Should We Invent Solar Equipment To Dig Swales?

MS Tûranor PlanetSolar circumnavigated the globe with just solar power.  It has 537m^2 of panels producing around 110kw of photovoltaics  

My 3 Questions For You
Swales and check dams can be dug via electric power with BEV equipment already on the market.   Using tech from the Solar Car Challenge we could dig these with solar directly to motors instead of via batteries. I think solar-direct would use a lot less resources+$ and have less externalities than any other mobile power tech.  I think this could enable scale-able, low cost, desert>swale>seed+microbiology>flash flood>planned rotational grazing>meadow [fast land restoration] sequences.  Is this an important thing for me to work on?  What am I missing?  Would you like to help?

Current Battery Electric Heavy Equipment




Plug-in battery-electric heavy equipment is already* on the market and is higher performance** and more agile than diesel.  BEVs (Battery Electric Vehicles) are more expensive to buy than diesel, but electric is probably a lot cheaper over its life cycle. Electric is clean and quiet.  BEV heavy equip is new, maybe that's why the equip's capital costs seem overpriced relative to the cost of their components.  

Solar for Swales, Concept

-solarcarchallenge.org
Solar panels directly wired to motors are not only cheaper than batteries, but panels lifecycle is 1.5x-10x longer than batteries.  So the effectiveness value would be much greater on a machine which avoided both diesel and batteries by going photovoltaic direct to motors. Going solar direct has design challenges related to the large surface area used by panels, but because it might use orders of magnitude less resources than a diesel drive or hybrid drive... while still avoiding the massive capital cost of battery electric drive it is probably a good candidate technology for scalable, climate positive, carbon negative, eco restoration earthworks.  Solar panels have dropped in price by at least 10% per year, every year since 1980 and they keep getting more efficient.  The power per surface-area density of solar-panels-direct-to-motors is massively lower than diesel or batteries... this is why the first picture looks like a megafauna Stingray made outa monocrystalline solar panels bolted on top of a high performance yacht.  I dont see this as that big of a problem in open landscapes.

Why modern deserts sometimes greatly benefit from access to scalable earthwork digging ability
Earthworks may be more helpful in deserts during climate change than in other ecosystems and climates because global rainfall is increasing with rising temps but is more haphazard and more extreme.  Many deserts, desertified ag land, and wide concrete regions are prone to flashfloods.  See below.  Factor in groundwater depletion and soil loss from big ag and the result tends to be desertification. Fortunately, swales and check dams can slow flashfloods down enough to recharge groundwater and turn deserts back into savannas.

Solar Swale Bulldozer or Motor Grader
Imagine a 100m long centipede-looking machine with solar panels on its 5m wide back.
The solar panels would produce roughly 100kw (~135hp) of power***.  
Wheels where its legs would be.
Some digging blades in front or underneath.
Cameras monitor each digging blade.  
It would have hinged trailer sections just like a train for maneuverability.  
Maybe it would be slow, idk.  It could certainly be upgraded to autopilot itself if it was slower than is worth having a driver for.
100kw is how much power a 14,000kg bulldozer with a  3.5m blade is rated as having****.  I would rather it has distributed drive motors on many wheels throughout the machine... but for mechanical force transfer reasons it might need to look like a regular dozer or grader with a long trailer-cape of solar panels.  Distributed drive motors would allow traction with much lower ground compaction relative to the conventional high-psi-for-traction approach.  

Solar Shovel Climber
Imagine you're laying on a skateboard and pulling yourself up a hill with a shovel by shoving it into wet ground uphill and tugging yourself towards the shovel. That same motion could be done by a machine to dig a series of boomerang swales for trees or check-dams for beavering surface water into groundwater.  This motion might cause less fungal and structural disturbance to the swale or dam than an excavator bucket method.  This motion may also be more energy efficient per effect.  The machine would use its weight to pull downhill against the shovel in the ground.  It would also use tire traction to pull against the shovel by reversing once the shovel was in the ground .


Solar Climate Swaler (SCS) Biz Plan Draft 0.2.1
0. research, consult, design, make & test tiny prototypes, rework
1. seek partners
2. seek investment, seek loans or self fund it
3.make solar diggers
4. buy or contract low cost desert land
5. map, analyze, test, monitor, consult with neighbors, get permits
6. design the swales and check dams needed to sink the typical annual flash flood
7. buy biochar or make it from clean mill scrap from the nearest post-wildfire area
8. make good compost with with the biochar and with added local microorganisms and confirm its good via a pro
9. collect rainwater onsite or get water from the ground or neighbors or via trucks
11. make actively aerated compost tea with some of that good compost and have a pro check its quality
12. water the area to dig and cut using that good fresh compost tea, watered down
13. dig and cut with the SCS, while recording data on performance, effects, harm caused, power consumption etc
14. add a lil good compost and native grass seeds. Either mulch or plant the seeds. Plant larger native plants if temporary irrigation can support them until the swale's catchment can
15. remap the area and review data while waiting on rain
16. monitor and make adjustments when it rains or flash floods
17. let the seeds grow
18. holistically planned graze or it sell it to someone who will definitely do so properly.


