Solar Energy Harvesting with Epishine Flexible Solar Cell - Pt 1: intro

RE: Solar Energy Harvesting with Epishine Flexible Solar Cell - Pt 1: intro

Jan Cumps — Sun, 28 Nov 2021 18:22:52 GMT

I'm trying to use the harvester for a low power design. It's been stored for a year, in the original package.
It doesn't want to charge the super CAP. I've tried the kit in the 1.8 V and 3.3 V configuration. It never gets above 40 mV.
[mention:193ac2434c814a24b46635a2210baec1:e9ed411860ed4f2ba0265705b8793d05], [mention:ef601b47037147bfb9b0b4a3ab63026a:e9ed411860ed4f2ba0265705b8793d05], what do you measure at the output if you put it in light for a few hours?
The photovoltaic cell outputs a voltage. It seems to be the charging circuit that's not getting energy into the super cap.

RE: Solar Energy Harvesting with Epishine Flexible Solar Cell - Pt 1: intro

jc2048 — Thu, 30 Jul 2020 15:16:19 GMT

Looks interesting to experiment with.

I found these patents

https://worldwide.espacenet.com/patent/search?q=epishine

Their IP seems to be in the area of the lamination and printing, rather than the cell material.

They give hints as to the problems with organic polymers for the conversion from light: ageing and degradation are obviously the key ones. Not necessarily a problem - depends a lot on the kind of application and the lifetime required, and what they've done to mitigate the issues. One thing to watch is that it might not be protected too well from UV. Do they say it's suitable for outdoor use? All the applications shown on the website are under artificial light.

There's also a mention of protecting the polymer from mechanical damage, so perhaps don't flex the panel too tightly. It's flexible to go round a printing drum, but that could be large and not too much of a curve at all.

On the cell side of the circuit, you might consider measuring the VI curve directly [is it a diode curve?], without the charging circuit connected, to determine the maximum power point at several different levels of illumination. Then reconnect the charging circuit and see if it manages to get it close to those points. You wouldn't need a calibrated light source; just different distances away from something like a desk lamp, so that it was repeatable between the two sets of tests, would do.

RE: Solar Energy Harvesting with Epishine Flexible Solar Cell - Pt 1: intro

dubbie — Thu, 30 Jul 2020 13:55:37 GMT

I purchased some small Supercapcitors a few months ago to try out with a solar cell although I have not done much with them yet, so I am interested to see what this system will achieve. I have played with an energy harvesting kit before (I cannot remember which one, but it was probably 10 years ago and it was quite small) and it wasn't really my thing. It needed too much understanding of analogue electronics - which is definitely not my thing - for me to get it to work effectively, it was only gathering micro Watts so wasn't in my usage area of at least milliWatts.

Flexible solar cells will also be good - for rounder mobile robots and I have looked at them in the past, but they were just too expensive for my budget. Do you know how much the Epishine ones cost?

Dubbie

RE: Solar Energy Harvesting with Epishine Flexible Solar Cell - Pt 1: intro

robbarter — Thu, 30 Jul 2020 11:51:06 GMT

Very interested in this especially for powering low power IoT sensors and in Northen European weather conditions (i.e. grey!). Any idea what the MPPT voltage would be? I assume somewhere around 2v? I've just added a MPPT enabled solar charger device into my LoraWan board which this solar panel would be very interesting.

RE: Solar Energy Harvesting with Epishine Flexible Solar Cell - Pt 1: intro

genebren — Wed, 29 Jul 2020 22:22:52 GMT

Very interesting blog. I look forward to seeing more about this devices performance.

RE: Solar Energy Harvesting with Epishine Flexible Solar Cell - Pt 1: intro

DAB — Wed, 29 Jul 2020 18:47:47 GMT

Hi Jan,

I have heard about these flexible solar cells, so I am very interested to see how well they work.

DAB