Scrobby Solar, a solar panel cleaning robot on Kickstarter - Page 1
Forum section: electronics / general

author: StefanHamminga
author_rank: Contributor
timestamp: September 11, 2014, 01:49:50 pm
content: Hi people, I'd like to know what you think of my solar panel cleaning robot.You can find the Kickstarter campaign here:https://www.kickstarter.com/projects/stefanhamminga/scrobby-solar-keeping-your-solar-panels-cleanI'll do my best to answer any questions you might have.

author: CanadianAvenger
author_rank: Regular Contributor
timestamp: September 11, 2014, 02:45:42 pm
content: I hope you succeed, Looks like you've got a cool idea, and have done a good amount of work to get it working.

author: StefanHamminga
author_rank: Contributor
timestamp: September 11, 2014, 03:07:27 pm
content: Thanks for the compliment! Believe it or not, for me one of the bigger challenges for this campaign was to overcome my natural shyness. On the electronics side a fair amount of work got into getting the analog side the way I wanted (I'm using six ultrasonic sensors at short range to detect if there is a next panel). Luckily it's pretty affordable to do 'theory->implement->test' loops with electronics.

author: ferrix
author_rank: Contributor
timestamp: September 11, 2014, 03:57:09 pm
content: Stay tuned formyupcoming kickstarter project, a tiny robot to clean the solar panel of the Scrobby. It will be solar-powered of course. It's turtles all the way down.

author: mtdoc
author_rank: Super Contributor
timestamp: September 11, 2014, 04:15:54 pm
content: Cool idea. My PV arrays are on a shed roof and on a pole mounted tracker so I can clean them without much trouble for but for the majority who have panels on their home's roof this would be useful.I'm a big fan of our Roomba - it works amazingly well. I'm surprised the folks at iRobot have not done this already. Perhaps if you're successful they will buy you out...

author: PlainName
author_rank: Super Contributor
timestamp: September 11, 2014, 04:41:16 pm
content: This is a great idea. If I had panels (nearly had 10kW installed but got shafted by invisible Great Crested Newts) I would have one or more of these.But... don't panels reallyreallydislike shadows, like the shadow of a branch or something over 1 cell will take out the full row? So whichever panel this thing is on is going to be seriously degraded unless you have an off-panel parking area.Or am I wrong here?

author: StefanHamminga
author_rank: Contributor
timestamp: September 11, 2014, 05:55:05 pm
content: dunkemhigh: You are definitely not wrong here! That's why it comes with a small aluminium pad (shown at about 3/4th of the page) that bolts to the side of the solar panels. Besides that I've been trying to keep the device as small and low as possible.Digi-Key did an article about some developments in this area a while ago:http://www.digikey.com/en/articles/techzone/2012/dec/active-bypass-diodes-improve-solar-panel-efficiency-and-performancemtdoc: I love my Roomba too! I've actually studied some of these vacuum and mopping bots (they didn't turn out to be as relevant as I expected, but still, interesting stuff).ferrix: It's been suggested a few times before, haha! The solar cell is really a bit overkill by design, to accommodate for this.

author: BillyD
author_rank: Regular Contributor
timestamp: September 11, 2014, 08:34:20 pm
content: Quote from: ferrix on September 11, 2014, 03:57:09 pmHah, good point!Although come to think of it, one could mount a small sponge or brush to the top of the parking pad which would wipe the top of the Scrobby whenever it goes in our out of parking.

author: DavidDLC
author_rank: Frequent Contributor
timestamp: September 11, 2014, 08:52:48 pm
content: Quote from: ferrix on September 11, 2014, 03:57:09 pm

author: PlainName
author_rank: Super Contributor
timestamp: September 11, 2014, 10:30:57 pm
content: QuoteOh! I missed that bit, sorry.As you were...

