Kicking Natural Gas, how to get off of Natural Gas without a service upgrade

[jeffrey.miller]

At the August 2024 meeting I discussed how to migrate off of Natural Gas even if you only have 100 amp service.  We also went over the standard 200 amp all electric house configuration, and how that works with normal appliances. 

While we didn't record this session, I did a similar presentation to the Environmental Defenders a couple of months ago, and they recorded it:
https://youtu.be/g_cERbbJa6o?feature=shared

There was some additional information that came out of the FVEAA meeting, notably Chuck offered his thoughts on a heat pump water heater, and how people often shift them to be more resistance based in the winter, to keep from chilling the house too much.  The second major addition was the data from Ian, who uses all mini-split type heat pumps to heat and cool his house.  He has a 1600 square foot house in Chicago, and his highest energy usage month was 1795KWH.  That is pretty fantastic for a nearly all electric house in a cold winter month.  His only remaining gas appliance is a hot water heater.  So in theory he would add a few more KWH to get rid of that, it's a really small portion of the changeover.  This data also provided his maximum power draw of about 7KW, which confirms that you can definitely get in well under a 100 amp service (24KW) using this strategy.  Ian also charges his Model 3 on a 120 volt outlet in his detached garage, as part of that 1795KWH.

Ian has insulated his house quite effectively, putting in the effort to get his leakage rate down.  That in combination with his high efficiency heat pumps, makes him a poster person for how to Kick Your GAS Habit! 

[jeffrey.miller]

Adding text from the presentation below:

All the gas appliances you might have, and how to get rid of them

To prevent your house from suddenly exploding
To reduce co2 emissions
There is an island in Panama that is being evacuated due to sea level rise
To save money
Some of these are so energy efficient that it just makes sense
There is a price difference between a KWH or gas, and a KWH of electricity, however many of these options are so efficient that they more than overcome that difference in price
Gas prices are unstable

[jeffrey.miller]

Worldwide Natural Gas prices

We pay much lower prices than the worldwide average, as we continue to build capacity to liquefy and export NG, we will get exposed to the global gas prices.  Oil is a global market, and our prices largely reflect the global prices.  Over time NG will become more and more like that because there is money to be made by doing it.

[jeffrey.miller]

Heat Pumps, what are they

Uses a compressor to raise the temperature of a working gas
Takes the heat from that gas, and liquefies it in the process
Sends the liquid to another place to pick up heat, turning liquid back into a gas
Gas goes back to the compressor to start over again
Heat can be moved:
Outside to inside: Heat Pump in heating mode
Inside to Outside: AC / Refrigerator
In the same air flow path: dehumidifier


Power available in your home

Most homes have 100 or 200 amps of service
Some may have 400 amp, also known as Comed Class 320
Amperage x 240 volts = total Kilowatts (KW) available
100 amps = 24000 watts or 24KW
200 amps = 48000 watts or 48KW
400 amps = 96000 watts or 96KW


How much capacity do I have left?

You know your total capacity now
We need to understand how much is already in use
Allocated power can also be reduced in a few ways
Some houses may need service upgrades
This isn?t cheap, best case $4000


Standard method to calculate current load

NEC standard method for calculating load allocates power per square foot, kitchen and laundry circuits. 
Add on additional power for fixed appliances
1500 square foot home would have a base of 5100 watts or 21.25 amps
Add on for garbage disposal, ceiling fans, sump pumps, dishwasher, microwave, range vent fan, bathroom fans
Basic additional equipment can easily add up to another 5000 watts, bringing you up to about 40 amps

Common gas appliances and the electric equivalent demand

Heating 10KW to 40KW
Stove  8KW
Oven   6KW (if separate from the stove)
Water heater 6KW (there are models that heat pump only that are less)
Pool heater  heat pump models available
Clothes dryer  5KW
Vehicles  usually gasoline, but we are trying to kick that too!  7 to 11KW

#note that this has nothing to do with energy usage, and everything to do with power allocation of the electrical service.  Allocating power of the service doesn't mean you will ever even get close to this level at any point, however it is conservative by it's nature to make sure that the odds of anything going wrong is very rare.

Simple home demand, standard all electric house appliances, what you find all over the country

10KW from the standard stuff most homes have
5KW for a clothes drier
6KW for a water heater
8KW for a stove
6KW for a Heat Pump / AC with Nat Gas backup
35KW, 145 amps and you still have a gas furnace and no car charging
If you add electric backup heat that is usually at least 10, if not 20KW
NEC derates backup heat to 65%, so 20KW is 13KW in load calc
This brings up to exactly 200 amp service!


Then add a car!?

If your service is near the limit, then you can use a charging station that monitors your mains power feed, and only charges your car when you have capacity
Most of us have upgraded to LED lighting, so we tend to be under the 3watts per square foot allocated in the standard calculation


100 Amp service
Heat pump washer / dryer combo unit (included in standard)
Heat pump water heater without backup resistance 1.5KW
Stove 8KW
Heat pump / AC 5KW with gas backup
10KW of standard stuff
Car charger with load monitoring
You still have gas, but should have rather low usage
MUCH lower utility bills overall

[jeffrey.miller]

Other electrical load calculation options

Measure peak load
80% of the available capacity can be used for new loads

You really need an energy monitoring system to do this
This can be the same energy monitoring device that manages a car charging station 
Emporia makes a kit for this



Formulate a plan

Determine which appliances you want to change
Oldest first is a good way to start planning
Survey the units on the market, their power requirements, and how the NEC calculates the load for that device
Build a load calculation by adding the estimated future appliances
If it?s close, there are ways to adjust or automate reductions
Car charging stations that dynamically adjust
Electrical panels that dynamically manager power, currently $$$

Other ways to get your usage down

Air seal and insulate your home
If practical, do this before changing the HVAC system
Ideally this should reduce the size of your system, and the resulting demand on the electrical system
If taken far enough, improvements could reduce, or eliminate the need for a service upgrade that is being driven by backup heat


Next steps

Decide if you want to kick gas completely
Naturally as appliances die, and age out
Aggressively to get rid of gas right away
Tax credits, comed utility credits
There is money out there to do many of these things
Inflation Reduction Act
Comed Heat Pump and thermostat credit from the installers
Look at the tax credits, it?s often best to spread this out over more than one year
Illinois EPA will hopefully release their program in 2025 to help out more



Insulate, and air seal until your demand for heating and cooling falls into the range you can serve with your existing service is a valid method to get there. 

[tom.hoffmann]

I removed two 40,000 btu gas water heaters and installed 1 5500 watt electric. This is a 4 minute video I did at the time. It has some hard consumption data. ( I overestimated the efficency  of the gas units, fyi)

My summer gas bill is literally $2.00 for gas and $33 for fees and taxes.

https://youtu.be/xvkUpf5SM-8?si=no-R3-ig8BTqrAWM

[jeffrey.miller]

Nice video!

If you were doing it again, would you consider a heat pump or hybrid heat pump and resistance water heater?

[tom.hoffmann]

I did consider a heat pump. I was concerned about the noise they make. Maybe they are improved now?

[jeffrey.miller]

They make noise, but the AO Smith unit I just looked up is rated at 45dba, which is pretty quiet.  It is hard to find a place with a noise floor below that, without intentionally trying to create it.  People far out into the country might have a natural noise floor that low, but any furnace is much louder than that.

[tom.hoffmann]

They are likely improved in the past 3 years. As I recall they were louder than 45. Some of the criticism was the the particular type of noise was a high pitched whine. I would certainly consider it today.