Chaz TeplinA thread on my home’s heat pump performance during the recent Colorado cold spell. There will be data and #Chartz and grid context! But the TL;DR – My system performed great! But did use lots of power. (1/n) #Heatpump #EnergyTwitter #electrify
Context: I have #ElectrifyEverything. My 2400 sq ft townhouse has a Mitsubishi heat pump with resistance backup running ducted system. My @SpanIO electric panel monitors everything. See previous thread, sadly on my Twitter. (2/n)
It was cold last week, below -10°F in Boulder! So how did my system do? Most importantly, it kept my home comfortable. This chart has LOTS of data. (3/n)
The vast majority of heating was provided by the heat pump, which worked well below 0°F. My controller added resistance heat briefly during the two coldest nights (Dec 22 and Dec 23). (4/n)
Total electricity use was high! I used over 100 kWh for heating on both Dec 22 and Dec 23. Of course, gas heating systems also used tons of energy! Compare to my total daily (non-EV) power use of <24 kWh for most temperate days. (5/n)
Now how did my grid provide that electricity? And more importantly, how could it supply my power as Colorado continues its decarbonization path? Here is Xcel’s generation mix on these days (from EIA) (6/n)
While coal and gas ran a lot, wind and solar played large roles. While it was cold, it was also clear. Solar, presumably from utility-scale systems that protected themselves from the snow that fell overnight from Dec 21-22, performed well. (7/n)
If we look at just wind and solar generation, we can imagine that more renewable deployment (especially solar) and ~4 hour storage could have provided basically all the needed power during this cold spell. (8/n)
Of course, there are days when wind and solar output are low for longer periods and we may need more than today’s Li-ion batteries – but I think this “postcard from the future” shows just how far we can go even during challenging conditions! (9/9)
bslotterback@chazteplin great thread!!
Extra Super@chazteplin good food for thought. We expect to begin the installation of our heat pump system next month.
harshal@chazteplin if you do the math on how much storage would be needed to replace nat gas on extreme cold days, it is insane. your graph on 6/n basically shows 4 GW of nat / coal
I'm all for electrification and getting of fossil fuels.
These extreme cold days shows me how challenging that will be (we'll need massive storage, DERs, DR, way more gen, higher capacity T&D, etc)
@chazteplin does EIA have this for all utilities? I find PJM's real-time emissions factors tool very hard to use
@bslotterback mostly yes.