Introduction
Our modern world has been built on the copious use of inexpensive energy. Along with motor vehicles, electricity is the major foundation of modern civilization. Because of electricity, our lives are easier and safer. We do things and live in ways that would amaze our ancestors. My father had told me stories of growing up on the farm without electricity, but it took my own experience to make it click and understand how crucial it is to have a stable source of electric power.
It was in 1998, and the power had gone out, again. While our local grid service consistently went out for several hours every quarter or so, this time it didn’t come back that day, or the next, or the next. Driving to get water to cook and flush the toilets became a real pain. Luckily, it was the summer, so we didn’t need the furnace. While relatively minor, this four-day-long event made it finally sink in that being without backup to the grid is a serious issue that affects me and my family. I needed to do something, and it started my road to backup power. And I am not the only one: it affects the vast majority of people in our world. The devastating hurricanes we saw in the last year in the Carolinas reinforced the terrible problems that can occur when grid power fails.
Reasons for backup – What can happen?
There are many problems that can cause loss of grid power. At some point most people face short term power losses due to trees falling on the power lines. We know it’s not unusual for major storms, tornados, and hurricanes to take the power down for days, weeks, or even months. We are facing possible next steps in danger from EMP, terrorist strikes, or cyber attacks on the energy industry. And even without natural or human attacks, we face gradual reduction of available power from phasing out of existing generating facilities without replacement of their capacity, increased demand for things such as EV car charging, electric heat pumps, cryptomining, data centers, AI farms, and growth in population. All this demand may result in the need for more than utilities can supply. That probably means brownouts and blackouts in the future.
Given the importance of electricity in our lives, the need to support devices (such as sump pumps and furnaces) when we are away, and the potential for destruction of parts with year-plus replacement lead times, (lead time for electrical substation transformers is getting even worse), having your own power backup is a necessary part of preparation. “Two is one and one is none” is very crucial when considering your power needs.
Disclaimer
This article is just a primer and is intended to provide guidance for your move to backup power. I am experienced with electricity, both by education and experience, but I am not an electrician nor licensed to design your system. This article lists the things that I have studied and things that I did to make my family less dependent on grid power. Do your own study and take advantage of the available experts in your area to ensure that your system fits your needs and complies with local laws and regulations.
Power System Basics
Electrical power systems have these basic components:
- Generation
- Distribution
- Loads (Usage) by homes and businesses
- Safety & Monitoring systems
These components are part of every system, from small to large. A modern utility power AC grid uses large generation plants, very high voltage distribution lines, local substations, local area distribution lines at mid-range voltages, and local transformers to provide the power to your home or business. Multiple safety devices and systems are included. And, of course, the local electrical company will handle the billing. These grid systems provide low-cost AC power, but the many components and growth over the last 150 years have added many potential points of failure.
Cost/Budget
Consider the costs, when budgeting for your backup power system:
- For Initial construction
- For Production (fuel, for generators)
- For Maintenance (like battery replacement)
Cost is a key consideration. If your home’s power loads exceed your budget for purchasing and installing a backup system, then you will have to install a smaller system and therefore you will have to curtail your power use.
A significant part of the cost and potential for problems comes from the transmission needs of the grid. For efficiency, power is converted multiple times from one voltage level to another, requiring many transformers. Transmission lines, high, medium and low voltage, suspended on poles/towers or buried, are a well-known source of problems. Behind the scenes are some critical pieces of the grid. These are the monitoring and control systems. These use supervisory control and data acquisition (SCADA) software that is susceptible to EMP, solar flares, as well as Internet communications loss, or variety of computer errors.
A small, single-family system will need the same functionality and components as a grid power supplier, but without the complexity that is needed to transmit power over long distances.
Items to Consider When Looking at Backup Power
If you decide to add an electric power system, either as a primary source for an off-grid application or as a backup to your grid provider, you need to consider a multitude of items. Among those are what is available, what your electrical needs are, what type fits your situation, what type of local expertise and parts are available, the costs in your area, and what you can afford to install.
Another critical item to pay attention to is safety. You need to provide for your personal safety and the safety of the power crews working on the grid. First, always be aware of the power that you are producing, how and where any electric wires and/or cords are running, and the environment your system is running in. Electricity can kill you, so be careful.
Secondly, and critically, never feed power back into the grid without a properly built system with a transfer switch. If you backfeed power, then you could kill a power lineman. A properly designed AC backup power generation system must include a transfer switch that automatically disconnects your system from the grid. These should only be installed by a properly trained and licensed electrician. The only safe backfeeding is via a net-metered system that sells your excess power to your utility company.
Common Types of Power and backup
There are a variety of technologies available to provide power to your home power system and your needs. Here are some of the most common ways available to provide personal power.
- Grid supply (Generated from Coal, Natural Gas, Hydroelectric, Nuclear, Solar, Wind, etc.)
- Engine-driven Generator (using diesel, gasoline, LP, and/or Natural Gas. (Note that some generators are multi-fuel)
- Photovoltaic (PV) Panel Systems
- Small Hydroelectric generation (“Microhydro”)
- Wind turbines
Note that there is growth in size, features, and options, depending on your power needs and your budget.
Choosing a backup System
You need to determine which type of power system you will use for backup. Unfortunately, that decision is not automatic; it depends on your situation. Making the decision on what system, (or systems), to install requires some skull sweat on your part.
First, figure out how you will use the power. Common basic needs for a grid-tied system are your water supply, heating system, food preservation, cooking, and lighting. Electricity is used by most modern systems for at least part of each of these. List your loads for each need and determine how much and what kind of electricity is needed for each.
The basics are Direct Current (DC) versus Alternating Current (AC), and what voltage is required. DC is commonly used at a low voltage (USB) level, 12 or 24 Volts, with 48 Volts sometimes used industrially, or for charging golf carts. Even higher voltage DC is used for forklifts. AC is commonly 120 Volts but typically well pumps and arc welders require 240 Volts. (Note: If an appliance doesn’t use electricity — for example, a propane refrigerator or stove — then do a similar calculation for the propane needs of those appliances.)
Given the importance of electricity in contemporary society, the usage list grows well beyond the basics. Electric appliances, medical devices such as oxygen concentrators, Internet access, computers, phone charging, power tools, air conditioning, and a myriad other items add to the list. Decide what you must have for the short term, both continuously and intermittently, and what you need to consider if grid power is gone for a longer period.
A good tool to determine your home’s power load is the Kill-A-Watt meter. This device allows you to measure the power used for each light or appliance. You can use that data to extrapolate your total load needs for the period you are looking to back up.
You’ll also need to consider the Peak Load versus Continuous Load current draw. Most electric motor (or motor-driven compressor) equipment draws up to twice the Continuous Load Current during its brief startup. And if more than one motor starts at the same time, then they can draw more current than your system can provide. That will often result in circuit breakers tripping and/or equipment not starting properly. Starting at slightly different times will minimize this issue. Usually, the startup load is listed as twice the Continuous Load, in the equipment documentation.
Summary: Develop a list of what devices you need to back up and for how long. Then determine the power requirements for those needs: voltage level used, peak and continuous amperage, and the power requirements for a length of time. Determine which need to run at the same time and whether it is practical to alternate when the various devices run. That will give you the information to evaluate the different options for backup power.
(To be continued tomorrow, in Part 2.)
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