SageBrush wrote: ↑
Sun Aug 04, 2019 6:34 am
iPlug wrote: ↑
Sat Aug 03, 2019 3:20 pm
Finally yesterday EcoNet 2.0 software was available and installed on my iPhone with TOU controls. Thus far with 1 day of scheduling, testing has worked appropriately. I have the water heater set now only to act as a thermal battery and run the heat pump only during lowest TOU timeframes.
I'm surprised you do not take the heat pump efficiency into account as well.
Second, I thought you have PV ?
Not sure I understand.
Do you mean why not run the heat pump more when the ambient air temperatures are highest? It is true that peak TOU is associated with higher ambient air temperatures.
Our TOU plan is off peak, partial peak, and peak. We remain off peak if avoid the following hours:
Summer 6 months: M-F 10am-9pm; Sat/Sun: 5-8pm
Winter 6 months: M-F 5-8pm, all other hours off peak
Not desert climate here, so it's still fairly warm in the late evening with plenty of ambient heat to extract from 9pm-midnight in the summer when the heat pump only needs to run a few hours a day. Also, we have large black garage doors that face SE so get a greenhouse effect in the morning as soon as sunlight hits. For example, just checked the ambient temperature by the air intake of the water heater this morning at 7:30am and it's low 80s ºF. During the winter 6 months, we only would have to avoid M-F 5-8pm TOU so little problem there.
I'll keep an eye on the daily energy use to see if efficiency seems to be significantly suffering by avoiding the highest ambient air temperatures that happen during peak TOU.
We do have solar PV and run a net surplus (to offset some of our carbon footprint beyond household energy use and personal transportation). In California, we are ok from an energy and environmental accounting standpoint of contributing more solar PV energy to the grid when it is in most demand and pulling in some high renewable/low carbon grid sourced electricity during off peak.
'19 Model 3 SR+ (own), '19 Leaf SV (leased), '12 Plug-in Prius (sold 3/19), '16 Leaf SV (prior lease), 11.43kW Solar PV (16MWh/yr real production), 20.5 SEER/13.0 HSPF ducted air-source heat pump, 3.70 UEF heat pump water heater, Induction Cooktop