Electrical upgrade perils

The rate you're paying from the electric company shouldn't change, though your electric bill will obviously increase.

The cost to upgrade the panel to larger service (200 amps) could be an order of magnitude greater than adding a breaker in the existing panel, as you may have to run new wires from the electric meter to the apartment panel (if it's even possible). Will your building permit it?

93A is 10kW -- are you really drawing 10kW at peak load times? That seems fairly high.

Is there something you can change in the apartment that would reduce the peak loads, to free up capacity for the dryer? For example if you have ten 100W bulbs in light fixtures, buy CFLs to cut 1000W down to 250W or so. Or upgrade air conditioning to more-efficient equipment. That's way cheaper than running a larger service feeder, and saves you money over time in energy/operating costs too.

Also, consider a gas dryer? If you are able to vent the electric dryer outside, perhaps you can just as easily run the gas flue out.

As Aaron says I don't believe that initiating a service upgrade would put you in a different rate structure with ConEd -- I think the options for residential customers are standard market-rate metering or optional time-of-use metering. You could call ConEd and ask to be sure, or consult the official tariff documents on their website.

It doesn't matter what your actual usage/draw is (e.g. CFL vs. incandescent). Each circuit has to be the capacity specified (15,20,30 amps) with its own breaker, and the sum cannot exceed the service provided in the panel. Additionally, code requires all kinds of things be on their own individual circuit/breaker (each window/wall AC unit, for example; technically, I believe, a microwave oven). That quickly puts you over the edge.

So Aaron2's concerns about the difficulty of bringing more power to your panel kicks in.

uptown_joe's gas-dryer suggestion should be the first thing to try for, and then proceed with electrical upgrade inquiries only if that's no-go. Most of the world, even when they use washing machines, air-dries laundry on racks or lines, by the way. It's another option.

Alan - it's actually not true that the sum of the branch circuit breakers cannot exceed the main breaker. Electrical codes and design practices allow just the opposite -- your engineer or electrician will evaluate the actual expected loads overall, taking into consideration a diversity factor to reflect that not everything draws its full rated current at the same time, all the time.

Interesting. And worrisome.

You would have no electric service if the sum of the individual breakers had to be less than the panel capacity. You could only have five 20 amp circuits on a 100 amp panel. The circuits serving a single ktchen alone probably exceed the panel capacity (separate 15 amp circuits for refrigerator, microwave, lights, GFI, and 220V circuit for oven).

The "we're currently using 93 amps" is an odd observation. What does that purport to measure?