Going Off-Grid When Grid-Tied Is an Option
There was a time when home solar energy had the reputation of only being useful for “back to the land” types who lived so far from civilization that they couldn’t affordably run power lines to their properties. And, truth be told, there is a healthy market for using solar to supply power to middle-of-nowhere homes. But, these days, going “off-grid” via solar is an option for anyone no matter where they live. The question for grid connected homeowners is, does going off-grid make sense?
In this article, we walk you through the considerations of going off-grid versus installing a grid-tied solar system.
What it Takes to Go “Off-Grid”
What does it take to go off-grid? In a word: money. An off-grid solar system requires not only an investment in solar panels and related equipment but also in a battery storage system that’s adequate to store and release enough power to carry your home through periods – days, not hours – when the panels are not generating enough to meet your 24-hour needs, especially during the winter. Although prices are dropping, a battery stack with the capacity to serve the needs of an average size home in the mid-Atlantic region is still very expensive to purchase in today’s market.
And, that’s not all. Relying on battery storage also adds expense because batteries cycled daily tend to need replacement sooner than solar panels do, and can require additional maintenance too. These costs add up. In fact, some off-grid homeowners have concluded that it’s more cost-effective to add a second source of power generation such as a wind turbine or even a fossil fuel generator to their systems to help carry them through periods of low solar production, rather than to invest in a larger battery storage system.
Grid-Tied Systems Use The Power Company as Your Battery
For the time being, a grid-tied system is always substantially less expensive than an off-grid system, with the same environmental footprint. Why? Because, if you have access to the power grid, building a grid-tied solar system effectively lets you use the existing energy infrastructure as your battery stack, saving you the cost of purchasing your own.
That doesn’t mean the power company actually stores power for you. Instead, in all of the areas we serve at Mountain View Solar, power companies must accept the excess electricity generated by a grid-tied solar system that goes unused by the homeowner. The utilities typically pay for that energy with credits against future energy use by the homeowner during times when the solar system is not generating enough power to meet the homeowner’s consumption. This power bill crediting/debiting process is called net metering.
So, although the solar panels on a grid-tied home solar installation might not always meet a homeowner’s energy needs on an hour-by-hour basis, they can achieve a zeroed out electricity bill by generating enough power to meet the homeowner’s needs on an annual net basis. The utility, in effect, “stores” the homeowner’s excess solar-generated electricity in credits that she can later spend to recover that power. We call this state of producing all of the kWh you need in a year “Net Zero”.
A Solar Battery Backup System is a Great In-between Option for Many
Another option is to install a smaller battery backup along with your solar array. This permits critical loads, such as refrigeration, water pumps, receptacles and other important devices to receive power during occasional utility grid outages. Unlike an off-grid system, the system doesn’t need to be large enough to run the entire house and is therefore much less expensive. Some battery backup systems can also incorporate a fossil fuel generator to assist such as when the panels are buried in snow.
Another point to make is that should net metering ever go away, a battery can be added for the purposes of self consumption, so that you don’t need to rely on the utility as your battery. Unlike going off-grid, this battery doesn’t need to be so large as to carry you through winter days as it works with the grid to permit self consumption of your own produced kilowatt-hours. These batteries can also serve dual purposes, as both self consumption and critical load backup.
Tips for Lowering Costs, On-Grid or Off
Whether grid-tied or off-grid, there are steps solar homeowners can take to reduce their energy costs and thereby make achieving Net Zero much more affordable. Most significantly, owners of existing homes can make energy efficiency improvements to lower their overall energy consumption. Some simple ideas include converting lighting to LED, installing adequate insulation, purchasing energy-efficient appliances, and upgrading windows and doors to eliminate heat loss.
In addition to those improvements, owners building a new home can also reduce their energy consumption by making careful choices about home design and how the home is sited on their property. A home constructed and oriented to take maximum advantage of sunlight, not just as a source of electricity but also as a means of heating through passive solar gain, can deliver meaningful reductions in home energy demands.
Advances in Technology May Change the Equation
At Mountain View Solar, one reason we love working in the solar energy field is because it’s constantly evolving. Researchers continue to make advances in the size, efficiency, and cost-profile of solar panels, batteries, and alternative energy storage options. So, while the cost calculus of grid-tied versus off-grid systems described above holds true today, we wouldn’t be surprised if new technologies make off-grid systems more cost-competitive with grid-tied systems in the not-too-distant future.
By staying current with those advances, Mountain View Solar stands ready to help our customers choose the best solar energy system for their needs. If you are considering installing a solar system in your new or existing home, contact us today to start a conversation about what works best for you. Taking our cue from innovators around the globe, we strive to put solar panels to use improving the lives of our neighbors, making local businesses run more efficiently, and finding creative ways to bring solar power to corners of the region in need of an economic and environmental boost. As your local licensed and experienced contractor, let us put the sun to work for you!