We just got back from our first demo on a 150MW solar construction site, where we showed off our initial prototype: an autonomous forklift that unloads pallets of solar modules from a truck and stages them around the site. It’s a huge milestone for us, and we felt like now would be a good time to share what we’re working on more publicly. You can see a couple videos of our robot in action here:
Staging modules on the site: https://youtu.be/Fwf4v8upuoI
Performing a two-pallet sliding and unloading operation in our warehouse: https://youtu.be/EOJiyMXpVeQ
As solar modules have become commoditized and prices have plummeted, solar has become the cheapest form of power generation in many regions. Demand has skyrocketed, and now the primary barrier to getting it installed is labor logistics and bandwidth. Every solar construction company we've talked to is drowning in demand and turning down projects because they don't have the capacity to build them. 1/5th of all the solar that exists in the US was installed last year!
We're engineers who have been friends since living together at MIT where we studied robotics and CS. We always wanted to start a company together. We zeroed in on solar after seeing compelling statistics about its cost effectiveness and projected growth – and because we shared a motivation to do something about climate change. We actually started out writing software to predict optimal locations for solar sites (searching land for sale and scoring by price, amount of sunlight, proximity to existing substations) when we decided to learn more about what comes next.
Utility-scale solar farms (2MW+) are mechanically quite simple. They feature a steel racking system held to the ground by vertical posts ("piles"), and overwhelmingly (90%+) feature a single motorized axis to track the sun over the course of the day. Modules are then fastened to this axis with brackets.
We're using a two-part robotic system to build this racking structure. First, a portable robotic factory placed on-site assembles sections of racking hardware and solar modules. This factory fits inside a shipping container. Robotic arms pick up solar modules from a stack and fasten them to a long metal tube (the "torque tube"). Second, autonomous delivery vehicles distribute these assembled sections into the field and fasten them in place onto target destination piles.
This is a hard technical problem, but not research-level hard. We think of it as the "homework version" of self-driving cars, as we're operating in a semi-structured environment (flattened dirt field) with drastically fewer edge cases. Manual construction today breaks about 0.1%-0.5% of modules during installation, which is an easier bar for us to target than the stringent performance requirements of the AV world.
We're operating in a risk-averse industry, though, which makes deploying new technology more challenging. One industry-standard term we've become very familiar with is "bankability". It's difficult for projects to secure funding from lenders if they aren't using parts that have already spent years out in the field.
We've seen surprisingly little penetration of technology into this space in general. Projects are largely tracked with sticky notes in a "command room", material delivery schedules are highly volatile and often not known until days in advance, and there's no live monitoring of construction progress, making current status opaque. We actually had a site we visited outright lose a forklift – we were surprised that all vehicles aren't GPS tagged and monitored, especially given they're operating on multi-thousand acre sites.
Our system is the first to handle the full mechanical installation of existing solar components (remember bankability). We've tweaked the order of construction operations slightly to be more robot-friendly, as the more precise operations involved in fastening modules to steel tubes happen in a more controlled factory environment.
For our mobile robots, we’re building on top of existing vehicles (called telehandlers, or reach lifts) which are already ubiquitous on these sites due to their enormous tires and broad capabilities. They're able to unload shipping containers due to their extending boom, as well as move materials around the site. On our prototype vehicle, we did some significant up-front reverse engineering including mapping out CAN messages sans documentation. The steering and brake were directly hydraulically actuated (no drive-by-wire), so we added motors to both in order to control them with our software stack. The most unique sensor we contributed was an optical mouse sensor mounted onto the boom joint, telling us the extension distance.
The backbone of our robotic sensing is a robust vision system. We're using stereo cameras for SLAM and object detection. Fortunately, solar construction sites already have detailed engineering drawings including GPS coordinates of each vertical post in the ground, so we have a detailed map of the site to localize ourselves on.
Watching the existing process for large-scale solar installation in real time evokes the sense of watching paint dry or grass grow, only it involves hundreds of workers. After witnessing the physically grueling and inefficient process of workers manually installing thousands of solar modules, we realized there had to be a better way of building solar, and that increased automation was the way forward.
Our goal is to transition the world to renewable energy as quickly as possible. We’re excited to share what we’re working on with HN - please let us know what you think in the comments and we’ll be around to respond!
P.S. We’re hiring! If you want to work on cool robots with a positive climate impact, please reach out: https://chargerobotics.com/careers.html
Install labor is relatively cheap but more importantly flexible - relative to the cost of the project install is low double digits %. If a job isn't running smoothly you cut your temps and move your main crew over to another site or send them home if they're local. I would wonder how this work fit in with an automated build/install solution.
Unless you have control at the GC level you're going to be start/stop with electricians cutting trenches in front of you, missing materials (tariffs/port strikes), permitting delays, etc, and you'll have expensive idling equipment that's tough to move.
I get that this is the problem you're trying to solve - but I'd definitely suggest going to enough bread and butter 2-10MW sites where this sort of thing is more common. Also keep in mind Central CA in summer is not Massachusetts in November, weather makes all this 10x worse.
Totally hear you on the CA vs MA weather swings (I've lived in both!). We actually see this as a key advantage for us. Sites we've visited in central CA have significant water distribution logistics, frequent shade breaks, and still have high heat exhaustion rates. Sites we've visited in northern climates report about 50% speed reduction in work due to gloves/cold, and will send workers home if the temperatures drop far enough. Our robots can handle both climates without an impact on installation rates (or any of the associated health risks for workers!).
