Picking The Right Battery
So, which solar battery is right for you? There are a few different battery types commonly used for off-grid storage systems:
Flooded Lead Acid
- No maintenance, no venting
- Highest efficiency, faster charging, more usable capacity
The two main battery chemistries for off-grid are Lead Acid and Lithium. These two chemistries have unique characteristics. Lithium batteries are more efficient, which means less power is wasted in the charge/discharge process. They also have a greater discharge depth allowing you to fully utilize all of your battery capacity.
Lead acid batteries are sensitive and need to be fully recharged every day, where Lithium batteries can stay at a partial charge without any adverse effect. Lead acid batteries also have a more limited amount of usable capacity and are typically discharged only 50%.
Because of the better efficiency and deeper discharge depth, Lithium battery banks tend to be only 50-60% of the size of a comparable lead acid bank! The Lithium batteries we use are purpose-built for off-grid solar, and utilize a special Lithium chemistry called Lithium Ferro Phosphate .
This type of Lithium battery is engineered to provide a long service life while also being safe, with a stable chemistry and sophisticated electronic protection features.
| 55.2kWh: 1150ah 48v Sealed LA 57.6kWh: 1200ah 48v Flooded LA |
This is not intended to be a comprehensive guide on off-grid design.
Other Factors Influence Battery Sizing:
- Ambient Temperature – Heat or cold has a big impact on battery performance and capacity.
- Seasonal Factors – People use more power at different times of the year. The sun produces more power in the summer than in the winter.
- Budget – Battery bank size is often a compromise between what you want to spend on batteries and how often you’ll need to run your backup generator.
Advantages Of Off Grid Solar Systems
While the cost of installing an off grid solar system might seem like a lot, it is worth it as these systems come with many advantages. Since the system relies on batteries to store the power generated by the solar system, you will have electricity to use even when the panels are not working. For example, during the night.
Another advantage is that since the system is completely separate from the electrical grid, you will have power to use even when there is a widespread power outage.
Who wants to keep on paying electricity bills for the rest of his/her life? When you install an off grid solar system, you dont have to worry about electricity bills as all your power will be provided by solar energy which is free!
The other huge benefit is the power quality you receive through an off grid solar system. With a high-quality inverter charger like Selectronic SP PRO, we can guarantee you a pure sine wave of power and a steady voltage that is usually substantially better than the power from the grid. This means your appliances and machinery will last longer and need less maintenance.
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Best Off Grid Solar System Installation
For ideal results, you should make sure that your system is installed by a professional team of solar system installers. For it to safely and reliably provide you with the power you need for a long time, you should ensure that you install high-quality solar panels such as Q CELLS, Phono Solar or SunPower and batteries like Sonnenschein, Exide or Hitachi.
Often The Only Feasible Option
When youre seeking to power a building in a really remote location – say a hunting cabin out in the woods – theres a good chance theres no grid to connect to at all.
If you contact the utility for a connection, they will probably tell you that you are out of their coverage area. Alternatively, they could offer to lay the wire to connect you to the grid but only at an astronomical cost.
That means that youll have to produce your own power. You could use a backup generator, but fuel for it is expensive, while renewable energy like hydropower and wind arent available most places. This leaves solar as the only practical option for off-grid power.
A beautiful off-grid A-frame cabin in the Catskill Mountains. Image source: Chris Daniele via OffGridWorld
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Hybrid Solar Energy Systems
A hybrid solar energy system is one that is tied to the grid but also has a battery bank to store unused electricity. Hybrid systems, though more expensive due to the added cost of batteries, allow their owners to keep the lights on when the grid goes down, and can even help reduce demand charges for businesses.
If youre interested in learning more about a hybrid solar energy system, check out our blog: How to Size Batteries for a Solar System.
There are two ways for grid-tied solar systems to be connected to batteries: DC Coupling and AC Coupling.
While there are distinct differences between off-grid and grid-tied solar systems, the one that is best for you is dependent on your situation. Off-grid systems allow for complete freedom from the utility, but theyre often more expensive. Grid-tied systems marry significant electricity savings with grid-backed dependence, so youll never have to worry about not having the electricity needed to power your house or business.
