Can I Go Completely Off-Grid with Solar Panels?

Are you thinking about going off-grid with solar power like we did a year ago? It is a big step, but one that’s becoming more popular as homeowners look for ways to cut ties with traditional utility companies and live more sustainably. For some the decision is also about the insufficient grid reliability. 

Going off-grid can be exciting, it means you won’t rely on the public power grid for electricity – you will generate your own with solar panels. This lifestyle shift isn’t just about saving money on your electricity bill, although that’s a nice bonus. It is about gaining independence and being in control of your spendings, reducing your environmental impact, and taking control of your energy usage patterns (yes, there is some adjusting to do).

But let’s be real – going off-grid isn’t as simple as attaching a few solar panels on your roof and calling it a day. There are some things you need to understand before diving in. For one, the upfront cost can be significant. 

On average, a full off-grid solar system can range from $12,000 to $50,000, depending on the size of your home and your energy needs. However, considering that the average American household spends about $1,400 a year on electricity, the long-term savings can be substantial. In many cases, homeowners see a return on investment within 7 to 15 years.

But let’s discuss everything you need to know step by step in more detail. 

Understanding off-grid solar power: Can I go completely off grid with solar panels?

Being “off-grid” means you are not connected to the public electricity grid. Instead, you produce your own power. Solar panels are a popular choice because this new and exciting technology is efficient and renewable. 

Here is how they work: solar panels are made up of photovoltaic (PV) cells that capture sunlight and convert it into electricity. This electricity is then used to power your home, from running your refrigerator to charging your devices.

The electric current generated by the PV cells is direct current (DC) electricity. However, most home appliances use alternating current (AC) electricity. To make the electricity usable for your home, it needs to be converted from DC to AC. This is done using a device called an inverter, which is a key component of any solar power system.

For example, a typical off-grid home might use a 5 kW solar system. This sized system can generate approximately 20 kilowatt-hours (kWh) of electricity per day under good conditions. This amount of electricity is generally enough to power essential appliances and electronics, such as lighting, a refrigerator, a few small appliances, and electronic devices like phones and laptops. 

How many solar panels do I need to go completely off-grid?

The big question when off-grid is: how many solar panels do you actually need? The answer isn’t one-size-fits-all, but let’s break it down so you can get a clear idea.

First, you need to determine your daily power consumption. This is where the math comes in, but don’t worry, it’s pretty straightforward. 

Start by listing all the appliances and devices you use daily – everything from your refrigerator and lights to your laptop and phone charger. 

Each of these uses a certain amount of electricity, measured in kilowatt-hours (kWh). For example, the average American household consumes about 30 kWh per day. If you are looking to go off-grid, this number is crucial because it will determine how many solar panels you need.

Once you have got your daily power consumption figured out, you can start thinking about the minimum solar panel setup. As a rough estimate, a single solar panel typically produces about 1.5 kWh to 2 kWh of electricity per day, depending on its efficiency and your location. 

So, if your household uses 30 kWh per day, you will need around 15 to 20 solar panels. 

Several factors affect the number of panels you will need. One of the biggest is your geographic location. Solar panels produce more electricity in sunny areas – for example, a home in Arizona might need fewer panels than one in New York to generate the same amount of power. The angle of your roof and the amount of shade it gets also play a role.

Another key factor is the energy efficiency of your appliances. If you are using older, less efficient appliances, they will consume more power. On the flip side, upgrading to energy-efficient appliances can reduce your overall power consumption, allowing you to get by with fewer panels.

Let’s look at an example. If you are in a sunny area like Southern California and your home uses around 20 kWh per day, you might only need 10 to 12 solar panels, assuming they are high-efficiency models. However, if you are in a cloudier region or your roof gets a lot of shade, you might need to bump that up to 15 or even 20 panels to generate the same amount of power.

But to truly be off-grid, you also need a way to store that energy for use when the sun isn’t shining – which is where batteries come in. Modern lithium-ion batteries, for example, can store enough energy to keep your home running through the night or during cloudy days. 

How much battery storage do you need for off-grid solar?

Now that we got solar panels figured out, here is another critical piece of the off-grid puzzle: battery storage. If you are going off-grid, you cannot rely on the sun shining 24/7. That is where you need batteries to store the excess energy your solar panels produce during the day so you can use it when the sun goes down or on those cloudy days when your panels aren’t generating as much power.

