hybridfree/eevblog-posts huggingface dataset:
Baby steps towards dispatchable Solar - Page 1
Forum section: electronics / general

author: josecamoessilva
author_rank: Regular Contributor
timestamp: May 07, 2017, 03:13:46 am
content: Amid the discussion in another thread found some research by Evelyn Wang of MIT mechanical engineering on solar cells with thermal accumulation:Interesting idea, making solar power dispatchable right at the generation point (rather than using grid-scale batteries); that would be a game changer for solar. (And somewhat bad news for Wang's MIT colleague Don Sadoway, who's been developing grid scale molten-salt batteries at Ambri.)Yes, it's old-ish, but I only found it today. A press release from last year:http://news.mit.edu/2016/hot-new-solar-cell-0523Yes, I know about solar thermal plants that are somewhat dispatchable (same principle: hot stuff), but we're talking flat panel solar cells here.(Rats! They published inNature. As a member of the AAAS, I can readSciencefor free, but to readNatureI have to find an open proxy in some university library. Idaho State at Potatoville, maybe; state schools in square states usually don't check IP location or require users to log in.The San Francisco Public Library doesn't subscribe toNature, only toNaturalist Today, which is completely different.)

author: Seekonk
author_rank: Super Contributor
timestamp: May 07, 2017, 03:07:29 pm
content: If you are going to use industry specific terms like power dispatchable, you should explain them. I could watch the movie, but I have lost interest already.

author: Red Squirrel
author_rank: Super Contributor
timestamp: May 07, 2017, 07:31:59 pm
content: Is this essentially like a peltier but more efficient? If this is more efficient than steam it could be viable for other heat sources too like a wood stove. It would make it viable to go off grid even in winter.
Solar Compass Project - Kamloops, BC - Page 1
Forum section: electronics / general

author: LabSpokane
author_rank: Super Contributor
timestamp: April 24, 2017, 05:20:07 pm
content: This one is so blatantly bad, it makes SolarRoadways look like a model of integrity.They are claiming up to 13kWe of power from 13m^2 of solar panels embedded in a walkway. For those not in on the joke, sunlight strikes the earth at a maximum power of approx. 1kW/m^2, so these jokers are claiming 100% efficiency. The cells might be 15-20% efficient at best. And as we all know by now, a Solar Road might generate 25% of what well-sited solar can produce.http://infotel.ca/newsitem/first-solar-road-in-canada-coming-to-kamloops-this-summer/it41171#.WPzKIHFe1NY.twitterhttp://solarcompass.blogspot.ca/?m=1http://kamino.tru.ca/experts/home/main/bio.html?id=mmehta

author: Ian.M
author_rank: Super Contributor
timestamp: April 24, 2017, 05:40:23 pm
content: Worse, they are claiming over-unity! Kamloops is at 50° 40' 34" N, 120° 20' 27" W, which is 27.24° north of the Tropic of Cancer so, on level ground you loose another 11% insolation due to the incidence angle even at full noon on Midsummer's day.

author: boffin
author_rank: Unknown
timestamp: April 24, 2017, 05:42:38 pm
content: I'm sure AvE will wander by and show that it just doesn't chooch.

author: LabSpokane
author_rank: Super Contributor
timestamp: April 24, 2017, 06:46:02 pm
content: Quote from: Ian.M on April 24, 2017, 05:40:23 pmGood catch. For those playing along at home, Ian is referring to Lambert's cosine law, which is detailed here:http://www.geog.ucsb.edu/ideas/Insolation.html#insolationandlatitudeCos(27.24) = 0.89 = 89% of theoretical maximum solar insolation at Kamloops' latitude.
regarding solar and battery systems for renewable based system - Page 1
Forum section: electronics / general

author: msrinivasan1995
author_rank: Contributor
timestamp: March 13, 2017, 07:08:29 am
content: As Elon Musk said that he can power South Australia upto 100MW, What will he use for Battery storage. LI-ion batteries? They will have maximum of 1000 cycles of working, after that do we need to keep on changing the battery system,isnt it costly? My general doubt is that how batteries can replace traditional grid system as batteries working cycle must also be considered as a fact? Wont it result in much more high cost for developing such plants. Enlighten me in this topic? sorry if the question is silly as I'm new to this field.

author: Ian.M
author_rank: Super Contributor
timestamp: March 13, 2017, 07:46:02 am
content: Lithium batteries aren't the only technology available for stationary applications. e.g.Edison NiFe cells- can have a 50 year lifespan with a small amount of maintenance.

author: msrinivasan1995
author_rank: Contributor
timestamp: March 13, 2017, 07:56:25 am
content: But tesla uses Li-Ion right? My major doubt is such kind of battery technologies are feasible for long term like our Power distributed stations.

author: Codebird
author_rank: Regular Contributor
timestamp: March 13, 2017, 12:02:59 pm
content: Tesla uses li-ion, but for this application you want something like LiFePo4. Expensive, certainly - but also similar enough to conventional li-ion that the existing Tesla production lines should be able to churn them out without too much alteration.Or you could do it old-school. After all, weight and size are no object - what's to stop you from just using a heap of lead-acids? Really cheap, very long life, and when they do wear out they are highly recyclable.

