#278

[@richard_wenner]

Very glad you have addressed this Andreas. Has saved me a lot of time. Wonderfully dissected analysis - worthy of the land that gave us the self winding watch. (Just think of all of those fingers, around the world, saved from dislocation, as a result) :) Cheers!

[@raguaviva]

The amount of time you are saving us by sharing this info is amazing, at the same thanks for putting some pressure on device makers to encourage improve their solutions! This is pretty awesome!

[@deangreenhough3479]

As always, my Sunday is brighter and my knowledge expanded, just by watching your work. Always worth the time, always. Thank you Andreas 🏴󠁧󠁢󠁥󠁮󠁧󠁿👍

[@mrfoameruk]

Really interesting. You have saved a lot of people a lot of time looking into the feasibility of this idea in their projects.

[@DenfordBerriman]

Disappointing results but good to know and once again a thorough investigation. Thanks!

[@AgozieAni]

You are the best in this area!! I've binged watched almost all your videos. Very educative, I will always recommend this channel.

[@portlyoldman]

Getting up early on a Sunday has definite benefits 😀

[@AndreasSpiess]

:-)

[@ryanitchon]

Thank you for sharing this. I am working on a Carabao tracker on my farm based on LoRa and you videos are very helpful.

[@AndreasSpiess]

Glad my content is helpful. I hope you will be successful!

[@MakerFabio]

Many thanks. You saved me lot of time. I will purchase the second one you presented

[@AndreasSpiess]

Glad it helped

[@Golgafrincham]

It seems you got some stuff wrong about the LTC3108. Me and a colleague were working with this circuit a little bit a while back. 1. There is a main output that is programmable to 4 different fixed values: 2.35V, 3.3V, 4.1V and even 5V. 3. There is a Power Good Output that you can use for Warning / Load cut-off. If Vout drops below 9% of its programmed value, the PGD-pin is set low. Still missing the MPPT though. Read that it is because this device is intended for TEGs as well as PV and that rules out a simple MPPT-circuit. Not sure if it is true though, but it makes sense. The AEM10941 seems really nice though! Thanks for the great video!

[@northshorepx]

That was quite interesting. Thanks for doing the experiments for us.

[@AndreasSpiess]

You are welcome!

[@juststeve5542]

Very interesting Andreas. Thank you. MOOvement... lol! Someone had fun coming up with that name!

[@epeas]

Hi Andreas, e-peas is here. Thanks for making this video and reviewing our product. It was interesting to see how it compares to others through someone else's eyes. We can send you evaluation boards for other AEMs for further testing and should you consider it interesting to drop by our Swiss office in La Neuveville to discover our new solutions, we will be happy to invite you.

[@AndreasSpiess]

Thank you for your offer. For the moment I have no plans for that because most makers need more energy than these harvesters can deliver.

[@paulrichmond6903]

Thank you for the clear and thorough presentation. It’s one of those topics I often wonder about.

[@AndreasSpiess]

It was the same here ;-) That was the reason for the video.

[@skewedmaker]

Thanks for another excellent presentation with detailed information and insights for its practical application. Keep up the good work!

[@AndreasSpiess]

Thank you!

[@peterowens4770]

Thanks Andreas. I tested the official breakout boards from Analog, the LTC3106 (DC2255A) and LTC3107 (DC2103A). I was using the LTC3106 with a small solar cell (5.5V OCV) and the LTC3107 with a 40mm Peltier device since I work in the steam world. With an 8C temp delta on the TEG I could harvest 5x more power than I used in my LoRa device. I had this configured to harvest to supercap with primary battery extender. I measured this on my Keysight N6705 w/ N6781A module. I also tested Jasper's device and found it worked well in "slowly" charging an RCC123A cell as long as solar cell had some exposure to sunlight like in my office. Like you, I found ambient office light to not perform well. Of all the harvesting sources, I found thermal and TEG to be the best if your application allows it.

[@AndreasSpiess]

Thank you for sharing your experience! Temperature differences, of course, have a lot of potentials (as we see in our power plants). But, as you write, it is not easy and not everywhere because it needs sustained temperature differences.

[@soud_295]

Still so great to get technical comparisons... Thanks !

[@AndreasSpiess]

You are welcome!

[@sunroad7228]

No wonder the outcome of this hugely valuable exercise comes inline with the 2017 proposed Fifth Law of Thermodynamics;: The Arrow of Energy - "No energy system can produce sum useful energy in excess of the total energy put into constructing it. Energy, like time, flows from past to future" (The Fifth Law). Thank You Andreas.

[@BartAnderson_writer]

Interesting topic to think about - In what circumstances is it true (e.g. energy harvesting) , in which false (water wheels)? - When is an energy system worthwhile, even if there is a net loss of energy?