How Much Does A Typical Off
Placing an exact cost to an off-grid solar system is difficult given the range of options open to you. As an average, a complete off grid power system for a three bedroom family home would cost between £15,000 and £28,000 including fitting. A smaller 2.2kw option as described above could cost around £12,000. Prices correct as of September 2019.
Considering the average household spends between £1,000 and £1,300 per year on combined gas and electricity, you could recoup your investment in as little as ten years. Add the fact youre off-grid, totally energy independent and using completely renewable energy sources, we think that makes a sound investment!
Energy prices are only going up and that shows no signs of changing anytime soon. Energy independence is a huge step in self sufficiency. Whatever your motives for wanting to go off-grid, the technology we have now not only makes it possible but makes perfect sense!
Sunstore has the products, the knowledge and the expertise to walk you through the entire process of going off-grid. Our off-grid solar systems offer great value, superb reliability and use the latest, most efficient solar panels and batteries to generate the highest amount of energy.
Contact Sunstore today for help, advice or to order your off-grid solar system. We are here to help!
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Solar Charge Controller Cost
The solar charge controller charges your batteries. The batteries cannot handle the energy on their own at this time. The charge controller helps convert the energy into a storable form. Each battery needs its own controller, with costs of around $550 to $600 each. You may have 2 to 8 batteries in your home, depending on the type of battery you have and the system size you need.
Two Calculate Solar Panels Required
Now we are ready to calculate how many solar panels we need.
Solar panels are rated by their how much power they would produce on a bright sunny day, using a standard Sun brightness of 1kW/m^2. How many kWh per day it will produce depends on your climate, and how much daylight you have.
The easiest way to estimate how much power you have available is to use the solar maps provided by u the US Department of Energy. Near the bottom of the page there is a box labeled Photovoltaic Solar Radiation, which you can click to show links to month by month maps. Look at each month in the summer and winter, and take note of the lowest number for each in your area.
In my area, we only get 2 hours or less, and we get about 4 hours in the summer.
To get the solar panel size you need, use the following simple formula.
panelwatts=dailykWh÷sunhours÷0.7
Here the 0.7 is an estimated total system efficiency which takes in to account losses during storage of the energy, wire losses, and conversion of the energy from the panels in to a usable form via the charge controller and potentially the sine wave inverter.
In my example I would need 140 W of panels in the summer, and 311 W in the winter. Go with the highest value of the two, and start shopping for solar panels. But, as a rule of thumb, you can get decent 100 W panels for under $100 delivered. So, Ill estimate my panel cost to be $400, for 4 ea. 100W panels.
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Difference #: What Happens When The Grid Goes Down
Power Outages with Off-Grid Systems
Your solar system is working independently from the power grid. If theres a bad storm or event that knocks out the power, your solar system can continue operating. You wont notice changes in your service or access to electricity.
Power Outages with Grid-Tied Systems
By connecting to the grid, you get access to electricity whenever you need it. However, youre also subject to some rules. If you have a grid-tied solar system and the grid goes down, you will not have electricity, unless you opt for a grid-tied solar system with battery backup.
Why is this? The shutdown of solar systems when the grid goes down is required by the Underwriters Laboratories . This is for the safety of utility workers who are fixing the power lines.
While this is a disadvantage of grid-tied systems over off-grid systems, if keeping things up-and-running during a power outage is important to you, then you may be interested in adding batteries to your grid-tied system.
Ideal Candidates For Solar Energy
Not every home is right for solar energy. Some homes are too shady, or the climate may not be ideal, making the installation and system costs prohibitively expensive. The ideal candidates have good sun exposure and above-average energy needs. They also have occupants who intend to stay in the home long enough to see the financial benefits of reduced or eliminated energy bills.
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Three Off Grid Battery Costs
After the panels, your next biggest expense will most likely be the battery storage. Without batteries, you will not have power at night, or on dim stormy days.
The most important thing to consider when sizing your batteries is how long you might need to go without recharging from the panels. If you live in a place that is consistently sunny, then you might only need 24h of power in you battery bank. However, if you live in an area, like me, where the weather is frequently cloudy you may need 3 or more days of reserve power to make it through.
One nice thing, is that you can always add more batteries, so dont worry if you size the system too small initially.