author: bazza
author_rank: Contributor
timestamp: April 02, 2017, 02:02:23 pm
content: Elon Musk is the poster-boy for Big Energy."Grid-'til-the-grave"* Residential electric energy use will go up several-fold if electric cars become mainstream.* Savings for The Network will be huge if batteries-at-home becomes mainstream - it will make it much easier for them to control peak demand. Of course those savings will not be passed on to the residential slave.So really, Big Energy's investments are just given a different product mix. All under an enviro-propaganda umbrella.Just like today's solar scams, with home Solar Slaves generating cheap power for The Fossilised Grid, the Network always wins - while using your tax dollars. Nice work if you can get it. Elon Musk is part of the problem: a media darling calling for more 'sustainable' living while in reality just pushing the same wasteful energy use elsewhere while his company stands to benefit the most from all the environmental propaganda he spews forth.Meanwhile, truly sustainable living and self-sufficiency gets pushed out to the fringes & outlawed by political parasites. After all, it means rebalancing the power from centralised control to non-centralised - and we can't have that. Elon Musk is part of the problem.
Lithium 18650 battery bank , reduce voltage ? - Page 1
Forum section: electronics / general

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: April 25, 2017, 02:12:51 pm
content: I am collecting old 18650's to start to experiment with using on medium size and then maybe something like home-brew Tesla power wall .The mid size is for ham radio gear , most of that runs on 13.8vdc & to maintain high RF output , many rigs should have a steady voltage close to 13.8 .Then putting together a 18650 block , so using 4 in series & maintaining , lets say 13.6 , a fully charged 4.2 x 4 = 16.8Image result for 18650 state of charge chart - not sure if the copy/paste is going to work ?But keeping the battery block from discharging too much to extend battery life and trading off with that to maintain useful voltage .The main question is controlling voltage high point [ 13.8 ] WITHOUT dissipating capacity [ using resistor ] ?I am guessing some type of DC-DC auto regulator .A side note , I have been using solar for decades with Trojan L16 x4 , 5000 watt inverter / charger and now around 1,200-1,500 watts in solar panels , the FLD - flooded lead acid batteries last over 12+ yrs. and need replacing , and now about double the cost $1,000 - $1,400 .

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: April 29, 2017, 02:27:16 pm
content: Was hoping to shorten the shopping , there are lots of DC-DC converter out there , so many that trying to find something that fits gets lost in all the options and seems like what I am looking for is not all that common , I am not stuck on but have a good inverter now 12v .So with building a lithium battery starting with 4 in series gets [ depending on state of charge ] 16.8 to just above 12v .And the min. draw I would like would be 25-35 amps at 13.8vdc .Then latter on my full-time RVing , up to 4-5kw peak and min. continuous 1,500 - 2,000 watts .Also helping a friend that is looking at similar , but ready to start at a 24v battery system , but has 12v [ 13.8 ] loads - regular RV stuff , plus ham radio - this is where the 13.8 min. 20amps is ?

author: Inverted18650
author_rank: Frequent Contributor
timestamp: May 06, 2017, 02:13:51 am
content: You can use an LM338 (a few in parallel) to build your own voltage regulator with the current draw you need. I recommend a 24V pack and buck it down to your needs. If you don't want to build it. you can buy the "Uxcell" branded high powered DC-DC buck boxes from Amazon.I have no real complaints about them. They make a 24-to-12VDC @100Amp box that sells for about $110USD. They have them 2-/40/60/85A as well. To be clear, I am not promoting the brand, just saying I haven't had any issues and I use them to run a small solar bank straight into my Turnigy Reaktor Quadcore 1200W battery charger to ensure smooth & steady power.Building your own is the best route because you can tailor it to your exact needs. There are a bunch of great schematics available, the best of which is directly on the datasheet for the LM338, and itll be cheaper than buying a prefabbed box.Cheers.
Nanotechnology Boosts Power of Solar Cells - Page 1
Forum section: electronics / general

author: rramirez
author_rank: Contributor
timestamp: January 19, 2017, 05:30:10 pm
content: This could be kind of a big deal.http://bit.ly/2iXeeCoRuss

author: electrodacus
author_rank: Super Contributor
timestamp: January 19, 2017, 06:57:39 pm
content: Quote from: rramirez on January 19, 2017, 05:30:10 pmIt depends if they can be cost competitive with the current PV technology. Cost of traditional PV cells is so low now that it will be hard for anything else to compete.The increase in efficiency has only the advantage of reduced collector area for same power output and almost no one will be willing to pay more.The life of this cells may also be significantly lower negating the benefits of increased efficiency.There are already cells with above 40% efficiency by some time now and still they are not popular. The multi-junction solar cells can even get close to 50% efficiency and they are not that new and have an insignificant % of the market.
ElectRoad wireless charging solution: Another idea for debunking? - Page 1
Forum section: electronics / general

author: akos_nemeth
author_rank: Contributor
timestamp: January 05, 2017, 08:31:23 pm
content: Electroad wireless charging solutionNot really a new "development", but this news is just appeared in the hungarian news portals.In the image video, they show an electric bus powered by wireless charges placed under the surface of the road.https://youtu.be/mkpcavw_vFIIn the "test footage video" they show a golf cart going slowly over the charger strip, but those wires looks a bit thin...https://youtu.be/dQ-DzXirW08I guess the golf cart was using its own batteries, maybe the batteries were charged by the strip to some extent.www.electroad.mehttp://inhabitat.com/israel-to-test-electric-roads-that-wirelessly-charge-vehicles-as-they-drive/

