Off-Grid Basics
1. What does "living off-the-grid" mean?
2. Why go off-grid?
3. Common Off-Grid Applications
4. Before Going Off the Grid
5. Off-Grid Advantages
6. Off-Grid Disadvantages
7. Designing Your Off-Grid System
8. How Much Power Do I Need?
9. Sizing an Off-Grid Solar System
10. Major Off-Grid System Components
11. Which Brands and Products are the Best?
12. How Much Will My Off-Grid Solar System Cost?
13. Off Grid Incentives
14. Choosing a Solar Contractor
15. And finally...
1. What does "living off-the-grid" mean?
Living off-grid does not mean living without electricity, nor does it have to mean a very rustic lifestyle. Simply put, being "off-the-grid" just means you are your own power company. You can be off-grid in the middle of nowhere, or you can be off-grid in the middle of everything.
2. Why go off-grid?
There are many reasons to be off-the-grid, but typically off-grid (stand alone) solar electric systems are used in remote locations where connecting to the local utility grid is impossible or prohibitively expensive, in areas where grid power is inconsistent, or due to the appeal of an independent lifestyle. With an off-the-grid system, solar panels, a small wind turbine, a micro-hydro system, or a combination of these technologies and others, is used to supply all of the power a cabin, home or business needs. In some off-grid systems a home backup generator may also be included, to supply power when the renewable technologies can't produce enough to meet demand.
Off-grid living completely relieves you of dependency on the electrical utility, because the system provides all of your power. Due to this, off-grid systems are generally larger than grid-ties. To be fully independent, a system must have a larger wind generator or array of solar panels, and greater battery storage capacity than in applications where grid power is available. However, if done properly, living off-the-grid can save you thousands of dollars over the life of the system.
3. Common Off-Grid Applications
Remote homes and cabins, water pumping systems, livestock watering, telecommunications, RV's, boats, sign lighting and traffic warning lights are just some of the places off grid solar and renewable energy are utilized.
4. Before Going Off the Grid
If you are considering the off-grid lifestyle, you first need to fully understand your own power use habits, as well as exactly how an off-grid system works. To live off-grid you will likely need to make adjustments to when and how you use electricity so you can live within the limitations of your system's design, and to keep the system cost reasonable. This doesn't necessarily imply doing without, but rather a shift to a more conscientious use of electricity.
When designing an off-grid system it is critical that electricity consumption be determined for everything in your home or business, and to calculate for those cold, dark winter days and nights when energy consumption is at its peak and power production is at its minimum. It is recommended to take energy conservation measures first, such as installing fluorescent or LED lighting and energy efficient appliances, before investing in an off-the-grid system.
It is also recommended that before you choose an off-grid lifestyle you talk with a few folks who are already doing it. This will give you practical information that you may not come across in your other research.
Another great resource for seeing off-grid or on-grid solar systems that are actually in use is to attend the National Solar Tour in your area. The Solar Tour is organized by the American Solar Energy Society (ASES) and its member groups. The main tour is held the first Saturday of October all across the country, but in some areas tours are held at different times of the year. The Solar Tour is designed so that people just like you can visit homes and businesses in your area where renewable energy and other green living products and practices are in place. It is a wonderful opportunity to talk with end-users about the ins and outs, ups and downs, and all arounds of what they're doing. For more information about the National Solar Tour please give us a call, or visit the ASES website at www.ases.org
5. Off-Grid Advantages
Off-grid solar, wind and micro-hydro allow you to live independent from utility power, and/or off the beaten path. A well designed off-grid system also has an environmental advantage, helping you reduce your carbon footprint.
6. Off-Grid Disadvantages
It is generally not cost effective or feasible to install a renewable energy system large enough to provide power for things like electric heat, air-conditioning, electric cooking or electric hot water. Geothermal, solar hot water, and of course, gas appliances, are just some of the alternatives available that will allow you to maintain a comfortable lifestyle without relying on utility power.
Now that you understand the purpose, benefits and limitations of going off-the-grid, let's take a look at how to actually do it.
7. Designing Your Off-Grid System
From here on we will focus on off-grid solar, but keep in mind that the process of determining how much power you will need to produce and store in an off-grid application is basically the same no matter what renewable energy technology you choose. The main difference between types of RE technology is what size and how much equipment you'll need. To answer those questions we recommend you give us a call, and we can help you determine exactly which products will make your off-grid life simple and comfortable.
