Replacing on-board gas with lithium/solar & induction hob.

[dunedin]

Lets not go down that habit hole please.

As I said in my original post, my curiosity is around how much solar/batteries one would need to replace gas and that the 'normal' domestic load / solar was already accounted for.

Why not do the sums then, as that will tell you.

Most who have done the sums say cooking and heating water use a lot of power, and the energy density of gas is hugely better than batteries

 

[Alan S]

I have recently changed to all electric galley - 3kw inverter , 500Ah LifePo4 batteries and 1600w solar (at 38v with MPPT controllers so more like 2500w at 12v) I also had to up the internal 240v wiring to 32amp to the galley so that the induction hob, coffee maker, microwave and Ninja Foodie can all work happily

So far doesn't seem to be a problem - we've done away with a full oven as nothing has sensible power usage - the Ninja Foodie allows us to bake, air fry, slow cook, roast, pressure cook etc for 1400w and (other than the slow cook which uses less power) quite quickly so overall power use is minimal. We may have to change the microwave for one with a grill too as we can't now do cheese on toast etc but thats the only tweak we foresee so far.

We do have a small camping gas hob as our emergency back up if all electrics fail

That's a magic solar controller if it can get 2500 Watts out of 1600 Watts of panels!
;-)

 

[noelex]

We use quite a lot of induction cooking and virtually all our electrical power is produced via solar. Assuming you do a reasonable amount of cooking in summer in the UK my estimation would be around 400-500w extra of solar coupled with around 200-300 extra usable AHrs of battery capacity.

In winter the required solar increases enormously and would not be practical even on a large cat with a huge solar array. In these months we switch to diesel/propane cooking.

 

[MathiasW]

On SAN, a 51' tri, we have 3400 Wp installed in terms of solar power, and 720 Ah x 24 V Li batteries. With this we are self-sufficient, but we have both, gas and induction. The latter as two single 2.1 kW max units that we can stow away and we hardly use more than 600Wh per day for these two units. Perhaps 3/4 of our cooking is done using induction, and so a big gas bottle as they are typical for Germany lasts for a year for us. Having said this, most of this is happening in locations considerably more sunny than either UK or Germany...

For what it is worth, here is a link with my installation: Autonomous Solar System on SAN - SAN - autonomy with solar!

 

[AngusMcDoon]

...use more than 600kWh per day for these two units.

600kWh per day! What are you doing with it all? Smelting steel? That's £40k per year of electricity at domestic price.

 

[MathiasW]

600kWh per day! What are you doing with it all? Smelting steel? That's £40k per year of electricity at domestic price.

Sorry, my usual problem with units... I meant 600Wh...

 

[vas]

I see some solar panel # in here that are crazy! would love to go up to 1kW solar but difficult to do unless on a large cat or willing to mess the lines of the boat way too much.
600W (to be swapped for mono 740W before the summer) typically produce 2kWh on a good day in med summer. fridges/laptops/leds/nav/bit of watermaker, etc easily reach that with tired FLA trojans.
Switching to 304Ah@24V LifePO4 soon would probably enable 1/2-1h watermaker per day. If that works, next step is a portable induction thingie for when we run out of gas (I'm well organised- happens every year with 3lt bottle and a spare...)
Wouldn't really consider it in Northen Europe unless I could cram 2X solar, not easy imho

 

[Pete7]

Sailing Cadoha with an electric galley, lithium and 750w of solar had to run the engine during the summer in Dartmouth to make up the shortfall after a couple of days at anchor.

We have a portable induction hob, electric kettle and toaster plus slow cooker, but have recently ordered a new gas cooker. We plan a mix of cooking options so we don't have the problem of running out of gas. This happened 4 years ago in the West Country with camping Gaz when the distributer just failed in August. None to be had in garages, campsites or chandlers. We bought the last small sized cylinder in Nos marina and it just lasted us until we got home. Determined not to have that again, we switched to Calor gas which is still in short supply. However, the electric kettle and induction hob do drastically cut down the amount of gas we need.

This looks interesting, but the price is a bit eye watering:

Techimpex Horizon 2 Micro Compact - 2 x Ceramic Hobs & Microwave Oven - 230V or 110V

 

[Travelling Westerly]

This looks interesting, but the price is a bit eye watering:

Techimpex Horizon 2 Micro Compact - 2 x Ceramic Hobs & Microwave Oven - 230V or 110V

I wonder why that Techimpex has regular electric hob elements and not induction units? Seems like they had a good idea of designing an all electric cooker for a boat then ruined it by using old tech basic electric hob! Those old heating elements are nowhere near as efficient as an induction hob and spending £2k for that privilege would be madness IMHO.

 

[Stemar]

I'm quite happy with my gas system, but if I were to go electric, I really wouldn't consider anything but an induction hob. They're just so much more efficient as near enough all the energy goes into heating the pan. We have one in our home kitchen and I wouldn't go back to gas,

However, If you only go marina to marina, with the occasional brew on route, it may be feasible, but I reckon the extra solar panels and batteries would be seriously expensive, especially as I reckon you'd need to go LiFePO to keep the weight reasonable for off-grid use.

