The headline is “Design And Implementation of a Solar Wheelbarrow System” [1]. I know what a wheelbarrow is, and I know what solar power is, but what in the world is a “solar wheelbarrow”? I mean a wheelbarrow generally doesn’t have a motor or any kind of electrical system, so what could solar power do? In fact, the whole genius of a wheelbarrow is that is it simple and unpowered, yet vastly useful—without solar or any other kind of external energy input except for human muscles.
The article doesn’t really make it easy to figure out just what this concept is supposed to be. The lede is buried deep; not until Figure 5 at the end of Section 5 is there a clear view of the basic concept: this is a personal solar powered charging station attached to a wheelbarrow. The idea is that the wheelbarrow is to be used outdoors in tropical sun, charging up while the worker does usual (non-solar) activity. The accumulated charge is then available to personal use, household devices, or for a “micro business”, e.g., recharging phones for small fees.
The bulk of the paper goes into considerable detail to calculate how much energy would be available in rural Nigeria, estimating exposure in typical use, and sizing the components. Basically, they show that you can put a solar collector with batteries on a wheelbarrow that will generate enough power to charge a phone at the end of the day.
OK, sure. I guess I wasn’t in doubt that you could build something like this.
But, why would you? Why wheelbarrows, anyway?
The article correctly notes that the same technology could be set up on homes, businesses, or other locations. Such solar charging stations have been promoted for many years. (More expensive materials can put such a system on clothing or, at the really high end, in roofing or other building materials.)
If I understand correctly, the target customers are traders and workers who transport goods several kilometers from home to market. This system would charge up batteries on the wheelbarrow during the commute, for use at work (or to be sold). I guess that a key part of use case is that (a) the wheelbarrow is basically the portable shop supporting the business, and (b) there is no other infrastructure at the worksite. So power collecting wheelbarrows upgrades the worksite without requiring other infrastructure.
The article doesn’t discuss the economics of this product. Let’s be generous and say that this system can be added to a wheelbarrow for $100. That’s a lot of money (whatever the true price would be) for a daily phone charge and a couple of hours of dim light.
I have to note that the market research is sketchy. How many potential customers are there? Do rural wheelbarrowists want this product, and what would be their price point? And so on.
But, by far the biggest missing piece is the lack of a prototype and field tests. Wheelbarrows operate in dusty and muddy environments, which can seriously reduce solar productivity and potentially break electronics and batteries. Wheelbarrows are also prone to rough handling, accidents, and other events that could break this technology.
I would want to see some serious testing to demonstrate that the system is rugged enough to survive real use in the target environment. (And, pessimist that I am, I want the system to be easily repairable in the field when it does break or just get dirty.) At the very least, it may be necessary to ruggedize the design and use more expensive components in order to achieve reasonable reliability.
For that matter, it would be good to demonstrate that the concept even works. I mean, I could imagine that the loaded wheelbarrow might shade the collector. Or some workers might use a sunshade which occludes the collector. Or the wheelbarrow might be parked in the shade (I certainly would do so). Or the batteries are unpleasantly hot for the user. Or any number of other real life details that are not apparent from the concept drawings. and theoretical studies
Overall, this is reasonable idea, though the use case is incomplete and, more than anything, there is a need to actually build one and demonstrate that it actually works in the intended environment. That will almost certainly mean additional iterations to refine the design based on real life.
- Abel E. Airoboman, Neville S. Idiagi, Wunuken C. Solomon, and Emmanuel Sueshi, Design And Implementation of a Solar Wheelbarrow System for Rural Communities in Nigeria, in Renewable Energy Institute – Energy Learning Journal, May 18, 2022. https://www.renewableinstitute.org/solar-wheelbarrows-nigeria/
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