Power systems (fuel) - help me decide

[Chorky]

As the title suggests. I cannot seem to make a decision on keeping with industry standard of LP, or go the diesel route, or some sort of combination between the two.

LP:
US industry standard
lots of parts/appliance available - though not always good quality
relatively simple
can be dangerous (volatile)
can be expensive / difficult to find good LP sources nation wide and in Canada
not as efficient as other options especially with elevation and temp changes

Diesel:
Higher efficiency
Can have large on board tank to last significant amounts of time
easier to source diesel than LP
not as volatile
costly systems
not industry standard meaning sourcing parts could be more difficult
would require 12v fridge/freezer route - more extensive electrical system
would require LP system if wanting to cook with gas
could introduce cold weather concerns


I'm sure theres a ton of other pros/cons, but these are the primary ones that pop up in my head for now.

 

[luthj]

Can you flesh out your usage case for me? There is obviously no single correct answer. After cooking with induction for several years, I have little interest with going back to LPG, at least for inside cooking. This does mean significant electrical system investment, though its pretty dependent on how often you cook, and for how long. Being able to use electric cooking appliances has some value. Waffle makers, small toaster ovens, etc.

 

[Chorky]

Sure thing. I'll give it my best shot. First I must say though that I very very rarely if ever use things like waffle makers or toasters. I think the last time I used something like that was 10 years ago.

I do most cooking over a gas stove as it is now. Even coffee I prefer older methods and use a french press. My major electrical draws would be the micro to heat food (could be done in an oven) TV, computer, AC in summer, and space heater (although pending a better system I could rid of the space heater). I usually meal prep, meaning I usually cook a few weeks worth of main dishes, so daily usually all I cook is breakfast, and sides (like boiling broccoli or pasta) and then heat up the precooked meals. although, at times I do cook more frequently. This would be for a full time living situation. I do expect to have a genset, but will still need a fuel source for gen and for appliances. Weight still needs to be respectable though, as travel on winter icy roads will be frequent. The ability to have a outside source to charge batteries will be possible, but likely infrequent and/or not reliable.

 

[Joe917]

LP is not an issue in North America. You can get it everywhere and there is nowhere in North America high enough to cause problems. If you intend to travel to South America things are different.

 

[Chorky]

Thanks Joe I appreciate your input!!! I have heard of some running into big issues finding LP in Canada. And I know connections are different, but that can be easily resolved. I have no desires to go south. Mostly I'm interested in deciding the best option for cold weather, efficiency, high altitudes, accessibility, and ease of repair/maintenance. Which in total would seem to point to LP even though my initial thoughts were heavily against it.

LP
If LP was decided on, I would like to find a way to safely carry over 100#'s which should be sufficient for 2 months of cold weather.
This would be heavy considering weight of the tanks.
This would also allow for a duel fuel genset for redundancy
It would be 'simple' as it's common
I do like to cook over gas - however have never had the opportunity to use a diesel stove/oven, maybe its better?

Diesel
If diesel was decided on, fuel storage would be simple
systems are proven to be highly effective in the community, and desireable
Likely would still need to carry LP for when desiring to cook outside (many places dislike charcoal these days)
would require a diesel genset
My truck is in fact diesel - single fuel source
safer fuel option
more supsceptible to cold weather (requires additive or winter blend)



One other thing I failed to mention is the desire to leave systems running in cold weather for lengthy periods of time without my presence

 

[DiploStrat]

Another option - kerosene. Burns hotter than diesel in diesel appliances and is less prone to sooting up at altitude.

We use diesel heat/hot water and and cook electrically - diesel stoves are really annoying, but adding a kerosene tank, for our Webasto Dual Top, is in the future as it burns cleaner.

Building an electrical system that can support an induction cook top and a microwave, as well as a toaster and espresso machine is possible, but that is another discussion.

 

[Joe917]

Diesel ovens and cook tops can be temperamental(anecdotal) I have no experience with them. Best solution for refrigeration is a 12v compressor fridge(Danfoss). For heat do not go propane. You have a diesel vehicle so use a coolant heater system, Webasto or Esparcher (love our Webasto).Now you are down to your cooking appliance, I like cooking on gas but is it worth all the propane issues just to cook, I would suggest electric and eliminate the propane completely.

 

[Joe917]

With our Webasto we can leave the truck anywhere and set the thermostat to frost protect, if temp drops below 5C heat comes on. Consumes very little diesel. With a 450liter tank we could probably leave it all winter!

 

[DiploStrat]

With our Webasto we can leave the truck anywhere and set the thermostat to frost protect, if temp drops below 5C heat comes on. Consumes very little diesel. With a 450liter tank we could probably leave it all winter!

