How to Choose the Best Supercapacitors for Micro-Generators

Microgrids are becoming increasingly important as a backup power source when there’s a massive disruption. And to power these microgrids, engineers insist on utilizing supercapacitors. Also known as ultracapacitors, these devices offer many advantages over regular capacitors and batteries. Click here to explore more on supercapacitors.

In this article, you’ll learn how to choose the best supercapacitors for your micro-generators.

Power Density

The power density is defined as the amount of power per unit volume. A supercapacitor that you intend to use in a microgrid should have high power density. Because of this feature, it will take a lesser time to charge up. And when discharging the power, it’ll be super fast as well. And that’s what you expect from a supercapacitor. When the primary electricity source is down, you want it to deliver power reliably.

Most supercapacitors have a faster charge and discharge rate than batteries, but they do not store much power like batteries. Because of high power density, the supercapacitors can charge up quickly and discharge at the same rate. It’s best to have ultracapacitors with higher power density, depending on how valuable your microgrid is to the entire system.

Energy Density

When evaluating supercapacitors, energy density is not emphasized as much as power density. The former is defined as the amount of charge a device can hold. Supercapacitors offer a better energy density than capacitors but worse than batteries.

When buying ultracapacitors, it’s better to have a higher energy density. Researchers have already discovered supercapacitors that could charge 10X faster and hold more energy. This could revolutionize electric cars and the slow charging rate associated with them.

Voltage Rating

Supercapacitors have a lower voltage rating. This makes it harder to charge them at a higher voltage range. As a rule, you shouldn’t exceed the capacitor voltage rating. So if the manual reads 4.5V, you should charge it in between the 4V to 4.3V range. 

If you exceed the rating, you run the risk of damaging the integrity of the supercapacitor. Therefore, it’s better if the ultracapacitor has a higher voltage rating.

Temperature Range

Microgrids are installed at places with fluctuating temperatures. If the temperature plummets below -15°C, then conventional batteries and capacitors do not function properly.

But ultracapacitors are designed to work properly in both hot and cold temperatures. And they differ by this temperature range. The best ultracapacitors are made to work even in extreme conditions like 85°C and -40°C.

Besides the environmental temperature, the energy storage devices also need to cope up with internal heat. So when you’re using a supercapacitor for a microgrid, you should consider the ones with a broader temperature range.


Ultracapacitors are designed to last long. But exactly how long depends on the particular product and brand. Some supercapacitors can last multiple decades because they do not rely on chemical reactions as batteries do. The lifetime also depends on how you use them. So invest in supercapacitors that have longer validity.


Supercapacitors aren’t cheap and come with a high initial cost. Expect to pay a hefty amount when investing in these. But the price also varies from brand to brand. So it’s better if the supercapacitors are within your price range.

Buying supercapacitors for your micro-generator doesn’t have to be complicated. You should keep things simple and look at the above characteristics. With the right investment, you can ensure a reliable power supply from your microgrid when there’s an outage. 

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