So You Want to Go Off-Grid...: Page 4 of 4


Inside this Article

The author's homestead
Inverter and disconnects
ompared to battery-based systems, batteryless grid-tied systems have fewer overall components—usually just an inverter, a couple of disconnects, and a production meter.
Utility workers
Off-grid systems work independently­—they are not connected to the electrical utility grid and, therefore, are not susceptible to brownouts or blackouts.
Road to off grid
How far your site is from the grid affects the cost of bringing in utility power—the farther away, the greater the economic viability of an off-grid RE system. But living where you want may make those costs worth it in the long run.
Off-grid solar
Off-grid systems are often sized to meet a home’s daily energy demands during the season with the fewest sun-hours.
Off-Grid PV components
With additional components like charge controllers, metering, DC breakers, batteries, and backup generators, they are more complex than batteryless systems.
Batteries for off-grid
With additional components like charge controllers, metering, DC breakers, batteries, and backup generators, they are more complex than batteryless systems.
Wood space heater
Space heating with electricity is usually prohibitively expensive with off-grid PV systems. Diverting heating loads to other resources­—such as passive solar, solar hydronic, propane, wood, or a combination—is usually a necessity.
Solar water heater
While the low cost of PV modules has made the economic viability of solar water heating (SWH) systems questionable for on-grid applications, in an off-grid situation, SWH may be the best renewable option.
Wood cookstove
In the author’s off-grid kitchen, a wood cookstove shares space with a propane range. The former can be used for some or all of the cooking in the winter, when the cookstove serves as the primary source for space and water heating.
Propane tank, part of off-grid living
Load-shifting to propane for space or water heating, or to fuel a backup generator means relying on another “grid”­— the petroleum industry—and recurring bills.
Wind energy is a difficult resource to verify. Measuring your wind resource with an anemometer over time is a smart first step.
Solar Pathfinder tool
A solar siting tool like the Solar Pathfinder helps determine shading at the potential PV array site.
Generators are often part of off-grid systems
Despite their drawbacks (noisy, dirty, expensive, and high-maintenance), generators are used in most off-grid systems for cloudy season backup power and battery equalization. Installing a PV system that’s large enough to meet wintertime demands without a generator usually means excess (wasted) generating capacity in the summer months.
Batteries for off-grid
Batteries make off-grid living and backup power for on-grid systems possible. But they can be expensive and may require some regular maintenance. The pros and cons of having a battery-based system should be carefully considered.
Electric popcorn maker
An electric hot-air popcorn popper may draw a lot of power, but it’s not used for very long, so its overall energy use is low—about 0.05 kWh per batch, according to the author’s watt-hour meter.
Firewood Portal
A firewood portal makes heating with wood more accessible and minimizes the mess, but the cabin also has an easier option for space heating—the minisplit heat pump (far right).
The author's homestead
Inverter and disconnects
Utility workers
Road to off grid
Off-grid solar
Off-Grid PV components
Batteries for off-grid
Wood space heater
Solar water heater
Wood cookstove
Propane tank, part of off-grid living
Solar Pathfinder tool
Generators are often part of off-grid systems
Batteries for off-grid
Electric popcorn maker
Firewood Portal

Have you dreamed of “going off the grid”—being independent of the electric utility? I’ve lived that way for more than half my life—30+ years. It’s a lifestyle full of benefits and responsibilities. But before you consider it further, let’s take a look at what it really means, and figure out if it’s the destination you want.

Why Off-Grid?

It’s important to clarify the terminology. When I hear people say “off-grid,” I often assume that they mean they want their home to be renewably powered with independent systems that make energy on-site. However, when I pry further—and ask if they actually want to cut the cord to the utility, the answer is usually no.

In the renewable energy (RE) industry—and in this article—when we say “off-grid,” we mean that literally. The phrase refers to systems that have no connection with the utility grid, and must make all the electricity necessary for the home, business, or application.

Going off-grid is possible and practical in many cases, and the experience of thousands of early RE pioneers and recent off-gridders confirms that. But many people who toss out the phrase have a fairly romantic idea floating in their minds. They imagine having no utility bill, and energy and life being free and easy. The reality is that most utilities supply electricity at a modest cost, and if you take on their job, you have to play all the roles that the utility plays.

Identifying your motivation for going off-grid can clarify your goals and help you understand if the reality will please you. Your specific goals may affect whether going off-grid makes the most sense, and they also may affect the type of system you design and how you live with it. Common off-grid motivations include:

  • Environmental concerns—a desire to use less energy and make as much as possible from renewable sources;
  • Independence from the electrical utility for philosophical reasons or to eliminate vulnerability from utility outages
  • Political/social values, such as taking responsibility for your energy impacts;
  • Cost—depending on how far you are from the grid, it may make economic sense to stay disconnected.