author: Codebird
author_rank: Regular Contributor
timestamp: January 06, 2017, 09:47:13 am
content: I recall China experimenting with something similar some years ago, except their bus used pantograph chargers. It ran on supercaps - they only last a few minutes, but that's long enough to get to the next stop. I don't want to think about the peak charging current though!
Think this will send Dave over the edge? - Page 1
Forum section: electronics / general

author: xrious
author_rank: Newbie
timestamp: December 06, 2016, 10:19:41 pm
content: More solar fricking roadways?https://www.bloomberg.com/news/articles/2016-11-24/solar-panel-roads-to-be-built-across-four-continents-next-year

author: josecamoessilva
author_rank: Regular Contributor
timestamp: December 07, 2016, 08:53:42 pm
content: Solar roadways is a bad engineering concept, but as a political source of funding it's brilliant!No really, think about it for a moment: most people don't understand anything about science, engineering, math, economics, or logic, but they like shiny things. The sun is shiny, solar panels are shiny, and celebrities with bleached teeth talking about solar roadways are shiny. Easy sell.I wrote about the budget-oriented logic of getting a solar roadways _project_ in a blog post here:http://sitacuisses.blogspot.com/2016/07/a-rational-case-for-solar-roadways.htmlAnd for visual learners here's a picture:https://www.flickr.com/photos/josecamoessilva/29632160643Cheers,JCS
Scored some Siemens Panels, usable? - Page 1
Forum section: electronics / general

author: calli
author_rank: Regular Contributor
timestamp: November 19, 2016, 01:37:42 pm
content: Hi,I scored some Siemens panels, rated 53W. However beeing a noob in this, I get feared about the 600V open current voltage. I guess I should better not touch a contact when the panel is in the light. One can sure shorten the panels when installing I guess?So my main concern is what type of solar regulator I need? Does it have to deal with the 600V? If so it would be useless as they are too expensive for a hack. Or is the OPEN CKT. 21.7V the value the regulator have to deal with?O wait... MAX SYST. OPEN CKT. V. ... Does that mean several panels in serial should not exceed 600V in total?Cheers,Carsten

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: November 19, 2016, 03:10:44 pm
content: Carsten,There are two open circuit voltages listed on the label 21.7V is the open circuit voltage for an individual panel.The 'Max. System Open Ckt V' is 600V'.The system open circuit is for all the panels connected in series. So the limit is:600/21.7 =27 panelsSo they basically saying don't connect more than 27 panels in series.The 600V is an expression of how good the insulation is on each panel from the cells to the frame.Regards,Jay_Diddy_B

author: calli
author_rank: Regular Contributor
timestamp: November 19, 2016, 05:11:11 pm
content: Yea, I already suspected it while writing... But thanks for the confirm!So I can use any solar regulator which else fits in the specs and can deal with 30V (to be safe) and also fits in the other specs.Carsten
Making every photon count? - Page 1
Forum section: electronics / general

author: jwhitmore
author_rank: Regular Contributor
timestamp: November 05, 2016, 02:55:38 am
content: Still learning stuff, mainly from youtube videos and looking at other people solutions but I have a question about making the most out of the photons.In an ideal world every photon would add stored energy to the batteries, but it appears that if you're charging 12V batteries you're not going to store anything until the voltage from a solar panel reaches a value above 12v. Maybe it's not worth chasing after the energy of a 9V solar panel as you'd have to add fancy electronics and charge pumps or something. Maybe you could charge a different battery technology at a lower voltage which would require the intelligence of a micro-controller which might burn up more energy then you'd generate so there's no point chasing after that energy.Yes perhaps many more youtube videos are required. I have bought a few books but none I was happy with, basically they had a list of things to plug together which didn't help my understanding of the subject.

author: Kleinstein
author_rank: Super Contributor
timestamp: November 05, 2016, 09:05:21 am
content: If the open circuit voltage on an solar panel drops a lot, like from > 12 V to below 9 V, there is only very little power (e.g less than 0.1 % of rated power) left to be used. So usual it is not worth the effort. The more important point is to have good efficiency when you have a reasonable amount of light (e.g. 20%-90% of rated).The usual way to get high efficiency in charging a battery from a solar panel is using a panel with a somewhat higher voltage (e.g. 18-25 V for a 12 V battery, that is actually more like 14 V when full) and have a step down converter, that keeps the solar panel at its maximum power point.