 

[ashtead]

I gather some Bavaria 46 cruisers have induction hobs fitted with a genset but it seems a pricy extra option. As a back up a cobb barbecue which works fine in the cockpit might be a choice to support a stack of solar panels if genset doesn’t appeal. We just have standard couple of gas bottles . I would one day like to upgrade oven but serious expense and a bread maker is somewhat cheaper ,

 

[ibbo]

There are some 12 or 24v kettles if you want to save some gas, but not spend a fortune setting up for something that won't quite do what is needed when it's all done.

Slow boiling, but work fine.

Mike

 

[noelex]

The big advantage of electric cooking is the elimination (or in our case reduction) in the need to replace/refill gas bottles. There are slight cost savings, but the real motivation is convenience. For long distance cruising boats the multiple standards of gas bottle sizes and fittings can be frustrating.

The big drawback of electric cooking is producing the power. This can be done with solar alone and lead acid batteries, without using shore power (this is how our boat is set up), but if this is your only form of cooking you will be limited to cruising areas of reasonable solar insolation.

The solution on our current boat is to use a combination of electric, diesel and propane. This means we can cruise areas such as Scotland in winter, but we can comfortably carry several years worth of propane and therefore organise replacement in a country and location where this is reasonably convenient. The multiple systems also ensure redundancy.

Electric induction hotplates are very inexpensive. , as are electric kettles, so it is easy to try this sytem, but you will need a reasonable solar system, and a good electric system with a decent inverter (but a larger lead acid bank is fine) and these items are expensive.

 

[simonfraser]

wallas diesel hob would be far simpler, uses v little fuel

 

[AngusMcDoon]

wallas diesel hob would be far simpler, uses v little fuel

Or hob plus oven, or hob plus oven plus cabin heater. Expensive, but probably less than a big solar installation. Single, safe fuel on board, available anywhere.

Downsides, apart from price, are slow to get going, not as controllable as other cooking methods, need some electricity, and I don't think they've figured out a diesel grill yet.

 

[Kelpie]

This is our setup:
520w of solar (another 400w in the pipeline).
Epever MPPT
DIY 271Ah LFP
Epever 3kw inverter
Vango Sizzle two burner induction hob
Remoska electric oven

The whole lot cost around £1000. Some of it was secondhand. It's not just for cooking, the fridge also runs off the lithium, and the inverter gets used for the hairdryer, hoover, and laser printer.

I originally priced up Trojan T105s but that would have cost £700 vs £407 for my lithium battery, which has greater practical capacity, much better charge acceptance, and probably longer life.

We installed the system just before leaving Ireland, heading south. Cooked exclusively using solar from A Coruna onwards. We have never run the engine to recharge the lithium, because we can't- it's not connected to the alternator.

We've been in a marina for the last few weeks and have switched to shore power, so it's hard to say whether the solar would have kept up with demand. Possibly not in the depths of winter.

We did not remove the gas system. Occasionally we need a second oven, and at sea pans sit more securely on the gas hob so we sometimes use gas on passage for safety. At one point we did switch back to gas cooking for a day because the batteries were getting low, but that was literally one day out of several months, and that was following two days of rain in Galicia.

Don't believe people who say it's not possible.

 

[syvictoria]

It's no wonder that average boat size has increased dramatically in recent decades! Much like life ashore, everyone seems to need everything in order to be 'happy' these days... Not only are two heads deemed all but essential, but two galleys increasing so too it would seem!

Personally, the less I have, the happier I seem to be!

 

[Pete7]

This is our setup:
Vango Sizzle two burner induction hob

I believe the Vango has two 800w hobs and the width is narrow enough to fit in place of a gas cooker which is promising. Is the 800w enough to cook with in a pan? say a good fry up?

Pete

 

[Kelpie]

I believe the Vango has two 800w hobs and the width is narrow enough to fit in place of a gas cooker which is promising. Is the 800w enough to cook with in a pan? say a good fry up?

Pete

It's 'good enough'. Not as powerful as gas. Where you really notice it is frying off cheap watery cuts of meat, which can tend to stew rather than searing. But if you buy better quality meat that doesn't happen. We can always swap back to gas if we need to, but in all honesty we rarely do. The kettle takes a bit longer to boil, which is more incentive to measure out the water carefully. I used to camp with a Trangia alcohol stove and the Vango is streets ahead of that, although that is a pretty low bar.

The Vango sits perfectly on top of our Neptune 2500 cooker. I slightly bent the surround for the pan clamps to raise them. It takes a few seconds to swap between gas and induction- generally by the time one of us has gone and turned the gas on, the other one has already packed away the hob.

if I was going to get rid of gas altogether, I would probably look at a more powerful induction hob. I have also toyed with the idea of a more powerful single ring, they are widely and cheaply available.

 

[rotrax]

Sorry guy's - to me it seems a very complicated answer for a non existent problem.

I'm sticking to Propane!

I will install 400w of Solar and an Eperver MPPT controller this season though. Thatshould allow less use of the genset.