On-Grid RE

I urge most folks to use the utility grid with their RE system. More than 40 U.S. states have some form of net metering available. This means that a large majority of U.S. utility customers can “bank” any surplus energy their PV system produces with their local utility, and use the credit to pay for future utility electricity usage.

Almost all U.S. homes have grid service available, and it’s surprisingly reliable. Some locations may be less reliable, and it makes sense to find out how often your region has outages, and how long they typically last. If having completely uninterrupted electricity is important to you, a battery-based grid-tied system could be the best of both worlds—renewable electricity with utility outage protection. These systems provide electricity (usually for dedicated, not whole-house, loads) when the grid is down.

The most common grid-tied systems do not use batteries, and therefore do not have outage protection—their one disadvantage. Their advantages include lower cost, less complexity, lower maintenance, lower environmental impact, higher operational efficiency, and a longer overall system life, since there are no batteries to replace and fewer components.

When Does Off-Grid Make Sense?

Your motivations and goals are key in coming up with your own answer. It doesn’t need to make sense to anyone else if you want to be off-grid. But it is important to be realistic about what can be done and what it will cost—both in dollars, and in your time and attention. Additionally, there are some situations that make off-grid living either the only possible option or the most appropriate.

If you have property miles from the grid, or in a location that has no grid, your only affordable option may be to set up an independent system. If extending the utility grid to your property is possible, find out how much it will cost, and what the ongoing cost will be. Then you can make a sensible comparison to base your decision on. While $20,000 in line-extension costs may seem high, if you are looking to power a large home that has many loads, spending that money may be the best option. Be realistic about the burden (financial and otherwise) of living off-grid! On the other end of the scale, if it’s going to cost you a quarter of a million dollars to extend the grid, an off-grid system may be very economical and sensible. (See “Methods” in this issue for more on the economics.)

There are situations where utility policies make connection costly or difficult. While many utilities encourage RE systems, others seem to throw up roadblocks to easy interconnection. Some utilities have high monthly base charges. Others require expensive equipment that is not necessary to safe interconnection. And others have burdensome paperwork and/or insurance requirements. Talking with your local utility, installers, and other RE users will help you understand the full cost and difficulty. Then you can make a sensible decision.

Off-Grid System Design

The first major task in off-grid system design is load analysis. Without accurate measurements or estimates of energy use, it’s impossible to design a system that will satisfy the need in the most economical way. Electricity consumption is measured in kilowatt-hours (kWh), and an accurate daily or monthly number is needed to start your system design.

If you currently live on-grid, you can start with your utility bill, which tells you how many kWh were used during the last billing period, and often summarizes the last year or more. Even better would be to have a year’s worth of bills—which should be available from your utility. This will give you a baseline for your current energy lifestyle. Then you need to estimate how much energy your off-grid lifestyle will use. To be most cost-effective, you need to identify energy-efficiency and conservation measures you can implement, and you’ll likely need to shift some loads from electricity to other energy sources.

It’s fairly easy to reduce the energy load in a typical North American home by 15% to 20% using common energy-efficiency measures. More radical efficiency work can reduce the load up to 50% or more. On-grid, reducing your energy demand not only saves you money, but also reduces demand for energy created by nonrenewable sources. Off-grid, this strategy is especially profitable, since every kWh comes at a cost in generating capacity, battery bank size, and the need for a backup generator.

Most off-grid systems will need to find non-electric ways to provide for:

  • Space heating
  • Water heating
  • Other significant heating loads, often including clothes dryer and range

Options include passive solar design; solar hot water; solar cooking; wood heat and cooking; and propane. Larger RE systems on homes that include ultra-efficient appliances (such as minisplit heat pumps) may be able to handle some of these loads. But these will come at a high cost in RE generating capacity, depending on the need and the resource.

The second step in off-grid system design is resource assessment. How much sun, wind, and/or falling water do you have?

Most off-grid properties rely on solar electricity, since sunshine is the most common resource. How much you have—measured in peak sun-hours—and when you get it is crucial to successful system design. Using measured data to find out your regional resource, and then a shade-analysis tool, such as the Solar Pathfinder, will give you a good idea of what a solar-electric system will do for you.

