Tag Archives: solar oven

Eggplant

This is my favorite way (pretty much, only way) to prepare eggplant.

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Eggplant sliced a 1/2 inch thick, sliced fresh tomatoes, and grated or sliced cheese.  Grind black pepper liberally (I added sliced green olives to this batch).   Hose down with olive oil and bake until the cheese bubbles.

Really, it’s like mini-pizzas with eggplant for the “crust”.

Solar granola

We’ve been making a steady supply of granola in the wonderful Sun Oven.

This stems from a compound realization:  1. We both like granola.  A lot.  We eat it very often.  In spite of the risk of being called granolas.  2. It’s bloody expensive!  Analyzing monthly expenditures turned up an alarming number on bulk granola.  Oh, but it’s so good!  Can’t stop! (see #1).   3.  Rolled oats- not so much.  Very cheap, or relatively so for these days. Really, it beggars belief how much the price for an oat can inflate if you drip some sugar on it and toast it.

We can make it ourselves!

So we’ve been mixing up big batches of granola and toasting by the panful on sunny days, which have arrived in abundance in April.

Our granola kicks a** on the granola we used to buy, and HW even muses that what makes it really special is he can “taste the sun in it”.  We won’t be going back.  Making enough to last through the winter might be a challenge…hmmm.

Our recipe:

(we usu do twice this much at a time, and amounts are approximate, but this is the basic)

  • 3 cups oats
  • Cinnamon, and often the usual pumpkin pie culprits- nutmeg, ginger, and cloves.
  • Dash of salt
  • Optional 1/2 cup of some deluxe optional additions, like sliced almonds, pecan pieces, hazelnuts, flax seeds or pumpkin seeds; finely chopped dried pineapple, or candied ginger, or dried strawberries.  This is what adds the wow!

These are the dry ingredients.  Stir ’em up.

  • 1/3 cup coconut oil
  • Splash of maple syrup
  • 1/4 cup honey
  • 2 Tbsps brown sugar
  • 1 Tsp vanilla

These are the liquids.  Heat them, together, and drizzle them over the dry while rapidly tumbling the dry ingredients with a wooden spoon.

Bake.  Normally this might say 15 min at 350F? or some such.  It’s about twenty minutes in the sun oven, and then stir it up and leave it another 10-15.  Watch the oven!  If it gets to dark brown, it could be just fine with milk, but there might be too much sun in it.

 

 

Inflating an Off-grid Greenhouse

The short answer: a bilge blower fan on 6v.

The first question to ask yourself if you’re considering an off-grid greenhouse, is, should I choose an inflatable?

It’s more work stretching the plastic perfectly tight over a non-inflating greenhouse, but, then you’re done.  An inflatable is stronger, and warmer, but, is it worth it?

If you have a robust solar system and can hardwire your inflatable greenhouse into it, great.  Otherwise, say if there’s a possibility of having to carry batteries from a charging station to the greenhouse, you may want to choose more work up-front vs. more ongoing work maintaining power to the GH.

We  have an adequate solar array,  not a generous one, and it is set up too far from the GH to directly wire it or the batteries stationed there into the controller.  Therefore, we assumed from the beginning that we’d be carrying batteries.  How often was another story.

Choosing an inflated GH off-grid, the first hurdle is the inflator fan. AC fans are readily available, but DC fans are not, and the issue is not readily answered by Google either.  That’s why I’m writing this.

I’ll spare you the harrowing hair-pulling details in this quick overview of our journey to get our off-grid GH inflated:

1) Can the squirrel cage blower be detached from the AC motor it came with and be retrofit to a heater fan out of a car?  Yes.  It depletes a 12v battery in a few hours.  Not sustainable.

2) Go see an electric motor specialist.  Can a DC motor of appropriate specs be obtained that will run the squirrel cage at the right rate?  In theory.  It’s $349, and wait, no, it’s out of production.

Feeling very much trapped inside the box, 3) Call Inventor Dad. In 48 hours, he found the right thing.  A bilge blower fan from a marine supply.  It’s cheap ($25ish), it’s made to run on 12v, it’s the right size, and compact into the bargain.  Yay!!!!  This one is from Binnacle.com.

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Our troubles are not over…

I hooked it all up, plugged it in, it started blowing like it was born to, filling the envelope entirely in about 7 seconds, and then it kept blowing, and blowing.  Oh crap!  The plastic started to strain and at about 12 seconds I lunged to yank the leads off the battery before it blew.  Far too powerful.

