Solar electric oven is not such a far fetched thought as I originally considered; when thinking about powering your home from the sun, mostly one is thinking of LED lights, your computer and perhaps the television.
That's where I started, and it was so successful that I started considering various upgrades.
My strong advice is that, like me, you will probably become enamoured, no, infatuated with the free energy from Mr Golden Sun, as my granddaughter calls him.
This page was last updated by Bernard Preston on 20th December, 2018.
So, don't purchase a small inverter that you will probably upgrade at considerable unnecessary expense; go straight to the 5kW solar generator, or larger.
With the grid becoming unreliable in South Africa, and frequent rolling blackouts by the utility to prevent complete collapse, we made the decision to change over to a gas stove. But she who must be obeyed dug her heels in when it came to the oven; only electric would do.
Despite all my pleading, envisioning no baked food when the grid goes down, we chose a gas hob with an electric oven. How glad I am that I demurred to her; now we have hot food at night when the utility does its load shedding, but during the day she can bake and roast for free, and we fry and steam our vegetables mainly using the induction stove; they draw so little power and can also be energised by the solar generator.
We rarely use gas now; only for cooking at night when the utility fails.
Solar electric oven draws about 2.5kW of electricity.
No more waffle; back to the solar electric oven.
Modern stoves are a lot more energy efficient; whether it's induction plates on top, that use less than half the power of the old fashioned coil elements, or the electric oven that draws only 2.5kW, they are much more efficient.
Solar power energy is free; it's capturing and storing it that costs money.
So, if you are planning to use the sun to energise your solar electric oven, I would go for at least a 5kW inverter, and 3,000 watts of photovoltaic panels. If these terms mean nothing to you, then go to our solar power energy page, using the search function in the navigation bar.
In short, the sun's energy is captured by PV panels on the roof; the direct current is regulated by a gadget called a MPPT (on the right) and stored in batteries (below). An inverter (on the left) then steps up the voltage to 110 or 220V, and turns it into alternating current for normal use in your home.
This is my original system; the MPPT on the right, the inverter for home on the left, and batteries below.
But that 2kW inverter won't be adequate for a solar electric oven; go straight to the 5, then it hurts only once and you won't be doing an unnecessarily expensive upgrade like I had to do when we fell in love with that ball of fire in the sky. He's reduced our electricity bill dramatically.
In fact, we've gone even more radical with a 10kW inverter for home; now we can run the solar electric oven and simultaneously mow the grass; the new west facing PV panels provide more power in the afternoon when one needs more energy for the appliances.
Last night we had our first solar electric oven baked dish; pilchard fish cakes are one of my favourites. They only take half an hour, so Helen cooked them in the late afternoon when there was still adequate sunshine; and then the buttered gem squash and green beans were prepared just before supper on the induction stove using grid power from the utility. They only take five minutes in the steamer.
Up until now we have been using about 50 units of electricity per month; now with the baking and roasting being done in our solar electric oven it will be even less.
Going completely off the grid is something of a pipe dream; you need a huge bank of costly batteries. Or, accept that when you have an occasional three days of inclement weather that you will lead something of a deprived life; no hot water and no electric oven.
Even on misty days the photovolaic panels produce enough energy for lights and computers.
I'm giving no advice about the batteries; there is so much research being done that by tomorrow it would be out of date; but, for its worth, we are using lead crystal cells and they are proving most satisfactory; after five years there's no appreciable decline.
Remember batteries don't like being drained below 50 percent; in fact I try not to go below 80.
One thing is important though; do use only sealed batteries. You don't want toxic odours if the electrical room is in your home.
Changing the oven over to solar proved very simple. The input to the breaker was altered from the mains supply to a line from the change over switch; that enables me to toggle over from the utility to the sun in the morning when the PVs start providing about 500W and changing back in the late afternoon, all with one flick.
Purchase only the very best change over switch; our first one lasted just a year. Get advice from a local electrician.