Wind resource assessment is more complicated, as are wind-electric systems in general. Your goal is to measure or predict the average wind speed at your proposed wind turbine location and height. With this hard-to-get information, you can make an accurate prediction of how many kWh your chosen wind turbine could produce in a month or year.

Hydro resource assessment is fairly straightforward, and very specific to your stream. Measuring the “head” (vertical drop) and flow allows you to calculate the power and energy potential. If you have a decent hydro resource, it may be all you need.

System design also includes battery bank and backup generator sizing. Both are influenced by your loads—in the amount of energy they use and when they’re needed. RE capacity, battery bank, and generator sizing need to take into account your weak season. Solar-only systems have a season of fewer sun-hours (usually, during the winter), and this needs to be planned for. Hybrid (two or more sources) systems may find a balance that reduces the need for a larger battery bank and backup generator.

Reality Check

On-grid RE system owners have a great deal. When their resource—sun, wind, or water—is available, they use it. When they make too much energy, the grid takes the surplus and gives credit. And when it’s dark, calm, or the creek is dry, the utility is there to provide the needed energy. Off-grid system owners have to take all the responsibility of generating all of their energy, all of the time.

The most challenging part of off-grid living is dealing with the variable resource. Raising a bunch of kids off-grid taught me a lot of lessons. One is that folks usually assume that electricity will be constant and abundant. This is part of our culture, and off-grid folks are not immune, since they interact with the on-grid culture on a regular basis. While there are many times when RE is very abundant—most every sunny day and whenever there’s a windstorm, for example—there are other times when it’s scarce. Surfing this wave of abundance and scarcity can be satisfying to some of us, but it’s challenging to others.

Systems can easily be designed to overcome the variation, and to allow use of any load at any time. But this will come at the increased expense of needing more RE generation capacity, a larger energy storage system, and a larger backup generator. This also means a less efficient and less environmentally friendly system.

Your solar-electric array will give you 30 to 50 years of trouble-free service. Meanwhile, your battery bank—even if well cared-for—will need to be replaced multiple times. And if you don’t treat it well, you may learn a hard lesson of having to replace this expensive component in just a few years. Some RE professionals suggest that new off-grid systems use a less costly battery bank initially—since there’s a learning curve with battery care and it’s best not to risk ruining an expensive bank while you learn.

Typical battery maintenance includes adding water, cleaning, and checking connections. More difficult but even more important is setting up a charging regimen to work well. Batteries last longest if they are regularly recharged fully. The worst thing you can do for your battery bank is to discharge it and leave it in that state for days. Ideally, your battery bank should be fully recharged every few days—one way (RE) or another (fuel-fired generator).

A few off-grid systems are blessed with year-round hydro, or with a balance of resources (sun/wind and sun/hydro are common) that eliminate or radically reduce the need for a backup generator. And there are also users willing to reduce their usage when resources are not available, limiting the need for backup. But for most off-grid systems, a fuel-fired generator is a crucial part of the system. It’s also one of the weaker parts—a loud, dirty, inefficient, and costly way to make electricity. Best system design includes a modest backup generator that is used as little as possible.

Getting it Done

If you’re determined to live off-grid, you need to figure out how to make it happen. A crucial decision is whether you will leave the system design and installation to the pros or do it yourself.

If DIY sounds like fun, you’ll need to get an education. Home Power articles, and classes, workshops, and more advanced training may be part of your learning process. And in the end, you’ll need to buy your equipment from someone. I recommend not buying from the cheapest online source, but finding a source (preferably local) that can also give you advice and support as you design and install your system. This will be worth the somewhat higher cost, since one or two bad buying or design choices can negate a “bargain” purchase.

Most modern RE systems are installed by experienced contractors. But bear in mind that nearly all solar contractors spend their time selling and installing batteryless on-grid systems. And many of them have zero experience with battery-based systems—avoid these companies, even if they are professional and want to help. Find an RE contractor with a history of designing and installing off-grid systems, or at least one who has experience with battery-based systems.

Take a hard look at your situation before you jump into the off-grid lifestyle. You may find that a grid-tied system will serve your motivations and goals best—at a lower cost and lower environmental impact. If you choose to be off-grid, get realistic, get educated, and get good help. And then enjoy your independence with renewable electricity!