4) Try a 6v battery.  Perfect.  It runs for two days on a charged 6v at exactly the right pressure.  Are we done?

Not quite.  The 70lb 6v batts that we have are, to put it mildly, no effing fun to carry back and forth from the cabin where our solar panels are mounted to the greenhouse.  Put a panel by the greenhouse?  A possibility, but there’s nowhere to mount ON the greenhouse, so it would require its own stand.

One last attempt. 5) Aha, I think, a dimmer switch.  An AC dimmer switch does not work in a 12v line.  DC dimmer switches exist, and are super cheap on eBay.  I thought this would be the final answer.  12v batts are no prob to carry, and the dimmer would cut it down to 6v.  The dimmer blew up on the first day.  Turns out you really can’t load them with a motor.

If this sounds bad and you’re wondering how much hair-pulling I left out, just imagine 100s of trips over months at all hours, in all weather, carrying batteries, and add in periods of despair (while carrying batteries) between each breakthrough.

Especially sucky is that in the winter, when you really need it inflated, there’s no sun to keep the batts charged.

Our reality: Most of the time it is not inflated.  That’s because we still have to carry 70lb 6v batteries back and forth, and it just doesn’t need to be inflated 100% of the time.  We turn it on for windy and snowy days and nights. I was a nervous Nellie at first about it, but the first winter it saw was one of the worst for snowload ever in the Maritimes, and it handily evaded Greenhouse collapse disorder.  I tightened up the plastic much more assiduously than usual for an inflated GH,  to quite smooth, and cold, there’s hardly any slack to flap.  In the heat of the summer sun, I’ll have to reevaluate how often it needs to be inflated, and perhaps dedicate a panel to it.  Then the battery-carrying might be eliminated or limited to the wintertime.

The moral of the story: think hard about inflating vs. not, before you buy.

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May 2015- We dedicated a panel to it.  Built a simple frame with legs.   It rotates manually:)  It’s working really well, now that the summer time sun is here – now we just leave GH inflated all the time, as it was intended to be.  It’s a bit of a waste for a 120W panel, perhaps, from our home system, but then, maybe it will be just right for the shorter days of winter and be not such a waste.

Solar oven

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First loaf of real (yeast) bread on the go

One essential off-grid accessory is the solar oven.  It was on my list of early things we would have to build, but my Dad gave us this commercial oven (Sun Oven, from Illinois), and is it ever wonderful.

Its praises:

Portable.  Oh so portable, because it’s ultra light, and it’s a perfect size dimensionally for picking up with two hands and toting around, even when there’s something stewing or brewing in it.

Incredibly well-designed.  The inside is easy to wipe clean; there’s an adjustable landing leg on the back for easily adjusting the tilt to aim it at the sun;  when you stow the reflective panels, which takes about 2 seconds, there’s a snap strap that secures them, and then there’s a suitcase handle; the exterior is molded plastic, without seams; the glass has a airtight rubber seal; it holds a tall pot or two bread pans side by side.  Especially, there’s a cradle inside that holds the pot or pan, and it swings to keep the contents level no matter of the tilt you put on the oven.   The cradle has a little edge to keep your food aboard.  All so very very well-designed.

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The internal thermometer is obscured by condensation pretty quickly when it heats up.  This oven heats up very fast, hitting boiling in about 20 minutes.  It takes 3-4 hours to bake, say, banana bread.  I scoot it around in the afternoon and adjust the leg to keep it aimed at the sun.  On a sunny hot day, I can bake two items.

It’s not just for baking of course.  It boils water, cooks rice (like a dream), cooks anything in a pot, really.  I even managed to burn something.  I’m trying to get into bread, in the spirit of reducing things that we purchase.  H.W. got a lot of discount bananas though, so there was a run of banana bread, which does very well in the Sun Oven.

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Starting to steam up. Looks like a banana bread loaf.

I try to use it for cooking every sunny day.  Every time I use it instead of the stove, I save that much propane.  And when it’s hot, no one wants to heat and steam up the camper, ugh.  This keeps the heat outside.  I pick it up and set it in the sun, open the reflective wings, set something to bake and turn it to optimum sun a couple times during the baking, then fold in the reflectors and put it away for the night.  E-Z.  Awesome.  I’m really glad I didn’t know until now what this oven goes for, (phew!), but it does have a lot of advantages over the bulky, heavy, less portable and versatile homemade possibilities, and I can’t imagine any possible improvements.  This is the top of the heap of solar ovens.