Our research into efficient electric cooking continues. This time with an apple pie in the combination microwave/convection oven onboard Wind Horse. The results are encouraging.
First a small detail which pleases the head pastry chef. There is a pan which comes with this oven which is used for (amongst other things) catching drips, the function of which is demonstrated at the bottom of the first photo.
Linda is using her Kevlar gloves for handling the hot oven gear. The pie was baked for 50 minutes at a temperature of 200C / 410F. Power consumption was roughly 25 amp hours at 24volts, or 600 Watts of power. If we were to calculate the generator time to put this back into the batteries it would be about nine minutes. The pie shown is nine inches (225mm) in diameter. There is room in this small oven for an eleven inch (275mm) pie plate.
Not bad for a first try, and the taste can only be described as yummy! The browning on top is a little uneven, but this will be corrected in future production runs.
Posted by Steve Dashew (September 22, 2009)
September 27th, 2009 at 7:03 am
Hi Steve and Linda, do you think that the new induction cooktops and microwave/convection ovens are efficient enough on the weight/battery-usage/generator-runtime scale, where they are now a viable alternative for sailboats? I have had a (larger than the one you have, probably less efficient) Sharp microwave/convection oven on board, but have never tried an induction cooktop. I also was wondering how one might gimbal an induction cooktop (aside from just putting it on bracket where the pivot is above the top of the biggest pot), as it has little weight for the pendulum below the cooking surface (it looks like yours is to be mounted into the counter).
September 27th, 2009 at 10:44 am
Craig:
For many sailboats induction will make sense, in particular because it offers a relatively painless way to get rid of propane. Gimballing is not difficult. But some weight will be required below the cook top enclosure. However, fabricating the cook top enclosure will cost more than the stove.
September 27th, 2009 at 7:52 am
Now that looks tasty 🙂
From what I’ve read, you guys aren’t carrying much in the way of solar charging equipment. Still, as solar panels get cheaper, we seem to be seeing more and more of them fitted to boats. 600 watt-hours for almost an hour of cooking- that could be replenished by about three square metres of good solar panels in an hour or so, or by one of those new variable-speed DC gensets in even less than the nine minutes you estimate your current genset would need. With induction cooktops and these combination ovens at their current level of development, there should really be no need for a boat to carry propane or other volatile fuel for cooking anymore.
These ovens, especially in microwave mode, have been reported to put considerable strain on inverters in some cases; it’ll be interesting to see how your inverter bank holds up now that electricity has taken over the galley.
September 27th, 2009 at 10:40 am
Hi Matt:
We have been using microwaves with inverters for years without problems. The solar issues are more complicated, and so far, for the FPBs, these have not made sense. But it depends on your style of cruising.
September 28th, 2009 at 8:36 am
Hi Steve, I thought that a weight would have to be added, probably best to stick with the single burner “double” gimballed (disposable cylinder) stove for under way cooking, and mount the induction unit in the counter. The convection microwave I would think can be mounted as one would mount a conventional oven (adding weight to the bottom to move the CG so that it matches the (front to back) center of the “cooking” part of the unit (so adding food will not change the CG)) so I could use it underway, (one of the disadvantages of life at 12 degrees).
I’m interested in your “stack” of inverters in parallel, do you have them on a “load” switch (like on a heat pump) so they turn on as more power is required, do you turn on as many as you anticipate needing, or do you just leave all of them on without worrying about the “no load” current drain from the inverters? (you can tell I’m a sailor pinching amphrs…)
Never had any trouble with my inverter for the microwave/computer etc. either. I have however had the inverter inadvertently left on (after one of those LONG dinners Dark and Stormy’s…) only to wake up to the battery alarm at 4:00 am, with a headache and one flat battery bank. Are the new inverters “smart” enough that this issue is avoided?
December 17th, 2009 at 11:18 am
Thank you for your help! This was what I needed to know.
April 21st, 2010 at 1:43 pm
I have 2 Victrons Multis in parallel, but the software will not (yet) allow the slave one to be switched off if not required. The Multis have to be controlled through a PC, which is all rather dull.
April 21st, 2010 at 4:41 pm
Colin:
Something is wrong with y our settings. Check with Victron as they should work in parallel.