With recent emergencies in Texas and other parts of the country, especially where the power grid failed due to inclement weather, it’s reasonable for many to be looking for emergency backup power systems. One appeal of solar energy is its reliability and independence from the main power grid. With the right planning and setup, it’s easy to purchase a solar setup to power critical life-saving appliances in emergency situations.
Off-Grid Solar Power For Short-Term Power Grid Disruptions
With the recent explosion in solar popularity, it’s never been easier or cheaper to purchase a solar setup. With a few panels and batteries, you’ll be able to rest easy knowing that your phone will maintain its charge and your rooms will continue to have light throughout a power outage.
In this section, we’ll be covering a few basic concepts and pieces of equipment relating to solar power that you’ll need to understand to begin planning your setup. These pieces of equipment include solar panels, batteries, solar charge controllers, and power inverters.
Calculating Your Drain
Each solar consumer will need to estimate a projected drain before making their purchases. If you’re only looking to power some LED lights and a phone charger, your solar setup will look vastly different than someone looking to power their central heating and refrigerator.
You can use SanTan’s solar calculator to get some idea of your potential drain before making any purchases.
Solar Panels
Solar panels are what jumps to mind when planning out solar power setups, and with good reason. They’re what converts sunlight into usable electricity. Not all solar panels built equally. Larger panels will be able to gather more light than smaller panels, and more expensive panels will typically incorporate technology that makes them more efficient than cheaper panels.
It’s likely that your panels will be the single largest expense in your solar setup, so it’s important to do your research. At SanTan Solar, we recommend buying refurbished panels at a discounted price for most solar Do-It-Yourself’ers. You can see our selection of refurbished solar panels at:
Battery Bank
An important concept to understand is how batteries are rated. The amount of energy a given battery can contain is measured in amp-hours. This rating tells you how long the battery will be able to provide energy for. If your battery is rated for 200 amp-hours and your appliances drain 10 amps per hour, that means your battery will be able to provide useful voltage for around 20 hours (200amp-hours/10 hours).
Just as with your solar panels, the size and type of battery bank you’ll need will vary greatly depending on your needs. Most small-scale projects use lead-acid deep cycle batteries which will be damaged if depleted below half charge. That means you should plan out how much drain your appliances will pull, then ensure that you can cover more than double that per day.
Solar Charge Controllers
If you want to install a solar setup that you can then forget about until an emergency occurs, you’ll want to buy a solar charge controller. In the same way you’d get sick if you drink too much water all at once, batteries can get damaged if they get charged by a current that’s too powerful. Solar charge controllers automatically limit incoming voltage from your panels to prevent battery damage.
Inverters
Electrical current comes in two forms, Alternating Current (AC) and Direct Current (DC). Cars and solar panels both use DC while most household appliances use AC. This means that in order to power your appliances off of your batteries, you’ll need an inverter. Inverters take the DC current from your solar panels and batteries and convert it into useful AC.
Be aware, just as with many other items on this list, not all inverters are the same. If you’re powering a space heater your setup will differ massively from the lighter examples from above.
Installing Your Equipment
Now that you’ve got your panels, your batteries, your solar charge controller, and your inverter, it’s time to install your setup. Warning: This section will not go into every detail of solar panel installation. Electrical systems are inherently dangerous, so be sure to do plenty of research before taking any step referenced here.
Connecting Your Battery Bank to Your Solar Charge Controller
Your first step should be to connect your battery bank to your solar charge controller. Many solar charge controllers have useful diagrams painted onto them to show you where to attach positive and negative leads.
You’ll partially extend the screws located underneath the battery diagram, then insert wires connected to the positive and negative leads of your battery bank. It’s important that you perform this step BEFORE you connect your solar panels. After your wires are in the right spot, you’ll screw them tight.
If you have multiple batteries, you may have wired them in series, or you may have added their total capacity by wiring them in parallel. Certain inverters may require a certain amount of voltage, for example. You can read our article on series vs parallel to find out which wiring setup is right for you:
Installing Your Panels
Perhaps the single most important step in your small-scale solar installation is to decide where to put your panels. While the initial spot most people think of with solar panels is on the roof, there’s no rule saying that you must keep them there. All that’s important is that you find a place where they’ll stay out of your way, and in sunlight.
You can find a variety of racks to hold your solar panels, ranging from fancy to cheap. Similar to batteries, solar panels can be wired in series or parallel. The article linked above contains more information about that.
When your panels are installed in your chosen location, you’re ready to wire them to your solar charge controller. MCT connectors are the industry standard for wiring solar panels, so you’ll typically connect your panels to each other with those, then strip wire to connect them to your solar charge controller.
Connecting Your Inverter
When connecting your inverter, you typically have two options: connecting directly to the battery bank, or connecting directly to the solar charge controller.
Connecting to the battery bank directly can be dangerous. If your batteries drop below a certain voltage, it will permanently damage them. For novice users, it’s possible to deplete them while never knowing you’re close. Luckily, there are some low-voltage disconnects that you can buy that will trigger when your battery depletes to a certain level.
Alternatively, you can connect your inverter directly to your solar charge controller. This is useful because most solar charge controllers contain automatic cutoff systems which will prevent your batteries from overly depleting.
However, most solar charge controllers won’t supply the amount of energy you’ll need to power anything larger than lights or charging power tools. If you’re powering anything more intense than those LED’s, it’s likely you’ll have to connect them directly to your battery bank.
Why Shouldn’t You Buy An On-Grid Setup?
On-grid solar setups differ from those we’ve already discussed in one important way: They’re wired directly into your electrical box. With on-grid setups, everything happens behind the scenes. You won’t need to hook into an inverter because that’s included in your installation. Your solar setup will feed power back into the electrical grid, which the power company will pay for in some states.
Because this kind of installation taps into the same energy system that powers your house, you’ll typically need to hire professional electricians and get permits from the city to complete your installation.
Most houses you see with solar panels installed are working with On-Grid setups. However: If the electrical grid’s power goes out, your on-grid setup will not provide power to your house, even if your panels are generating power.
We have an entire article dedicated to On-Grid setups which you can see linked below.
Hybrid Solar Power
If Off-Grid doesn’t connect to your power outlets and On-Grid loses power during outages, Hybrid solar setups get the best of both worlds. A Hybrid setup will connect directly to your house’s power grid just like with On-Grid setups, but it will include a battery bank. This battery bank will be able to store your energy and use it during outages.
Examples of a Hybrid setup include Tesla’s power walls. Many consumers choose to use lithium batteries for their Hybrid setups due to their long lifespans and low maintenance. Be warned, however, lithium batteries are far more expensive than led acid deep cycle batteries that Off-Grid solar setups typically use.These hybrid setups combine the continued use of off-grid setups with the electrical savings of on-grid setups. They’re also the most expensive option available.
Some people buy larger solar setups for the same reason they invest in gold. It never hurts to prepare for a worst-case scenario. If you’re looking to power your entire house or cabin with a solar setup, you should prepare for a more involved and expensive process. However, few things will give you the peace that comes with knowing that, no matter what, house won’t lose it’s power.
Conclusion
With climate change and political instability a growing concern, it’s reasonable to invest in a green reliable backup system like solar power. While an on-grid setup will provide energy savings if the electrical grid is up, your house will still lose energy unless you have an energy storage system like a lithium ion battery bank. An off-grid system will typically be enough to power some appliances during most short-term power outages and a serious investment into a hybrid solar setup will allow you to sleep knowing that your family will always be able to turn on the lights.
Check out our store for great deals on reliable refurbished solar panels.