Unlike grid-tied solar setups, where you can draw power from the utility grid when the sun isn’t shining, an off-grid system needs to be completely self-sufficient. This means you need enough battery storage to keep your home running through the night and during periods of bad weather. Without adequate storage, you could find yourself in the dark – literally.

So, how do you calculate how much battery storage you need? It all comes down to your daily energy consumption and how many days you want to be prepared for. A good rule of thumb is to have enough storage for at least three to five days of energy usage. This is known as “days of autonomy,” and it ensures you have a buffer for periods of low sunlight.

Let’s crunch some numbers. If your home uses 30 kWh per day (the average for many households), and you want three days of autonomy, you would need 90 kWh of storage capacity. 

However, it is important to remember that not all the energy stored in batteries is usable. For example, lead acid batteries should only be discharged to about 50% of their total capacity to avoid damaging them. This means you actually need a total battery capacity of around 180 kWh to have 90 kWh of usable energy.

The types of batteries in off-grid setups

The two main contenders are lead-acid and lithium-ion batteries. Lead-acid batteries are the older, more established technology. They are cheaper upfront, but they have a shorter lifespan and lower efficiency compared to lithium-ion batteries. 

On the other hand, lithium-ion batteries, like the Tesla Powerwall, are more expensive but offer better performance. They have a longer lifespan (typically 10-15 years), higher efficiency (up to 95%), and can be discharged more deeply without damage.

For example, a single Tesla Powerwall has a usable capacity of around 13.5 kWh. So, if you need 90 kWh of storage, you are looking at around 7 Powerwalls. While this might seem like a lot, it is an investment in ensuring you have reliable power no matter what the weather throws at you.

When you are living off-grid, the reliability of your solar battery storage is crucial – after all, it’s what keeps your home powered when the sun isn’t shining. But how long can you expect your solar batteries to last? 

Typical lifespan of different types of solar batteries

Let’s dive into the lifespan of different types of solar batteries and what you can do to maximize their longevity.

Lead-acid batteries: They are the most established type of solar battery, often used in off-grid systems because of their lower upfront cost. However, they typically have a shorter lifespan, usually around 5 to 7 years. This type includes both flooded lead-acid (FLA) and sealed lead-acid (SLA) batteries. FLA batteries often last longer if properly maintained.

Lithium-ion batteries: The newer kid on the block, lithium-ion batteries, are quickly becoming the go-to choice for off-grid solar systems. They have a much longer lifespan, typically around 10 to 15 years, and they can handle more charge-discharge cycles without degradation. 

For example, the popular Tesla Powerwall, a lithium-ion battery, comes with a warranty of 10 years, but many experts expect it to last even longer.

Nickel-iron (NiFe) batteries: Though less common, NiFe batteries are known for their incredibly long lifespan, often exceeding 20 years. However, they are bulkier, less efficient, and more expensive upfront compared to lithium-ion batteries.

Factors affecting battery longevity

Several factors influence how long your solar batteries will last:

The way you use your batteries has a significant impact on their lifespan. Deep discharging (using up most of the battery’s stored energy) shortens the battery life, especially with lead-acid batteries. To extend their life, it is generally recommended to keep the depth of discharge (DoD) below 50% for lead-acid batteries and around 80-90% for lithium-ion batteries.

Temperature is the second factor that matters. Batteries tend to perform best at moderate temperatures – ideally around 77°F (25°C). Extreme cold can reduce the battery’s ability to hold a charge, while extreme heat can accelerate degradation. It is recommended to store batteries in a temperature-controlled environment to maximize their lifespan.

Regular maintenance, especially for lead-acid batteries, matters. These batteries need to be checked regularly for water levels (in the case of flooded lead-acid batteries) and kept clean and free from corrosion. Lithium-ion batteries require less maintenance but still benefit from being checked once a while.

Over time, all batteries will start to degrade, meaning they will not hold a charge as well as they did when new. Here are some signs that your batteries may be nearing the end of their life:

• Reduced capacity: If you notice that your batteries aren’t storing as much energy as they used to, or if they are discharging faster than before, this could be a sign of capacity loss. For instance, a battery that once powered your home for 12 hours might only last 8 hours after several years of use.
• Increased maintenance issues: For lead-acid batteries, more frequent topping off of water levels or noticeable corrosion might indicate that the battery is aging and struggling to maintain its charge.
• Voltage drops: If your system’s voltage is dropping more quickly or frequently, it might be time to consider new batteries. This is a common sign that the battery’s internal resistance is increasing, making it less efficient.