Web Extras

For more details about the differences between on- and off-grid systems, see

“Before You Go Off Grid” by Allan Sindelar •

“PV Systems Simplified” by Justine Sanchez & Ian Woofenden •

For more on load analysis, see “Analyzing Your Electrical Loads” by Ian Woofenden •

“Off-Grid Appliances” by Ian Woofenden •

For more on system design, see “Designing a Stand-Alone PV System” by Khanti Munro •

“Getting Started with Renewable Energy” by Ian Woofenden with Chris LaForge •

“Choosing the Best Batteries” by Chris LaForge •

For more on generator selection and sizing, see “Engine Generator Basics” by Allan Sindelar •

“Sizing a Generator for Your RE System” by Jim Goodnight •

“DIY or Pro?” by Joe Schwartz, Ian Woofenden & Justine Sanchez •

Check out our many off-grid system profiles at

Comments (36)

Tod duBois's picture

Ian, when looking at a horse do you stand behind the horse and say, wow that really produces a lot of fertilizer or do you stand in the front of the horse and say, wow that eats a lot? Fossil fuels are solar generated, therefore sustainable on some level. Net positive is when you can share your power with your neighbor in times of need. With blockchain payments, we can even bypass the banking grid. I get that I think a little differently but I'm working on a future where the grid is the backup.

Tod duBois's picture

How many of you think that a 24x7x365 off-grid power system is by definition a net-positive power system? Why? If you can "keep it up", you must be producing more than you use due to losses and other waste. Maybe we need to rebrand off grid as "net positive" - what do you think?

Ian Woofenden's picture
Hi Tod,
It depends on what you're being positive about. ;-) Most off-grid system have a fossil fuel generator involved, and though they run a large renewable energy surplus many times, there are other times of shortage. I think fossil fuels are a negative...
Off-grid systems can be seen as very wasteful, because we must produce MUCH more than we use to have enough in times of low sun/wind/water, and we have to keep the batteries charged. If the grid is close and not expensive/burdensome to connect to, you can be net positive with a much smaller system, and have no generator. Regards, Ian Woofenden, Home Power senior editor
Tod duBois's picture

I to have struggled with the terminology, in Northern California we think we have about 50,000 off grid homes. Yet the term is now used for advertising and marketing of people turning off their cell phones...and now living without technology. One commenter mentioned the propane grid - good point. How many grids do we actually live on? Power, water, waste, fuel, cable, is radio a grid? Let's open a discussion on what it means to be off ALL grids and what that looks like.

Ian Woofenden's picture
Hi Tod,
The terminology CAN be confusing. People also use "off-grid" to mean renewably powered. When I scratch beneath the surface of this usage, I often find that people don't want to actually disconnect from the grid. At Home Power, we mean no connection to the electricity grid when we say "off-grid."
Everyone has different values. I have students, readers, and clients who value renewable energy for its environmental qualities, for independence, for financial reasons, and because it's techie. Some people want to be off-grid for energy security; others to lower their environmental footprint. Deep environmentalists might say "There is no 'away' to throw things", and want to have "zero waste." We are communicating here because of the Internet, my cable connection to it, and whatever your connection is. So my "off-grid" homestead still uses not only this connection, but a (tiny) bit of propane, and UPS and FedEx trucks that bring stuff in, plus the truck and trailer of hay that came in this morning for my compost and mulch.
We're all connected in various ways. Our values determine how we want to change those connections, and why.
Best, Ian Woofenden, Home Power senior editor
Dan S's picture

With the threat of foreign agents shutting down parts of the grid, how can I "fool" my system with enough battery power (trick it to believe grid power is "on") so I can operate off-grid while the sun is shining? I don't want the expense and bother of a full time, fully-off grid system. I have an 8.8Kw system and isolation circuitry already set up and operational for generator operation (when the grid goes down), all signed off by local utility and local government. Located in suburban/rural Prince William County in Virginia.

Dwoo2319's picture

I already have solar power and get credit from the power company but there's been way to many power outages here and its 120 in summer here. Company claims there upgrading but so far there been at least two to three time within a month this has happened. I was wondering if I should get a generator? Can I hook it up to my system? If so what do I need? The whole community is on solar here on reservation so it effects everyone. Most of the time the power company notifies us but lately they haven't. Its getting costly with food spoiling every time power is out. I can't figure out how to get my solar power to work off grid if connection is off from company. Any advice would help.

Fred Golden's picture

Dwoo 2319, you did not mention where you are located, your solar system size or KW needs during a power failure. Some recent grid tied batteryless systems can provide a nominal amount of 120 volt power through one receptacle during daylight power failure.

If you need more power, the Outback GVFX 3648 inverter is Grid intertied (capible) Vented inverter. 3600 watts with 48 volt input. I would suggest a small battery bank, say 8X 6 volt 220 AH Trojan T-105 batteries. This will store up to 10 KW for nightime use, with minimal energy loss compared with larger batteries.