After the pain and cost of dealing with anti-freeze and the pain of recommissioning the truck for winter trips, we are simply leaving the Wesbasto on. The cost of a winter's worth of diesel is much less than one load of anti-freeze. Granted that Washington, DC doesn't often get below about 15F and doesn't stay there that long, but it does get nippy.

 

[Chorky]

Diesel ovens and cook tops can be temperamental(anecdotal) I have no experience with them. Best solution for refrigeration is a 12v compressor fridge(Danfoss). For heat do not go propane. You have a diesel vehicle so use a coolant heater system, Webasto or Esparcher (love our Webasto).Now you are down to your cooking appliance, I like cooking on gas but is it worth all the propane issues just to cook, I would suggest electric and eliminate the propane completely.

I certainly like the idea of diesel for air heat and water heat. It's proven itself significantly. For my application I wont have the luxury of having the coolant system tied together. Theres too many complications in that for me. Good to know that diesel ovens/cook tops are a pain. I have not experienced them before. Currently I do run a 12v compressor fridge - snomaster LP67. It runs good, and hasn't failed yet in 2 years. But, it seems to eat up batteries much quicker than expected. Possibly it's because its a snomaster and maybe a Danfoss would be much better. It will run my bank (not a robust one currently) down in 2.5 days. I figure either way I will need a auto-engaging genset to rebuild battery banks if gone for a week to a month. Temps here can get below 0F easy, and often into the negatives at night mid winter. LP works for now, but it can be consumed rather fast and looses pressure at cold temps. I already had an instance this morning where the pressure wasn't high enough to heat, and it was only 20 out... But I think theres another issue there.

My biggest concern with the diesel route would be the ability to build a electrical system robust enough to power everything else (12v fridge, 12v freezer (yes, would need 2 after a hunt), cooktop, convection oven, and other normal electrical devices. Especially through the winter when I would rely on a combination of genset charging and plugging in at places here and there - as solar just wont work well when theres clouds and snow on the roof. This does present itself another issue of requiring a large fuel tank if in the winter I'm mostly using a genset to charge batteries up, or run heavy appliances... I think the 3 of us chatted about battery banks not long ago, but my math just wasn't coming up in a positive way. So I would certainly want a good genset to charge/top off things probably every other day, if not daily I would imagine.

I suppose another option would be a gasoline system. I believe they are available. That would allow for a duel fuel genset, proane cooking, but gas heat/water. That seems like a big compromise for little gain though.

 

[DiploStrat]

Some random thoughts:

-- Cooking all electric (dinner and breakfast) and running diesel heat all night runs us in the neighborhood of 135Ah. Others make get other numbers. For example, using LP gas for cooking may save you as much as 50A and, of course, the actual temperature will impact the amount of electricity needed to circulate your heat. There is no reason you can't cook with LP and heat with kerosene or diesel.

-- You need to calculate the number of days of autonomy that you require. That is, how many days of rain without driving. This will determine the size of your battery bank.

-- Solar should generally be sized at 100w per 100Ah battery. In good sun, you can expect about 5A per 100w x 6 hours per day. Rain/snow/clouds and you will get less. Solar, or periodic overnights of shore power or genset use are essential to fully charge lead acid batteries and reduce sulfating. Lithium is more forgiving.

-- Your Ford can be equipped with an alternator robust enough to provide a good bulk charge.

-- I don't know of any energy source that can match diesel or kerosene for cold weather. (We use our camper in the Hudson Valley during the winter. Below 0F is hard, but it is harder to start the engine than to run the heater. Most people who use propane have to stay put and use a large tank mounted on the ground.

-- All electric refrigerators generally provide better cooling than LP gas units.

-- The new generation of inverter/generators is much quieter and offers new options.

 

[Chorky]

Some great thoughts. I always appreciate your input and am happy to have you on this discussion. ?

I suppose one thing I still need to do is just dive into more depths of electric cooking. I have looked into it some, but obviously not as extensively as necessary. And possibly picking up a small cooktop to 'test' at home is needed since I have never used them either.

135ah is way less than the numbers I come up with. I must be doing some math wrong somewhere... Something I need to revisit. I did certainly plan on a genset for a daily or every 2 day charge when shore power is not available - which shore would probably only be available 25% of the time

The truck does have a 200a alternator, although not currently installed. I have consiered getting the brackets for a second alternator specific to the house batteries, although I'm not sure that's necessary.

I do agree that for super cold temps diesel is the best. And suppose having a combination of diesel, LP, and elec. isn't a terrible thing. Just means I would have to be very careful about building sufficiently since it seems the more systems one adds the more options for failure there are. I like the idea of a single fuel source. So either diesel or LP. Then again, if using diesel for heat, which is a major consumer, one could easily run for 3 months of cooking on LP - as I did this summer. Went through 2 20# tanks in 4 months (some did include using propane water heat when the elec element had a failure). However, one could also consider having 3 systems (diesel, LP, elec) to be a benefit of redundancy in case of a system failure, if even only to 'get by' while working up a fix....

