# How much energy does it take to cook a steak?

Grilling in the park today I started to wonder just how implausible a portable battery-powered grill would be. There are of course a lot of parameters in this question, so let's narrow it down for now: How much energy does it take to cook a steak?

To be a bit more specific let's say a 2.5cm thick steak to a core temperature of 63°C. And since we probably need one more measurement, let's say it's circular with a radius of 5cm.

Everything from numbers for cylindrical steaks in a vacuum to precisely the numbers that are needed to get an actual tasty steak would be interesting.

• Assuming a similar specific heat capacity as water and starting at room temperature, it should be about 35 kJ which is slightly less than what my camera battery of 7.2 V and 1500 mAh can supply. So, it should be possible. – Count Iblis Jun 16 '14 at 0:13
• Your question is still not nearly precise enough. Count Iblis provided a lower limit under pretty much adiabatic conditions. Frying it in a normal pan will require approximately 1000kJ. Everything in between just depends on the conditions. – Alexander Jun 16 '14 at 0:18
• How fast do you want to cook it? The cooking temperature is not necessarily designed to supply the energy for an endothermic reaction; it may just speed up an exothermic reaction... – DJohnM Jun 16 '14 at 0:28
• @Alexander : Of course it doesn't have all the necessary parameters. That was exactly why I was asking here. The comment by Count Iblis is a decent answer in the "spherical cow"-range even though I don't know if that is average temperature or core temperature. But 1000kJ for frying in a normal pan? How would I calculate that? Does that include the energy disappearing into the room? Does it include heat-up and cool-down? Is it an essentially nonsensical physics question no matter the assumptions that can only be properly answered by testing and measuring? – Erik Vesteraas Jun 16 '14 at 1:04
• It is not a nonsensical question, it just has a large range of answers. 1000kJ comes from my stove, where a single burner uses 2kW and including warming up the pan such a steak might need 8 minutes (well done). – Alexander Jun 16 '14 at 2:24