I recommend starting with at least a full day of battery reserves. But, you are free to choose any number you like. With that in mind, use the following formulate to calculate how much battery storage you need in Amp hours.
batterystorageAh=dailykWh×daysofstorage÷12
With my example, using 436 kWh/day with one full day of battery storage I would need 36 Ah of battery storage .
Batteries are typically sold by the number of Ah they provide, but be aware that most types of batteries can only be discharged 50%, which means you can only actually use half of the Amp hours they put on the label.
| Battery Type |
|---|
| 10k+ |
Knowing the Ah that you are looking for in a battery bank, you are ready to go shopping for batteries.
Function Abaft The Components
Batteries accomplish the acquaintance of off-grid solar possible. After a account filigree you will charge to acquisition a defended way to abundance energy.
That way is through befitting a array coffer which helps accumulate your accessories active during the night and alike in the winter. it is acutely important to acquirement a array coffer that can accumulate activity stored through times area the sun may not be animated as often.
Some frequently acclimated array types are listed below:
- Flooded Advance Acid: This blazon of array has a aerial accommodation and can be purchased either online or bounded food and alike car dealerships. This array can aftermost you up to 3 years but will charge aliment every 30-45 days. The array coffer can amount $972.
- Sealed Advance Acerbic : Sealed batteries can be created to aftermost a continued time and authority a aerial capacity. Abnormally in areas area active off-grid can appeal a lot from it. This array can aftermost 7 years and it doesnt crave maintenance. This array coffer can amount $1,042.
- Lithium: Finally, a lithium battery. This specific array has the longest lifespan of the two above. It can additionally be recharged faster and quicker. This will aftermost you 10 years and additionally doesnt crave maintenance. This array coffer can amount $6,495.
Roof-mounts: charge clamps to authority your console in place.
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Can I Run My Fridge On Solar Power
Yes, but check your fridge carefully to see how. Remember that an RV fridge that runs on propane still needs some electricity to power the pump and control board – but ours is only around 3W, so easily achieved with solar power.
Our fridge is a two-way fridge, so as well as propane it can run on AC power. However, as is common for RV fridges, it’s an absorption fridge – this means it’s really inefficient when running on AC and uses around 300W.
If your fridge can run on 12V DC power, then that’s a great option – check to see how much power it draws though so you can size your solar panels accordingly.
If your RV has a residential fridge , then you’ll need an inverter to run it when off-grid. Electrical consumption can vary widely on residential fridges from as little as 100w on very efficient models, to many times that on less efficient models with an ice maker and defrost mode.
Your manufacturer’s website or instruction manual should have the information you need to calculate how much power it draws, or better yet, use a device like a Kill-A-Watt to measure it.
Sizing Your Solar System
Once youve decided that off-grid solar may be a good option for you, you can determine the appropriate solar system size in a few steps.
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Medium House Or Bach Ultra
*Excludes generator and install. Your package includes:
Free design service to correctly size your system 16 x 380W high-efficiency solar panels 1 x 5.6 kW all-in-one inverter, charger, controller unit 4 x 3.2 kWh Lithium Ferrous Phosphate battery modules All fusing, isolators, fittings, rails, DC cabling. NZ Compliant Pre assembled, tested, plug and play to save on installationDouble cabinet, warranties ongoing supportWiFi and APP monitoring
With 16 solar panels and 4 x 3.2 kWh battery modules , the PS3 system will power most of the appliances found in a standard home.
This system is at its limit of expansion. Read below to learn more.
How To Size An Off
It will affect the kind of equipment you need, how much work the installation will involve, and, of course, the total cost of the project. Solar setup sizes are based on the amount of power the system needs to provide.
There are two different ways to figure out the number you need, and they are based on:
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Questions To Consider Before Quitting The Grid
With the growing popularity of solar energy for use at home, a number of Kiwi homeowners are wondering if they can use solar alone to power their daily lives.
Relying completely on energy generated by solar panels with no utility grid connection is more possible now than ever before, thanks to the increased availability and falling prices of solar panels and batteries. But while being completely grid-independent can be an attractive idea, it does come along with some budgeting considerations and lifestyle adjustments.
Is going off-grid right for you? Its not an easy yes or no, as every homeowner is different. Here, well share 9 questions to consider before you quit the grid.