- From Seth Itzkan's 2014 article about HPG available on planet-tech.com Note, they're just grazing properly as far as I know. I think they aren't even using swales, biochar, added native seeds or compost tea
19. improve methods and repeat elsewhere if justified


*:
- Cat already makes an expensive, heavy, battery electric loader. Its mostly used in tunnels.


https://electrek.co/wp-content/uploads/sites/3/2019/01/electric-caterpillar-excavator-e1548740266295.jpg?quality=82&strip=all&w=1600
- A Norwegian company modded a huge Cat excavator to be fully electric, using 300kw of battery storage.  Lots of Cat equipment already has its main drive via electric motors [bc they're higher performance] and get charged up via onboard diesel generators. So, I assume the Norwegian folks pulled out the diesel generator and replaced it with the 300kwh of batteries and kept the stock electric motors. I think this prototype became the "Cat zline", maybe as a cat publicity stunt.

- Montreal has used 3 EV buses since 2017. The buses alone only cost about 1,200,000CAD each vs 900,000CAD each for diesel, however they also managed to spend 800,000CAD each on three quick-charge stations... wow.

- Green Machine Co makes the e240 and e210 Electric Mini Excavators, its a BEV. I think the e240 costs over $100k though which is about 2x to 3x  higher than an average mini excavator.  
  " This machine is the first in the world to match the performance metrics of a diesel powered unit – and with a lithium-ion battery.
        • 100% cleaner than diesel
        • 90% less expensive to operate
        • 50% quieter
        • Zero Emissions "  -from Green machine co website


**:
Electric vehicles may retain their value a lot longer than diesel.  Plus, in 2020 the fastest production supercar will likely be the electric Tesla Roadster with about a 2 second 0-62mph acceleration. Its going to cost around $250k (don't buy it) and all comparable performance gas hypercars cost over $1M.  2019 BEV sedans above about $40k price range also tend to be massively higher performance than similar priced ICE (gas) sedans.  Therefor electric cars are probably both faster than gas and massively higher performance per cost than gas... but for now this may only apply to rich people.  The lifecycle cost of ownership of a BEV which you solar charge at your home is massively cheaper than a similar priced ICE car. Fortunately this is already true across the car price range.


***:
100m * 5m = 500m^2 of solar panels.  
the sun shines about 1kw per m^2
20% solar panel efficiency is realistic
500m^2 * 1kw/1m^2 * 20% = 100kw
100kw / 0.74kw/1hp = 135 horsepower per


**** :
John Deer - "700k crawler dozer, Engine Netpower = 97kw, 130hp at 1800rpm.   Operating weight = 13,733–14,193 kg (30,275–31,290 lb.) Track On Ground = 2,590 mm (102 in.)  Blade Width Range = 3,200–3,658 mm (126–144 in.)". https://www.deere.com/en/dozers/
Cat - "Since 1996 the D6K at 125 hp and 28,409 lb... has been introduced" https://en.wikipedia.org/wiki/Caterpillar_D6


dutch solar boat race https://www.upsbatterycenter.com/blog/wp-content/uploads/2017/03/Dutch-Solar-Competition--e1490032448798.jpg

SCS research questions:
A.  Toxicity levels, lifecycle and recycle-ability of contemporary, efficient solar panel types and brands?
B.  Psi heavy vs distributed traction for drive?
C.  Price of Sunpower's 25% efficiency, flexible panels?
D.  Feather-like mounting of panels to trailer for aerodynamic resilience?
E.  Relevance of making a ebike powertrailer as a prototype component to add to a micro-bulldozer or micro-motor grader later?
F.   Does the probable depth of misuse of SCS tech by big ag and ignorant land owners outweigh the benefits of inventing it?

This post is a work in progress and I intend to keep improving it. I intend to publish it more widely if the concepts improve via my research, your input here and at the Bioneers conference in San Rafael, CA this weekend.

Big swales are not necessarily better.

The ideal farm has the right sized swales...often smaller sized swales, in the right location. A big swale in the wrong location is just a waste of effort.

