V off-grid solar system is a solar power system that uses only 48 volts to overcome the loss on long runs of high-voltage wire. This type of solar electric system typically consists of 12 or more solar panels, two inverters, various electronic devices needed for protection and monitoring, plus cabling and hardware.

Although it depends on your particular situation, this type of system can be built using about 100 feet of 2/0 welding cable if long runs are not required between the batteries and charge controller or inverter(s).  If smaller gauge wiring must be used due to circuit lengths being longer than 100 feet, you should use about 200' of 1/0 battery cable. 

Factors to Consider Before Building an Off-Grid Solar System

Getting power from the sun can be very beneficial. However, it is important to know what you're doing and how much solar panels cost. It's useful to understand how many Watts or Amp-hours you need per day so that you don't overdo it and spend too much money on solar panels. Here are some things to put into consideration

Your household energy consumption rateImage showing household electricity need: Credit: https://www.teachengineering.org/

To determine how many watts your household needs per day, take a look at your monthly electric bill for kWh (Kilowatt hour) usage data. To calculate this yourself easily, simply multiply the number listed on the last page of your bill by 30 (the number of days in a month). 

This will give you an estimate of how many kWh are used every month. For example, if you have a 1000 kWh/month energy bill, you will consume 30kWh every day. This means that daily usage should be somewhere between 25-40kWh per day. 

Amount of sunlight in your area

Check to see what kind of sunlight your area gets throughout the year. If either you or your panels are going to be shaded by other buildings for most of the day, there will not be enough sunlight to produce electricity efficiently. Ideally, you should look for an area with about 4-6 hours of unobstructed sunlight per day to benefit most from the off-grid solar system.

Determine the number of panels needed

After doing this, you can safely determine the number of solar panels needed for your home. Solar panels are measured in peak output, usually given in either peak watts or peak Amps (or both). Peak wattage is simply the maximum amount of power produced by the solar panel at any given time. 

To get the number of peak watts needed, multiply this number by 48 (this is due to voltage modification). For example, 2000W peak x 48V gives 96000W required to run all appliances on your house (including air conditioning and lighting). The peak Amps rating of a solar panel is the maximum amount of current that the panel can provide at any given point in time.

To determine how many peak amps you need, multiply your peak watts and your daily average energy usage (kWh/day) for each month in that year. For example: 2000W x 40kWh per day = 800A. After calculating the number of peak amps required, look up the size of solar panels to get an idea of what you should do next. For example, it takes multiple solar panels to provide 96000W (or 800A), so you'll need 4-6 large (100-200+ Watt) solar panels or 20-30 small (5-10W) solar panels. 

To keep it simple, your best option may be to purchase a pre-made 48V off-grid solar kit that contains everything you'll need for your home or business. However, be sure to research the company and its reputation before committing to this option, as not all companies are trustworthy.

Solar Tax returns

Make sure that you are eligible for any rewards or tax breaks available when producing solar energy at home. Many states still do not offer any form of financial incentive when installing solar panels, but this varies depending on location. For example, California offers up to $2,500 back to a solar energy producer when installing a system. 

Finally, price and compare multiple suppliers and dealers before buying any components needed to install an off-grid solar power system. This will help ensure that you are getting the right equipment for the best price.

Materials needed to build a 48V off-grid solar system.

The materials needed to build a 48V off-grid solar system are:

• Lithium Batteries: Lithium batteries have been very popular in recent times. With the development of technology, these batteries have shown their supremacy over other energy storage devices. People have started using them for powering most of the appliances used in houses today. 
• Solar Inverter: A solar inverter converts the DC power produced by a photovoltaic (PV) system into an alternate current (AC). The conversion process uses electronic and electromechanical devices, and the output is delivered to a load. A solar inverter allows any size of a PV system to connect to the utility grid.
• Charge Controller: Charge controllers simply monitor how much current is being outputted by the panels and then regulate the amount into your battery bank. You can find many types online. Ensure you opt for those from a reputable company.
• Solar Panels: A solar panel is a device used to capture the sun's energy as a usable form of power. Solar panels are usually made up of multiple cells. Each cell consists of two semiconducting parts that can absorb more than one type of energy, and it builds a potential difference across the parts. For example, a typical commercial solar cell converts light into about 0.5 volts of electricity. This means that roughly 24 of these cells will produce about 12 volts of electricity from sunlight exposure during standard conditions. 
• Charge Controller Wire: This wire connects one end to the battery and another to the charge controller. It doesn't matter whether you get this one or not, but it will work just fine. 
• Battery Wire: It connects the battery to the charge controller. It's better to get thicker wire than needed because you can always cut off what is not used and use it elsewhere in the future. It also comes in different shapes, so choose whatever fits your needs.
• Fuses: Because there isn't any other way to protect your system from short-circuiting than using fuses, so do yourself a favor and install them on all of your panels. 

Other equipment are Mechanical-Breaker Box, Lugs, Cable, Voltage Meter/Monitor, among others.

Detailed Steps To Build Your 48V Off-Grid Solar System.

Step 1: Assemble your solar panel and inverter.

Assemble the solar panels, inverter, and the necessary hardware into the wood box, ensuring enough spaces between them to allow airflow (if using air cooled inverter). It's better if you can place them elevated from the ground to allow more airflow underneath as well as raising them above the ground will protect them from dust and water. If you are not using an inverter(s) with fans, ensure enough airflow around the panels to keep them cool - they may heat up to more than 50°C depending on their size.

