The Off-Grid Process from Initial Inquiry to Lights at Night

By Allan Sindelar, Positive Energy’s Off-Grid Specialist

When you first call us to inquire about solar power for your home, you will likely be directed to me, Allan. When I started Positive Energy in 1997, off-grid systems made up about 98% of our work. We do nearly as much off-grid work now than we did then, but it makes up only about 5% of our total business. This is simply because most of the tremendous growth in the solar power field has been with utility-intertied (“grid-tied”) systems – the mainstream application of solar power.

As we have grown, I have assumed primary responsibility for the off-grid part of Positive Energy’s business. With the most years of experience, I’m most likely to have seen a particular problem before. It’s also the aspect of our work that I most enjoy. I value the friendships I have made over the years, and appreciate the likelihood that I’ll be called on from time to time with a question, problem, upgrade, or just a friendly check-in. I have observed that off-grid living tends to attract the “cultural creatives”: more socially and politically out of the mainstream. This work fits my own eccentric nature.

We will begin a multiple-step design process with you. The process will more or less follow the steps described in this article. If this is your first time living off-grid, there’s a fair amount of education necessary. You may wish to start by reviewing the Home Power article "Toast, Pancakes and Waffles: Planning Wisely for Off-Grid Living", available here. At times the design process may appear tedious, or even seem as though we are putting up barriers. It’s true; we are. I am far more interested in your long-term success and satisfaction than in making the initial sale. Sometimes I believe (right or wrong) that I have to slow you down and insist that you deal with a potential problem that may not appear obvious. 

For most folks, working with us to design, install and service a power system is akin to entering a long-term relationship. You are your own little utility, and you must remain involved in the care and use of your system. Depending on your own technical skills, you may need to depend on us to guide you through the long-term care and feeding of your system, and to be available, sometimes on short notice, when problems occur. You need to feel confident that we’ll be there to support you for years to come.

1. The Initial Conversation

We will generally start with an initial conversation, either in person at the shop or by telephone. I will generally ask you such questions as these:

•Have you already bought property, or are you still in the process of looking for land or a home? (This helps me understand what sort of information you’re looking for at this stage.)
•Where is the property, or where are you looking? (If far from our shop, I will often suggest a good installing dealer who is located closer to you.)
•Is there an existing home or other building on the property (or prospective property) or are you planning to build a new home?
•If you are building a new home, are you doing the work yourself, or are you working with a general contractor?

•If you are building new, how far are you into the design or building process? (We are best included in the design process from the very beginning, well before ground is broken.)
•What are your motivations for wanting to be off-grid?
•How far away is utility power and what will it cost to bring it in and hook up to it?
•Do you have specific needs related to your lifestyle and life situation, such as young children or elder care, plans to work at home, livestock, etc.?
•What is your current familiarity with off-grid living?
•What are your plans for heating your home?
•What are your water supply plans?
•What budget range do you have in mind, and how will you finance your project?

This conversation serves several purposes, and I listen carefully. It gives me a good initial profile of what you are seeking, and at what level of technical detail I should address your questions. But at the same time I am usually hearing much more “between the lines” than in your actual words. I have done this work for so many years that I can often sense (and answer) the questions you don’t yet know to ask, and even whether or not you are likely to be a good candidate for off-grid living.

If you have read this before initially contacting us, you may have downloaded and begun the load analysis process. When possible, email me your best first attempt at a load analysis (discussed in detail below) before our initial discussion; I’ll have more to work with, and we’ll cover more during our time together in conversation.

This initial discussion typically takes 45 minutes to an hour, and is at no charge to you. I suggest that you think of it as a mutual “employment interview”: at its conclusion, we will both have a pretty good sense of our compatibility. At this point we’ll decide whether to move on to the next steps in the design process.

2. The Load Analysis

A load analysis is an essential part of the off-grid design process and always has been. It is a systematic and methodical listing of everything you expect to power in your off-grid home (or cabin, shop, RV, etc.) with the expected power consumption and hours of use.

It’s an admittedly rigorous and time-consuming process, but necessary. For me as your system designer, it serves four distinct purposes:
1) The obvious intent of your load analysis is to list and quantify your loads, in order to give me the hard information to size your system with confidence.
2) As I review your loads, I often can suggest ways to achieve end results more efficiently and thus use less energy to achieve the same result. This can reduce system size and cost.
3) Likewise, from experience I can identify overlooked or inappropriate loads, potential problems and special cases, and suggest alternative ways of achieving desired results using less electrical energy. Past examples of this have included “Softub” hot tubs and “Multi-Flo” wastewater systems, both inappropriate loads in systems of average size.
4) The load analysis serves as a document of record – that is, if a system proves insufficient in the future, we have a record of how much energy was expected. We can measure actual consumption and either reduce the loads or expand the system.

For you, in addition to each of these benefits, there is a fifth benefit that is really the most important of all. Most of us who have lived with utility power have taken it for granted: we use it as needed and pay the bill each month. Often we have never had reason to know how the energy is used, how much and for what. The load analysis process is a fine consciousness-raising activity. By understanding how and where this precious, finite solar electricity is used, you are far more likely to be satisfied with your power system, its limits and blessings, over the many years you will enjoy it.

Here are some resources to help you begin the load analysis process. Home Power has published many good articles over the years; we suggest you start with “Getting Started with Renewable Energy: Professional Load Analysis and Site Survey”, available here. A 1997 article titled “Doing a Load Analysis: The First Step in System Design” available here remains just as relevant today.

We have used a simple two-page load analysis spreadsheet, available here. Use this form; as an active spreadsheet, we can modify data and test ideas, showing you the results at each step. Specific instructions for this form can be found here, but don’t worry if these instructions aren’t clear. The loads listing is the most important part; enter what you can and we will work with you to fill in the rest.