8. How Much Power Do I Need?
Determining how much power your solar PV system needs to produce for off-the-grid living is similar to sizing a grid-tie solar system, except that there is no utility bill to refer to for historic usage. So the first step is to make a list of all the items you plan to power in your off-grid home. Just remember that the more power you use, the more you will need to produce.
To be very accurate, you can refer to the label on each appliance or piece of equipment, and then estimate the amount of time you will using them each day, then do some math. For some items it is reasonable to use a guesstimate, but for those that have higher power consumption we suggest actual ratings for off-grid calculations.
Click here for a worksheet to help you calculate your AC loads.
The simplest way though, is to let us help you. We can save you time and ensure you have accurate information on which to base your PV array sizing, As with any questions you may have about using renewable energy, feel free to give us a call at 1-360-422-5610 or 1-877-230-7710 from your land line.
9. Sizing an Off-Grid Solar System
Once you know how much power you use, you can proceed to sizing your solar PV system. In an off-grid application it is critical the system is properly sized, because you will not have utility power to draw from if your RE system does not provide enough to meet demand. That is why we recommend getting expert professional help sizing your off-grid system, so you can be sure that you have all the power you will need.
If you want to get a ballpark idea of what size system you will need, click here to go to our off-grid sizing worksheet.
Once you know how large of solar array is required to meet your power demands, you can select the appropriate products. Here is a list of some of the items you will/may need:
10. Major Off-Grid System Components
Solar Panels
Solar panels absorb solar energy from the sun and convert it to DC power. Your power consumption, as well as your geographic location, affects the type and quantity of panels you will need. Because each solar panel only produces a small amount of energy, most solar electric systems consist of multiple solar panels interconnected together in "strings". This is called a PV (photovoltaic) or solar array.
Solar Panel Mounts (Racks) and Solar Trackers
Solar panel mounts are important to maximize production, provide proper directional and latitudinal orientation, and to provide the stability needed to protect your investment from the force of the wind. Solar panels can be mounted on the roof, ground, or on a pole.
A solar tracker is a device for orienting a solar panel or solar array toward the sun. Solar trackers increase morning and afternoon exposure, which at the right latitudes and in the right climates can substantially improve the amount of power produced by your system.
Power Inverter
A DC power inverter converts the DC power from your solar panels into AC power for your use. Some power inverters include a solar charge controller.
Some people choose to eliminate the power inverter to save money on their PV system, and instead purchase DC powered appliances and lighting. This is an option, however we usually we do not recommend this approach. The reasons are these:
- DC appliances and lighting are typically more expensive than standard AC products, meaning that over the life of your system you could end up spending quite a bit more to have all the modern conveniences.
- Finding these specialized products can at times be difficult or inconvenient, because many of them are only available through specialty retailers.
- Some items just aren't available in DC versions, meaning you may have to do without a convenience that is important to you.
Deep Cycle Batteries
A battery bank – a group of batteries wired together (also known as a string of batteries) – is a key component in stand-alone (off-grid) wind, solar and micro-hydro electric systems. Batteries store energy you collect from your renewable energy system or backup generator for use when you are generating less power than you are consuming.
When you're off-grid, if you don't have batteries you can only use power at the time you produce it. In other words, you will not have power when the sun isn’t shining on your solar panels (or the wind isn't turning your wind turbine, etc.) if you don’t have batteries to store the power when your renewable energy (RE) system is producing power.
Important Note: Renewable energy systems require batteries that are designed for frequent, deep cycling, appropriately called deep cycle batteries. Car batteries, and even some types of deep cycle batteries, are not appropriate in RE systems. For more information on batteries for solar, wind and other RE systems, please give us a call, or refer to Batteries under Learn More About Products.
Solar Charge Controller
Battery-based RE systems should have a charge controller to manage the charging of your battery bank. It is important that your charge controller be programmed with the correct set points for your specific battery type in order to reduce the risk of damage from inconsistent charging or overcharging.
Battery Monitor
Battery monitors provide crucial information for managing and protecting your battery bank, yet many battery-based systems don't have one. A good quality battery monitor is relatively inexpensive, and provides important data such as accumulated amp hours, charge status of your battery bank, and maintenance and troubleshooting information.
