I believe I saw somewhere that there are different things you can use for fuels. I use trunks for my spark. I feel like that’s not idea. What would be the most efficient, player level around 17 so nothing crazy.
I’m just not sure what best fuels what and there’s not really any information in game aside from sticking random things in the fuel. I wish it was more user friendly but that’s what the community is so very helpful on 
If you put your fuel in a furnace it will tell you how much heat value it has. You will get the same amount of Spark out of the fuel if you put it in a spark core instead.
Soft coal is decent for a starter fuel. If you have to use wood, you get more value if you mass craft timber out of it first.
Efficiency by how long it takes to gather vs spark and fuel generated.
Timber until you have compactor.
Compacted soil until you have power for compactor.
Not sure what then but probably compacted hard coal.
Everything of course masscrafted for best efficiency.
I always see people suggesting compact peat for spark, but I don’t really know why.
It comes down to how much spark is generated from one block of soil.
Even decreased by amount required for compacting it beats every other not compacted fuel. And with right spec you can one shot break soil using copper tools.
I get its use before you get power coils, but pre-wipe I saw people often suggest it over compacted coals.
Again I would guess efficiency in gathering. If you can gather 2700 soil in around an hour - and I think I can make it faster, it is most efficient use of your time.
Not sure right now about coal as I’m just gathering rubies, but imho for quick spark up I will keep my shovel guy.
Because some people can’t afford power
Compacting coal isn’t going to be cheap, first you are going to need 500 power in the compactor, which is at least 2 advanced ruby power coils or 5 low tier ruby coils, that’s just for soft coal…the requirements become steeper as you progress up the coal tiers. Oh I also forgot to mention that if you plan on making the advanced coils yourself, because lets be honest buying advanced coils right now is ridiculous due to the pricing I’m seeing of everything, you will need a workbench with 1,500 power, so got to build at least 15 workbench diamond power coils first or know someone who has and will make them for you…that’s just the beginning. So you better be bomb mining like everyone else or you won’t be powering anything for a long time, or you are rich in coin so you can pay the huge prices for gems etc to make them…
Due to the materials you need and the spark required to make all this, compacting coal isn’t something most casual players are going to be doing for a long while…
People are burning dirt for a reason…
^^ This. Given the scarcity and the grind regarding Power Coils, I made a conscious decision to live without them for now.
Note that I’m not complaining about the current state of Power coils and I’ve accepted my reality. It’s just not worth going through all the headaches of leveling and grinding. I’ll happily go shovel for my peat.
Well kind of disagree on bomb mining or nothing. I’ve got my diamonds myself and bootstrapping everything (but portal, first one I bought 
and oort - I am happy to buy it) myself.
Did already diamonds, took like 4-8 hours after.i prepared. Now doing rubies which will take a bit more time and so on 
edit: I really and passionately hate android auto-correction…
From what I recall, in EA if you were buying fuel in a store compact peat usually gave the most heat per coin spent. I think compact coal’s sale value was inflated some due to its faster spark conversion rate and perceived superiority as a fuel. But I could be misremembering 
Imho that depends what are you optimizing for. Fuel efficiency based on time spent on gathering or fuel efficiency based on how much spark or fuel per 1 entity of soil or coal.
At low level Compact Peat is the best choice but as you progress… Compact Hard Coal is the only way!
If you look at Jiivita’s videos on bomb mining, like I did, you would also completely abandon the hammering rocks method. I am amazed at how ineffective hammers are when gem mining compared to bombs for the time and results, there is no comparison. I felt like a total fool not to be doing this from the get go as soon as I was able to.
I plan to just totally reverse my whole mining game in light of what I have seen, it makes no sense not to be bomb mining with the way things are currently.
Actually I did and won’t switch in near future. Difference is from time to time I do enjoy brainless grind. Besides another color of the stone is always nice to have + exp for my crafter from breaking, refining and making decorative stone is quite nice and it gives me a steady stream of material for building in particular colors.
For me bomb mining is the most efficient way of getting gems or particular ores, not for generalized progression as I understand it.
Maybe if I have a very strong need for particular ore, but for now more generalized approach works.
Oh I totally get you on the therapeutic effects of donking rocks for hours and obtaining rocks for builds 
, but if you are looking to power your machines, bomb mining is the only sensible way to go.
Compact peat does not work anymore for me, it used to now it just sits there. My spark generator is in fully repaired. Other fuel sources work but not compact peat?
Compact peat was burning for me yesterday. Bug? Any other form of compact resources else would require power.