Step 2: Place Your Panel Under The direct sunlight

Place solar panels where they receive the most direct sunlight all through the day if possible, or at least between 10 am and 3 pm. Solar panel orientation is very important because power generation efficiency decreases significantly for either East-West or West-East panels. The solar panel angle should be set to face the north (for the Northern hemisphere). Set tilt angle to match latitude +15° for summertime or +30° for wintertime. Example: At 41° latitude, panels should be tilted at 56°. If you live in very high latitudes (above 60°) and plan to use your system for more than one month per year, then an extra panel(s) may be needed. Consult with a solar power specialist before installing anything.

Step 3: Wire The Solar Panels

Wire the solar panels to the Lithium battery using heavy gauge copper wires following correct polarity - positive to positive and negative to negative. Then connect the controller board of the charge controller between the battery's positive terminal and the first solar panel's positive cable using thick wire. The next step is wiring two or three inverters in parallel via a common DC bus bar attached to their AC output terminals, again using large wires. Again, the wiring should be done by a licensed electrician and labeled accordingly.

Step 4: Turn on the inverter.

Please turn on the inverters and let their battery charge mode begin charging the batteries with AC power from the grid or generator, whatever is available at that moment. The solar charge controller should be set to switch off the solar panels when batteries are full (float charge voltage of at least 13.8V for 12V batteries and 26.4V for 48V batteries).  Try not to discharge your batteries below 50% if possible because it's bad for their lifespan - you don't have to worry about this too much if you're going off-grid because cloudy weather doesn't affect on-grid solar systems as they use grid power 24/7 anyway - unless the utility company turns them off. If your solar charge controller doesn't have load control, add a power regulator between the inverter(s) and the controller.

Step 5: Add Extra Features

You can add extra features at this point or go live with your system - you may want to install a switch near solar panels so that they can be switched off when there is no sun, remove isolator from AC output terminal on the inverter if it's not needed, add a voltage meter in line after voltage regulator (if any), mount a cold light LED flashlight inside case somewhere to use in case of a long-term power outage. Once all systems are set up properly and working, place one or two mobile chargers into each room that appliance requiring 48V DC voltage will be used - they can be powered from the inverter(s) directly without using batteries. Then place another mobile charger to your vehicle's cig lighter, and you're all set.

Step 6: Consider placing more than one battery into the system.

You may want to consider placing more than one battery into the system for redundancy purposes. Just remember that if a battery goes bad/dies, you have to replace them all since they are wired in series.  Also, don't mix different types of batteries or brands with varying Ah capacity because it will affect the system's performance. For example, lithium iron phosphate (LiFePO4) batteries are superior to lead-acid batteries but three times more expensive ($500+). 

Enjoy your off-grid system.

Why Use Lithium-ion Batteries for Your Off-grid Solar system?

Lithium-ion batteries are the most recommended type of battery for off-grid solar systems because they are the easiest to get, have good power density, are lightweight, can be easily mounted with no special tools required, are low maintenance, and have a long life. For example, if you charge it to 90% every day, it will retain 90% of its original capacity after more than four years of use! Some of the advantages of lithium batteries include: 

•  Saving costs: One of the biggest reasons most folks looking to use rechargeable batteries is to save money. Unlike lead-based batteries, lithium-ion ones are more efficient when it comes to storing power and re-using it. If you live off-grid where your only source of electricity is solar power, you need a smart battery. These batteries can store more power and will give you the energy to use at night.
•  Durability: Another great advantage of using lithium-ion batteries is that they have a very high life cycle. The question of replacing them often does not arise as they last up to 4-5 years even if used for powering appliances requiring a higher level current, i.e., 100 amps. This means saving money from buying new ones now and then.
• Less maintenance required: Compared with other types, these batteries require almost no maintenance as there are no sulphuric acid leaks to worry about, as in the case of flooded lead-acid type batteries. Also, you do not need to check electrolytes levels, nor do you need to top them up. This makes it a favorite with people who like to do it yourself.
• Safer for the environment: There are no toxic lead fumes released when charging or discharging lithium batteries, which means you will not be harming your family and the surrounding environment in any way. Also, their lightweight nature ( about half of equal capacity lead-acid ones) allows easy mounting on roofs or wherever they can get enough sunlight. You can move them around without much hassle. These two advantages make lithium-ion chargeable batteries perfect for off-grid use where you want to minimize noise and other disturbances in your daily life while maximizing energy output and saving costs.
• Completely safe for children: Lithium batteries are completely safe for your kids. They do not emit toxic fumes or chemicals when charging, nor will they spill over as happens with lead-acid ones. This is an advantage for people living in urban areas where space may be a problem, and you need to keep everything well out of the way of children. Also, it means that if they break open one by accident, there will be no leakage at all. You can even leave them charging unattended without worrying about any accidents happening because of their hazardous nature!

Conclusion

The 48 V off-grid system is a valuable and affordable option for homeowners who want to make their homes completely off the electric grid. If you're interested in installing this type of solar power, contact our team of solar installation expert today! We can help you maximize your energy savings with one of these systems and other renewable energy solutions too.