It’s astounding to realize how far we’ve come in the solar industry. At the end of 2024, global combined PV capacity reached 2.2 terrawatts. The International Energy Agency expects global renewable power capacity to increase by 4,600 gigawatts by 2030, and solar PV will account for 80% of the growth. Solar energy installation is becoming a mainstream power source.
Yet, the solar secondary market is still in its infancy. According to the United Nations Global E-Waste Monitor 2024, only 22.3% of the 62 million tonnes of global e-waste is formally recycled. Meanwhile, industries are hastening to develop circular economies that prioritize reuse and recycling over landfilling.
One challenge in the solar PV industry is the information gap that exists to quickly determine the resale value of used PV hardware products as well as the value of rare earth materials of end-of-life assets. With the dawn of artificial intelligence, an appraisal system created by Buckstop to accurately and efficiently report on such value is poised to fill the gap.
We interviewed Nick Kumleben, one of four co-founders and Chief Business Development Officer at Buckstop, about the company’s agentic platform to understand how it works and why it matters for the solar industry’s circular economy. Buckstop has been a member of EnergyBin since August 2025.
EB: Tell us about your background and how you got involved with Buckstop.
To start, I came to the United States about a decade ago. I grew up in the United Kingdom and South Africa. My background consists of various research analysis and investment advisory roles within the energy transition. I’ve worked for a geopolitical advisory firm, a hedge fund focused on the energy transition, and at a private equity-funded clean energy development.
With experience in commodity and energy markets, I turned my focus to the issue of critical minerals, that is, those minerals necessary for an electrified and decarbonized economy. This issue piqued my interest for two reasons. First, because there isn’t a lot of supply outside China, which creates a geopolitical problem for the U.S. and the West. Second, because as we move from an economy based on fossil fuels to one based on electrification and decarbonized energy sources, we’re going to need a lot more of these critical minerals. There’s a movement to mine these resources in the domestic U.S.; however, the process to bring such mining and processing facilities online takes up to three decades. Meanwhile, the energy transition boom is happening now.
I started to think about how much of these crucial materials we have embedded in the economy around us and how we can keep them out of landfills. I expressed these thoughts with an old friend, Alexander Olesen, who is now one of the co-founders at Buckstop. He started Babylon Micro-Farms in 2016, which is a vertically integrated modular hydroponic solution to address food scarcity. Alexandar explained he faced a similar challenge of having nowhere to recycle and retrieve valuable materials once the hydroponic appliances were at end-of-life.
We began looking at the recycling rate in the U.S. and various circularity metrics for each component. We quickly discovered that there was an information gap between the asset owners and the recycling markets. The asset owners knew they had something valuable but didn’t know what it was worth in monetary terms. That hindered their ability to accurately explain to scrap dealers, shredders, or smelting plants what exactly was in these assets and the value that could be recovered.
This discovery led to the development of a sophisticated computing system that utilizes artificial intelligence to draw information about these assets to formulate an algorithmic assay. That’s how Buckstop came to be.
EB: This development happened recently, correct?
Exactly! Yes, we’ve been working on the idea for about two years and launched the company in July 2025. We took our beta product for AI-generated appraisals to market in mid-September. This product will greatly improve in time as more solar assets come offline. We also plan to take this framework and apply it to other markets, like battery storage, data centers, and other IT hardware assets.
EB: Very exciting! What inspires you to keep doing what you do?
I see what we are doing as an opportunity to solve two of the most pressing challenges of our time. The first is that we need more valuable materials to build a decarbonized economy. The U.S. currently recycles around 20% of electronic waste, which is a much lower figure than comparable advanced economies. That figure is around 40% in Europe, and 80%+ in parts of East Asia.
It’s also a national security challenge as we've seen over the last few months with respect to our reliance on China for key inputs into our economy. That reliance is not a feasible solution going forward. In terms of growing the market for circular solutions and the electronics waste space, I believe we’re helping to solve these national and environmental challenges as well as providing a financial upside for asset owners who are otherwise paying for trash hauling.
I find what we’re doing an exciting and inspiring opportunity, and I’m eager to jump out of bed every morning to play my small part in solving these challenges.
EB: In the business world, we always hear ‘time is money’. How will this solution accelerate the turnaround of valuable materials available for new manufacturing?
Your question is best answered within the context of urban mining, a term coined in Japan in the 1980s. The World Economic Forum defines urban mining as the process of extracting valuable materials from waste, of which there is a finite supply, and with the goal of limiting the environmental impact of disposal and added harm from land-mining.
Japan has a large, industrialized economy, which requires significant mineral inputs of all kinds. But it doesn’t have a lot of minerals below the ground. So, the government has had to think hard about supply security and then look for innovative solutions to resolve the scarcity. One of those key solutions has been urban mining. The process of tracking not just what's embedded in the economy but also finding innovative ways through partnerships with originators, recyclers, processors, and end users has been successful for Japan and in other countries that have adopted urban mining strategies.
Now, we’re seeking to do the same in the U.S. by putting the informational pieces in place to support a robust urban mine here.