It would require rewiring all the panels to an acceptable voltage going into the right power controllers. Perhaps selling your current inverter can offset some costs, or perhaps installing a new 2,000 to 3,000 solar system tied just to the Outback inverter and selected circuits in the home will work. Solar panels are fairly cheap today. Installing them on racks, inverters and batteries are a much higher percentage of the installed cost today.

I would suggest a 12,000 to 15,000 Btu high efficiency 115 volt ductless split heat pump connected to the Outback inverter. This will cool one room or section of your home during a power failure. 20 SEER 9,000 btu ductless unit should only use about 500 watts.

EdwardThirlwall's picture

I should think that wanting to go off grid will constitute a lot of planning! And you'll need to schedule trips into civilisation quite well too right? That and ensuring that you buy everything you need so you can have it all in storage for when you run out of this and that!

Ian Woofenden's picture
Hi Edward,
One can be "off-grid" in the city or in the wilderness. As an island dweller, I see myself (off-grid) and my neighbors (mostly on-grid) planning differently than folks who can walk to the grocery and hardware stores. We think ahead, make lists, keep larger stock of food and parts and such, and rely on our neighbors to save trips to town for just one thing. I find that it brings out both efficiency and community in people!
Regards, Ian Woofenden, Home Power senior editor
Marc Fontana's picture

The phrase "Off-grid" is completely appropriate and in my mind doesn't imply anything about one's personal motivation for making that choice. You can still live sustainably while connected to the grid. Off-griders may or may not be interested in sustainability. Every time I hear or read about the local utility putting up more barriers to residential solar, I think about going "off-grid". The truth is that there are too many self-serving entities resisting our switch to renewable energy and sustainable living to make a significant impact on climate change. We're all going to have to adapt to a very different world in the very near future, on the grid or not...

webb.rowan's picture

It's interesting to live off grid, but it sounds so conspiracy theorist as if we are trying so hard to get away from Big Brother because he resides in every and all technology around us. Sustainable living is a much better description for such things and it reflects exactly what living off grid is trying to achieve.

Michael Welch's picture
But I'm not enamored with "sustainable living" as the new descriptive term. Nothing we do with technology is sustainable. The best we can do is to use it as a comparison between two options -- as in, "does one choice approach sustainability more closely than another?" In this day and age, true sustainable living is an impossible goal. So maybe we are still searching for the terminology to replace "living off grid."
Ian Woofenden's picture
Hi Webb,
I echo Ben's comments, and it was/is foreign to me to use the term "off-grid" to mean cutting off from technology. For me, one of the beauties of renewable energy technology is that we can be closer to nature while still being connected to the rest of the world, and to technology that makes our lives better.
My homestead -- shown in the aerial photo in the article -- is off the electrical grid. But we have cable for Internet, a hard-line phone line that was used for decades before cell phones, and we're on the "propane grid", though that's become a tiny part of the energy use here in recent times. The Internet makes us very connected, and in fact enabled me to write this article and communicate with the rest of the crew about its production. I'm "living off-grid" right this moment, while conversing with you in a very public forum.
I agree with Ben, let's reclaim the phrase "off-the-grid" to mean not connected to a utility electrical grid.
Ian Woofenden, Home Power magazine senior editor
Marc Fontana's picture

Ian, You mention using "cable" to connect your "off-grid" homestead to the Internet. How does that work? I think it would be interesting to see a HomePower article describing what options are possible for folks who live "off-grid" to be connected. I imagine there are bandwidth limitations that depend on your location and available services.

Ian Woofenden's picture
Hi Marc,
I'm not very far off-grid, and the local cable TV/Internet company has perhaps the best Internet connectivity available at my site. I paid about $2K some years ago to have an underground cable put in, and it's provided reasonable connectivity -- significantly better than dial-up, which we lived with for many years.
An article on off-grid Internet service is an idea I like — I'll float it to the rest of the crew. Where I am, the options are cable, various forms of satellite, DSL in places, dial-up, and cell-based services. Each has its advantages and disadvantages, including cost, reliability, speed, delay, etc.
Ian Woofenden, Home Power senior editor
Ben Root's picture
Hi Webb, I agree completely! I think it's a nomenclature distinction, with two camps trying to use the same term. When I first started with Home Power, I was living "off-grid" with the founders, way up in the woods. That off-grid meant that we weren't connected to the electrical utility grid, but we were "connected": there were lights in the house, computers, internet, technology, power. It was there, in the woods when I first read in Wired magazine, the use of off-grid to mean "technologically disconnected", or detached from the "system" or living "without." I was offended that they were stealing our technical term to use as some sort of luddite, anti-technology, value-judgement slur. I suggest we double-down with the clarification that "off-grid" means independently-powered, and not "hiding from the real world." And we need to remind people new to the idea of renewable energy, that they don't need to go off-grid to be able to choose renewable fact, in most cases, it's not the best use of the technology.
craigmerrow's picture