We sell a $30 measurement device called a "Kill-a-Watt" meter, which allows you to plug in any AC device and measure consumption, including over time, such as a fridge. It's very easy to use and we include our own instructions for its use (our instructions can be found here) as a load analysis tool. In some cases we'll even lend you one of our meters.

3. The Budget

We have installed off-grid systems for under $3,000 and well over $100,000. To a large degree, the same design and education processes hold for both.

When asked what a power system will cost “to power a 2,000 square foot home”, I first answer that the size of the home is nearly irrelevant to the question being asked. Two homes of the same overall size can have electrical needs that differ by a factor of ten or more. I then answer that a modern, well-designed Code-compliant off-grid PV system for full-time residential use, including installation, generally costs between $15,000 and $25,000. I acknowledge that this is a pretty wide range, and explain that it depends directly on the loads, lifestyle, and budget of the customer. It’s hard to do a Code-compliant system for less than around $10-12,000, as there is a diseconomy of scale below that – the sacrifices to meet the budget become too substantial.

I can also narrow this figure a bit. A typical modern, full-feature system for a customer who has properly reduced his or her loads, with a PV array of roughly one kilowatt and around three days’ worth of mid-level battery storage capacity, will run around $18-22,000 installed. This typically includes all major system components, design, and support. It excludes efficient appliances, carpentry work such as a battery box, and trenching, excavation, and concrete work, as these are usually best done by you, or by another tradesperson at lower cost. It may or may not include a backup generator. We also generally wire the system output only to the home’s breaker panel; we usually don’t install conventional AC distribution wiring.

We are entirely capable of designing and supplying larger systems to meet greater load profiles. We have completed several systems with PV arrays over three kilowatts, several times this base system size.

From this figure, you may expect to receive tax credits of up to 40%, providing that the system is properly permitted and inspected. We will generally prepare the necessary state tax credit support documents for you as part of out installation and support documentation. If you are replacing or upgrading an existing power system, we can generally resell your old components on a consignment basis with a nominal commission structure.

While we don’t offer financing directly, we can direct you to some local financing resources that others have used successfully in the past. Several years ago, a local mortgage broker and I co-wrote a Home Power article titled “How to Finance Your Renewable Energy Home”, available here, that remains relevant today.

4. The Site Visit

Once we have a general idea of your loads, lifestyle, and budget, we will usually arrange a visit to your property. This is best done with you; both of you if you have a partner. During this visit we will suggest one or more PV array locations using the Solar Pathfinder or SolMetric SunEye site survey tools. We’ll measure conduit and wire runs, select a location for equipment and batteries, look for potential pitfalls to avoid, locate your well, plan for a backup generator, and generally plan the details of the system installation.

Following the site visit, we will generally complete the system design, providing you with a System Component List and/or a full Proposal, as preferred. With the List or Proposal we will include our first Invoice, for all design work to date.

By knowing your desired budget range up front, you may expect that the List or Proposal will be generally in order with what you can afford. If you are ready to proceed, a deposit of at least one-half of the total, along with a signed copy of the Proposal or System Component List, will start the installation process and will confirm your component prices against periodic increases. We will set a tentative date for the actual installation.

5. The Installation

We will stay in regular touch with you as the installation days approach. Questions will come up, changes may be necessary, the starting date may move up or back. We’ll typically arrive for the first day of installation with a larger crew of two to four technicians. One or two will begin assembling the array and rack, one will begin the “balance-of-system” – the inverter, charge controller, disconnects, etc. A fourth may run conduit or set and connect batteries, depending on the job. We will usually encourage you to be present and available during installation, as we will inevitably face questions that you can best answer. We will also put you to work from time to time, saving us hours and you money, as off-grid installations are nearly always billed on a time-and-materials basis (see our Rates and Policies for details, available here). As you lend a hand it becomes “your” system with your time invested, and as you watch it come together it becomes less forbidding and mysterious. Plus we enjoy your company!

Subsequent days typically bring smaller crews, as the number of separate tasks is reduced. We usually don’t work on the same installation on consecutive days, as days following can be used to resolve unforeseen problems, secure missed or specialty installation materials, and prepare for an efficient return trip.

6. The Commissioning

Finally the system is ready to be powered up: the array is wired, breakers are in place but still off, the batteries are connected. We double-check voltage and polarity and then methodically power up the system. Generally all goes well and the lights come on. Next come programming of the inverter, charge controller, and system monitor, and the myriad details to complete the installation.

All of our systems include a system monitor such as the Tri-Metric, preferably located in a well-traveled spot in your home, rather than with the power equipment. At minimum we will leave you with a basic understanding of your monitor, so that you may easily live within your energy budget. Depending on the course of the commissioning day, we may go over system operation and maintenance, or may return on a subsequent day for this. Plan to spend about an hour with us on this, taking notes if it helps you. 

If this is your first off-grid experience, we may teach you only the basics at the time of commissioning, with a plan to return after a month or so to present additional maintenance guidance once the system is more familiar. You will get a full owner’s manual with all component manuals, our design records and notes, maintenance procedures, a copy of the electrical permit, etc., but this may not be ready for you until after the installation is in operation.

7. The Follow-up and the Magic

You may expect to have us available by telephone for questions that may arise – this is normal, and you may count on our support as you become familiar with your system’s capacities and limitations. We warrant our work for two full years, and support manufacturers’ warranties as well. The details of our warranty, as well as a full description of our rates and policies, may be found here.

I haven’t yet lost my sense of wonder that comes with powering a home on sunlight - I still haven't. You will have the tools to live well with minimal dependence on fossil fuels. You will have gained an appreciation of how to use electricity wisely, and how to match your living habits with the natural rhythms of weather and season. It’s a wonderful way to live.