Electric Whole House Generator Considerations
Anthony Chen posted this in the NWA Neighborhood Association Facebook group after the last ice storm. It’s a great write up. Here’s a link to the screenshot:
Instead of being mad at the city, take control of your electricity. A “whole house” generator”can cost as little as $1300 installed. You might even be able to get things installed monday or tuesday.
During the 2021 event I had a 2kw honda generator. Some of you might remember that I cut the wire to one of furnaces and put a plug on the end and plugged it into the generator. This took part of my house from 38 degrees to like 60 degrees. In addition I was able to run the refrigerator and power small electronics as well as plug the tankless water heater (gas heat, but electric pump) in as well. Unfortunately there was no way to power the grinder pump which caused a sewage backup (yuck).
After the storm I decided to improve my system by installing a generator that would directly power my house.
The generac 20kw systems are awesome, but are a bit of overkill for texas. They will let you run multiple air conditioners and pretty much all your appliances at the same time. They detect when electricity goes out and automatically switch on. They also cost around $15-$20K to install and often times require monthly maintenance service/monitoring contracts. For me it was too much for something that you only need once or twice a decade (I can live a few hours without power so I dont consider that a need).
However, a typical house with natural gas can get away with a manual interlock, generator outlet, and a 6kw-13kw portable generator (this one is forsale at lowes right now for about $900).
Amazon might even be able to deliver you one this week and you will get more features and power than the briggs and stratton one.
You can use extension cords to plug electronics in directly, but where these really shine is if you can use it to power your whole house using your existing wiring. To do this you need a generator outlet that feeds directly into one or two of your main breaker slots. You then plug the generator into the outlet and you have power to your whole house.
When you energize your house and the grid is down, you will feed electricity into the power lines which can electrocute linemen working to restore power. Therefore you must disconnect your breaker from the grid. Modern breakers will have a disconnect at your main breaker. However to avoid accidentally forgetting to disconnect from the grid, you are required to install a manual interlock.
The manual interlock slides back and forth and has a shape designed for your breaker box. It prevents the generator outlet from feeding your breaker when the breaker panel is connected to the grid. When your breaker is connected to the grid, the interlock physically prevents your generator outlet from being turned on. Even if your generator is running, no electricity will reach your breaker box. Once you disconnect your breaker box from the grid, you can slide the interlock, which allows the generator breakers to be turned on.
Here are 3 companies that people in the neighborhood have used to install the generator outlet and interlock for about $500
- Klock $500
- Max electrical $450
- Morning star electrical
If you run a small generator you have to have an idea of the amount of power you are using. If you have electric heat or electric stove for example, you might need a much larger generator. But gas appliances and furnaces use very little electricity and a 6kw generator should be sufficient to run your whole house in the winter (no ac)
Here are some examples of appliances and their power uses: refrigerator 600 watts (not continuous), gas furnace 600 watts, microwave 1000watts, gas tankless water heater – 350 watts, led light bulb 10 watts, laptop charger 65 watts, pool pump 1000-3000 watts – you get the idea.
Unless you have a very large propane tank, it can be a pain to run off propane. There are tri fuel portable generators and you can get a plumber to connect your portable generator to your natural gas line. I dont have a reference for a plumber, but I am looking for one. I ended up using gasoline when my generator used a grill sized propane tank in 3 hours. My 13kw generator used about .7 gallons/hour of gasoline during the day and about .5 gallons/hour at night. I filled the 8 gallon tank (with about 5 gallons) about every 8 hours. 8am, 4pm, and midnight. I have four 5 gallon jerry cans which are technically not EPA legal to use anymore. I never let myself get below 5 gallons on hand.
Some cons of the portable generator method:
- you need to change the oil. this is messy and I got oil everywhere as I dont have a proper oil drain pan. Ill get one for the future.
- it was loud – my neighbors werent that happy when the generator was surging (I didnt have the choke properly adjusted and eco mode on).
- When you are done, you will need to do certain maintenance tasks to make sure the gas left in the generator doesnt ruin the carbeurator preventing you from using it the next time you need it.
- You should really run the generator periodically to make sure it is working ok and to charge the battery if it has a battery start.
- You need to learn how to operate it and start it, chokes, battery trickle chargers, pull starters, etc can be a pain
- You will have to plug it in yourself, flip your breakers, etc when the power goes out. If you are not home, it wont start up (though technically you could put it on an automatic transfer switch that turns the generator on when the power goes out).
- You will have to learn how it all works as you will have to troubleshoot problems yourself.
- can be stolen
Some pros
- Much cheaper than a generac system.
- If there is a problem you can just buy another generator and plug it in vs having someone come out to service it. I can buy 10-15 replacement generators for the price of a generac system.
- The portable generator can be moved and used for other things (though they weigh in excess of 200 pounds)
- They come in tri fuel configurations so you can use propane, gas, or natural gas. If natural gas turns off, you can still run on gasoline.
- If you already have a generator all you need is the generator outlet and manual interlock.