[@sunroad7228]

@@BartAnderson_writer Before wear and tear shreds it to pieces, a water wheel will never pay off a fraction of all the solar energy the plants the woods of the wheel have came from - were exposed to, and the total energy expended in mining for the axe and what has forged the axe, not to mention what energy sustained people involved to that process, knowledge acquiring, skills capture, industrial base build-up and organisation. No one can start afresh with Time, as there was always a past. No one can start afresh with Energy, thinking more sum useful Energy can be produced out of the total Energy made in the past. This applies to all energy systems, including nuclear, fusion, solar, wind, hydro, the sun and you name it. The thermodynamics experiment anyone can exercise that helps visualise the new law can be read about here; the-fifth-law.com/pages/press-release

[@BartAnderson_writer]

SunRoad, it sounds like a restatement of the other Laws of Thermodynamics. And so - very true! All we are doing in ”generating” energy is harvesting a tiny bit of the energy flows going on around us. Mostly solar energy in one form or another. The question is can we get the energy we need without destroying the planet.

[@sunroad7228]

@@BartAnderson_writer "The question is can we get the energy we need - [ with or ] without destroying the planet"? The answer is no? Forget about the planet for a minute, Energy itself is not going be around for much longer. All the energy you see today and all the energy you'll see tomorrow is a subproduct of the severely depleting, finite, gold-grade, once-only fossil fuels, until they are gone. The amount of of fossil fuels burned in manufacturing all the gears and technology Andreas has used in this video is immense, yet he's not been able to produce more than micro wattas, despite the sun was high on the sky. This relationship between what energy is expended in constructing an energy system to the tiny sum useful energy the system produces during its life time, remains the same, even when scaled up and you build a fusion reactor. In the long run, the planet is safe, as fossil fuels will definitely not be with us for very long.

[@takix2007]

@@BartAnderson_writer come to think of it, there are only 3 kinds of sources of energy we use: nuclear fusion (for the moment, all sun-related sources, like biomass, PV cells, solar heating, windfarms, hydroelectric dams or water mill wheels, sea current mills, even fossil fuels that stored solar energy millions of years ago...), nuclear fission, and gravitational potential energy (anything related to tides).

[@DmitriIvanov]

Hey Andreas, I've watched a few of your videos now. Really nice explanations and information, thanks a lot for sharing! Greetings from Germany!

[@AndreasSpiess]

Glad you like them!

[@ericoudammerveld424]

Great review, Andreas! I was really looking forward to your tests on Jaspers boards.

[@AndreasSpiess]

:-)

[@ats89117]

Thanks for the useful and interesting video. PZT based energy harvesting is good for transferring power through metal barriers in a wireless manner. You put a lot of power into a PZT disc on one side, and take out a lot less with a PZT disc on the other side. This is useful if you want to go through a bulkhead without a penetrator, or if you want to power an external sensor in a hostile environment such as a down-well application or an undersea pipeline or outboard on a submarine or even through the wall of a safe. The efficiency of the power transfer across a metallic boundary is claimed to be over 50% by some researchers with more than 10 Watts transferred in some applications. But I agree that for most makers, solar cell based energy harvesting is much more applicable unless they are powering something at a rock concert or at one of the clubs here in Las Vegas...

[@jenskaa4044]

Its not very hard to replace the resistors on the BQ25570, use two soldering irons to remove the resistors, clean up the flux and insert two new resistors then you can get the 3,3v. I am using this chip for my low power weather station , I even made my own board soldering all resistors and the chip (without legs) not that big problem. The only problem is the price for the chip, its rather high $8. A cheaper solution is to use the BQ25505 its only $4, but lags the output regulator, but a small low power LDO can be added. Regarding problems with solar cells that gives above 5v, I have added a TL431 (set for 4,5V) a cross the solar cell to make sure that the voltage is below 5V, I know that I lose some energy by doing that, but it doesn't really matter when the sun is at it highest.

[@AndreasSpiess]

Thank you for your "motivation"! I do not like those small parts :-( And they are not necessary on these (rather big) boards...

[@JungleJake1664]

Many thanks for this Andreas, it is appreciated, I find the hardest part of any design is "knowing" what is available on the market, for example, I was about to manufacture prototypes using the BQ25570, now there is a spanner in the works and I must test the AEM10941 as i was not aware of it. I am very thankful for your channel and always look forward to the next one. Cheers !!!

[@JasperSikken]

Hi Shaun, you can buy my board configured for Li-ion or supercapacitors, or you can buy the evaluation board from e-peas, there you have all possibilities to change all configuration settings. www.tindie.com/products/jaspersikken/solar-harvesting-into-supercapacitors/

[@johnwest7993]

A friend told me it was foolish to use small alternative energy systems to replace central grid power because the cost was far greater than the cost of grid power. I've heard that same argument many times from many people. But I told my friend that what actually mattered far more than the cost of electricity per kW was simply having the electricity where you needed it, when you needed it. The cost of PV panels on the roof of an RV parked out in the desert is far, far cheaper than the cost of running grid power all the way out to the RV in the desert. So there is always a time and place for energy harvesting in the grand scheme of things, and we should use it everywhere it makes sense.

[@AndreasSpiess]

I make a difference between energy harvesting (which is for extremely low power devices) and PV (which rivals or enhances the grid). In my newer videos you see that I also installed a PV plant on my roof. I completely agree with you.