It might be too early to tell.
Those telehandlers and skidsteers are almost always rentals, so they get called off and picked up at the site. Moving heavy machinery is much more difficult than moving people, and all of your equipment is unique so it’s glued to that job site until it’s complete. Owning your own equipment presents its own set of challenges - you have to store it when it isn’t being utilized, keep excess capacity in case it becomes unavailable, fix/repair on your own, etc. All of the costs in the current installer model, while perhaps higher, are tightly coupled with the cash flows from the job portfolio. This might decouple the cash going out from the cash coming in, to say nothing of the fixed costs of having having hardware/software engineers on staff.
I really want this to succeed so please keep in mind this is just food for thought.
EDIT: Autonomous forklifts are old tech by now, most container ports are close to be fully automated as are tons of factories all over the world. Heck, we even have automated lawn mowers and hoovers...
Important to keep in mind, but I would suspect(and hope), most solar farms will be installed, where it is sunny and dry.
Weather patterns on East coast can be unpredictable, much more so than central valley CA. torrential rain = mud leading to bogged down equipment, this can be the difference between a profitable job and unmitigated disaster for an installer.
Second, construction cycles in utility solar can be a bit wonky because of ITC tax credits, lots of turnkey providers looking to have construction starts in q4.
What a great automation environment! Almost clean-slate too, you don't need to integrate with a patchwork of other solutions that are different per site.
Robots as a service is definitely the way to go. Much lower apparent risk for your clients, less support costs for out of date product you sold early on... many great reasons.
Years ago I 'worked' at Scott Technologies, around the time they were making this 'smart' straw making machine that had the chocolate/strawberry flavour inside the straw and you just put it in some milk and bam. Really cool going from planning to actually testing the robot (was for some client, can't remember who). I did this while on a high school placement programme in year 13.
I really love robotics, but I moved in a different direction after that!
I agree though that being in NZ seems to stunt you as an engineer. America appears to be overflowing with incredible companies that even normal people, not only "rockstars" can work at.
Access to capital. It's obvious that this venture would require huge investment to achieve profitability, way more than has ever been pumped into any kiwi company prior to turning a profit.
Investors here have a much smaller vision.
It's a shame, because this must be one of the worthiest targets for investment ever on the face of it. But it could never get off the ground in NZ.
We find that beyond the direct cost, the logistics of getting hundreds of people to a remote site is a significant challenge for construction companies. We directly saw how much of a hurdle this can be when we were on a site with the closest city an hour and a half away. Weather conditions are also a factor here, work on the site was actually shut down due to conditions that were too cold for laborers.
As we've interviewed solar construction companies, all of them have told us that they're turning down potential jobs just because they don't have enough people/capacity to build them. Unfortunately they can't simply raise their hourly rate by a few dollars to make this problem go away, because the challenges are more the regional specificity and logistical challenges of getting workers to sites.
(For home use, I worry about my neighborhood becoming a superfund site in event of a fire. I read claims that fire burning the house under CdTe panels will not release the 8g/m^2 of cadmium on them, but don't know how to evaluate that.)
TLDR Worker housing and logistics vs robotics.
Maybe 10-15% of total cost depending on install type.
Have you considered, or have views on, the scope for using telerobotics in this field as a step to full automation? Point being the qualified labour could be anywhere in the world for a particular job and the data generated from that could be used towards the drive for full automation.
[1] https://www.thirdwave.ai/ [2] http://www.teleo.ai/
Sharing with row crops seems like the next level, where you probably need to share with irrigation and harvesting equipment. In the near future, production of NH3 on-site for fertilizer and fuel when grid price bottoms might become practical.
The Construction Physics blog is mandatory lecture on this subject. You will find the many and varied ways huge companies failed at automating construction, and why construction is just different than other fields:
https://constructionphysics.substack.com/p/where-are-the-rob...
https://constructionphysics.substack.com/p/why-did-agricultu...
https://constructionphysics.substack.com/p/japans-skyscraper...
However, Charge Robotics has a problem that is generally free of much of the above hindrances and is employing a modular approach. Modular construction can lend itself very well to automation. See the modular housing boom that employs automation quite heavily.
One of the more complex construction portions of the build is handled by a portable factory:
"First, a portable robotic factory placed on-site assembles sections of racking hardware and solar modules. This factory fits inside a shipping container. Robotic arms pick up solar modules from a stack and fasten them to a long metal tube (the "torque tube")."
This process could also employ human labor as well. The rest of the build process requires a more simple transfer of these pre-built components with a final assembly:
"Second, autonomous delivery vehicles distribute these assembled sections into the field and fasten them in place onto target destination piles."
The locations of operation are large open fields with minimal occlusion (which often makes robots in many construction settings infeasible) and reuses prior equipment (bankability and minimizes setup/tear down costs).
I don't think this is an easy problem as there are significant technical engineering requirements, but if each modular process can be proven effective, then the external factors that prohibit automation adoption in construction outlined above are fairly minimal.
Also bathrooms started arriving as ready made modules etc. The factories that make these, I assume they actually are quite automated?
I guess the biggest questions are:
1. are telehandlers precise enough for final assembly on their own without humans? 2. if you need humans too, can they safely co-operate with the robots? 3. if you need humans too, how much will this save on workforce needs in the end?