Wood vs Briquettes vs Pellets

Pretty much all wood's (incl the likes of pallets which are compressed sawdust) sit at around 15 and 20 MJ/kg

https://cfnielsen.com/faq/calorific-values-for-different-raw-materials/

It doesn't really matter if it is hard or soft, Hardwood simple fits more weight (and energy) in less space.

If we run with say 17.5MJ/kg, that works out to 4.86 MJ/kWh. Burnt at 70% efficiency, thats 3.4kWh/kg of usable heat.

Using the 20kg firetime pellet bag cost from OP (66c/kg), this works out to 19c/kWh of usable heat.

The other option listed by OP work out to 30c/kWh for Briquettes and even more than that for the dry round wood.

Regarding the bulk wood, Macrocapa's density is 485kg/m^3. If we assume a thrown cube is half air and half wood, that means the 3 cubes that OP purchased for $400 weighs about 730kg.

3.4*730 = 2,474kWh. This works out to 16.1c/kWh.

Given the marginal cost of power at my place is 15.7c/kWh (incl GST), none of the above options make financial sense for me. I can run a cheap resistance heater for roughly the same price as the bulk wood, or run my heatpump at roughly 1/3 of that cost. All without the the effort & time associated with wood handling, storage, fire lighting, chimney sweeping etc.

In my mind using wood for heating is only a cost effective solution if you have access to wood for free, and only if you consider the time spent gathering, chopping etc to be recreational. (Plus people who are off grid or who have very expensive power)

With that in mind those buying wood to burn are unlikely to be doing it for financial reasons. Likely aesthetics is a key driver (fires do look great). Such buyers may prefer the aesthetics of logs rather than pallets.

Logs & Briquettes from hardware stores and supermarkets are very expensive. My assumption is that they are only purchased by people who only use the fire on special occasions (I.e. gathering at the house), or those who have been caught short with their wood supply and want something to bridge the gap until their next bulk wood delivery arrives in two days time...

I guess the wood pellet marketplace is a lot more competitive as people with pellet fires will buy a lot of them and hence shop around.

gchiu

Scott3