Really enjoyed this article! My previous home was grid-tied with PV's and DSHW, was looking to expand on this with my next house, a small passive-solar cottage. Found a nice lot, but it would cost me $35k to run a line extension 1/3 mile down the road (Central Maine Power must use gold-plated materials), so now I'm giving serious consideration to going off the grid. It's just me, and I use very little to begin with; still researching it, but it looks like a 3 kwh system will take care of my energy needs nicely.

Wayne Adams's picture

I have a cabin near Bangor that is 1 mile from a utility pole & Emera (Bangor Hydro Elect) wants $40k fir their work, $30k if I get all the property owners from the pole to my cabin permission for their poles, & $20k through a private contractor (then I pay flat monthly fee of $30 & $10 a pole on my property for 10 yrs). Are you going to due the work or someone else?

Sky's picture

I'll add one more motivation: going off-grid can clean up the power. Benefits include less wear and tear on electronic components due to power surges, better audio and video fidelity in home entertainment systems, and potentially, a healthier living environment with less AC radiation throughout the home. I'm suggesting DC power when possible, and well-regulated AC for the circuits that require it. While much clean power is possible with a well-designed grid-tied system, going off grid gives the installer better control of this imho.

HLCOKAYNE's picture

Sky, I see your points there is truth to what you are saying. I am aware that you have concerns about AC radiation.. I am curious about your concerns. I served on nuclear submarines and I worked with the sonar systems. Most systems had one-point grounding to eliminate EMI and signal noise. DC current works good for low wattage equipment but as the wattage increases so does the current, more current also radiates magnetic flux currents in the wires..
Simply the best is to put a AC Power Isolation transformer for important AC circuits.
Most of the common Power Inverters use a digital signal for converting DC to AC, and are not as efficient as Pure Sine Wave inverters are. Pure Sine Wave inverters produce a sine wave vs. the digital voltage spike of the non-sine wave inverters..
I have found several places (you-tube users) have put a AC Power Isolation transformer on their non-pure sine wave inverter and were able to run single-phase machine shop equipment with impressive results vs. not able to run the equipment on just the non-sine wave inverter alone.
DC Powered homes and off grid devices. If one can run 24vdc one can reduce the amperage on the wires which will cause less heat per watt used. however with this is the issues of some serious arcing and sparking. 48vdc is fine for the grid to the charge controllers however 48vdc is in the voltage ranges which can cause fatal shock... and this is why it is NOT recommended in the buildings primary wiring..
I hope this helps all...
Harold in Maine/Georgia

John Soileau's picture

48Vdc not recommended for house wiring? Can you explain? I don't understand the reasoning of that when typical home AC is 120Vac & 240Vac. There is an even greater chance for that AC to arc and/or kill.

Ian Woofenden's picture
Hi John,
I'm not sure exactly what Harold meant, but practically speaking, 24 VDC can be used for off-grid load wiring because you can actually buy 24 VDC light bulbs, refrigerators, freezers, and such, whereas 48 volt loads are not generally available.
Overall, most new off-grid homes are 120 VAC (usually no need for 240, and it keeps it simpler not to do that), but many of us old timers use some DC loads, and hands-on folks who want more efficient and resilient system still choose this option, though it is more complex and takes more knowledge and awareness.
Ian Woofenden, Home Power senior editor
Sky's picture

Thank you for your insights Harold. As a recording artist and technologist I've always been interested in the concept of DC in the studio, but acknowledge your comments about pros and cons. I agree a "whole-house" system would make most sense for a tiny house or perhaps a specific room, and not so much for a larger building. Thankfully, technology continues to advance. For example, today's LED lights are much cleaner (sonically) than the CF bulbs they've begun to replace. In operation, my project room is lit by two 7W LED task lamps on the desktop, cables are short, and AC hum is much less a problem than it used to be. Best regards

America Install Solar's picture

Ian W., Thanks again for your great informative articles!
My first designed solar energy systems were completely Stand-Alone for tropical islanders ( to most, 'grid' power was strange!).
Technically, for most independent energy systems, we should use this terminology to avoid so much confusion by gen. public :