author: jwhitmore
author_rank: Regular Contributor
timestamp: November 05, 2016, 12:29:15 pm
content: Thanks a million for that response, you've answered my question and saved me a load of thought ;-) thanks again
Just little thinking about Photovoltaic cost effectiveness over the world  - Page 1
Forum section: electronics / general

author: Miyuki
author_rank: Frequent Contributor
timestamp: October 21, 2016, 08:26:28 am
content: Hi,I'm just curious about situations at other countriesHere in middle of Europe it is complete economic nonsenseI have electricity from grid at prices BUY 84-112$ and 20-28$ SELL per MWhAnd solar power get from 1kWp installed 800-900kWh per year and most of it is summer peaks, at winter it is just about 800Wh per daySo it can cover just few percent of consumption, batteries are total nonsense with this grid prices and sell it to grid cant pay installation over lifetime.What about you at more sunny places over world ?
Aquion Energy Files for Banruptcy - Page 1
Forum section: electronics / general

author: ajm8127
author_rank: Contributor
timestamp: March 14, 2017, 07:49:28 pm
content: The saltwater battery maker is reducing its workforce by 80%.http://blog.aquionenergy.com/aquion-energy-inc.-files-voluntary-petition-under-chapter-11-to-target-a-sale-of-assetshttp://powersource.post-gazette.com/powersource/companies/2017/03/14/Aquion-Energy-bankruptcy-Taxpayers-line-up-for-money-from-once-promising-battery-maker/stories/201703140045Sounds like they took a good bit of money in the form of government grants that the state of Pennsylvania may be looking to recover.It really seemed like a good technology. Their datasheets claim 3000 cycles at 100%depth of discharge. The batteries also seemed relatively safe from a hazardous material and volatility standpoint.As a native of Pittsburgh it's twice as disappointing.

author: bazza
author_rank: Contributor
timestamp: April 03, 2017, 09:19:06 am
content: One of many. In my opinion, Redflow is headed in the same direction.
Solar Roadway #1 Visited - Install Photos - Page 1
Forum section: electronics / general

author: LabSpokane
author_rank: Super Contributor
timestamp: October 02, 2016, 11:31:10 pm
content: https://www.eevblog.com/forum/blog/eevblog-632-solar-roadways-are-bullshit!/msg1039685/#msg1039685Please post comments in main thread. And please be kind. The employees of SR have been killing themselves to get what they have online. I'm sure they read these threads, so I'll give credit where it's due.
Used Solar Panels in Ireland - Page 1
Forum section: electronics / general

author: Santa3
author_rank: Newbie
timestamp: September 20, 2016, 08:38:52 am
content: Can anyone recommend a good place to findused solar panels for salein the Rep of Ireland or Northern Ireland? I starting a project with my son and we need to source about about 5 panels to start with. I’ve been searching online but not found anything specific to Ireland other than the usual stuff on eBay. I’d prefer to source them as close to home a possible to avoid excessive shipping costs. If anybody could point me in the right direction it would be greatly appreciated. Willing to travel and pick up if required. Thanks in advance.

author: bitslice
author_rank: Frequent Contributor
timestamp: September 20, 2016, 06:17:39 pm
content: gumtree seems to cover Ireland,nothing at the moment though

author: Santa3
author_rank: Newbie
timestamp: September 21, 2016, 04:25:07 am
content: Quote from: bitslice on September 20, 2016, 06:17:39 pmThanks mate. I'll take a look.
Links for technical information or discussion about smart grid / microgrids? - Page 1
Forum section: electronics / general

author: magetoo
author_rank: Frequent Contributor
timestamp: September 12, 2016, 12:06:38 pm
content: Does anyone here know of any good places to read more about implementing "smart grids"? It comes up in every discussion on renewables (moving to DC? local generation? vehicles as grid storage? no worries!) but never with much technical detail about how it is supposed to work.It would be interesting to know what's being done in terms of simulations of fault tolerance, vulnerability against attacks, and those sorts of things.

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: September 19, 2016, 09:46:09 am
content: Fill your boots at Google Scholarhttps://scholar.google.co.uk/scholar?hl=en&q=smart+grid&btnG=&as_sdt=1%2C5&as_sdtp=If some papers are not accessible due to paywalls then you could chat to a friend who works at an academic institution and ask them to email you a pdf on the sly of anything you are particularly interested in.Obviously I would never dream of doing a thing like that because it's probably technically copyright infringement or something.Two completely irrelevant pieces of information;1. I work at an academic institution2. the forum has a private messaging facility

author: tronde
author_rank: Frequent Contributor
timestamp: September 19, 2016, 03:34:38 pm
content: Quote from: DenzilPenberthy on September 19, 2016, 09:46:09 amYou can also ask google about Alexandra Elbakyan

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: September 20, 2016, 09:32:34 am
content: There are also two relevant courses you can take for free at edX:https://www.edx.org/course/smart-grids-electricity-future-ieeex-smartgrid-x-0(Introductory Level)andhttps://www.edx.org/course/distributed-energy-smart-grid-resources-ieeex-smartgrid02-x(Intermediate Level)
Solar Bike Path done right... - Page 1
Forum section: electronics / general

author: Ice-Tea
author_rank: Super Contributor
timestamp: October 17, 2016, 08:34:09 pm
content: There you go:http://www.iflscience.com/environment/luminescent-bike-paths-light-up-town-in-poland/

author: Holmes34
author_rank: Contributor
timestamp: October 21, 2016, 11:45:54 pm
content: Linking IFLscience is like linking the Daily Fail. Heck I'd rather you cite a conversation you had with a man down the pub instead of IFLscience.Phosphorescent materials are incredibly low brightness compared to any other light source. If you've ever cycled through a field at night you'd know that this "invention" is basically pointless. Illuminating obstacles in front of you is more important that very slightly improving the visibility of the path you are cycling along.In addition, I'd like to see how weather resistant their materials are. I'd venture to say "not very".

