Thread by @ScottLuft

The other day @elephanteating produced a thread on the economics of his woodstove.

https://twitter.com/ElephantEating/status/1128748331428208641

I dug into some data for a home 148 miles northwest of Rochester.
Here's a thread with efficiency, rebound and relationships - including savings from a stove

I pulled the data together for my electricity and gas bills, and just roughly estimated wood consumption.
Gas conversion: 277.8 kWh per GJ (and .038 GJ per m3),
Wood: 20 GJ/cord - a different mix of ash, maples, willow, cherry yearly (whatever came down)

some context along with a graph of energy consumption: we moved to an abandoned century home with only electricity in 2003, living in about 60% of it for about 4 years - with the wood stove entering service soon after the back was moved into.

Since 2012 this is probably fairly typical of an average detached home's energy consumption, although the mix is different with more electricity and less gas (due to the hot water tank) - but that is not too shabby for an old house.

wood is treated as free.
there are many costs to chopping trees down and cutting them up, but there are also benefits other than firewood.
The savings are displaced electricity until the gas furnace enters service, and then displaced gas.

Same result as in Rochester - wood displacing natural gas is neutral if paying for wood (which is likely to cost over the $220/cord seen in recent years).
But savings was substantial where it displaced electricity, and probably significant displacing oil or propane.

but wood isn't the big story in my data - and I probably should note the bigger tale having criticized conservation spending recently (albeit in a way that I think was correctly interpreted by smart people like @energysmartohio)

EE shows the big savings
coldair.luftonline.net/2019/03/f-in-e…

this likely underestimate savings from efficiency (building envelope).

as with firewood, I treat efficiency costs as zero - which may sound nuts but lets say the money was spent of increased living space and property valuation.

only spending on utility bills is counted.

there's a contradiction: spending stayed flat the first couple of years with a furnace I claim saved over $1000 annually.
There's a couple of reasons for that: overall spending would have increased as electricity rates rose 20+%;
I computed rates as bill/consumption, but...

in reality almost 40% of my gas bills have been fixed charges (~$272/yr), and billing for electricity has moved from volumetric charges to pay for wires, to fixed.
This means that whereas gas diplaced ~20 cents/kWh in 2015, it now should displace 12.4 but does displace 8.2

The 4.14 cent difference is due to borrowing to curtail cost because of the [un]Fair Hydro Plan (which I despise).
This means efficiency spending is devalued now because of costs in the future expanding due to borrowing and debt.

but cheaper now.
hello rebound.

Which brings me to the "smart" thermostat.
NEST sends a monthly report with hours of use, and "Leafs" awarded for greenness.
in the beginning, I was a Leaf collector.

or maybe, I found out in the NYT, a domestic abuser
nytimes.com/2018/06/23/tec…

Striving to be the trophy husband, as I do, I've tried to abdicate control of the NEST to my wife.
Who, despite her choice of partner, likes it kind of hot.

We went from 23 Leafs in Jan. 2016 to 1 in Jan. 2019.

when we got the latter report, she asked if I'd been messing with her thermostat.

And after the heating days were over, and I'd reported our spending on energy had never been lower...

(I haven't use it yet, but good install experience facebook.com/SMhomecomfort/ )

so there's my nostalgic comments on savings from burning wood, energy efficiency, fuel switching, smart stuff and rebound.

I'll end with a simpler pitch for a wood stove:
your friends will love it.

please unroll @threadreaderapp