Cooking with solar panels

[Mike90250]

Even an 800w induction cooker (I've got one too, BTW) can be hard on a single battery 12V system. Heck, even my favorite pair of 6V, 200Ah Golf Cart batteries would be fading after half hour of trying to produce 80A. Sure the cooker will cycle OFF-ON after it heats up, but it's a pretty tough hit on batteries. A bank of at least 4, GC batteries would be needed, and because of the losses, needing at least 200-300W of PV array to recharge them, if you want to eat after a cloudy day. Yes, you can live off solar cooking 80% of the time, but you will quickly discover there are a lot more cloudy days than you think there are (unless you live in the desert)
A single GC battery has about 1140 watt hours in it, but it cannot process the chemistry for a half hour cooking session fast enough, so I think 4 of them wired series - parallel to provide a 12V 400ah battery, would be the minimum for your cooking job.

[fivewin]

Instead of ceramic cooking plate or older types of electric stoves i perhaps can use induction max 1000watt (also startup at max 1000watt)

Anyone ever (stir) fry and cook with induction with max 800-1000 watt ? Then i can just have a simple system as described above at 12volt. Inverter = 1000watt, so 12v is no problem then.

[Gerard Fivewin]

Thanks NothRick, i will follow your advice and start with 200Wp system 12volt with the right wiring voor this "cooking" setup.

[NorthRick]

For only boiling water its ok, white_wolf or cooking pots. I cook like a chinese thus more frying and while frying adding ingredients. And i want to cook in the evenings also. Can you post picts of your thermal oven?

Neoh, yes i understand your figures. Its thus possible but is it advisable or do i need a bigger system when i want to use daily 500Wh for a longer life of the battery(bank).

Get 200 to 300 watts of panels. Mount them where they won't be shaded at all. Get a 200-220ah battery, appropriate charge controller and inverter and you should be good to go with the use you are describing. The wires from the battery to the inverter need to be sized properly as it will be over 80 amps if you are at 12 volts.

[Wy_White_Wolf]

No pics on mine at this time. Commercial oven is a SOS Sport oven with reflectors. You can google it. If you want to fry then build/buy a solar skillet.

https://www.youtube.com/watch?v=nEY1qxVa5ro

WWW

[Gerard Fivewin]

For only boiling water its ok, white_wolf or cooking pots. I cook like a chinese thus more frying and while frying adding ingredients. And i want to cook in the evenings also. Can you post picts of your thermal oven?

Neoh, yes i understand your figures. Its thus possible but is it advisable or do i need a bigger system when i want to use daily 500Wh for a longer life of the battery(bank).

[Wy_White_Wolf]

Typing error miscalculation and wrong terminology.

In a tropical country i perhaps can produce 500Wh with a 100-120Wp daily. My intention is to cook 30 minutes daily with a 1000watt electric stove. If i setup a100-120Wp system with an agm battery 100-200Ah i can achieve my goal OR NOT? That was my initial question.

Why bother with PV for cooking? Thermal is way cheaper and more efficient.

My $250 solar oven will boil water in 10 minutes after it's warmed up. Just set it out a 1/2 hour before you want to cook. My homebuilt one from scrap material that I had laying around will do the same in under 15 minutes. Once I build reflectors for it it should match the commercial one.

WWW

[NEOH]

Typing error miscalculation and wrong terminology.

In a tropical country i perhaps can produce 500Wh with a 100-120Wp daily. My intention is to cook 30 minutes daily with a 1000watt electric stove. If i setup a100-120Wp system with an agm battery 100-200Ah i can achieve my goal OR NOT? That was my initial question.

My answer was in Message #2.

Do you understand Message #2 OR NOT ?

[Gerard Fivewin]

To be more specific:
I'm living in a tropical country and only few times a week I cook myself.
Going to a restaurant is cheaper here ...hehehehe

When I cook I cook Asian food and after preparing all the ingredients the (electric) cooking/frying takes only few minutes and two different kind of dishes max 20-30 minutes. So I thought I buy this 1000watt electric stove and use this instead of gas. Can I do this with a 100-120Wp system and 100-200Ah deep cycle battery.

Is it for the long term feasible (or recommendable) with such a relatively small solar system?