[@hoggif]

A very good video based on typical maker needs. I'm used to seeing term energy harvesting in other sources of energy than solar/wind. For makers those are probably the easiest though. I'd think of solar as a first choice too but outdoors wind can be a good addition, often when weather is bad and there is no sun it may be windy. Wind can provide energy in the night too. (components for wind are not as easy to get ready made, you probably need something clever like a propeller running a motor used as a generator) Other sources of energy include stuff like vibration/compression (piezo elements) or thermal difference (something similar to peltier elements) or whatever. Such alternate sources tend to be even lower power than solar but they can be used for example under ground where sun never shines or in polar regions where sun never shines for a period in the winter. In those niche applications there may be not other good choices available. Energy harvesting is definately no good for high power (or even solar is not with small panels). It is typically ok for very low power applications only. A milliwatt power during all the day gets you a long way if a micropower mcu does for example only a couple small tasks per day. Micropower applications benifit from low voltage mcu quite often. You can run many chips at 1.8V and they consume less power than running at 3.3V. For energy harvester powered applications you may even want to avoid 3.3V devices. It is not all about getting power, it is also about consuming it as little as possible.

[@JohnnieHougaardNielsen]

I've occasionally seen small wind generators used for field sensors for water levels, and possibly other things. The cost, size and maintenance risks are probably a lot worse than just buying a solar panel of sufficient size, unless in the far north or south with very dark winter days. Of course, winter climate have a high risk of conditions blocking a small wind generator, and to a lesser degree solar panels.

[@hoggif]

@@JohnnieHougaardNielsen Maintainance issue is a very good point indeeed!

[@aaron41]

Amorphous solar cells often do better indoors than poly or single crystalline. That's what you see on solar calculators.

[@Rob_65]

NIce one - I've been wanting to get my hands on some of those boards/chips for a long time. Good thing to show that most boards do not contain a complete solution. For cow tracking, why not use the movement of the bell-clapper to generate energy. I see a new summer project coming up 😁

[@AndreasSpiess]

A commenter left a link to a mechanical harvester for elephants ;-)

[@epeas]

Hey, from e-peas whose chip is integrated into Moovement tracker. We also have a chip for vibrational energy sources: e-peas.com/product/aem30940-2/ so, one can definitely harvest energy for trackers from movement, just like you said.

[@martinvollderpro]

11:43 the LTC3108 can be adjusted to output regulated 3,3V and also features a "Power good" output to turn off devices at critical voltages

[@AndreasSpiess]

Thank you for the information.

[@martinvollderpro]

@@AndreasSpiess gerne

[@uwezimmermann5427]

Thank you for a very reasonable look into this hyped topic!

[@AndreasSpiess]

You are welcome!

[@BerndFelsche]

Thank you for a valuable and rational perspective. My wristwatch is solar powered. Not Swiss but it saves battery changes for basic watch functions.

[@DrTune]

quality work from Andreas yet again! Winner!

[@AndreasSpiess]

Thank you!

[@Amir-kz6yq]

your videos remind me about PP-presentations back in the school. Very educational content btw

[@AndreasSpiess]

Thank you!

[@springwoodcottage4248]

I am confused by the whole subject. One set of approaches is to use the sort of chips that you describe, another is much simpler: solar panel, bms & battery. In the uk I have several solar lights that use a solar panel, a bms and either lithium ion or nickel metal hydride. These run all year & even put out a little light in December with no special siting other than pointing south & keeping clear of vegetation, some have been running a few years now. Given the power requirements of modern processors there seems little trouble running applications like weather stations & there are several videos on KZbin about such applications. In my case I modified a cat scaring device to run on a small, about 125 mm by 75 mm panel giving around 6 volts in good sun,, with just a Schotky diode, no bms & 4 Nimh cells. It has been running in a neighbours garden for a few years & still works fine, running a pir to detect the cat & then using a 555 chip to drive a speaker at around 20 kHz . Most of the problems I have seen with these kinds of systems have been water ingress, otherwise they seem to do fine.Thanks for sharing.

[@AndreasSpiess]

You describe a typical representative of the Solar energy fraction in my video.

[@springwoodcottage4248]

I was just trying to say that for a practical system that is low cost, a very simple approach gives useful power. It may not be very efficient, but usually all I want is something that works & is low cost. I may be missing something but the more sophisticated systems seem to add more cost & complication & don't work as well. Thank you for all you share.

[@nickvallianos]

Wow this was a great resource, thank you so much! I'm trying to make an energy harvesting design and this video has been most eye-opening. I'm settling towards the SPV1050, which (if it works as advertised) only lacks the shut-off time delay. I had a good look at the epeas but unfortunately they're a little expensive. Once again Thank You!

[@AndreasSpiess]

Glad it was helpful!

[@la6mp]

I was going to perform the same tests on the same energy boards from Aliexpress when I come home to Thailand, now my expectations are very sober :-) I think piezo-elements are for movement sensors and maybe sound generators. Great video again, Andreas!

[@AndreasSpiess]

Maybe you can concentrate on the better boards;-)

[@la6mp]

Andreas Spiess I will!