STAND-ALONE or completely "off-grid" power systems (avoids mis-interpreting as "temporarily living off-grid but having grid as 'back-up'")

Bi-Modal (PV systems) or "grid-tied with battery back-up", which are two solar electric systems in one PV system, iwith two 'modes':
1. Operates normally as the 'traditional',more efficient/less cost sys., in the 'grid-tied mode' (allowing energy storage,i.e. usu. 'battery bank) then,
2. Operates in Stand Alone mode automatically (or manually) if/when utility grid fails* by isolating grid-connection & then powering dedicated 'critical-load' circuits the owner has chosen to have operate.

*or anytime a Bimodal system customer decides to wean from grid, (like Lynn James...congratulations!), provided they have the array/power+energy storage capacities to live 'Off-the-grid".

Also, this option, as we recommend, is best for most customers without the lifestyle changes to Stand Alone like some of us.

Since solar module ('panel') prices have decreased drastically last few years, most aspiring solar PV system owners can now own a same size array bimodal PV system for less than a 'grid-tied only' sys. cost last decade! I also, believe living 'off-grid' is long-term affordable for most areas of the U.S.(& the world). The Islanders have been using solar & wind energy well for decades!

Thanks again for sharing your years of experience 'standing' on your own power, if one is committed to initial 'sacrifice' to live truly 'off-grid' the benefits are wonderful!

chaolysti's picture

I'd really love to see a "grid defection" vs. "off grid" article exploring the economics of solar+storage with the traditional off grid decision tree as explained in this article. In my 10+ years in the solar business, I've heard plenty people claiming to want to be "off grid" but not wanting to actually live off the grid, like Ian points out early in this piece.

Now, with the price of storage coming down and utility policy changes in a number of markets (like Hawaii) I think this would be a rich area to explore. Maybe even talk with some solar/storage/ongrid homeowners in Hawaii to analyze this new "on-grid" off-grid.

Sky's picture

We are a net energy producer about ten months per year in South Maui. This is a conventional home with 24 x 235W panels producing roughly 30 KWH per day on average. Energy credits have been working well for us with the local utility, but we are watching recent discussions about increasing fees and reducing credits. If this happens, the economics of going off-grid may become attractive, especially when any of the recently announced residential storage products comes to market.

The challenge would be occasional stormy days when daily production can dip to just a few KWH. Certainly no air conditioner, laundry or involved cooking on those days. Beyond the big three we're in good shape. Hot water is nearly 100% passive solar, and our general use of lights and electronic appliances is manageable.

Environmental is our key reason for going solar. Our home came with a PV system already installed, which was a priority for us during the property search. We wanted to be able to keep the temperature at a reasonable 79-80 degrees and still be net zero. Social/political is also a factor, as we are contributing to the community's growing perception that solar works. Philosophy is a third; I am imagining a desirable future and taking steps to practice it close to home.

Lynn Janes's picture

I was selling back to the grid, but with my local company I was paying them to take my extra power, so after 2 months I called them and told them to come and get their meter. Been off grid for about one year now!

richardnealnc's picture

As about the most "off grid" location possible, the Frying Pan Tower, I've still learning more about how to use less gas generation, use our PV effectively and have just installed some wind turbines to help on dark days. (ref: for my house) I'm considering replacing our must-run generator electric hot water tank with a solar system but am not quite sure how/where to start or if with very limited but heavy use (weekends usually) if I should just burn the propane for an on-demand heater? Thoughts are appreciated! Richard

Fred Golden's picture

While a flat plate solar hot water heater is fine for your non-freezing location, and will work well in your saltwater environment, a evacuated tube 20 tube system is much more likely to fit into a small box, and be easy to transport by helicopter or boat to your site. With an added advantage of being able to remove some of the tubes when you do not need much heat. You could remove 10 to 18 of the tubes when you will not be there for a few weeks. Installing more tubes under high demand conditions.

Good luck with your platform! Certainly a great place to go fishing, or raise shrimp.

Ian Woofenden's picture
Hi Richard, A search in our article archives -- such as -- will yield a wide variety of articles that can help you with your hot water thinking. Heavy use on weekends and plenty of sun during the week could lend itself to a substantial storage tank with an appropriately sized solar collector array. This approach seems more sensible to me than hauling propane way out there. The sunshine is delivered freely. Ian Woofenden Home Power senior editor
Michael Welch's picture
Solar thermal systems make economic sense in many places on the mainland. But when you add in the time, cost, and potential danger of shipping or helicoptering propane out there, I'd think it would be a no-brainer.
Marc Fontana's picture

Good Article Ian ! In your list of loads considered "too big" for off-grid, you don't mention EV charging. So, I'm wondering, can EV charging be practical for off-grid living? I know that some off-griders have small dedicated PV systems to charge up small electric tractors or golf carts, but what about a modern EV? I don't think it is practical or efficient to use the home battery bank to charge up the EV battery. Has anyone designed a charge controller which could be used to charge an EV's batteries direct from a PV array?

Ian Woofenden's picture
Hi Marc, Good question! Part of the answer is in my comments about the variability of off-grid energy. If you want to be able to charge an EV any time you want off-grid without starting the generator, "No!" is the answer. If you are willing to charge your EV when you have a surplus, and NOT use it (so it doesn't become deeply discharged and damage the battery bank) or charge it elsewhere when renewable energy is in short supply, "Sure!" is the answer. All well-designed off-grid systems have regular surpluses, but they also have times of scarcity. A back-up generator is necessary in most significant off-grid systems. Whether you want to run it to charge an EV is a complicated question, and runs into your values and some economics. I like to think of an EV (in my case, electric bike) charging as an "opportunity load" -- I charge and use my e-bike when I have the juice, and don't use it when I don't. Same goes for my electric chainsaw. If you have a backup generator, when it runs, it makes some sense to make the most of it, so that's when we start thinking of the energy intensive jobs. But the same thing happens around here in a windstorm, and any time in summer when we see that the batteries are full. It's not a complicated thing to set up a charging outlet that only comes on when your batteries are full -- we have the technology to do that built into the electronics of various inverters and charge controllers. I can also see the sensibleness of having a dedicated EV charging array. Then it charges when you have the resource, and you don't have to worry about dragging down the house system, or deciding when to charge. The drawbacks are twofold: you may not always get it charged when you want it, and your PV array will not get fully used, since it will shut down once the EV is charged. And you will need to find a charge controller that will handle the PV input and conversion to the EV battery parameters. I suspect that's out there, though I'm not up on the specific products in that realm. So you see that the answers aren't easy, which I hope many people are gradually seeing is often the case with off-grid systems... Regards, Ian Woofenden Home Power senior editor
Marc Fontana's picture

It makes sense to look for a non-electric way to heat water when going "off-grid". However, after adding 1800 Watts of PV to my Mother's original 1500 Watt off-grid PV system in Hawaii, we wondered if installing a small Whirlpool 12-gallon 120v 1500Watt electric heater could be used off-grid. Until 2013, she had been using a small Paloma tankless propane heater, but the heater is temperamental and she was looking to reduce her propane use. We looked at using a solar thermal heating system but it would cost more and be prone to failures because of excess heat. I realized that a small electric heater would be hard on the home's battery bank, but what if we ran the heater for a few hours at midday when the battery bank is more likely to be fully charged and the PV system has electrons to spare? So I installed the heater and an Intermatic Timer to turn it on from 1pm to 3pm every day. It works perfectly ! Hot water is available in the afternoon and evening, and even the next morning, it's still warm enough for a quick shower ! It's been running for over a year with no significant impact on the battery bank's state of charge at the end of each day.

Ian Woofenden's picture
I like your strategy, Marc, but I'd urge caution to readers who may have less sun, and less predictable sun, than your mother's site perhaps has. A 1,500-watt load automatically turned on from 1-3 PM here in the Pacific NW would be pretty disastrous for most home battery banks for several months of the year. And it is a pretty significant load you're talking about, even for that very small tank heater. I haven't done the sleuthing to calculate my daily kWh use lately, but in the past it's been in the 6-9 kWh per day range or less. Adding 3 kWh per day for water heating would be a big hit. The math needs to be done for each particular case. In my case, solar thermal and wood heat most of my water (with a bit of propane for backup and lead time). This is a particular good match because we have plenty of sun for about half the year and heat with wood the other half. Your choice to use an electric tank heater off-grid will be a stretch for most systems, but worth considering. But unless I was fairly confident that the system fully charged the battery bank by noon most every day, I would lean toward a system that turned the heater on based on battery state of charge (or more likely voltage), instead of on time. Then you could set it up so that it only used energy that would not have been used, and it could have a very minimal impact on the system, with no risk of discharging the batteries at a time when they are low. I love the creative solutions people come up with, and some of the best are when people (sensibly) break "the rules"... ;-) Regards, Ian Woofenden Home Power senior editor
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