Capacitors and household current for high current loads?

Question

Is there a readily available consumer device, with a capacitor or some other mechanism that can store potential energy by collecting it from a household wall outlet- for the purpose of allowing a load to draw short term high current loads from an otherwise lower current circuit?

Say for example, a 15A 120V circuit input to a capacitor that would charge up and provide a 30A load for a certain amount of time on the output side?

I have two 13A heating elements for roasting coffee, that I want to run on a 15A or 20A circuit for 10 minutes at time.

Of course, I'd prefer and I WILL BE DOING the safer more reliable method- adding two new 15A branch circuits to the service panel- but my mind wandered and came up with this scenario when I started to think about an occasion where I may want to bring the heaters elsewhere, where I didn't have two circuits side by side.

I know, its ludicrous! I'm just being curious!

Answer 1

You could buy a UPS - an uninterruptable power supply - typically found in computer stores.

It's basically a battery, and a charger, instead of a capacitor and charger.

Where I live, by law, a kitchen outlet must be split - ie: the top half of the receptacle is fed from one breaker, and the bottom half is fed from another.  Both breakers must be side by side, and mechanically linked.

Answer 2

No, not for AC.  And even if it were DC, the capacitor that would store 20 amps for 10 minutes would be bigger than the room. And cost more than your rewiring.

But an interesting calc: CV=it

C = 20A*600sec/10v = 1200 farads. Such a cap rated for 150 volts would indeed be larger than your house.

.