I have an energy harvesting application and I want to use a capacitor to store energy. Due to the application being very low power, a capacitor of around 50uF might be enough. What is really important though, is to have the lowest discharge possible, since the charging of the capacitor might be happening over a long period. What type of capacitor is best suited for this case?

  • 3
    \$\begingroup\$ I suggest that you have a look what is commonly used. Texas Instruments takes energy harvesting seriously so have a look at: ti.com/solution/other-energy-harvesting and see how they do it. \$\endgroup\$ – Bimpelrekkie Jun 9 at 12:24
  • \$\begingroup\$ Why not use a rechargeable battery to harvest the energy? \$\endgroup\$ – Leoman12 Jun 9 at 14:38

You are looking for a capacitor with a high leakage resistance. A 50uF electrolytic capacitor is inexpensive and easy to find, but has a lower leakage resistance than other types of capacitors. You haven't mentioned the required voltage. That is an important consideration.

Here is a chart of capacitor technologies vs. leakage resistance:

Capasitor Technology vs. Leakage Resistance

The words "Values of" in the caption appear to be an error. The image is from page 8 of KEMET Corporation, Introduction to Capacitor Technologies Copyright 2013

Here is a chart showing the capacitance and voltage availability for several capacitor technologies. enter image description here

Image from: EPCI; ESA SPCD 2018 Symposium via https://epci.eu/capacitors-news-and-trends/

| improve this answer | |
  • \$\begingroup\$ A chart or additional information about voltages and capacitance values of each capacitor technology would complete the picture nicely. \$\endgroup\$ – NickG Jun 9 at 17:34
  • 1
    \$\begingroup\$ The document linked above has a similar chart showing "values of capacitors by dielectric." I will see what I can find about voltage ratings vs. capacitor type. \$\endgroup\$ – Charles Cowie Jun 9 at 21:05
  • 1
    \$\begingroup\$ Here is a site that has a lot of information about capacitors iequalscdvdt.com \$\endgroup\$ – Charles Cowie Jun 9 at 21:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.