The battery monitor should be mounted in a central location in your home where it can be easily seen, and it needs to be properly programmed, based on the parameters of your system. Programming is generally only needed during meter installation.
Automatic Back-up Generator
A back-up power supply is important to compensate for seasonal changes and weather patterns that affect the power production of your renewable energy system. An automatic back-up generator (rather than a manual starting) can make living off-the-grid convenient and worry-free.
Other Things You'll Need
- PV Combiner Box
- AC Breaker Panel
- DC Breaker Box
- DC Breakers
- Battery Cables
- Remote Temperature Sensor
- Solar Panel Cables (MC3 or MC4 cables)
- AC and DC Wire (Purchase locally)
- Miscellaneous other electrical small items (purchase locally)
- Gadgets and other add-ons you may want
The above items are generally what you'll need in an off-grid solar PV system, but because off-grid systems are customized to each specific location and customer, you may not need everything listed or there may be additional items suggested.
11. Which Brands and Products are the Best?
The number of companies offering solar equipment is rapidly increasing. And each solar professional you speak with will have certain products they recommend, and they usually have very convincing reasons for recommending those products. This can make it a challenge for consumers to know whose opinion to trust, and which products are truly the best.
So how do you choose? As with any major purchase, you will want to do your homework. With all the focus on renewable energy, it is easier than ever to get reliable information on manufacturers and specific technologies, but this can also leave you with an overwhelming pile of information to sort through.
Our best suggestion is to find a solar professional you trust, and allow them to guide you through the ever-changing maze of renewable technology. And then we suggest you get a second opinion. Because renewables are a major investment, it is always a good idea to talk with more than one professional to be sure you are receiving information that is accurate, pertinent and complete. For information on how to find a qualified, reputable solar professional, please go to How to Select Your Solar Contractor.
Once you have recommendations on products, you can also do some research online to see what others are saying about those products. Check out each manufacturer's website or give them a call. Check out one of the many industry blogs, the Better Business Bureau (BBB), and industry publications. (Remember, the manufacturer will naturally tell you the best about their products, so don't rely solely on the information they provide to make your decision.) Because of the increased demand for renewables, third party testing agencies such as Consumer Reports are also starting to offer consumers with quality information.
In our opinion, here are some things you'll want to consider as you're shopping for products and choosing brands:
How long has the manufacturer been making renewable energy products?
There are a plethora of new companies getting into the industry, and we have found many of them use "the new math" when they calculate their industry experience. Don't just take their word for it - ask around to find out if they really know what it takes to make good products.
What is the track record of their products?
Ask around about a manufacturer's reputation and about how their products perform in the field. You can find online sources for this information, or you can talk with consumers who are using their products.
Is it proven technology, or will you be "field testing" something new?
It often seems that the marketing and sales folks get all excited and start talking about new products that are only in the early stages of research and development and/or that are far from actual production. The most common thing about is new solar panel technology that will cost almost nothing and make gigawatts of power. So far, (unfortunately) none of those products have actually shown up in the market.
Is it the right product to do the job?
Sometimes you may hear of a couple of different products that have proven track records and that are made by reputable companies. So how do you know which one is right? Obviously the first consideration is whether or not they will do the job you need them to do. It naturally comes down practical details such as price, warranty, and extra features.
Which products is your solar contractor using at their home and/or business?
This is a great question to ask. It not only tells you something about the products, but also helps you determine if your solar professional has practical experience with the products they sell.
12. How Much Will My Off-Grid Solar System Cost?
The number of solar panels you need, how you want to mount them, how many batteries you need, and how far you need to run wiring are just some of the many factors that will affect the overall cost of your off-grid system.
13. Off-Grid Incentives
The Federal government offer incentives for off-grid solar systems. For more information on incentives available in your area, visit the Database of State Incentives for Renewable Energy (DSIRE) website at www.dsire.org.
14. Choosing a Solar Contractor
Overall value is important when choosing between the increasing number of professionals offering solar products and services. Often the low bid is from a company that is highly qualified and has a well-managed operation, but sometimes it comes from a company that will cut corners or that may not fully understand the job requirements.