There is much written about the Power Grids going down (for whatever reason) and how to prepare for that event. Recommendations have been made for the installation of a generator, solar panels, battery banks, inverters, automatic system switches, on and on and on. These systems range from a simple inexpensive plug in inverter for your car 12 VDC socket (which may power a lap top or a cell phone battery charger) to an extremely complicated self-sufficient system that will operate your whole house. The simple fact is that most people will not install such systems for a variety of reasons ranging from cost to placement and sometimes simply knowledge. Short of installing a complete off the grid system, almost every other solution will require some sort of hassle and inconvenience. If it is winter, the problem is compounded as it takes very large amounts of electricity to run electric heaters, electric stoves, etc.(anything that produces heat). The idea is to do what is absolutely necessary; conveniently, inexpensively effectively.
Many will buy a generator, fill its gas tank, start it to make sure it runs, place it in their garage, put a full five-gallon gas can in the corner and think they have the solution in hand. Over the course of a year, the gas will turn to kerosene, or worse, (gumming up the carburetor and eventually making the gas in the can useless). They will have forgotten how to start the gen set and connect it to the house; dust will gather on both. Without considerable effort and knowledge, this set up becomes useless. Any generator use will produce noise when in operation; broadcasting to all within ear shot that you are producing electricity and potentially make you a target. If you live in a small neighborhood in a city, as most do, this will be of particular concern.
With a little preparation, no ongoing maintenance and very little cost there is a more effective solution to powering part of your house, one or more appliances at a time, and not bring attention to yourself and enjoying the use of electrical power. This is particularly valuable if the power outage is in the winter. Powering only your furnace will keep you warm and keep your pipes from freezing. Most people reading this are already somewhat prepared in the areas of food, first aid, etc.
What Do I Need ?
In its most simple form, you will need the following:
- Heavy duty automotive jumper cables in the largest cable size (diameter of the wire) that you can get.
- A 12 VDC to 120 VAC inverter. For $200 or less you can buy this at a discount store, many auto parts or sporting goods stores, and a myriad of other places. Thy typically range in size from 1,000 watts to 2,000 watts in capacity, and are about the size of a small briefcase. The larger size is preferable to the smaller ones as they provide more power and therefore will power more items at the same time.
- A 120 VAC extension cord. This should also be of the largest wire diameter (gauge) that you can find.
- A replacement 120 VAC plug for the extension cord.
- Extra stored gasoline for your car.
What Do I Do With This Stuff?
First, locate the main power disconnect (breaker or switch) that connects your house to the Grid. This is normally on or in the meter box. Turn it off. In this condition, even if the power comes back on, you will have no power coming into your house. This also duplicates a Grid down condition. Under no circumstances turn the main power disconnect back on while the inverter is attached to the house.
Turn off all the sub-breakers in your house. (Hopefully you will have identified which breaker powers what items or rooms in your house). Do not turn off the main breaker in this panel. This second main breaker must be in addition to and separate from the main house power disconnect.
Next, cut the receptacle end (female) off the 120 VAC extension cord and install the replacement 120 VAC plug (male) to the cord. Make sure it’s wired correctly. (Black to black, white to white and green to green). You will now have a cord with a plug on both ends.
The shorter you can make any DC cables, the better. (There is significant “line loss” in DC cabling, but not in AC cables.) Make the cords and cables as short as you can between the inverter and car. Do not modify the jumper cables unless you have the tools to do so correctly.
[Editor’s Strong Warning: Putting AC power into an outlet in your house might seem like a simple solution, but it can create a dangerous “back feed” condition that could electrocute a power lineman, when an attempt is made to restore power to your neighborhood! It is ABSOLUTELTY ESSENTIAL that you turn off your home’s main circuit breaker before energizing your home’s wiring with any alternative power system. The main breaker should be “tagged out” with a prominent warning sign, or better yet both tagged out and “locked out” physically. The best and safest solution is to have a qualified electrician install a proper bypass circuit breaker panel that will eliminate any risk of a back feed! – J.W.R.]
Place the inverter on the ground in front of the car. Connect the inverter to the posts on your car battery (pos + to pos + and neg – to neg -) with the jumper cables. Make sure the connections are as tight as possible. After making sure the main power disconnect is off, plug in one end of the extension cord to the inverter and the other end into any 120 VAC outlet in your house.
At this point you should start your car. (Warning: Do not run your car in your garage, or you may get carbon monoxide poisoning.) When you then turn on the inverter, you will have 120 VAC going into your house to the breaker panel. Your car battery will start to discharge and may not have enough juice to start it later, so do not turn on the inverter without the car is running. As you turn on a breaker, it will send power to whatever is plugged into the outlets on that circuit, and those items will operate, unless they require more wattage than the inverter produces.
As long as you have fuel to run the car, the car alternator will charge the battery, which runs the inverter, which then produces 120 VAC power to your house. A car that is quietly idling, parked in the driveway, is not going to stand out. A car can often be idled safely for many hours in cold weather, but in warm weather, over-heating may be a problem.
What I have described is not the ideal, most efficient way to do this, but it is the least expensive and simplest way to have power while not alerting scavengers. As long as you have gas for the car, you are in business.
There Is A Catch
The inverter will only run items which do not exceed the wattage rating of the inverter. For example, if you bought a 1,500 watt inverter, it will only run 1,500 watts total at the same time. (e.g. fifteen 100-watt light bulbs). This necessitates you do a little homework. As you can see, you can quickly overload the inverter. Your electric oven, your electric dryer, and some other appliances will not work. (They require too much power, and are often on 220 VAC circuits.) [JWR Adds: And keep in mind that the peak current draw comes with an electric motor’s start-up.]
Your furnace may take 1,000 or more watts to run the blower, the microwave may take 1000 watts, the your refrigerator another 1,000 watts, and so forth. You must know how much power is consumed by each item in your house, or you will quickly overload the inverter. If the tag on the appliance doesn’t tell you how many watts it takes, it may tell you how many amps it draws. You can convert amps to watts by multiplying the amperage (it may say 2 amps) by the voltage (120 volts). This item will draw 240 watts. The amperage listed is almost always more than it actually takes.
As you can see, this arrangement will allow you to run individual appliances at the same time, but no more than the inverter will handle. You must do a inventory of every item that is plugged in and know what breaker controls each. If you have your refrigerator plugged into the same breaker as your furnace, the inverter may not power both at the same time. You will then need a bigger inverter. Unplug every item in your house that is plugged into an outlet, and know how much power you are using for every item. It may be that all you need to operate concurrently is the furnace and a few lights, or the refrigerator and a few lights. Do the math. You may not want to run lights anyway, as this will only draw attention to you.
If and when the grid power supply returns to normal, disconnect the inverter, from the car and then the house, turn your main house to grid disconnect back on, and you are back to normal.
A little organization, planning, and thought will allow you to continue on through a emergency without a lot of expense, undetected by the outside world.