No boiler usage for period to utilize low overnight electrical costs ?

Dave Carpentier

Looks like our util will be trying some very low overnight rates, like 2 or 3c.
Its thought that will be for ppl to charge EVs in the 11pm-7am window.
This is nearly half the current time-of-use lowest tier.

If you had an electric boiler, could you possibly restrict it to those hours ?
7am until 11pm is an awfully long period in the depths of winter.
In my case, I would possibly need 40k btu/hr to keep the on-peak use reasonable.

Overshoot the house temp some by 5 or 6am (or longer to heat the drywall/etc up better?), and then a large (massive ?) storage tank ?

mattmia2

i thikn the tank size you'd need would be in the thousands of gallons range. i have seen people use propane tanks with wood boilers. in europe they have electric heaters with the element in essentially dirt or concrete so it heats the mass at night and radiates all day

Hot_water_fan

Not a bad idea! You could overheat the house or try to store energy in water. If you have radiant floors and can get away with low temps, it could make a lot of sense. Baseboard using 180F water, probably not so practical. Or use a gas/oil and electric hybrid. I think it’s best not to store the entire design day worth of energy - (say 40,000 Btu/h x 16 on peak hours /3412 = 187kwh). Maybe 50-75% of that is the sweet spot of utilization and energy savings, since that 100% capacity would only be used a few days per year. 

hot_rod

I dont think your home  would be a very good thermal storage vessel unless you have some concrete slabs?  The air in the space is not a good  transfer medium or a storage container.

The math for storing energy in a container is pretty straight forward. The unknowns are the amount if load you need to cover for those hours
Start with design load for that period of time, then the temperature requirement. 16 hours at a 40K load?

unless you have low temperature emitters, I don’t think water storage will work, however.

If you need 180f SWT you would need to run a tank up beyond that.

The very best step when consider storing energy is getting the load as low as possible, as it relates to the amount if energy you need to store.

personally I prefer a cooler space during the sleeping hour. A 90 degree home doesn’t sound appealing.

Find a few Tesla Power Walls to run an a2whp heat pump, or mini split😗

JakeCK

hot_rod said:

I dont think your home  would be a very good thermal storage vessel unless you have some concrete slabs?  The air in the space is not a good  transfer medium or a storage container.

The math for storing energy in a container is pretty straight forward. The unknowns are the amount if load you need to cover for those hours
Start with design load for that period of time, then the temperature requirement. 16 hours at a 40K load?

unless you have low temperature emitters, I don’t think water storage will work, however.

If you need 180f SWT you would need to run a tank up beyond that.

The very best step when consider storing energy is getting the load as low as possible, as it relates to the amount if energy you need to store.

personally I prefer a cooler space during the sleeping hour. A 90 degree home doesn’t sound appealing.

Find a few Tesla Power Walls to run an a2whp heat pump, or mini split😗

Gah, just thinking of sleeping in a hot 90f room... 🥵