author: Richard Crowley
author_rank: Super Contributor
timestamp: October 21, 2016, 11:54:18 pm
content: Additional questions not addressed include how much it costs and how long it will last in outdoor weather.The metro area where I live has probably spend $100Ks in green paint to make wide swaths of roads "bicycle zones".I have not heard of any reduction in bicycle casualties as a result.And it looks like they will need to come back every 2-3 years and re-paint them as the sold areas are wearing badly.
Battery located far from solar panel and load - Page 1
Forum section: electronics / general

author: putrar
author_rank: Newbie
timestamp: June 23, 2016, 03:15:15 am
content: Hi all,I have a question here. if the battery is far away from the load, solar charger and the solar panel, let's say 20 meters away. Can I drive the load directly from the solar charger's BAT terminals (top setup) or I need another set of wires connecting the batteries to the load (bottom setup)?There shouldn't any significant difference but I never see this kind of setup on the internet.Thanks.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 23, 2016, 05:22:45 am
content: distance doesnt matter, the resistance matters. Get the cable you want to use and measure the resistance. Cable thickness matters for amps and distance and for that you may need to look up a chart.

author: Ian.M
author_rank: Super Contributor
timestamp: June 23, 2016, 05:56:50 am
content: The only other issue would be loop inductance - minimise the loop area!. If either the load or the solar controller uses PWM, a big, high ripple current electrolytic cap where the wires join may help - the controller *should* have enough bulk output decoupling not to need it, but caps cost money so cheaper designs may have cut corners here.

author: madalf71
author_rank: Contributor
timestamp: August 13, 2016, 08:17:30 am
content: Hi PutrarIt's not good to use the regulator terminals as the current draw from your loads may exceed the terminal design, in most setups it does.So best to run to a separate terminal block, then divide from there to your load and battery bankNote, some regulators have a load terminal that you can use for this very reason.Other considerations on long cable length, volts drop under load can give incorrect readings to the regulator from the battery bank.So look for a regulator with voltage sense terminals. In this case there are separate wires just to monitor the voltage. As they only measure voltage their volts drop is minimal. As an example, If you have at look at the link for this Morningstar you'll see the inner two terminals say "sense".http://www.morningstarcorp.com/products/prostar/Hope this helps, good luck with your system.
Smart battery syndrome - Page 1
Forum section: electronics / general

author: Circlotron
author_rank: Super Contributor
timestamp: August 12, 2016, 06:13:09 am
content: My camcorder has a smart battery and if I don't use it for a long period of time it discharges somewhat. I turn the camera on and it might say 10 minutes of battery time available. I let it run and after a short time the low battery logo comes on but it might still run another hour before it finally goes off.I can understand if the battery was lower than indicated because is has discharged without that current going through the gas gauge circuit, but why should the battery be better than indicated?

author: Kilrah
author_rank: Unknown
timestamp: August 12, 2016, 09:49:26 am
content: Do you leave your battery in the device?If yes the battery doesn't discharge because of its own smart circuitry, but because the attached device draws some current. It goes through the gauge circuit, but the circuit just can't measure such small currents accurately so accumulated error may be huge in one way or the other.The circuit could also be assuming a battery self-discharge rate much higher than what it actually is.

author: Circlotron
author_rank: Super Contributor
timestamp: August 12, 2016, 11:43:12 am
content: Quote from: Kilrah on August 12, 2016, 09:49:26 amNo, I always take them out. I have a large and a small battery and they both do the same thing.It's a Canon Legria HF G10, almost identical to the HF G20(?) Dave was using to make his videos up until recently, so it's not a cheap and nasty camera but something that you would expect to be properly engineered.
Philippines Sports car conversion project with a 3-phase AC motor.  - Page 1
Forum section: electronics / general

author: MotorMagic
author_rank: Newbie
timestamp: June 08, 2016, 02:57:32 am
content: My company makes the motor and controller. We recently had a customer convert a little known sport concept car with our kit in the Philippines, and wanted to share the progress with anyone who likes EV's here on EEVblog.

author: Muttley Snickers
author_rank: Unknown
timestamp: June 08, 2016, 03:12:56 am
content: Thank you for sharing this with us, it is very cool indeed.I wish my lawn mower sounded like that, it would inspire me to cut the grass more often.

author: MotorMagic
author_rank: Newbie
timestamp: June 08, 2016, 05:58:11 am
content: Quote from: Muttley Snickers on June 08, 2016, 03:12:56 amIf I ever have a house with a grass lawn, I'm going to need a remote control mower and a VR headset or I'm calling in a concrete mixer.

author: digsys
author_rank: Unknown
timestamp: June 08, 2016, 06:27:16 am
content: Post your link on our website -http://www.aeva.asn.au/Australian Electric Vehicle Association.Our members have been doing EV conversions for years, and I'm sure some will be very interested. NICE CAR
Repairing solar cells - Page 1
Forum section: electronics / general

author: woodchips
author_rank: Frequent Contributor
timestamp: April 29, 2016, 09:22:02 am
content: Did a search and came up with nothing, so....I bought several solar panels, 1/3 sq m, to power an off grid shed in a wood. High winds resulted in four of the panels ending up cracked from side to side.The question is, can they be repaired?These panels are over 10 years old, when BP used to sell them. They are glass with the solar bits deposited on the glass then a backing cover. They are the standard 12V type panel so have about 30 diodes in series across the panel. The crack reduces the area so whilst still work, they are much lower output.I have wondered if you can drill through the glass from the front to pick up on the connection strip on each side of the panel and connect using conductive paint. Has anyone done this at all.Why repair? Well, with all the talk of a collapse in prices they still don't seem much cheaper than what I paid 12 or so years ago, about £75 plus VAT.