EB: Thank you for the definition of urban mining. In terms of Buckstop’s appraisal solution, would you explain how it works?
In simple terms, what we’re doing is building massive databases that combine proprietary research and artificial intelligence on industries to get to a reasonable result for understanding the resale value of assets and the materials they’re made of. From there, the information is used to help asset owners understand what their assets are worth on any given market day.
When inputs, such as manufacturer, make, model, wattage, condition and location, are entered into the appraisal system, they are matched to collected data within our database of deployed assets. From there, the system provides a valuation in mere seconds.
EB: Interesting. Where else within the industry are you drawing data from for Buckstop’s database?
We are pulling data from resale markets like EnergyBin, commodity markets, and recycling markets. As the solar industry continues to develop, more data is becoming available. Historically, it’s been a fairly painful and manual process. You must figure out what you have, and then you may test it, pull it apart, and conduct research on resale sites. The Buckstop database is meant to pull information together to greatly reduce the time to do this.
EB: Would you explain a specific use case, for which developers or EPCs would find value in referring to Buckstop?
One common use case we’re seeing today has to do with the question of when to repower. We would grade the array and then focus on repowering any given part of the array. Say the asset owner wanted to keep the racking and wiring but replace the panels and inverters. We could assess the salvage cost and resale value of these specific product lines. Essentially, we would be able to provide a cost-benefit analysis needed to make a repowering decision.
Beyond repowering scenarios, there are several other use cases I’d like to mention. Developers and EPCs understand the importance of decommissioning bonds in various jurisdictions and need to estimate decommissioning costs as well as the salvage value of assets before a project is deployed. Buckstop can help with quickly calculating an accurate value. This function is also relevant to financial firms engaged in issuing surety bonds.
Another use case comes into play once a project has been commissioned concerning audits and annual financial reporting. We can provide rapid and consistent valuation reporting on a subscription basis. Additionally, we can provide an opinion as to the residual value of assets for an M&A transaction.
And then, of course, when the array gets to end-of-life or repowering, we can provide valuation details for resale and recycling. The valuation provides asset owners with a sense of what resale value they might receive on platforms like EnergyBin or what they can expect to pay to recycle obsolete components.
EB: What we’re hearing you describe sounds a lot like the used car market’s Kelley Blue Book. Is that an accurate comparison to what one would see on Buckstop’s platform?
Yes, we think Kelley Blue Book is a great example. As this product comes out of the beta phase and goes to market, we intend to present monetary ranges we have high confidence in, like what one would see on Kelley, because the market can move rapidly for any given reporting factor, like off-take charges to gate fees to freight costs, etc.
EB: How is the data on Buckstop validated?
There are several academic and governmental sources that we work with, including U.S. government labs and Solar Energy Industries Association, as well as other third-party non-profit sources with no vested interest in our company. There are also industry participants who’ve helped with clarifying resale and recycling values in market terms, EnergyBin principle among resellers. The data is continually refined, and we plan to add confidence scores to our valuation numbers.
EB: How can this appraisal tool help an asset owner determine compliance and regulation policies within any given U.S. jurisdiction?
Relevant to regulations, Buckstop operates across a few different stages of the lifecycle. On the permitting side, decommissioning bond regulations require a degree of financial transparency before the project gets built. On the decommissioning side, one would need to know what regulations he must adhere to, such as landfill bans. An asset owner can refer to Buckstop’s database for any given state to learn what regulations are in place and act accordingly.
It’s important to touch on why this kind of compliance matters at an industry level. At a time when solar energy has become politicized, solar companies and asset owners must be responsible stewards of both the local environment (in terms of what we put into the landfill) and on a national level of keeping our assets in circulation. Here at Buckstop, we’re seeking to provide the visibility that our customers need to be compliant and good citizens.
EB: Whether one is obligated by regulation or not, it’s the right thing to do – reuse and recycle – and doing the right thing will sustain one’s business for the long term. Looking ahead, what are Buckstop’s goals?
In the short term, we’re focused on finding more pilot customers to refine our model. We’re also collecting data for the battery storage market, and this product category will be launched early this year.
As the secondary market scales, which is expected to happen at a rapid pace, we’re going to see the resale and recycling markets explode in growth. We expect the volume of used panels for resale will jump to 1.8 billion by 2030.
For us as a sector, the difficulty lies in meeting that demand, and we need transparent and vetted marketplaces like EnergyBin. We need valuations from Buckstop and other firms. We need everyone to play their part, from resellers to recyclers.
EB: If you could make one wish for the solar industry, what would it be?
I would love to see the electronics and renewables sectors move towards the benchmark realized in the auto industry where 97% of each car in the U.S. is recycled. As Kelley Blue Book illustrates, all cars have more than one owner throughout their lifetimes. The resale market is operating well. Then at end-of-life, valuable materials are extracted and put back into the manufacturing process. The circular infrastructure is well established. I would love the electronics and renewables industries to achieve the same infrastructure.
A special thanks…
To Nick Kumleben, Co-Founder and Chief Business Development Officer at Buckstop, for sharing about the company’s AI appraisal system.
More Resources:
