Is burning wood cheaper than electricity?

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Re: Is burning wood cheaper than electricity?

Postby jules » Thu Jul 19, 2018 2:32 pm

This DOES NOT apply to an open fire.


I'd be the first to admit that open fires aren't efficient but I wouldn't be without one and some are much, much better than others. I built mine using Ken Kern dimensions and it remains the best open fire I've come across. It's shallower from front to back than most, does away with the traditional "shelf" which makes no aerodynamic sense, has a decent slope at the back with a steel reflector. The worst designs for open fires can actually extract heat from a room. Typically, they're deeply recessed with no thought to making the best of radiant heat and the ability to draw in any warm air that's been created.

I'm lucky in that I've got a virtually infinite supply of wood, just as long as I'm prepared to cut and split it.

Oddly enough I'm using a lot of blackwood wattle at the moment, largely because it's about 15 years since a large number of these trees germinated after a fire and now they're dying off. Some are quite big and the wood burns away entirely. For serious wood here I like bloodwood, ironbark and brushbox but there's plenty of other timbers that make great firwood when really dry.
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Re: Is burning wood cheaper than electricity?

Postby ruffraff » Thu Jul 19, 2018 3:09 pm

Very true Jules.
The design is absolutely everything with open fires and nice to see you went to the trouble of looking into it. I suppose the problem is that the bulk of fireplaces are truly appalling as you pointed out and burn much wood to no purpose, which is why I said my usage doesn't apply to them. I had to assume that most people won't have a well designed open fire.
I am familiar with the design you chose and it probably burns less fuel than my Coonara style. If only all open fires were equal.
Blackwood is fabulous burning and use it when I can get it. I generally get 3 weeks from 1 cubic metre.
I stupidly forgot to say in my post above that I pay $120 per cubic metre for Manna Gum.
I truly wish I had your fire!
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Re: Is burning wood cheaper than electricity?

Postby Gordon-Loomberah » Thu Jul 19, 2018 3:35 pm

ruffraff wrote:1 cubic metre lasts me approx. 2 weeks (@$120/m^3)
...
I have used a split system in the same town that cost $250 per month for combined lounge and kitchen only and was still cold from the knees down and definitely not running all night.

So about the same cost per month, but the AC must have been using >33kWh/day, (assuming 25c/kWh, more energy if less than that) and not running all night, so must have been a reasonably large system. 33kWh just for AC is about twice what the average Oz home uses IN TOTAL, so I'd suggest that house needs some insulation!
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Re: Is burning wood cheaper than electricity?

Postby ruffraff » Thu Jul 19, 2018 4:54 pm

lol. The last house probably did need insulation. My current one has insulation in the ceiling only.

My main point really is that with the split system at 19 or 20 degrees, I only heated 2 rooms and didn't dare try to heat the 2 bedrooms, bathroom and hall considering the cost of the 2 rooms and as stated by others, the heat is dry and stuffy. I currently heat 7 rooms with minimal insulation with the wood heater. All things considered I find wood heating far more economical than a split system would be for the comparable area.
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Re: Is burning wood cheaper than electricity?

Postby australsolarier » Wed Jul 25, 2018 10:09 am

ruffraff,

your experience with wood stoves and aircons probably is more indicative of your building than comparisons between aircons and wood fires. we also do not know how well that particular aircon worked or whether or not it was suitable for your climate.
also people try to save electricity and turn the aircon on when it gets cold inside ( cold and night outside) . rather than heating up the house during the day when it is comparably warm outside and the cop goes up. (i think there was a thread here before , although with hotwater heatpumps about night versus day and off peak versus peak electricity prices)
as for myself i am using the house as a heat sink. i turn on the aircon at maximum during the day. it does get a bit too warm by sunset (so 27 degrees). by the time i hit the sack it is still 22 degrees inside.
for me the wood cooking stove is now just a back up. just a few days during overcast winters. for hot water and heating the house.
the hydronic radiator space heating system gives off the most comfortable heat. woodstove maybe second but not much better than the aircon. the woodstove takes a long time to start heating. whereas the aircon instantly warm up the air.
the airconditioner does not remove moisture during heating mode any different than the hydronic or woodstove heating. the relative humidity goes down, but the same amount of moisture remains.
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Re: Is burning wood cheaper than electricity?

