It’s been 4 years since we commissioned our solar electric kitchen, and shut down the giant ground-based mirrors that launched BjornQorn. For the past ten years, solar electric has absolutely plummeted in price. This is great news for the world! Solar electricity is now broadly competitive in the marketplace with electricity from other sources. Just about every business should be investing in solar power. With almost zero maintenance, we have been able to generate significantly more power than our kitchen uses each year. Our ground-based mirror experiments have continued on the side, but have been mostly frustrating for the past few years. We’d been trying a modification of the original design but hadn’t been able to get it to work. We were almost ready to hang up our inventor’s spurs, and lay the solar basin project to rest. After all, why continue to pursue it with solar electric so cheap? 

Solar electric may be the right answer for our American business, but it is still not nearly affordable for everyone everywhere. The solar basin will still come in 5x-10x cheaper per watt, which makes it accessible to a much broader swath of the world. A solar basin can also be operated completely off-grid without expensive and perishable batteries. The materials that need to be imported are minimal and can ship rolled up. Our end game has always been to create something that could be used by small food businesses in the developing world, but the basins we began BjornQorn with weren’t easy enough to build and operate, and didn’t last long enough. 

This summer, we’ve had a bit of a breakthrough, and gotten the new trough-style solar basin to work. The crux of the new idea is still the same: the dish geometry can be built directly into the ground. This allows the use of dirt cheap materials, since it is literally made of dirt. But the trough solves a lot of problems with the original design. Here’s a list of some of the original basin problems, and the way the trough solves the problem:

Large holes required heavy equipment to dig 

With the trough the excavation scales linearly, instead of the square of power output, so the holes are much more manageable to dig at a commercial scale. 

Cooking surface was difficult to access 

The cooking receiver is a long level tube with the trough design, which can always be easily accessed.

Deep Basins were hard to drain

The trough design is much shallower than the original basin for a given power, making it much easier to create a passive drain in most locations.

Surface deteriorated rapidly

The 2 dimensional curvature of the trough allows the use of a much more robust professional reflective film on a thin metal substrate, making it much more durable, with a quoted lifespan of 25 years.

Low winter sun angles and snow cover

Don’t build basins in the northeast! This is a design for equatorial regions.

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solar roasted coffee 

solar biscuits

 boiling water to test power 

These pictures and video are from the first successful small scale test. The next step is to go back to a commercial scale prototype. We’re targeting 10 Kilowatts, about 15 times the size of this test. We’ll be blogging about it as we get underway.

infrared image of oven interior

ambient oven temperatures in the 400s F, surface temperatures in the 500s

some test popcorn popping

So that does it for 2019! It was a great growing year in both MN and NY. We harvested about 800-900 bushels total so far. That’s about 50,000 pounds of popping goodness.

We have one more field in NY that is still drying, and hopefully the most recent snowstorm doesn’t take a big toll. But sometimes waiting is the best option. At Kelder’s we opted to take it a day before the storm, and we’re drying it down in house now. In Minnesota we took it over a month ago and were able to bin dry it somewhat…But not completely.  We’ll have to wait for spring to finish the job.

Have a great holiday, pick out one of our Holiday Tins if you’re still thinking of a gift!

Bjorn

Snapped this nice picture of a Monarch butterfly with the BQ barn in the background. This guy should be one of the “super-generation” that will make the incredible flight from here to Mexico to overwinter. Most generations of Monarchs only live for one month, but this one will live up to 8 months! He’ll flutter 50 miles a day to reach Mexico, and no one knows exactly how he performs the navigational feat. Monarchs are on the decline, possibly because of the decline of the one plant they can lay their eggs on- milkweed. Milkweed produces a bitter sap that the Monarch caterpillar eats, which makes them taste bitter and discourages predators.

The BjornQorn barn has a one acre field that we only mow once a year, so that it can become a field of wildflowers and support pollinators like the monarch, instead of a sorta-pointless grass lawn.

As promised I will detail a bit more about cleaning popcorn. Usually when I talk to someone about this they wonder if I’m lathering and rinsing the seeds. I am not. The more appropriate name for the process would probably be classifying. Like panning for gold. I only want the gold.

To do this we start with a machine called a screener / scalper. It is commonly referred to as a ‘Clipper’. It takes in the shelled popcorn, scalps out the larger debris with the top screen and screens out the smaller debris with the bottom screen. This model is based after an older A.T. Farrell machine called an M2B Clipper. Commodities International in Trilla, Illinois manufactures this replicate. They call it the ‘Eliminator 224’.

The Eliminator does a great job getting rid of a whole bunch on unwanted debris and chaff. But it cannot get rid of debris the same size as popcorn like a stone or a pea. Density is not its concern. For that you need a gravity table.

Gravity tables of this small size are not commonly made anymore. This Forsberg #6 gravity table was manufactured in the 1950’s in Thief River Falls, MN. It was a bit of a rare find so we jumped at the opportunity to add it to our process. It shakes and blows air through an elevated deck causing the grain to ‘float.’ The action of the deck causes light objects (cull) to fall downward and the heavier objects to flow up towards the discharge spout. It has many knobs and adjustments and has a pretty steep learning curve to get it to do what you want. But I’m sure by the end of 22,000 lbs of popcorn anyone would feel pretty comfortable.

So now we have ourselves some pretty clean popcorn. The only thing left are seeds and other debris with the same size and density. For now we pick those out by hand. But the ideal next step is something amazing called a ‘color sorter.’ We might have our eyes on one…you can be sure I’ll tell you about it if so. 

I’ll sign off with a picture of my father’s beloved Farmall 560 which ran the hydraulic auger for the entire duration. Thanks!