One important issue is to also move the correct black line from the neutral mains bar to the change over switch.
Both live and neutral from mains and solar must remain completely and utterly separate.
Bernard Preston, semi retired chiropractor finds himself as something of a solar geek; admittedly he is a physics major. There were no solar electric ovens back in those days.
In my latest monthly newsletter which you can find at the bottom of any Chiropractic Help page, I quote Edith Wharton whom you've probably never heard of unless you're well read. I hadn't. She's the first woman to get a Pulitzer prize.
"In spite of illness, in spite even of the arch enemy sorrow, one can remain alive long past the usual date of disintegration if one is
My "big thing" on retiring was to go green and build this solar generator; it turned out not to be rocket science, but I do have a bachelor's degree in physics. You build your big thing.
Google doesn't like links in the body of a page near an advertisement so here are some of them that you may have wanted more information about. Firstly the solar powered generator upgrade; the whys and wherefores of the whole business; all about inverters, MPPTs, diodes and so on. And why, if you want to have a solar electric oven, you should go straight to a 5kW inverter or larger. I wasn't ambitious enough initially and had the unnecessary expense of an upgrade. You can be smarter and go bigger right from the start, then it hurts only once.
There's general concern about shadows fall across your panels during the day. My measurements are that we need not be overly concerned about shadows on PV panels.
Then there's the change over switch; that enables you to easily flip from the grid in the morning to solar, and back again in the late afternoon.
Here's that pilchard fish cakes recipe; half an hour to prepare and another thirty minutes in your solar electric oven.
This may look like a dog's breakfast, but I can assure you that you cannot get a healthier and more tasty dinner. Buttered gem squash and green beans straight from the garden and omega-3 rich pilchards with a tomato based sauce.
It's low in starch, so is perfect for our modified Banting diet. Butter is back and should never have been given the marching orders provided you have a balanced diet with foods like these.
If building a solar farm has been the "big thing", then a consuming interest in growing healthy choice foods is the "small thing". Or is it vice versa? My thoughts on backyard permaculture are what drive the whole; working with nature instead of against it.
Going off the grid means a big investment in batteries; or a very stable source of electricity from the utility, in which case no batteries at all are needed. Either way, there's plenty of power for a solar electric oven.
Disconnecting completely from the electrical utility is for most folk just a pipe dream; in the jargon it's known as going off the grid. You must have a vast bank of expensive batteries, and you'll still have cold showers if there is protracted inclement weather.
Your solar electric oven is then quite useless without sunshine.
My advice is to stay connected for the rainy days. Today is the fifth wet, misty day in a row. If we weren't connected to the grid, we'd be in for cold showers; the PV panels work tolerably well despite the weather, but with only enough energy for LED lights, computers and the TV.
This power surge from the utility that caused huge damage down our street is making me again consider going off the grid.
Bernard Preston books are in the main now only available on the net via Amazon; it's the future of literature. You can download most books in a jiffy at half the price.
I build these blogs on solar power energy just because I'm interested, and would like to encourage you to do the same. We need more greenies on the planet if it's to be habitable for our grandchildren. There's nothing else in it for me. The big plus is that we now have a solar electric oven.
Do you have any idea how satisfying it was to roast a chicken yesterday using our solar electric oven, knowing that it contributed not one iota to global warming?
But if you are a bookworm and want to say thank you, you could always nestle down under a LED light and enjoy one of my Bernard Preston books.
There are two genres; the chiropractic anecdotes and another more controversial book called A Family Affair. Read the reviews.
Folk do love them, though the latter may have you scratching the pate!
I'm busy now, my seventh book called "Priests Denied" but that won't be available until 2017; editing is a bear. It concerns the first married pope in a thousand years.
56 Groenekloof Rd,
What's this site about?
Consulting a chiropractor
Bernie's healthy choice foods
Bernie's rainwater harvest