is it possible to use solar energy to power an oven?

An ordinary electric oven used a lot of power, as much as 10000 watts (10 kW). This means a huge solar array, a huge set of batteries, and a large inverter, all very expensive.

The problem is that oven use is intermittent. You need it for an hour or two, then it sits unused for a day or two. That means the average power is low, perhaps 1/10th the the above number. So you heed a large amount of batteries to sustain it for those two hours. A large auto battery stores about 1 kW for 1 hour, so to provide 10 kW for 2 hours, you would need 20 of these large batteries.

Now for an oven only, no top burners, you may be able to cut down the power level, perhaps as low as 1 kW, which reduces the power requirements, although it makes an oven of limited usefulness.

Another problem:

A solar array must be used all the time there is sun in order to pay back the large cost investment, many thousands of dollars. Using it only to power an oven, which may go for days without being used, is very uneconomical. That is why solar arrays are intended to power the entire house, not just one appliance. In fact, even that can result in unused power, so good systems are designed so that you sell unused power back to the power company, which greatly reduces the need for batteries, as you are then using the power company for energy storage, buying from them for high peak power needs, and selling to them when you have excess power.

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I agree with the others that this is a poor application of solar, when the hot sun is right there to cook your food, already. But since this is a school assignment, maybe the point of this exercise is to make a comparison with a solar oven.

So let's see - you want 1200W for 20 minutes (1/3 hour). That's 0.4 kWh of energy. I would estimate that you need to actually draw 0.5 kWh from your battery bank, and must put in 0.6 kWh from the solar panels during charging.

Battery bank - you would not want to draw this below 80% capacity, so that's a 2.5 kWh bank. Assuming 12 volts, this is about a 200 amp-hour bank. A couple Trojan T-105 batteries would probably be enough. Bear in mind that the bank must source over 100 amps, so heavy wires would be needed.

Inverter - you would pick something that has a 1200-watt continuous (not peak) rating. The cheapest inverter available would be fine for a heating application like this. You might also look into the availability of an RV toaster oven that runs off 12V or 24V DC directly, and skip the inverter.

Solar panel - must replace 0.6 kWh over a day with (say) 6 hours of peak equivalent sun. That's a 100-watt panel. If there is less peak sun (like, it must work in the winter), double the panel size.

In short, yes solar power could power a conventional electric oven, But, it will come at a hefty price.

However, if you build a solar panel array from scratch yourself, you could get way with a several hundred dollars to build. If you found a really good deal on solar cells, you could probably get down to the $1.25 - 1.75 / watt price range. A in inverter would cost another $50-$200 depending on make, model and whether a modified sine wave or pure sine wave type. Tack on the cost of a batteries and controller, and you have a pretty sizable investment for a school project.

Why not just use one of those simple solar ovens that you can purchase over the Internet for a $50 or so? The way things look from your project description, you could end up spending a lot of money unless you find some used/damaged equipment via ebay, Amazon or manufacturer/supplier who is willing to give you some defective/damaged product.

PV is a very inefficient use of the energy from the sun. Efficiencies run at about 10 to 15%, so converting solar energy to electric power is not the most effective way to use it. You may be able to make a genuine "hybrid" by using the sun's energy to directly heat some of your oven, like using brick or stone to retain the heat of the daytime sun. You can concentrate the heat by using metallic reflectors. Then, you can use a smaller amount of PV generated electric to regulate the heat and get the temperatures you need.

I have baked biscuits in a solar oven that I made from wood and aluminum foil just using the sun.

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