[@wiskifrac]

Are there resources where i can deepen the topic 'energy produced vs energy needed for construction of them'?

[@AndreasSpiess]

I do not know. I would search for both topics independently.

[@s.sradon9782]

I just want to know how to power wireless active implants. An implant that uses wireless comms can also be charged by the energy from them, this is super useful for subdermal implants since you dont need a coin cell that will ho flat and put an expiry date on your cyberware

[@PhG1961]

Intersting... and just in time now that I would like to install some of those and an additional wind turbine from BangGood. I guess I may wait a little longer, thnxs for sharing!

[@AndreasSpiess]

The wind turbine is interesting in areas with wind. Here, it would not work.

[@PhG1961]

@@AndreasSpiess Here in Belgium (Flanders region) there's plenty of wind. The height and surroundings are very important and unfortunately height of a wind turbine is subject of local /municipal regulations. I'm still working it out.

[@leewarren8247]

Very informative channel!

[@AndreasSpiess]

Thank you!

[@DarrenRound]

Another great video thanks. Please can you do a video showing us an esp32 development board lora node powered by solar and battery and your source code explaining your deep sleep strategy to preserve battery life. Something like a remote temperature sensor? Keep up the great work :-)

[@suckinDiesel44]

i'd love to see something like this too.

[@AndreasSpiess]

Maybe. Usually I only show parts that my viewers can use for their projects.

[@kwazar6725]

Food for thought and a great sunday morning! Would be nice to know what energy budget i have even on a overcast day. Likely my sensor will power up and down many times a day 🤓

[@SAMIULLAH-hl5rs]

Can I use smd bq22570 after I get that using programmable resistors to configure?

[@AndreasSpiess]

You have to consult the datasheet.

[@AutomticHeart]

Hi Andreas, have you considered thermoelectric generators, such as Peltier modules? They could work for your indoor needs when attaching them to heat sources such as your radiator or benchtop instruments heat sinks (or even on cows in the Swiss winter)?

[@AndreasSpiess]

No, I never tried those.

[@AutomticHeart]

@@AndreasSpiess Then I have to wait or just have a go myself, probably not on cows though.

[@nldestinyx1440]

Is there any information available about the BQ25570 and the usage of it? I can't really get it to work

[@AndreasSpiess]

Maybe you look at the datasheet?

[@L-36]

Do you have a video on using the larger panels to get useful amounts of energy? I would like to power some led strings in my backyard.

[@AndreasSpiess]

I mentioned the two videos.

[@L-36]

@@AndreasSpiess OK, got it. btw, the link is at 5:36 but you say to look for the link at 5:44 and it is gone by then.

[@jobe451]

I recently bought from Ali-Express a water-turbine. The goal is to use it for garden watering. I own a "Gerdana AquaContour", which is crap, since it's solar cell does not provide enough power. So the basic idea is to use a water-powered-turbine to charge the battery. How exactly, I have no idea. I guess I will have to put some transformer inbetween, that can deal with a larger voltage-range and sudden spikes. Some hints from you would be highly appreciated, by another guy with a Swiss accent ;-) The generator I bough is called: "DC 12 v DC Generator 10 watt Micro Hydro Generator Wasser Turbine"

[@AndreasSpiess]

If it produces AC I would try a bridge rectifier and a big capacitor. Then you should be able to connect a buck converter down to 4.2 or 8.4 volts to charge one or two Lipos. These regulators have a big input range. But you have to do your own measurements.

[@saisrikargollamudi7892]

Wonderful video sir, thank you.

[@AndreasSpiess]

You are welcome!

[@tanmaywho]

You are the best. Thanks

[@AndreasSpiess]

:-)

[@larsniklassonhede3798]

Thank you again for your excellent channel. I am looking for a vid there you save your credentials in a header file. Where to find it. Thanks

[@AndreasSpiess]

I do this in most of my projects. So I do not know which one you search. I just include a text file with two lines where I define the credentials

[@larsniklassonhede3798]

@@AndreasSpiess Perhaps I remember wrong. I thougth it was you that had done a headerfile type file.h with your credentials so didn't need to have the credentials in the .ino-file

[@AndreasSpiess]

Yes. A .h file is a text file

[@electrodacus]

The max power point voltage will not fluctuate with the amount of light (as you mentioned a few times in the video), the max power point current is the one that will be proportional with the amount of light. So double the amount of light and you get double the current from your solar panel or solar cell. Solar cell is nothing more than a diode thus you can think of it as the reverse of an LED again a current controlled device. For battery charging say a single cell say LiFePO4 3.2V nominal or LiCoO2 3.7V you will just need a solar panel made with the appropriate number of cells in this case 8 cells is series should be ideal as each cell will have around 0.5V max power point voltage so with a 3.7V nominal cell that will work in the 3.3 to 4.1V range. Even a more common 10 PV cell (in series of course) solar panel will work great for one Lithium cell. All you need is a switch to be able to disconnect the PV panel from the Lithium cell when the cell is say at 4.1V and another switch to cut the power to your circuit when voltage is below 3.3 or 3.5V or maybe enter a low power mode You can have a set of compactors set maybe at 4.2V and at 3.2V as backup in case your software fails and all you need is an ADC pin from your device to measure the cell voltage and one or two digital pins to disconnect in case of cell fully charged or fully discharged. As you mentioned unless all you need is some micro-watt range of power indoor solar PV panels will not make sense.