To answer one question, I would require 45 days of autonotomy. This would account for sufficient time away in winter months for a work project. Any longer than that and I would just opt to drain tanks and winterize. This would in fact though be 45 days in a federal compound. Therefore no shore power - in dead winter. So auto engaging genset would be required, as well as sufficient fuel capacity.

 

[DiploStrat]

We need to use the same terms.

When I talk about autonomy I tend to mean:

-- Electricity - time between engine starts. In cold rain, we can go two to three days. If we run the engine during meal prep, then the only limit is the fuel tank, and, with sun, it is nearly unlimited, especially if we drive for three to six hours every three to four days.

-- Fuel - miles/kilometres between fill ups. We have about 60 USG so, depending on the roads, we can probably do 500 to 600 miles.

-- Water - two standards, "motorhome" with showers every day and "expedition" with showers every week. 100 USG gives us ten days with showers and three or four times that with conservation. (Back in the day, we crossed the Sahara with around 20 USG.)

-- Food - just what you think. We have a large refrigerator and can easily go one to two weeks.

-- Toilet - dump. Our composting toilet needs to dump about once a week.

Hope these data are useful.

 

[luthj]

Nothing wrong with LPG, but it gets heavy with the weight of large ASME style tanks. Its also large, as the density of the fuel is lower than diesel.

Kerosene burns at the same flame temp as diesel. Kerosene is more highly refined, so it burns cleaner. It also vaporizes much more easily, so is less likely to coke up combustion chambers.

If you are planning on leaving this rig unattended for long periods, you need to address the risk of a heating failure. This can be with a water system that is tolerant of freezing. This would include lines/fittings which can tolerate it, or a system that will self purge. Or you need some type of backup heat.

If I was going with diesel for full time winter camping (which I am making changes to my rig for). I would use hydronic heat combined with a diesel air heater. This would use a 2-4kw hydronic heater (espar, webasto) heating a glycol loop. This loop would heat all underbody tanks (interior tanks are the most desirable though). These tanks would need some insulation, as would the lines, to keep the fuel usage down. The interior would have a 2-4kw air heater. Espar, Planar, webasto. For backup a heater core could be plumbed with the hydronic heater for heating the cabin. The hydronic heater could easily be coupled with a water heater which had a heat exchanger loop. This provides stored hot water. Otherwise you could opt to use a simple plate heat exchanger and tempering valve. This would provide "on demand" hot water. Though you need to warm up the hydronic heater if its off, which takes a few minutes.

Depending on your needs, you can connect the hydronic loop to the engine, this allows you to use engine waste heat to warm the water tank, underbody tanks, etc. With some plumbing and pumps, you could also use the hydronic heater to pre-heat the engine.

Another approach is the all-in-one water/air heaters offered by Webasto and Truma. These use diesel (or LPG) to heat air and water in a combined unit. For underbody tanks you could use a thermostatic damper to direct some of the hot air into an enclosed and insulated compartment under the vehicle.

For cooking you could just opt for a portable LPG bottle in a storage box for safety. You could also go with induction, but that requires significant charging/batteries, or a genset running. In the winter solar charging would be signficantly reduced, and getting a lead bank to full several times a week will be challenging without regular shore power. If you went down the route, and plan to keep the cabin warm 95% of the time or more, I would suggest a lithium bank, as that eliminates the rapid degradation a lead bank would see due to abusive partial charge cycling.

Of course this electrical system rabbit hole is pretty deep. Basically you would need something like a 400AH lead, or 200AH lithium pack. 2kw pure sine inverter. 80-100A shore charger (could be part of the inverter). Since you have a gen set you could use that to charge a lithium pack at 100A easily. Lead would take a very long time with a generator. With Lithium you could also get 60A easily from the vehicle alternator. I would also suggest as much solar as you can reasonable fit on the roof. It will need the ability to til 20 degrees (or more if possible) to catch the low winter sun.

 

[shade]

Out of left field, a methanol fuel cell is another option. Size the battery bank & fuel cell to complement each other, and you could go all-electric, even if solar charging isn't reliable enough, and you want unattended operation (no alternator charging).

Fuel Cells For Truck Campers - Truck Camper Magazine

Duncan Crawford installs a fuel cell into his truck camper, and shares his portable hydroelectric experience with us.

www.truckcampermagazine.com

If starting from scratch, I really think electrical power is becoming the way forward for everything, with the possible exception of space heating. A powerful LFP battery bank can be carried by even smallish vehicles, and it can be coupled to solar & alternator charging (or fuel cell) to meet most power demands. Especially when solar power is the primary charge source, electrical power comes with no fuel penalty, and it's the most flexible form of power available.