This is my husband's idea:  Autonomous solar robots could be deployed in degraded deserts to imprint the soil and drop native seeds.

https://permaculturenews.org/2012/09/19/imprinting-soils-creating-instant-edge-for-large-scale-revegetation-of-barren-lands/

 Big swales are not necessarily better.

The ideal farm has the right sized swales...often smaller sized swales, in the right location. A big swale in the wrong location is just a waste of effort.

Excellent point Travis.  My original post was overly focused on large swales.  I've posted a requested edit to reflect the nuances of optimal design and I removed most of the "large" and "megafuana" language and replaced some with "scalable".  

I do continue to consider those deserts which typically experience drought, drought, drought, flash-flood as being stronger candidates for larger earthworks. [Refference- Neal Spackman's article "Greening the Desert", Permaculture Magazine, Issue #99 Spring 2019]

I have quite a few swales on my farm, some made in the 1930's, many put in in the 1950's, and then some I have installed. They help, but where I live, we have actually got an increase in rainfall, about 5 more inches of rain over the last twenty years, so swales are not as critical here as the deserts.

The electronics associated with solar are delicate. Building them sufficiently robustly to withstand the aggressive shock loads of heavy digging machinery is going to be prohibitively difficult. As in, either so heavy the digger can't move, or using technology that doesn't exist yet. And then you have an horrifically expensive piece of machinery that can't be used on cloudy days, in the shadow of trees or  in winter when light levels fall.

Fixed ground mounted solar with battery storage is a much better solution.

The cheap standard panels can be used, and can be located in optimal positions for solar generation. Smaller off the shelf batteries store energy for use in periods of low light.

Ball park figures from 30 seconds of google...
An excavator needs an average of 20kW power (ref 1)
20kW of direct supply requires 200 square meters of solar panels - rule of thumb is 10m per KW  ref 2.  That is around half a tennis court.
In practice you would need more than that, because you want to be able to use it in low light, and you won't be able to optimally position the panels to get best use of light 100% of the time.


I think your overall idea - autonomous solar excavators for remote areas - is interesting. But it might work better with a large semi-permanent solar base station for recharging, and a small fleet of semi-autonomous diggers. This would get the most from the solar -cheap, lightweight, easy to install - without impeding the diggers by overloading them.

I agree, Michael.

I think that a roomba-sized robot that can use GPS and a pre-mapped plan of contours to dig micro-swales would be more effective than a train of such, or a train of garden-tractor or front-end loader-sized autonomous diggers. You could make dozens of the roomba units, and they could be programmed to follow one after the other, perhaps using counter-turning helically grooved digging cylinders to move material mostly to the downhill side of the new swale. When the battery levels reached a level just above what was required to get it back to the nearest charging pylon (I would have charging stations at regular intervals, with movable structures for non-permanent placements) they would return themselves to the nearest dock.

Better to have two dozen roomba-sized units with half of them constantly charging, and a dozen required to do the work of the aforementioned centipede-thing, than having a single autonomous train of digger units that all shut down if there's damage or a malfunction. I bet they could do almost the same amount of work with 11 as with 12, whereas the centipede-thing would go down the moment one of its' least parts malfunctioned.

I think that in an environment where these units are simply texturing the land and planting natives based upon solar availability, with no charging pylons or infrastructure of any kind, the network-of-many-tiny-robots solution would be superior as well, for many of the same reasons. I think there would still be an onboard battery that would trickle-charge and stay charged in reserve to do things like operate wipers for the solar panels and to orient into the sun for optimal charging, but other than maintenance issues like that, and maybe onboard weather and environmental analysis and cataloguing, they would operate with the sun, as suggested in the OP, without needing to rely on extensive batteries and charging infrastructure, munching their way across barren landscape that could benefit from some on-contour swales, pooping an onboard store of native swale-digging plants appropriate to the individual project in their wake.

Conceptually, this is like the idea of the solar-and-wind-powered drone buoy that floats, generates electricity, and with an onboard spool of conductive iron form material, forms an iron shape through which electricity is run to cause the chemical deposition of sea minerals in what is colloquially referred to as Biorock atop that form material, allowing for the growing of anything from coral reefs (which the coral love, owing to either the low-level electric charge that flows through the iron formwork and the biorock itself, or due to the deposition of carbon in mineral form causing a localised reversal of acidification), sea walls (or really any sea-floor-based structure), textured reef and barrier structures that break up the momentum of hurricanes, tidal waves, and tsunami, or as I like to envision, iceberg-scale artificial islands that host coral reefs on their undersides.