[@AndreasSpiess]

Maybe you read about MPPT. Or you shortcut your solar panel and measure the power, not the current.

[@electrodacus]

@@AndreasSpiess Solar panels are current sources the short circuit current is about the same as max power point current. Solar cells are diodes so what you see as open circuit voltage is the actual forward voltage drop on the diode/PV cell around 0.7V for mono and poly crystalline cells slight variation based on cell temperature so max power point voltage needs to be lower than this else all power is lost as heat and that max power point voltage has just slight variation based on cell temperature but no effect based on amount of solar getting to that cell. Max power point tracking is an useless technology in offgrid type applications as is much more cost effective to have a PV panel matching your battery voltage and just have a simple mosfet type switch to stop the charging instead and DC-DC conversion. I'm offgrid powering my house fully with solar energy this includes fully heating the house here in Canada. I selected to do that because solar PV heating is the most cost effective heating option even when compared with thermal solar or natural gas. If curios about details see page 5 in my presentation electrodacus.com/DMPPT450/dmppt-presentation-v01.pdf

[@techman2471]

I would like to use these devices, but just don't have the energy to do it!

[@AndreasSpiess]

:-))

[@benni5541]

My favourite chip is the ltc3106 its hard to get and hard to solder but i love it. It has everything you want. Fake MPPT,boost converter,indicator line etc etc

[@AndreasSpiess]

Thanks for the tip. I did not focus on chips, I focused on boards because they are easier to handle for most of my viewers.

[@danielec]

What's the point in moving to bigger solar panels for cows? 30 min position reporting was not enough? More data/sensors added?

[@AndreasSpiess]

You have to ask the manufacturer. Maybe the manufacturing price?

[@codigoBinario01]

Thanks! Lot of [very interesting] information as usually! It would be really interesting to see you using other harvesting methods such as piezoelectric (e.g., used in a bike)... Thanks anyway and continue with your great work!

[@AndreasSpiess]

As I said: I tried and the energy levels were way too small for my purpose.

[@codigoBinario01]

@@AndreasSpiess sure! That's why I proposed to use piezoelectric for another project (e.g., a bike, car,... something with repetitive movements)

[@techno_mesh]

I am surprised nobody has developed a maker solution with the MAX17710 form Maxim IC. Despite old, it seem to fill the very low power niche, where you might transmit a report once a day probably depleting all what has been obtained. It has no MPPT as it is based on an inductor boost scheme. I agree if somebody wants to create maker boards the solution should integrate as much stuff as possible including eventually a LoRa transmitter. Available power will tell how many messages you get in a day. Of course the niche calls for small size so the Teg/Piezo/Solar/RF source has to be small too and the message frequency not that critical. I mean the power requirement for one message with 1000 bytes is less than 100 messages with 10 bytes due to overhead and transceiver stabilization times. Interesting video.

[@AndreasSpiess]

There are other chips around which you do not find on "cheap" boards. Maybe the market is too small?

[@WacKEDmaN]

thanks Andreas..ive been waiting for this one!..i know which modules to stay away from now!

[@AndreasSpiess]

That was one of my goals...

[@leocelente]

Could you use the piezo attached to a car to power something like that cow beacon?

[@AndreasSpiess]

No. Not enough power in vibration. At least not in my car ;-)

[@zaq_hack4987]

I wonder if there are updates to be had for this in 2022.

[@AndreasSpiess]

No update :-(

[@lagging_barish3736]

There is a very high pitched background noise. I just noticed this and dont know if your other videos have it.

[@AndreasSpiess]

Maybe you check? Then you know. So far nobody complained.

[@2609anjan]

Super! Great video. thanks again.

[@AndreasSpiess]

You are welcome!

[@sensesciencescenes7402]

Mr Spiess, as a high profile engineer, what is your perspective about the dangers of RF radiations. Is it a fact or just a myth? I couldn't resist asking this after seeing your citizens protesting against the launch of 5G.

[@AndreasSpiess]

If there would be a problem we should see it after 20 years of global field testing. 5G uses the same frequencies as 4G.

[@dennis8196]

The people protesting are uneducated in the field of RF engineering. They complain about using frequencies that cause various health issues without taking into consideration that we have been using these frequencies for decades without issue and the claims are made without peer reviewed research, only anecdotal claims based upon undocumented levels of power over equally undocumented durations. This alone tells you that the complaints about 5G are bunk. If anyone wants to challenge new tech, ask to see the peer reviewed research first, and even then ask for other contradictory peer reviewed research, then compare the method against real world, finally ask who pays for the research and who benefits. Until you have done this you have nothing to riot about.

[@dd0356]

interestingly, this is the same response as 20 years ago!!

[@dd0356]

i think bigger issue is what is the point of technology, other than makers why do we need technology, this question is more important..makers need technology just for the sake of it..but why other people need it.