author: MotorMagic
author_rank: Newbie
timestamp: June 08, 2016, 03:07:40 am
content: Manufacturing price of Mono is approaching .40 cents for A grade, low iron tempered glass and UV resistant silicon on aluminum frames. I sold 700 panels below manufacturing cost like a month ago when my friends factory was getting rid of inventory. I would replace them, but you could always try to put them in a new frame anyway, and salvage the good cells. I guess you may spend more in parts, and the end result will still be pretty inefficient given they are 10 year old cells.
Where do you get Solar cell 'slivers'? - Page 1
Forum section: electronics / general

author: aargee
author_rank: Frequent Contributor
timestamp: April 23, 2015, 06:49:23 am
content: Hi all,I was wondering if anyone knew where to get those small sliver like solar cells, the ones they chain together to make cells in garden lights, etc. They're often small rectangular or half moon pieces, 10-15mm wide and 25-50mm long. I need to make a mosaic like solar panel.I'm wanting some for a small project and the area is an odd size. Only looking to make up something around 5V@20-100mAI don't really want to buy cells and 'carve/break' them up to fit.TIA

author: sandos
author_rank: Contributor
timestamp: March 15, 2016, 09:13:40 am
content: I would go to aliexpress, and search "solar panel" and sort by lowest price. The cheapest is a 40x15mm cell, costing 0.67$.I recently bought a slightly larger one from someone on aliexpress, it seems to work fine.

author: bitslice
author_rank: Frequent Contributor
timestamp: June 16, 2016, 11:57:13 pm
content: I bought a pile from eBay for pennies.they were A grade 10x10cm cells with minor edge damage, you can tag them up to change the v/a ratio.
Solar power for remote sensors - Page 1
Forum section: electronics / general

author: wblock
author_rank: Regular Contributor
timestamp: May 08, 2016, 05:57:54 pm
content: I set up an ESP8266 outside to report temperature/humidity about once a minute. It is powered by a 12V 14AH SLA battery through an MP1584 buck converter module.The battery is good for a couple of months before recharging. But it would be more elegant to have a solar cell and charge controller recharging a battery and powering the ESP8266. A different battery chemistry might be better suited to the temperature range, which can be -20F (-29C) in the winter to 100F (38C) in the summer. The ESP8266 can draw 300mA at 5V when transmitting, but is only on for a few seconds every minute.In concept, this is pretty much what those solar walkway lights do. I have not taken any of those apart, but my impression is that most are junk. There are solar "power bank" units, but they do not look to have weatherproof construction.With enough continuous power, the ESP8266 could act as a charge controller. But that will involve charging algorithms and development.Adafruit has a small LiPo solar charge controller, but that seems like the wrong chemistry for cold weather.Any suggestions for small solar charge/power modules and battery technology?

author: Ian.M
author_rank: Super Contributor
timestamp: May 08, 2016, 06:19:36 pm
content: Other common battery technologies have similar or worse temperature limitations than SLA.At its cheapest and dumbest, to keep a SLA happy, you need enough solar panel area (assuming the worst month's average insolation) to cope with the average load + an extra 5% C/month for self-discharge (approx 10mA), and a temperature compensated linear regulator to maintain the correct temperature compensated float voltage for a SLA battery..

author: Seekonk
author_rank: Super Contributor
timestamp: May 08, 2016, 09:21:33 pm
content: There are various ways to add on a simple charge controller. Ujless the panel ig greatly over sized a controller will seldom ge beyond bulk charge mode. fixed voltage charge mode should be sufficient for your application. Consider harvesting more power by controlling input voltage to a buck and track power point voltage of panel with temperature.

author: bitslice
author_rank: Frequent Contributor
timestamp: May 12, 2016, 12:20:51 am
content: If you insulate the battery well enough, you can use part of its capacity to keep itself warm overnight.There is probably also a reversible chemical reaction that could do the same thing.
Potentially exciting battery breakthrough from UC Irvine - Page 1
Forum section: electronics / general

author: djacobow
author_rank: Super Contributor
timestamp: May 02, 2016, 08:34:08 pm
content: https://news.uci.edu/research/all-powered-up/Sounds like it is something that would make Li-ion batteries last much longer. Definitely convenient for our life-limited phones, but also an important factor in the economics of grid-scale battery storage. Because each charge / discharge cycle comes with a "cost" most grid batteries so far are actually exercised much less than might be desirable because of the affects on system lifetime.

author: Siwastaja
author_rank: Super Contributor
timestamp: May 09, 2016, 03:56:49 pm
content: These "battery breakthrough"s are reported almost daily. In most cases, they are scams. In others, they just popularize normal university research, giving false impressions. 0.1% of these things will actually make any real difference, but those that do are indeed extremely important, and that's the point in researching things.At some point, I started getting really tired of people asking me about "this new breakthrough that was reported just now", having to explain this over and over again to everyone.