I think it would be interesting to brainstorm the ways in which directly-solar-powered robots could be put to use to passively improve our lives, and actively geoengineer our planet to ends such as water infiltration, carbon farming and sequestration , the rewilding of toxic and/or radioactive wastelands for the purpose of toxin sequestration, breakdown, harvesting of biomass generated through bioremediation of damaged lands (perhaps including the dropping of harvested biomass into subduction zones), and maybe even autonomous amphibious craft pumping seawater to snow-generating cannons, as seen on ski hills, to slowly add to the polar ice caps, adding an insulative snow blanket and increasing surface albeido at one fell swoop. Or what if we had autonomous ocean vessels sitting on the edges of garbage gyres, straining out plastic and incinerating it cleanly, at high temperatures, for more plastic-straining energy? Or what if those vessels, instead, gathered toxic algal blooms, composting the algae to make soil, and pumped oxygen mechanically upcurrent of oxygen-depleted dead zones caused by the blooms?

Those are just a few of the ones rattling around in my head right now. I imagine there could easily be more. As noted above, the main benefit of having networks, or armadas, of autonomous drone systems going out and geoengineering for us is that they would require minimum supervision from humans, and once they're built, they go ahead with their programmed tasks until they malfunction or someone stops them, or until their programming is complete.

I would love to see such programmable autonomous systems. What could be accomplished if we each had a tiny army of these little things, simply doing micro-scale earthworks on land that would otherwise go untouched as we labour in the working world to pay for it? What could it mean for foresters if there were forestry mulching roombas that accompanied each operation, preparing the slash for seeding, which they would also do? No labour costs, less disruption of terrain, and the buzz bots could stick around to selectively clear non-target species from the area immediately surrounding plantings. Imagine forestry with less fire load and no glyphosate.

This has been something of a brainstorm in and of itself, so I hope it's useful to someone. I hope it helped to prove the point and analyse the question put forth by the OP.

-CK

Tyler Ludens wrote:This is my husband's idea:  Autonomous solar robots could be deployed in degraded deserts to imprint the soil and drop native seeds.

https://permaculturenews.org/2012/09/19/imprinting-soils-creating-instant-edge-for-large-scale-revegetation-of-barren-lands/

Great idea.  The imprinting article also references a technical paper by Robert Dixon that I'm reading https://www.imprinting.org/scientific-conservation/26%20Sept%2003%20Land%20Imprint%20Low-Cost%20Reveg%20of%20Degraded%20Land.htm

Autonomous restoration equipment may be more effective per cost than person-driven equip in rich countries, assuming the landscape is well mapped and is very simple and if the scale of the project is fairly large.  I think in less rich countries and in complex, rugged, or small sites its more realistic to have people drive the equipment.  I expect this balance to quickly move in favor of autonomous equipment throughout the next decade.

I agree with dropping native seeds.

I actually used to be a project lead on a university solar car team (competed in the American Solar Challenge twice) and one thing became clear to me.  Vehicles powered by on-board solar panels are not practical.  What is practical is an electric powered vehicle that can be charged by a stationary solar array (or plugged into a power grid powered by solar).  

My parents have a solar car right now; they own a Nissan Leaf with is 100% powered by their roof top solar array.  We are building our home right now and are planning on a ground based array of photovoltaic and where I can, I am buying electric equipment (the new 60volt tools are great).  I am really keeping an eye on the new electric tractor companies as well.

Alex, I believe what was being suggested was a direct-solar application for working robots, like autonomous tractor implements. In an autonomous rewilding application, they would operate above a certain level of ambient brightness in a manner that stressed efficiency over speed. Nobody would be waiting on these things, and there wouldn't be a requisite date of completion. They would make hay (or swales, or mulch forest slash, or whatever) while the sun shined, and go into a self-sheltering power-down mode when dark or overly cloudy. There might be an option to have on-board power reserves beyond a reserve that allows for power-downs and power-ups, and maintenance, but I think that the idea to have these things, whatever form they take, exist first in a stripped-down autonomous version is a good one, keeping them cheap, easily accessible, and ideally reparable for anyone familiar with, say, lawnmower mechanics.

-CK

Great detail Michael. Thank you

Michael Cox wrote:The electronics associated with solar are delicate. Building them sufficiently robustly to withstand the aggressive shock loads of heavy digging machinery is going to be prohibitively difficult. As in, either so heavy the digger can't move, or using technology that doesn't exist yet. And then you have an horrifically expensive piece of machinery that can't be used on cloudy days, in the shadow of trees or  in winter when light levels fall.  