[@JohnnieHougaardNielsen]

Brain cancer rates have not gone up after many years of people putting small transmitters close to their ears. The only measurable effect is a very slight heating from the microwaves, but much less than easily tolerable and more powerful effects from things like sun or physical activity.

[@eriklaken1025]

Goodmorning , Holland (Europe) Day Temp 40 gr/cel night 30 gr/cel room Sleeping room 50m3, airco qlima P522 , 320$ , On time 24 our 26 gr/cel humidity 60 max 60 %. Solarpanels make 23 kWh , house use incl airco, 15 kWh . So the house keeps 7 kWh to much..... Conclusion you can keep cool and make energy with the airco On.

[@AndreasSpiess]

And you do not need energy harvesting ;-)

[@eriklaken1025]

Andreas Spiess yes, I will my energy stored for the house, but there is so little on the market and so expensive. I hear there are battery's from critical systems you can buy when they are good but have to replaced. I hope someday someone can tell me to buy them.....

[@IvyGrowing]

Thank you Andreas for comprehensive great comparison! How do these harvesters compare with simple TP4056?

[@AndreasSpiess]

They are completely different in all aspects.

[@PabloPazosGutierrez]

I have a small solar panel that outputs 6v with 1.1w, I connected a 5v buck converter and charged my cellphone, a little slow, but it's possible. Another thing I tried is connecting the solar panel to a li-ion charger, and it charges at 4.07v (it should be 4.2v at full charge, but worked). So it's possible if you have time. The battery can be charged in hours if there is direct sun.

[@AndreasSpiess]

You are right. I made a video about solar chargers where the TP4056 were quite good for 6 volt panels.

[@AltMarc]

The LTC3588 came a bit short... Instead of piezo, I had a project that "stole" energy from a very weak (

[@deangreenhough3479]

Neutrality & Mutualism with AI & Robots please explain a bit more my friend😁🏴󠁧󠁢󠁥󠁮󠁧󠁿

[@AltMarc]

@@deangreenhough3479 I had an esp32 sending me via wifi message each time some one ringed the doorbell, The buildings doorbell entry system could not provide enough for the esp to send. I order the LTC3588 from china, in the intend to "harvest" a bit of the low power provided,.. but it took 3 month and meanwhile the landlord put a new doorbell system in place...

[@ziranei5852]

What you think about using these harvesters to get energy from crude nuclear battery, for example one that nurdrage made few years ago. Is it possible to get enough energy from them to power something?

[@vylbird8014]

I looked into that myself. The power density is absolutely tiny. One of the few times you'll fine micro-watts a convenient unit.

[@Ed19601]

interesting stuff. I am just using a simple solar cell with a lipobattery charger, no MPTT and that works well,with seems to be your recommendation towards the end of the clip

[@AndreasSpiess]

And because the solar cells became much cheaper it is the way to go for most applications, I think.

[@Ed19601]

@@AndreasSpiess correct. I am also not moving my panels along with the sun. Just added 2 panels for early morning and late afternoon

[@nickname7152]

Hey Andreas, good to see that your channel is keep growing. Watched the video. However, now I'm wondering consumption of boards =)

[@AndreasSpiess]

You should find the efficiency in the data sheets.

[@bb-andersenaccount9216]

peltier might be considered from residual heat in industrial processes for WSN applications

[@AndreasSpiess]

Yes, the Peltier effect can be used for energy production. Especially where you have lots of heat.

[@jschroedl983]

Do you have any recommendations for similar devices for use with 9 volt 800 mA solar panels?

[@AndreasSpiess]

As mentioned in the video, this is another topic.

[@gstoian]

Excellent video. Thank you, Andreas. And something that can be read between the lines: to measure the performance of the bulls they must have sex with the light on. :))

[@AndreasSpiess]

I do not know the details ;-)

[@florremdiw]

Nice work Andreas - I'm waiting for the sequel! A pity that indoor PV (c-Si or m-Si) performs so badly - I think thin film (CdTe or CIGS) would improve the setup due to better matching spectra. I'd like to experiment with an "ultimate wall switch" for smart homes: a device powered by light and/or kinetic energy, using a touch sensitive e-ink surface, sending/receiving LoRa signals to switch loads (lights, appliances, ...) . Is something like this in the make?

[@AndreasSpiess]

Not here. Energy Harvesting is very special. And you have to adapt the whole design. So nothing for the ordinary maker in my opinion.

[@TheAuxLux]

Have you heard about perovskite solar cells? I know that polish company Saule Technologies are on the way to mass produce those, and they are quite promissing. They work with artificial light, can be transparent, flexible, and should be super cheap (10x cheaper than current). I hope they will make it :)

[@Muhomorchick]

Can you talk about using LTO batteries? Are there any special chips for this?

[@AndreasSpiess]

I never used LTO batteries and therefore never searched for a specific charger.

[@aneeshprasobhan]

That watch looks real nice for a 40 year old one. Good job taking care of it.