author: TerraHertz
author_rank: Super Contributor
timestamp: May 10, 2016, 11:53:53 pm
content: There's another factor. Watch 'The Lightbulb Conspiracy' (there's usually a copy online somewhere.)Point being, that products with extremely long lifetimes are not compatible with the Capitalist economic model, and are actively suppressed in favor of products with lifetimes more suitable for corporate profits. Because consumers have to keep buying new ones.Which is why we won't see perpetual batteries any time soon. Not till after the revolution - as if that's ever going to happen.If the battery technology mentioned is actually workable in production, some large corporation will buy the patent and sit on it. The only way it will be used is as part of a patent portfolio wielded as a legal sledgehammer, to damage or eliminate competition.
Ion lithium vs Fragant Accumulator Recycling Terminal energy - Page 1
Forum section: electronics / general

author: John Heath
author_rank: Frequent Contributor
timestamp: May 02, 2016, 12:01:42 pm
content: Methane energy recycling is an establish technology used on farms. Is a Fragrant Accumulator Recycling Terminal or FART phone vs smart phone in the range of a possibility? The energy density ratio of methane gas vs lithium battery is 50 to 1 in favor of methane gas. Is there enough methane gas in the general area of a human body? Can it be concentrated to a reasonable air to methane ratio for a micro power generator? It must also be the same size as a standard smart phone lithium battery. A smart phone kept in the back pocket would increase the odds , closer to the source. Is there an energy efficient way to separate air from methane gas? Is it enough energy for a Peltier heat pump or failing this a micro sterling engine to charge a much smaller lithium battery to the point that it will never need recharging for average cell phone use? More questions than answers. Any thoughts on this would be welcome.

author: Delta
author_rank: Super Contributor
timestamp: May 02, 2016, 12:43:39 pm
content: I have witnessed "scientists" performing thermal experiments confirming the calorific value of human produced methane...

author: John Heath
author_rank: Frequent Contributor
timestamp: May 02, 2016, 01:12:19 pm
content: Did they give any hard data to work with?

author: Delta
author_rank: Super Contributor
timestamp: May 02, 2016, 01:17:49 pm
content: Nah, we just got chucked out of the pub...

author: John Heath
author_rank: Frequent Contributor
timestamp: May 02, 2016, 11:08:01 pm
content: There is no respect for science. It occurred to myself that a pub with lots of beer going down would have a higher PPM methane count than regular air , hhhm.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 03, 2016, 03:16:28 am
content: Methane is odorless.
ARES Advanced Rail Energy Storage. 86% Efficient?  - Page 1
Forum section: electronics / general

author: rx8pilot
author_rank: Super Contributor
timestamp: May 03, 2016, 03:43:18 am
content: http://www.vox.com/2016/4/28/11524958/energy-storage-railI was reading this article on a project hoping to offer energy storage for unstable renewable sources. At first it seemed reasonable until I get to the part where they claim an 86% end-to-end efficiency which seems wildly over estimated. This is a complicated system and I don't have the skills or the time to do my own estimate so it is only a gut feeling. It seems like the solar roadway project.Anyone care to comment?

author: ataradov
author_rank: Super Contributor
timestamp: May 03, 2016, 04:31:40 am
content: https://www.eevblog.com/forum/chat/i-think-i-smell-something/msg931677/
Discovery of novel, reversible Zn-Mn battery chemistry - Page 1
Forum section: electronics / general

author: JimRemington
author_rank: Regular Contributor
timestamp: April 19, 2016, 04:35:03 am
content: This overview at techxplore.com describes a paper appearing today in Nature Energy, on the unexpected discovery of reversible chemical energy conversion in Zn-Mn batteries. The researchers expect this new insight to lead to cheap batteries with energy density higher than lead-acid batteries.http://techxplore.com/news/2016-04-renewable-energy-storage-chemical-conversions.html

author: jeremy
author_rank: Super Contributor
timestamp: April 19, 2016, 04:40:57 am
content: Very interesting, thank you for sharing this.
Voltage/current limiter for solar panel - Page 1
Forum section: electronics / general

author: luckyx182
author_rank: Newbie
timestamp: March 15, 2016, 11:58:28 pm
content: Hi, I'm building solar powered weather station and I'm looking for some circuit which would limit the outputting current and voltage. This max. output current and voltage should be adjustable depending on used battery. I'm going to use 6V 330 mA solar panel, 4 1300 mAh AA NiMh batteries in series and paralel , so I think I need 3,6 - 3,8 volts and 260 mA max. out of the desired circuit. Can anybody help please?

author: han
author_rank: Frequent Contributor
timestamp: March 16, 2016, 12:26:00 am
content: I suggest use typical commercial a viable MPPT module.you can find lot in aliexpress:http://www.aliexpress.com/wholesale?catId=0&initiative_id=AS_20160315162413&SearchText=mppt

author: Kleinstein
author_rank: Super Contributor
timestamp: March 16, 2016, 04:46:36 pm
content: Charging NIMh from solar is tricky: the only reliable way to detect the end of charging / full cells is via the temperature rise and resulting drop in voltage. This only works well when the charging current is constant, which is difficult from variable solar cells also a relatively high charging current (e.g. > 500 mA is preferred to get enough heating).So I don't see a need to limit the current. The voltage of the solar cells will also not rise very much above 8 V, and drop with load. At this low power an reasonably matching voltage, you might get away without a MPP charger.So the big question is how to reasonably detect the end of charging - thats really tricky. A charge counting chip might be an idea - so measure the charge and hope to get good conditions to do a charge at high reasonably high current to do charging by temperature form time to time.So it would be much easier with a single Li based cell.
Betavoltaic (Beta-Photo-Voltaic) - Page 1
Forum section: electronics / general