Postby bpratt » Wed Aug 01, 2018 11:26 am

FWIW, I leave the garage door open here during the cooler months here in SE Qld, and find the sun heating the slab floor during the daylight hours, makes a difference to the house of an evening.

I close the sectional garage door (insulated too) before the sun goes down, and the heated concrete floor of the garage re-radiates the heat in the garage that flows in to the house, through the internal door.

Reduces the requirement to heat the house up on all except for overcast days, when little sun gets in to the garage.

The garage faces due north, so gets plenty of sun. :)
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Re: Is burning wood cheaper than electricity?

Postby offgridQLD » Wed Aug 01, 2018 6:25 pm

I Think the issue for people on the grid is the (average) home even a reasonable well designed one needs some heating at night (in the colder parts of Australia)

If its from electricity then your paying for it overnight. Even during the day in winter if the sun is out enough to be able to run your RC aircon from your PV then you most likely don't need the heater that day.

The reverse is true for cooling a home Air conditioning works great as you have plenty of sun over the hottest part of the day to negate the cost.

In our temporary rental while our house gets built on our farm. We are ongrid and have no solar First SA winter rental not well insulated and only a 6kw old LG split system to heat the house......all I can say is running that thing is like turning on a tap that flows gold coins down the drain! I have been walking around the house in my snow gear :lol: as I refuse to run that energy hog.

If I didn't have 200ah of free fire wood heating a home in SA would be a considerable factor in your living costs. What I would suggest for people without any options is install a very high efficiency split system 2.5 or 3.5kw or so into a small winter retreat room and spend your evenings heating the one small space. heating 100% of your house isn't needed. That or get personal heating heated jacket or blankets/throw rugs.

That or move to QLD :lol:
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Re: Is burning wood cheaper than electricity?

Postby australsolarier » Thu Aug 02, 2018 8:47 am

if the house is not insulated, it does not matter how you heat it, it will be costly and not very comfortable.

talking to the air conditioner installer, this what he said:
at the coast ( here near sydney) air to air works quite good. in the highlands however it is worthwhile putting loops into the ground to take advantage of the warmth underground. higher upfront costs but much savings long range.
i have written this before, the heat pump works best for heating when it is warm outside. the way i see it, turn on the heat pump during the day, get a nice head of warmth. this way you can take advantage of your solar. the heat pump will ramp down after a while. the reverse with cooling. don't wait till late afternoon to cool the house when the heat pump has to fight 40C.

Kurt building a new house:
floor heating, heat pump water to water with that ground loop. maybe a large heatsink, a wall or thick insulated floor part to store that heat generated during the day. or a 1000l hot water tank. so you get around that "heating at night when there is no solar". i mean the principle is very similar like a battery.
hook up that floor heating with a wood cooking stove that has a water jacket, for a back up.

but good insulation and double glazing are the most important. the walls are very difficult to insulate after the fact. australia has very lousy building codes.
there is a golden scissor cut between insulation and solar heating input. there is quite a bit room to manoeuvre.
i had lived in an uninsulated house in the highlands. after a particularly cold day (snow) i returned home to a cold house. lighting the fire, after two hours i felt warming up. the thermometer read 8C. that gives you an idea how important insulation is.

as for floor heating, the heat pump only needs to heat the water to 30 degrees. now compare this to radiators where it needs so 55C.
wish you all the best with your new house.
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Re: Is burning wood cheaper than electricity?

Postby offgridQLD » Thu Aug 02, 2018 10:38 am

Im taking the easy option this time round for heating free fire wood and good insulation.
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Re: Is burning wood cheaper than electricity?

Postby gemini2544 » Fri Aug 31, 2018 1:42 pm

It's the last day of winter 2018 & my fire is still ticking away nicely. So how much wood did the 2018 winter burn.
Well in reality two big 70ft Gumtrees, but before the greenie's jump on me, both trees had to be removed in 2016 due to White ant & the danger of a crushed house. So is wood cheaper, well it cost $200 to drop & cut the trees up, took me 4 days to collect and stack the wood to dry off, two years later, weeks of collecting a useful load, splitting it & stacking the wood close to the house for use. Then once a month, the cleaning of powdered ash from the heater. WORK, WORK WORK! But as my wife says, " It's the ambiance of a home fire that's really nice." So the A/C has no real soul.

Overall labor wise power would be cheaper, But not as nice! IMO
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