[@AndreasSpiess]

They should last forever if you trust their leaflets ;-)

[@Ownedyou]

I visited a friend in the Basel canton in early July. I can confirm this is indeed a Swiss Accent. :-)

[@AndreasSpiess]

Basel is very close to where I live. So our accent is similar....

[@michalrzmichalrz6656]

I have a question. I'm not complaining (yet) but is it "okay" to harvest RF signals? GSM, WiFi, etc.? What I mean is that in a way it's capturing someone else's signal, and also with a big enough proliferation of this method broadcasters will have to boost transmit power and that's not really 'green', too. What am I missing?

[@AndreasSpiess]

I am not a big fan of RF harvesting because in most areas there is just not enough energy available :-( If you live across the street of a TV transmitter this might be different.

[@jedandecko5585]

Thanks a lot for this review, it saved me a lot of money :)

[@AndreasSpiess]

This is one of the goals of this channel ;-)

[@jedandecko5585]

@@AndreasSpiess I glad your Danube travel was great fun and expirience :)

[@bobvincent5921]

Thanks Mr Swiss man I. Learned much of the concept of low low power harvesting methods and it. Seems doing it is not practice.

[@AndreasSpiess]

As mentioned, it has its (limited) applications.

[@thekaiser4333]

@Andreas Spiess - 17:50 What is a "Laura Van Gateway""

[@Morris3190]

LoraWan Gateway

[@michaeltempsch5282]

LoRaWAN www.thethingsnetwork.org/docs/gateways/

[@matneu27]

Thank you for the summary and introduction of the systems! Radio wave harvesting could be punishment as power stealing if someone detects it 😉 Anyway I remember a newspaper note (I thought it was in Switzerland) back in the 80. where people close to a big AM station complained about singing and speaking kitchen pots. At least involontary energy harvesting.

[@AndreasSpiess]

When I was young I used to wirelessly power a fluorescent tube in my hand with my Yaesu FT-277 ham radio transmitter. Didn’t impress the girls : -(

[@phildodd9942]

In southern UK 10-15 years ago, there was a prosecution for stealing energy from an AM radio transmitter. Transmitter engineers discovered that the power output from the antenna dipped on one side. Investigation showed that a nearby farmer was capturing the radiated energy, and powering the lights in his cow shed from it !

[@patrichausammann]

4:13 Correct, but the LCD display technology, which was a requirement for the pocket calculator, was invented by a Swiss, who I met some years ago.😊 His name is Martin Schadt and he could be called the father of pixels.😉 I use since several weeks just Solar engery to recharge my smartphone and it works fine. I built my smallest system(12v) out of two old regenerated car batteries. These are connected to the battery charger with an array of 40w panels. On this little system I just use a pwm charger, which seems to be sufficient for my purposes like my small animal fence and to recharge powerbanks and mobile devices.

[@avejst]

Nice review and work through Thanks for sharing :-)

[@AndreasSpiess]

You are welcome! Counting the comments it seems to be an interesting topic...

[@roostertechchan]

Check the Enocean devices. I got temp sensor and it works great with ambient light even in darker rooms. There are development kits but they are quite expensive.

[@AndreasSpiess]

Thank you for the link. They have a wide range of products!

[@paulfontaine7819]

Great informative video as always Andreas, thanks. I missed something in the explanation. 18:09 Either do energy harvesting or increase the solar panel size. Why? Because the solutions analyzed are not compatible with larger panels? Which part is not needed with larger panels?

[@zukjeff]

put a piezo stack under the foodbed in your hiking shoe to allow you to charge a usb powerbank.

[@AndreasSpiess]

AFAIK this was done by a girl as a school project. If I remember right, she did not get a lot of energy.

[@KDM-Reloaded]

You should definetely make more energy harvisting videos based on wireless communication

[@AndreasSpiess]

So far I have no plans for this topic.

[@joba1560]

Very interessting, thank you. Not your fault, but unfortunately the result is still not cheap enough to just play around with it. E.g. some standalone solution with mcu, sensor and battery or usb power ~ 6€ (ok) versus additional panels and good harvester chip +~30€ -> 6 times more (too) expensive. I have some of those 1€ solar powerd garden leds with joule thieves that run the leds for hours in the evening. So I have the impression there is room for (price) improvement also for even wlan sensors, but I couldn't do it so far (plan: ESP32 ULP collecting i2c sensor data, joule thief collecting energy to push the data out when there is enough power for a wlan burst. Part cost ~ 10€. Maybe someday...)

[@JanCiger]

Um, you cannot compare a joule thief circuit lighting a LED with something that has to deliver regulated power, at the maximum possible efficiency, while also managing e.g. a LiPo so that it doesn't die or set your device on fire due to overcharging. The prices could go down only once this stops being a very niche application (and thus the chip production volumes will go up). E.g. the AEM10941 costs 4EUR alone (vs. cents for a transistor and few passives in a joule thief). For 99.9% of hobbyist projects there is little advantage of using an energy harvesting setup vs. e.g. a coin cell.

[@BartAnderson_writer]

Well done. Convinced me that energy harvesting will only be worthwhile in a few niche applications. Otherwise pointless and a waste of resources. DC microgrids seem much more promising. Also, learning how to meet our needs without unnecessary gadgets.

