Solar energy is a very liberating concept for most people. Words like energy independence and going off-the-grid have a very exciting feel to them. They spawn images in the minds of potential buyers, ranging from sustainable living to a rejection of, or at least freedom from, the constraints of modern society. The truth is actually a bit more mundane, but far more practical.
Before discussing off-the-grid v. grid-tied solar applications, it is important to consider a few practical points. First, it is a good idea to make sure the home is as energy efficient as possible before installing solar energy panels. The more energy a home uses, the more solar panels it takes to either defray or eliminate the electric bill. Often an inefficient hot water heater, dryer, or air conditioning unit will cost more in electricity over the course of a few short months, than the purchase price of a new appliance. It is important to replace inefficient appliances before estimating usage and installing solar equipment.
Solar energy needs are based on overall electricity usage, so it is necessary to calculate the number of panels necessary to create an efficient panel array for the house. Solar Estimator offers a tool for estimating how much energy one needs.
Choosing off-the-grid v. grid-tied systems really depends first on the location of the home, reliability of electrical service in the area, and the overall goals of the individual. Some people just want to save money on the electricity bill while others want to have electricity in the event of an emergency. A few just want that sense of freedom and independence. Some live in remote areas where electricity is not readily available.
Choose a grid-tied system if money is the only concern. In many areas, the energy company will pay to use the homeowner’s excess electricity and some people actually turn a profit at the end of each month. Grid-tied solar panels are also the most economical investment because that kind of system is far cheaper to install. Grid-tied solar panels don’t use the expensive battery arrays required in off-the-grid applications.
Off-the-grid v. grid-tied decisions are most commonly determined by budget considerations, and generally in a low budget situation grid-tied wins. Most home solar energy applications are grid-tied because it is a lot cheaper to install those battery-free systems that use the grid’s resources.
Solar energy applications in areas with excellent electrical repair response time may lend best to a grid-tied system. But for someone who wants emergency power, in the event of a long-term power failure, this just isn’t the way to go.
An off-the-grid system is by far the only choice for those interested in backup power in the event of a power failure. The biggest drawback of a grid-tied system is that in a power outage, the homeowner cannot use the solar array to restore electricity. Mother Earth News explains why the electric company ensures solar panels attached to their grid are not going to function in a power failure.
“However, for safety reasons, grid-tied systems cannot function when the grid power goes down (a live load on the line would present a danger to utility workers coming in to fix power outages), and to many independence-seeking homeowners, that is the biggest drawback of grid-tied systems.”
Solar energy users who feel comfortable with being without electricity whenever the grid fails to provide can cash in on the savings of a grid-tied system. If one lives in an area with consistently reliable utilities, and homeowners cannot imagine a situation in which the power could go out for days, a grid-tied system would be a good solution.
Off-the-grid systems can also leave their owners without power as well. Any time that usage exceeds output plus battery storage, power outages happen. For that reason, an ample array of batteries is desirable, and even a backup generator might be a good safeguard, especially in remote areas, in a situation of extended periods of cloud cover.
Off-the-grid solar applications require specialized deep cycle batteries, and it is these batteries that provide energy at night and on very cloudy days. Batteries are expensive, but the costs are going down.
Elon Musk, the Tesla car mastermind, is heavily invested in creating lithium ion batteries that would be cheaper and more efficient. He calls his latest invention a “power wall.” It is already competitive in price for the capacity it has. This 10kWh battery sells for just $3,500. Someday, not too long from now, these superior battery systems are expected to reduce considerably more in price, according to Revision Energy.
Off-the-grid solar energy systems will be revolutionized by this innovation, and become more reliable and affordable. So affordable, that according to Cleantechnia the power grid may eventually become obsolete. That isn’t happening soon, though.
Solar energy is currently far more commonly of the grid-tied variety rather than the off-the-grid application. That could change in the near future, as the cost of deep cycle batteries reduces and overall efficiency of the batteries increases.
Are there extremely inexpensive off-the-grid solar solutions now? Sure, there are, but they are generally designed by the homeowner and do not involve using traditional home wiring. These are minimalist systems that will afford very few modern conveniences. They usually involve moving a couple of golf cart batteries and an inverter around on a dolly from one usage point to another. It isn’t great, but it will work, and keeping such a primitive system around might be a good emergency preparedness measure. There are some determined individuals who use them every day, in cabins and tiny houses, but they aren’t designed to accommodate contemporary suburban lifestyles.
Off-the-grid v. grid-tied solar energy questions are easily answered by each individual depending on their needs, desires, and circumstances.
[Photo by Lisa Maree Williams/Getty Images]