author: julius oe.
author_rank: Contributor
timestamp: March 02, 2016, 09:37:04 pm
content: Here is a story:Everybody has a bunch of empty batteries ling around....What if they charge them self in the time you don't use them.The idea:Take a Tritium (12+ years) glowing stick:a small solar panel and a super cap.... that is what I tried. I only took a 22µF Cap and used a calculator solar panel. I packed everything together in a box. After a about 60mins the voltage climbed to 150mV. I got a new super cap with 0,47F and i got me some new solar panels, but those don't work at all.To make this in a AA batteries size product, i see following possibilities. The low voltage (solar) output can be collected but it must be boosted to, lets say, 1,8V into a super cap. to talk about efficiency: a round, to the inside looking, solar panel would take almost photon of the source. The Tritium glow stick could be more active, or it could be bigger. The radiation is Beta(minus) so we 'only' have fast electrons, witch can be shielded easily ..there is a lot more.. but i think its possible.The recharge time would take weeks or months.. but that's what I'm calling regenerative ! (;were can we use it?TV-IR-Transmitter, recharging LED-Flashlight.... ??(holding the solar panel a few second into sun-light would charge the cap in seconds .. i know)

author: julius oe.
author_rank: Contributor
timestamp: March 02, 2016, 09:45:42 pm
content: I'm just saying, the idea is great - it's not mine!what someone already have done:https://youtu.be/LUNDobqczW4

author: dmwahl
author_rank: Contributor
timestamp: March 11, 2016, 03:49:12 pm
content: The energy stored in a capacitor is 1/2*C*V^2, so for your 22uF cap at 150mV that's about 0.25 micro joules. Assuming a fully charged NiMH AA cell contains about 3Wh of energy (2.5Ah x 1.2V), that's 10,800 joules. At 0.25 micro joules per hour, it would take about 5 million years to charge the battery if you ignored self discharge.
Solar road ways!  - Page 1
Forum section: electronics / general

author: tomshirvo
author_rank: Regular Contributor
timestamp: February 03, 2016, 11:47:24 am
content: Thought I would post this here if you haven't already seen it!Dave will you do a blog about this?http://www.iflscience.com/technology/france-will-install-over-600-miles-solar-panelled-roads-2020

author: Neilm
author_rank: Super Contributor
timestamp: February 03, 2016, 07:53:13 pm
content: This is at least the third thread on the subject

author: miguelvp
author_rank: Super Contributor
timestamp: February 04, 2016, 09:20:42 am
content: I think is about the fifth one.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: February 04, 2016, 10:52:27 am
content: Just looking at the reflection of the guy in the panelsSeems to be a lot of light reflected??! Probably just a mock up.

author: collingtech
author_rank: Contributor
timestamp: March 02, 2016, 02:31:51 am
content: ohhh the solar road thing , meh i think dave made a very well analisys , a project doomed to fail in every aspect
Solar Stirling Engine - Page 1
Forum section: electronics / general

author: ToeJam
author_rank: Contributor
timestamp: March 01, 2016, 10:55:32 pm
content: Hi all;I'm doing a research project into solar stirling engines, and I'm just wondering if anyone has seen one in the wild, actually working and producing usable power?I've seen the promo videos for the ones that were supposed to be built in California, and heard about a European competitor.But I've never actually seen an array of them working and putting power into a grid.Thanks in advanceToejam"Flux capacitor ... fluxing"
Solar system for the house - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: August 31, 2015, 11:08:08 pm
content: I'm looking at a solar system for the house and was looking at the gear AGL provide. They use Hanwha branded panels (with 12 year product and 25 year performance warranties) and Solis branded inverters (8 year warranty). Has anyone used or have any knowledge of these two brands?Any good?
Breaking A Solar cell while live measurements - Page 1
Forum section: electronics / general

author: Kedar264
author_rank: Regular Contributor
timestamp: April 02, 2015, 04:02:16 pm
content: When solar panel is breaked its voltage remains same ,but the current output is get divided equally into pieces that it broken intoSee the videohttp://youtu.be/gsLiyB-ol2IExperimenting further do you have any suggestions. Please suggest me your thoughts
How does the Tesla battery impact the economics of solar? - Page 1
Forum section: electronics / general

author: nixfu
author_rank: Unknown
timestamp: May 05, 2015, 03:37:49 pm
content: Given this new innovation, does this make home solar even more affordable?http://rameznaam.com/2015/04/30/tesla-powerwall-battery-economics-almost-there/It would be interesting to hear dave's take on the idea since he has so much good experience with a pretty good size solar system at home.

author: jolshefsky
author_rank: Regular Contributor
timestamp: May 05, 2015, 03:44:03 pm
content: Here's a pretty dense article largely about the carbon balance:http://www.lowtechmagazine.com/2015/05/sustainability-off-grid-solar-power.htmlThe tl;dr version is: it's good only if the panels and batteries are manufactured near where they are deployed, and that they are manufactured in a country with low-carbon energy.