author: sunnyhighway
author_rank: Frequent Contributor
timestamp: September 12, 2014, 09:46:23 am
content: @StefanHammingaI have two rows of horizontally aligned panels separated by a pvc air vent pipe.I guess the cleaning robot could drive from the left row to the right row if I made some sort of bridge between them on the high side of the panels.There is plenty of room to make such bridge between both high sides of the rows.The downside is that one rope to one would not be able to go in a straight line toward the attachment in the top corner. It would angle around the pvc pipe when the lower parts are being cleaned.I'm wondering if the robot cleaner would still be able to function considering the friction between the ropes and the pvc chimney and one rope being in an angle?

author: Refrigerator
author_rank: Super Contributor
timestamp: September 12, 2014, 01:05:45 pm
content: It could use something like a little windshield wiper on top of the cleaner itself, could use a small servo to move the wiper.

author: EEVblog
author_rank: Unknown
timestamp: September 12, 2014, 01:45:33 pm
content: That's neat!Kind of a bit silly at first thought, but you can't help but want oneWhat about strong wind flipping it off?That reminds me, I haven't cleaned my panels since they were installed...

author: StefanHamminga
author_rank: Contributor
timestamp: September 12, 2014, 02:01:43 pm
content: @sunnyhighway: Without seeing the actual installation it's a bit of guesswork, but in general a bridge between panels is no problem. The ultrasonic sensors measure almost continuously, so a reasonably sized bridge will allow it to cross over. The angling around pipes has come up before, the friction is not really an issue, since the variation of length of the wire is within the robot (so the wire itself won't continuously slide up or down). What is an issue is the angle of the pipe to the solar panels, this will force the wire down and might cause snags. I guess some strategically placed guide rods would fix this, but this specific scenario might require some testing before stating en public that it's a done deal.@Dave: I know the idea doesn't come to mind when buying the panels (believe me, I've spoken to many people telling me just that)!About the strong winds: The Scrobby just fits under the ring, which has a triangular cross section, giving it some centring force (plus the ring mounts are at the outside, preventing it from sliding). When resting at the side of the panels the furthest extension wire has a very nice angle for taking up wind force towards the outside of the installation. Besides that I've done some consulting with an aerodynamics expert on this very subject (improving the body shape to prevent lifting and side displacement).The wires extend from the body very close to each other, forming a hinge point. This in turn is used together with the compass and accelerometer to get an idea of current brush torque (the rotating of the body) vs expected and any bounces or wind gusts.

author: Lightages
author_rank: Unknown
timestamp: September 13, 2014, 02:37:16 am
content: I like the idea. Too bad it won't be as useful for me. You say it uses rain water. In the Atacama Desert where I live we get a little rain during January and February that totals an average of something like 15mm. For people in low rain areas you need to come up with a way to use other sources of water and clean based on a schedule or based on an efficiency drop of the panels.

author: corrado33
author_rank: Frequent Contributor
timestamp: September 17, 2014, 06:55:31 pm
content: Quote from: ferrix on September 11, 2014, 03:57:09 pmYou took my idea... That was literally my first thought when he said that it was solar powered.Alternatively, it could be powered by the solar panels that it's cleaning. Instead of a string to pull it around just use a power wire.I think it's a cool project. How will it cope with solar-tracking panels?

author: DavidDLC
author_rank: Frequent Contributor
timestamp: September 17, 2014, 06:58:02 pm
content: Quote from: corrado33 on September 17, 2014, 06:55:31 pmThat is going to be Scrobby Doo O0 the next version of the Scrobby

author: StefanHamminga
author_rank: Contributor
timestamp: September 17, 2014, 07:48:49 pm
content: Lightages: You are right, the Scrobby just isn't suitable for a dry climate like that. Maybe at a future date I'll be in a position to work on something affordable and working for that.corrado33: At a very early stage I've actually toyed with an idea using stainless steel tethers that could carry power. There were several reasons to bin the idea, amongst them worries about the life expectancy. Like the desert situations, solar tracking installations simply haven't been the focus for this product.About the Russian doll concept: I'll back whoever shows a working prototype of the Scrobby cleaning the Scrobby of the Scrobby