Participant Forum: App Tech

App tech possibilities and pitfalls

Picture of Kathy Partridge
App tech possibilities and pitfalls
by Kathy Partridge - Sunday, November 15, 2020, 8:38 PM

I watched all the videos and the two that I've most often thought about for my site are solar cooking and food drying. I also have a book, The Solar Food Dryer by Eben Fodor that shows how to build a table/cabinet style of food dryer that strikes me as being more suitable for smaller urban and suburban permaculture properties.  This video will give you an idea of what it looks like. It's not nearly as elaborate or "contraption-y" as the huge ones in the videos. 

Anyway, as much as I love the idea of cooking and dehydrating food using only the sun's energy, I'm hesitant to jump in, because I don't live in an area of the country that gets long stretches of reliable sunshine, even in the summer. For example, thanks to the Great Lakes, Syracuse (50 miles to the west of me) only gets 44% of the available sunshine throughout the year.

Here in the Mohawk Valley of central New York State, cold, cloudy weather starts by November, and can extend through June (our highest precipitation month). Later in the summer, it's warm/hot but while our days often start out sunny, as the air warms, clouds will build and threaten rain (which, more often than not, doesn't materialize). Opportunities for several days of sun to dry plums (as mentioned in one of the videos) would often be hard to come by most years, especially if you have boxes of perfectly ripe fruit that need to be out in that dehydrator now. I also wonder how our increasingly humid summers (we seem to be having many more days with dew points over 70 than I ever remember when I was growing up here) would complicate all this.

Cooking would be similarly problematic, I think; how do you keep a solar oven at a consistently high temperature to cook everything through if you can't count on a full day's sunshine to do the job?

Having said all that, this past summer was one of the sunniest I can remember, and I often found myself thinking that this was the year to have a solar dehydrator!

For me, my two cold frames represent my most successful attempt at appropriate technology. Basically a raised garden bed with a clear, slanted top, they have no moving parts and with  polycarbonate twinwall greenhouse panels covering on the "lights", they can stand up to the heaviest, wettest lake effect snow that Mother Nature can throw at us. Mine are built to last, and with them, I can harvest a surprising amount of food throughout our Zone 5 winter. They are easy to understand and manage, easy to work on if they need repair, made mostly from materials that are available from locally owned businesses, are reasonably affordable (mine are a little more elaborate than usual for ease of use as I get older), and use the simplest solar technology that works to the degree needed even on cloudy days. I have digital thermometers to monitor the cold frame temps and on the gloomiest of days (like today), they're running 7 to 8 degrees warmer than the outside air temperature.

I sometimes think about building a small greenhouse or high tunnel, but I'm not sure the headaches of constructing and managing such an elaborate structure (compared to simple cold frames) would offer any more benefit than my current system. I'll try and upload a photo below.

I also think "appropriate" will vary from one permaculturist to another depending on their age, finances, living situation, and other considerations. The rocket stove bench, bike powered flour mills and blenders, and massive compost piles large enough to heat a greenhouse seem out of reach for me. All of them are clever and intriguing, but seem more appropriate for younger folks with strong backs who are tinkerers at heart. (And I haven't seen a rocket stove bench yet that looks like anyone would want to sit on it for more than 5 minutes. LOL.)

Cold frames with covers propped open for ventilation

Picture of Deb Winther
Re: App tech possibilities and pitfalls
by Deb Winther - Tuesday, November 17, 2020, 6:09 PM

Hi Kathy,

I enjoyed your post and agree that some of the "contraptions" we saw in the videos are either too big for my small site, or beyond my basic carpentry skills. I'm also thinking about looking into different ways to preserve my garden's output or extend the growing season. I was very impressed with your cold frames. Did you make those yourself?

I found some plans for a simple dehydrator from Home Depot that is more suitable to my site and carpentry skills. I've attached them below in case you want to take a look.

Thanks for sharing your thoughts.


Picture of Kathy Partridge
Re: App tech possibilities and pitfalls
by Kathy Partridge - Wednesday, November 18, 2020, 9:11 PM

Wow, thanks for sharing that plan! Yes, it definitely looks like a more appropriate "appropriate technology" for me and my skill set. 

To answer your question, yes, I did build the cold frames myself. They're based on the classic cold frame design that Eliot Coleman discusses in his book, "The Four Season Harvest".

I found your thread on solar panels interesting. It's something I have in mind for someday, but for now I pay a few pennies extra per kWh to National Grid for 100% green energy. However, the site I visited for the permaculture site assignment has a small set up and the owner found a number of creative ways to cut her electricity use so a small system is all she needs. I replied to your post with some of her ideas... maybe some of them will help cut your costs. it's fun to think outside the box. I'm leaning toward the small-freezer-as-fridge idea myself.