Glass covers on rigid panels could break... but I think you're pointing out that the jarring motion of hitting rocks and bumps could cause micro-fractures in the panel's cells.  Flexible solar cells which can be bent about 30 degrees and can probable handle a lot, but they cost about 2x as much as rigid and maybe even they could breakdown if direct mounted to digger.  Maybe the microwiring between cells in a panel could also fracture.  The digging turbulence of the equipment could be decoupled from the solar trailer-cap by connecting the digger to its power via a slack power wire and by mounting drive motors in the solar trailer to follow the digger.  There would still be some jarring from the solar trailer hitting bumps.  Sites may need to be relatively smooth.  

The solar direct version of this hypothetical system might need to be designed specifically the lowest hanging ecological-potential-fruit... that being flash flood prone, sparse, non-rugged, deserts with simple slopes and good sun like the Mojave Desert, the Sahel etc.

Mojave Desert has plenty of mellow, barren slopes to improve.

Excellent. I'll respond more to you and Chris Kott this evening.  I appreciate the group analysis.

Chris Kott wrote:
Conceptually, this is like the idea of the solar-and-wind-powered drone buoy that floats, generates electricity, and with an onboard spool of conductive iron form material, forms an iron shape through which electricity is run to cause the chemical deposition of sea minerals in what is colloquially referred to as Biorock atop that form material, allowing for the growing of anything from coral reefs (which the coral love, owing to either the low-level electric charge that flows through the iron formwork and the biorock itself, or due to the deposition of carbon in mineral form causing a localised reversal of acidification), sea walls (or really any sea-floor-based structure), textured reef and barrier structures that break up the momentum of hurricanes, tidal waves, and tsunami, or as I like to envision, iceberg-scale artificial islands that host coral reefs on their undersides.

-CK

I'd never heard of biorock, and a quick search hasn't brought up much info. Great idea that deserves its own thread.

Chris Kott wrote:Alex, I believe what was being suggested was a direct-solar application for working robots, like autonomous tractor implements. In an autonomous rewilding application, they would operate above a certain level of ambient brightness in a manner that stressed efficiency over speed. Nobody would be waiting on these things, and there wouldn't be a requisite date of completion. They would make hay (or swales, or mulch forest slash, or whatever) while the sun shined, and go into a self-sheltering power-down mode when dark or overly cloudy. There might be an option to have on-board power reserves beyond a reserve that allows for power-downs and power-ups, and maintenance, but I think that the idea to have these things, whatever form they take, exist first in a stripped-down autonomous version is a good one, keeping them cheap, easily accessible, and ideally reparable for anyone familiar with, say, lawnmower mechanics.

-CK

It's practical application for mowing lawns or pastures (as long as they arn't over grown) but i'm nore sure they could do heavy work like making swales.  Our solar car (similar to those pictured) use a gallium arsnide PV array which cost quite a bit (I want to say it was 10-20k) which was capable of powering a small portable hairdryer if it was really sunny while the car weighed only a few hundred pounds.  This was more than 15 years ago so I am sure there have been some improvements but I think something similar could be accomplished better using more of the roomba aproach.  Centralized power stations that utilize the cheaper silicone based PV (or even thermal systems) which the smaller machines return to for charges.

update:
I just got off the phone with Justin Solomon, a commercial sales rep for SunPower.  I called them because they seem to have strong as well as the most efficient panels and solar cells.   He thinks they could sell their ~18% efficient flexable panels for prototyping.  Their ~22% efficient rigid glass panels they reserve for standard projects and he wasn't allowed to talk about the solar cells inside them, so those ones wouldn't be available for prototyping.  Rigids would be available if bought in bulk for an installation. Justin was confident that both their glass and flex panels could handle mounting on digging equipment.  I'm less confident than he is, but I'm more confident in their durability than Micheal.

I'm emailing their flex panel staff now.

I would suggest a slightly different path. The reason the battery pack seems so huge is its sized for a full work day. Instead of sizing the pack for a full day or trying to create a machine with a tennis court of solar panels on it create a flexible smaller battery pack and have two of them. One charges at a solar base station, one is used on the machine. You would be half way to your goal and be able to use off the shelf existing equipment. If I was doing it I would be searching for a mini ex with a dead diesel engine or a 3 point hitch backhoe attachment to pair with an electric tractor that are already showing up on the market. The mini ex example is a better choice since it is basically a gigantic hydraulic pump already and should not care what turns it... As far as weight goes excavators need weight for traction. Usually the base of the excavator is purposely made as heavy as possible to provide it so battery weight isn't really an issue.
Cheers,  David