Clean and relatively predictable, solar technology has made some significant advancements in recent decades. Many households (ours included) are moving to off-grid solar or hybrid systems, but when electronic devices that need a constant connection to electricity are involved, things become complicated. A UPS is a critical tool to protect your devices, but can a solar panel be connected to a UPS?
The article below investigates the issues relating to connecting a solar panel with a UPS. Some of the points include:
- How are solar panels connected to a UPS
- Types of Solar Systems that might use a UPS
- Are there store-bought products, or do you need to make your own
- And is it necessary to connect a UPS to a solar system
When connecting a UPS to a solar system, there are some critical questions to ask yourself beforehand. Why do I need a UPS connection? Can my solar system support a UPS? Is there a difference between a solar UPS and an Inverter, and should I use a regular UPS too?
The Ins And Outs Of Connecting A UPS To A Solar Panel
With the rate at which we humans are burning fossil fuels, alternative energy sources have become a greater necessity. Solar power systems have seen incredible improvements over the last few decades, with whole households switching to solar power.
These systems can either be with or without battery banks.
Most solar systems include:
- A Solar Panel
This is the part that converts solar energy into DC.
- A Charge Controller
This unit regulates the current and voltage traveling from the panels to the load, sending additional power to the battery bank. They prevent the battery from being overcharged.
- Consumption monitor
Not critical, but it will allow you to monitor how much power you use in a day.
What the solar panels are mounted on, on the roof.
- An Inverter (or UPS)
Sting inverters, microinverters, and Optimizer systems convert DC (current) from the solar panel into AC (current) to be used by the load. They can be off-grid, hybrid, or grid-tied solar systems.
- A Battery/Battery Bank
Batteries store additional power produced to power the load when current from the panels is lost.
Solar Power Systems, UPSs, And Inverters
Solar panels can be connected to a solar or a regular UPS.
Solar UPSs have a solar charge controller incorporated in their design, which allows the solar panel to charge the UPS’s battery. A hybrid system uses both solar power and electricity from the grid to charge the UPS’s battery.
There is a bit of confusion between a solar UPS and a solar inverter. Fundamentally they achieve the same purpose, converting DC into AC power for electronics, and charging a battery in the case of hybrid or off-grid inverters.
A UPS has a built-in inverter, whereas separate inverters require a charge controller to be connected to ensure the correct amount of current is sent to it.
Solar UPS In A Solar Power System
In the case of solar-powered homes, many operate on a grid-tied system. Grid-tied systems are connected to the electricity grid while having solar power as a backup in case of an outage.
A battery is not typically used in a situation like this. However, oftentimes your house will still have its electricity turned off if there is a power cut (to prevent injury to anyone working on the line by supplying power to the grid).
If, however, you have a UPS/inverter and a battery bank connected to the system, you can have uninterrupted power, as intended because your appliances run directly off of the stored energy in the battery. This is a hybrid system, and many stores sell a UPS (or hybrid/off-grid inverter) designed specifically for solar power.
A solar UPS/inverter works in the same way as a regular UPS, with the difference being that a solar one has its batteries charged by the sun, while a standard UPS battery chargers by power supplied from the grid.
A solar UPS/inverter connects between the solar panels and the batteries in the system.
With a built-in charge controller, the battery connected to the UPS is charged by surplus DC, which comes from the solar panels, which the load does not need.
(e.g., if your panels produce 500w, while your load is only 250W, the remaining 250w is directed to charge your battery via the built-in charge controller).
UPSs have a built-in inverter, which transforms the stored DC into AC, which most appliances need to operate when the power goes out.
Many store-bought solar UPS/Inverters are hybrid models. These dual power source UPSs are connected to the power grid and solar panels.
Some solar UPSs are designed to give preference to solar power, only switching to the mains when an internal sensor detects that solar energy has dropped below a voltage threshold (night time, overcast conditions, etc.).
Some Examples Of Solar UPSs And Hybrid Inverters On The Market
Although there is some debate, a hybrid inverter is fundamentally a solar UPS.
Below are some examples of solar UPSs and Hybrid Inverters available.
|Product Name||Cost (Estimated)||Specs|
|Luminous Solar Hybrid 1100||$100 (Amazon)||700VA, 12V Rating 98% efficiency fast charging with 40A, 12V Charge Controller|
|Microtek Msun 2200VA PWM 2550/24V Solar Inverter||$170 (Moglix)||2200 VA, 24V 50A, Pure Sine Wave|
|Sol-Ark 12K Hybrid Inverter/Charger||$7,452.00 (Real Goods)||120/208/240VAC, 185A, 48V nominal|
Outback Radian Multi-Mode Inverter
|$ 2,182.98 (Iron Edison)||170-280VAC, 200-260V nominal|
|Temank Solar Hybrid Inverter||$549.89 (Amazon)||3000W, 24V DC, 110V-120V AC|
There are many products available. In the USA, the majority of what you will find is Inverters.
Regular UPS In A Solar Power System
When it comes to store-bought solar UPSs, there is quite a high cost involved. For that reason, some people have taken it upon themselves to take their pre-existing (owned) UPSs and modify them to support a solar power system.
The addition of a charge controller is the most significant modification. This addition allows the battery to be sufficiently charged while supplying the UPS with DC power, which in turn will convert the current to AC for use by the load.
An alternative method of incorporating a UPS into a solar system is:
- Solar Panels
- Charge Controller
- Solar Battery
- Home/Regular UPS
By using this method, your UPS will be charged by solar power instead of the grid while still providing extra (although probably unnecessary) support for your electronics.
Is It Viable To Connect A Regular UPS To A Solar Panel?
When deciding if connecting a regular UPS to solar is viable, it is essential to determine what goal you are trying to achieve.
A great idea is if you are trying to charge the UPS’s battery without using the grid.
However, when using the UPS as a backup power source, it is crucial to ensure that the solar system is big enough to run as an “off-grid” system.
This size consideration would ensure that the UPS is charged during the day while the solar system powers the appliances connected so that the UPS could effectively work once the sunsets.
You will garner no real benefit from adding a UPS if the system is not big enough.
If, however, you have the money to install a big enough solar system, installing an off-grid or hybrid system is far more convenient, which will act like a UPS.
Many products on the market allow your solar system to work with both solar power and the grid. Off-grid and hybrid systems have batteries that are charged and then used when there is a break in the electricity, functioning in the same way as a UPS. Although you can install a regular UPS to the solar system, it doesn’t really seem worthwhile to do so.