[@AndreasSpiess]

I showed a "DC microgrid" in one of my last videos (POE) ;-)

[@BartAnderson_writer]

@@AndreasSpiess, thanks. Just watched it. Yes, POE seems more promising.

[@TheBrassn]

Did I miss the part where he talks about solar panels that deliver more than 5V, as teasered at 14:30?

[@AndreasSpiess]

Yes

[@Herebuss]

Good job!

[@leocurious9919]

It is a matter of efficiency! In a normal lit office, say 500lux, we are talking about ~5W of light per m². For a 4x4cm solar cell thats 1.6mW (20% efficiency), enough to power things that usually last half a year on a 18650 (10 Wh) battery, so a normal low-power application. But this is not possible due to the quiescent current and/or efficiency of these chips. Edit: I just checked the MPP of a cheapo 0.5W solar cell (6cmx5cm) in a room with lights on and I get 0.03W or 10W/m² at 1.5V (lights off = 0.001W). If that could be "harvested" at 50% efficiency it would be 15mW, equivalent to less than 1 month of runtime with a 18650 cell, thus capable to power anything that lasts longer than 1 month forever.

[@AndreasSpiess]

AFAIK solar cells have a quite low efficiency of less than 20%. And it seems it depends also on the spectrum of the light harvested. All I can say: I was not very successful indoors :-(

[@leocurious9919]

@@AndreasSpiess Yes, 20% is about right. But thats enough, unless the room is dark. I had a look and those chips (at least the AEM10941) should actually be able to use these low powers. So maybe measure one of these small solar moduls to get the maximum power in your lab, then see what the chip(s) can get out of it. That would be a important test.

[@AndreasSpiess]

This is what I did. And I did not get a lot :-(

[@eriklaken1025]

Thank you for doing this. :)

[@AndreasSpiess]

You are welcome!

[@zoltanr15]

I really like this guy!

[@SianaGearz]

I wonder about low-power projects that only need maybe 1-10 mA and indoor harvesting. Have you played around with amorphous silicon panels? They are relatively useless in the sun but might be better indoors. There was a video by NurdRage ("Make a Tritium Nuclear Battery or Radioisotope Photovoltaic Generator") which made some very good points towards that conclusion. I'm thinking also due to very limited maximum current of the amorphous cells, a lot of complexity can be dispensed with. You can just as well charge 3- or 4-series NiMH battery and simply trust the battery to bleed off all excess charge as heat as they near their capacity limit - as long as the current is small enough to not heat them up appreciably, they survive this treatment for a nice long time, also catastrophic failure is i believe fundamentally impossible. I always tend to be slightly apprehensive of Li-Ion, even though the only cases of failure of Li-Ion cells i have personally experienced have been relatively well-behaved at their worst.

[@AndreasSpiess]

Thank you for the link. Interesting channel! I do not know which "sort" of solar panels I had. Maybe I have to have a closer look once.

[@SianaGearz]

@@AndreasSpiess The blueish colour is a hint that yours are crystalline. The amorphous cells are brownish in colour. I'm not sure whether that's a 100% rule, but seems so? You'll find that if you have a solar powered wrist watch, weighing scales, calculator, or even a wireless keyboard like the K750, low power items that are designed to work indoors, that they're going to have brownish colour solar elements.

[@moyukhamin3679]

Long time follower of your videos. Which one would you recommend for a 5v2amp output with lipo backup and 12v input? Its a Raspberry pi portable project

[@AndreasSpiess]

I never did such a project. So I do not know these products.

[@chriscauwelier]

A few weeks ago, a friend of mine sent me a documentary of Michael Moore (a film-maker I like) addressing the second inconvenient truth, as you mentioned at the start of your video . I was kind of disappointed because I was always pro green energy.

[@AndreasSpiess]

I am still pro green...

[@chriscauwelier]

@@AndreasSpiess Me too, every bit of wasted energy is a bit to much. I was already thinking of smaller wind-mills with few durable and reusable parts, especially the alternator. Like it used to be: motor/alternator broken: revision, new winding and back in service.

[@electronic7979]

Super 👍

[@AndreasSpiess]

Thank you!

[@Piotr_T]

This brown energy harvester was the best :)

[@AndreasSpiess]

:-))

[@martintatak8851]

What about LTC3106? I want to play with this circuit because it looks rather promising. It has MPPT and charges battery as a backup, so it combines energy harvesting IC and buck converter IC into one because the output voltage is convenient 3,3V. You should definitely check this one. Also if you combined this with TPL5110 and TPS22860 you should get a pretty neat solution for a solar powered sensor which sends data periodically. How about a video on these chips? :)

[@AndreasSpiess]

There is another comment about that chip. seems to be hard to get.

[@martintatak8851]

@@AndreasSpiess The chips can be bought on Mouser or Digikey or you can ask for samples from Analog Devices. Unfortunately I did not found any boards with the chip ready to test.

[@AndreasSpiess]

That was the reason for my "not-selection". Most people prefer to buy small SMD chips ready-made on a board.