Higher voltage does not inherently provide any more power but for a given current, higher voltage provides a linearly higher power assuming a zero power factor (i.e. pure resistive load). Safe wire guage requirements depend completely on current. What this means is if 12awg wire is considered safe for maximum current of 20A for the given length run, then having 240v on that circuit would provide twice the power as compared to a 120v circuit. So, given real world limitation and conditions, it can be said that more power can be delivered using higher voltage. As for efficiency, you have to look at the problem in another way. Given two 2400W appliances, one running on 120v and another running at 240v. The 120v would be running at 20A whereas the 240v would be running at 10A, again assuming zero power factor pure resistive load. That would result in the the 120v appliance having 4x the line loss (power lost to the transmission line) because P = I^2 * R. With a given resistance, double the current means quadruple the power. That said, the wire R is very low given large enough cabling so even quadruple the power is still very low compared to the delivered 2400W. BTW, this is the main reason high voltage transmission lines are used for long distances. US long distance high voltage lines are > 100kv (or even more than 200kv) which allow for a large amount of power with reasonably low current.

Why not just replace it with a new 4 or 8 circuit breaker panel and feed it with some new wire?

Thanks, musicgal! Tracie, my daughter was told or maybe she read somewhere (here? ikeafans.com?) that the Numerar butcherblock counters sell out very quickly so I should check the website regularly for stock and then go immediately to get them when they had them. So that's what I did. Later I realized I should have ordered another 6' one; i was still within the kitchen sale period so I got a rain check and was able to get the 6' counter at the sale price as soon as they were in stock again. (They don't call it a rain check though---maybe "shopping list"? Something like that.) I don't believe that they're not ever going to get them again, at least not if they're still listed on the website. I've heard so many differing things about this and that at IKEA---FROM Ikea employees! It seems like it's really hard to get consistent answers about stuff. (Just in the past two days I've gotten four very different answers to a question I had about their faucet warranty. Sheesh!) edited to add: it wasn't more than 2-3 weeks that I had to wait for a new delivery of counters. And when I said I went immediately, I did--like within an hour of checking the stock. This post was edited by spanky_md on Wed, Aug 6, 14 at 17:59

Thanks very much everyone for the feedback! Sorry for picture difficulties, I couldn't get the pictures to load otherwise for some reason! I had 3 contractors and a kitchen/cabinet designer over yesterday. Fortunately, it seems like my budget range overlaps with ballpark figures the contractors were willing to throw out, so that's a relief! The KD agreed with the general layout and said I should have minimum of 36" from the pantry to the peninsula, but I will see about trying to make the clearance there as much as possible, like up to the ~42". I can put down some tape and stack some boxes and see what clearance would work best for me. Its already a small kitchen, so anything I can do to make it feel a little more spacious would be valuable. Also in agreement on the lazy susan - it adds nothing and drawers would be nice, and I could put in a cookie sheet insert or something, just generally get more out of the cabinet. I will definitely do that! The KD also mentioned that instead of a kidney-shape pullout in the blind corner, I should just give up on that space and go with normal drawers as it would be a good way to get more fixed-size drawers in the kitchen (right now, the only fixed-size drawers I'd have would be those next to the oven, probably 15" wide, and ones at the top of the peninsula). So eating that dead space would add 3 or 4 drawers. The KD also recommended a single bowl sink. I don't know, it seems so convenient to have 2 bowls, though maybe 36" cabinet isn't big enough to have a 2 bowl sink with at least one bowl big enough for pots and pans? The KD also said that reducing the sink size doesn't really give me much benefit, only a wider cabinet at the other end of the counter that will be up against a wall anyway. I will have to research if a huge one bowl sink or maybe a 70/30 two bowl sink might work. Out of curiousity, would more than 24" between sink and oven be for more prep space? I can't fit anything bigger than about 24" in my oven, so I figured if I was doing a pizza or turkey, I could pull it out and put it right on the counter. Unfortunately I am pretty restricted on the sink because I can't move the drain enough to put it on the other wall with my state's plumbing codes. I can easily run water line down for fridge, but the drain is the greater issue. I actually mapped out a plan with my sister very much like yours mama goose, but the building engineer said people tried in the past and it wouldn't pass inspection. I don't like the corner sink, just a personal thing, and I like having my drying rack in the corner there. Any recommendations on where the trash can pullout should go? I'd like it to go in one of the bases.. If I were to drop down to 60" of cabinets on the peninsula, could I switch to a 30" cabinet, 12" cabinet and 18" cabinet for trash? Or maybe they'll have a 15" trash can pullout, though I doubt it. I still get a drawer above the trash cans, but would the top drawer get smelly and gross with trash underneath? KD also recommended microwave in a center cutout of the pantry, which I'm inclined to do as it would take away a small eyesore and I personally very rarely use a microwave (though I know future owner may want a place for one). As an aside, two of the three contractors told me they'd only work with me if I used their cabinet lines, as its where they make most of their money. One of them only used Bellmont cabinets, which I read about and was not impressed. The other had a little more selection: Marsh, Wolf, and J&K Cabinetry (Chinese made). The Marsh seem ok.. but reviews are mixed and contractor estimated $6-7k for my small kitchen. The last contractor said they are fine with whatever cabinets I choose, and, despite having carpenters that can install them, would understand if I wanted to have cabients installed by someone else. If Woodharbor comes back in my price range, I'll almost certainly go with their cabinets and the contractor that offered flexibility.