Specs of the stove:
Features:

• Adjustable temperature control with Off, Warm, Low, Med, and High settings
• 1000 watts of power for faster cooking
• Easy to clean heavy duty cast-iron flat heating plate
• Cool-touch base and non-skid rubber feet for stable cooking
• Power indicator light
• 1000 Watts of power for faster cooking
• Adjustable temperature control with Off, Warm, Low, Med, and High settings
• Easy to clean heavy duty cast-iron flat heating plate
• Cool-touch base
• Power indicator light
• Non-skid rubber feet for stable cooking

Product Details:

• Product Dimensions: 10.7 x 9.2 x 3.6 inches
• Item Weight: 3.9 pounds
• Shipping Weight: 3.9 pounds

[Gerard Fivewin]

Then please explain this statement

I do not understand how you "only draw 300 watt" ?

I say, 1000 watts x 1/2 hour = 500 watt-hours

Typing error miscalculation and wrong terminology.

In a tropical country i perhaps can produce 500Wh with a 100-120Wp daily. My intention is to cook 30 minutes daily with a 1000watt electric stove. If i setup a100-120Wp system with an agm battery 100-200Ah i can achieve my goal OR NOT? That was my initial question.

[sensij]

well if you look at the bigger picture he may not be so- he probably got grant for this 'research', got team of student helpers + all of them spent some time in Uganda on taxpayer's dime. The last bit I'm not sure was advantageous but some ppl pay good money for the exotic travel. At the end they all might even got some scientific recognition- printed article, gave speech etc. Trouble is this activity is very detrimental to the cause they proclaim and distorts reality in those young minds crippling them for life.

From what I can see, it looks like the trip to Uganda / Rwanda / Ghana was just for four students, sponsored by AidAfrica (which prominently displays a "6 brick rocket stove" on their website, with no mention of anything PV).

[max2k]

Well, the guy that posted that is a moron. I get all my hot water from PV and not like those idiots on youtube. On the entire earth, why isn't there just one person on youtube that knows how to do it? Just sticking a resistance element on PV will give you very poor performance. The Panel has to be operated at its power point. A mismatch will cause a drastic power drop. The sun, panel orientation and resistance of the heater is almost never ideal. The electronics to optimize power costs less than $10. No reason to do it the idiots way.

well if you look at the bigger picture he may not be so- he probably got grant for this 'research', got team of student helpers + all of them spent some time in Uganda on taxpayer's dime. The last bit I'm not sure was advantageous but some ppl pay good money for the exotic travel. At the end they all might even got some scientific recognition- printed article, gave speech etc. Trouble is this activity is very detrimental to the cause they proclaim and distorts reality in those young minds crippling them for life.

[J.P.M.]

Well, the guy that posted that is a moron. I get all my hot water from PV and not like those idiots on youtube. On the entire earth, why isn't there just one person on youtube that knows how to do it? Just sticking a resistance element on PV will give you very poor performance. The Panel has to be operated at its power point. A mismatch will cause a drastic power drop. The sun, panel orientation and resistance of the heater is almost never ideal. The electronics to optimize power costs less than $10. No reason to do it the idiots way.

I get ~ 95 % of my hot water from solar thermal. ~ 2X as efficient as PV and about as efficient as PV/heat pump combination. The u-tube poster is about like most of the rest of those folks who preach from the idiot's bible of u-tube. Seems to me that maybe some rather well developed and much more appropriate technology could be used for heating and cooking rather than PV.

[PNPmacnab]

Well, the guy that posted that is a moron. I get all my hot water from PV and not like those idiots on youtube. On the entire earth, why isn't there just one person on youtube that knows how to do it? Just sticking a resistance element on PV will give you very poor performance. The Panel has to be operated at its power point. A mismatch will cause a drastic power drop. The sun, panel orientation and resistance of the heater is almost never ideal. The electronics to optimize power costs less than $10. No reason to do it the idiots way.

[J.P.M.]

Or just use a well-insulated glass-covered box and reflect solar energy into it - no need for PV panels.

Back in the day, I made an easily recognizable solar oven out of an inverted 20 gal. fish tank and 4 side reflectors of Al foil on fiber board. Boiled H2O etc. Even cooked some scalloped potatoes in it one time. The inside of the glass quickly fouled from steam and splatter etc. and slowed down the cooking process, but it worked well enough provided I adjusted the orientation ~~ every 20 min. or so. The spuds took most of the day to cook as I seem to recall. Proof/confirmation of concept was fun. The oven in the kitchen was faster and easier.