While lithium-ion batteries might last up to 15 years, lead-acid batteries will likely need replacement closer to every 6 years. Keeping an eye on the signs of degradation will help you plan for replacements.

What is the average cost of setting up an off-grid solar system?

Setting up an off-grid solar system is a significant investment – at this point, you are probably well aware that it costs more than just getting solar panels on your roof. So, what can you expect to spend on the key components and how does it all add up?

First, let’s look at the main elements of an off-grid solar system:

#1 Photovoltaic solar panels: Solar panels are the heart of your system. The cost of solar panels varies depending on the type and efficiency, but you can expect to pay around $1,000 to $3,000 per kilowatt (kW) of capacity. 

For a typical off-grid home that requires a 5 kW system, this would amount to about $5,000 to $15,000 for the panels alone.

#2 Batteries: The cost of battery storage depends on the type and capacity. For example, lithium-ion batteries like the Tesla Powerwall cost about $10,000 to $15,000 each, with a typical off-grid system needing several to meet energy demands. 

A complete battery setup might run you anywhere from $15,000 to $40,000.

#3 Inverters: The inverter is what converts the direct current (DC) electricity generated by your solar panels into alternating current (AC) electricity that your home appliances use. 

A good quality inverter can cost between $1,000 and $3,000.

#4 Charge controllers: These devices regulate the voltage and current coming from your solar panels to prevent overcharging your batteries. 

Expect to spend around $500 to $2,000 on a charge controller, depending on the system size.

#5 Installation labor: Unless you are an experienced DIYer, you will need to hire professionals to install your system. 

Installation costs typically range from $5,000 to $10,000, depending on the complexity of the system and your location.

When you add all this up, the total cost of setting up an off-grid solar system can range from about $25,000 to $70,000 or more – depending on the size of your system and the quality of components you choose.

Now, let’s compare this with staying connected to the grid. The average American household spends around $1,400 a year on electricity. Over 20 years, that adds up to $28,000 – this is without accounting for rising energy costs. 

In contrast, while the upfront cost of going off-grid is higher, you are essentially pre-paying for your electricity for the next 20 years or more. Plus, you are protected from utility rate hikes and have the added benefit of energy independence.

Do you need a backup generator for off-grid solar?

Solar power is fantastic, but what happens when the sun doesn’t shine for days on end, or you are hit with an unexpected surge in energy demand? This is where a backup generator comes into play. 

There are a few scenarios where having a backup generator is not just a good idea but might be essential. The most obvious is during extended periods of low sunlight. Even with a robust battery bank, if you go several days without enough sun, you might find yourself running low on power. In regions prone to long winters or frequent overcast weather, a backup generator can be a lifesaver.

Another situation is during times of high energy demand. Let’s say you are hosting a gathering or using more power than usual – perhaps running several appliances at once or using heavy-duty equipment. Your solar system might not be able to keep up, especially if it is sized just right for your typical usage. A backup generator can kick in to cover the extra load and you don’t have to worry about overloading your system.

If something goes wrong with your solar setup – maybe a component fails or needs repair – a generator still has power while you troubleshoot the issue.

Types of generators suitable for off-grid solar systems

Not all generators are created equal, especially when it comes to off-grid solar systems. You want to choose one that is reliable, efficient, and compatible with your setup. 

There are a few types to consider:

Diesel generators: Diesel generators can run for long periods without refueling. They are a solid choice for off-grid living. They are more fuel-efficient than gasoline generators, especially under heavy loads, and tend to last longer.

Propane generators: Propane is a clean-burning fuel that doesn’t degrade over time. These generators are a popular option for off-grid use. They are quieter than diesel generators and can be easily connected to an existing propane supply if you are already using propane for heating or cooking.

Dual-fuel generators: If you want flexibility, a dual-fuel generator that runs on both gasoline and propane might be the way to go. This gives you the option to choose your fuel based on availability and cost.

Inverter generators: They are great for smaller setups or as a backup for less frequent use. Inverter generators also produce cleaner power, which is better for sensitive electronics.

What are the legal requirements for off-grid solar?

The legal requirements for going completely off-grid solar vary widely depending on where you live. In some areas, off-grid living is relatively straightforward, with minimal regulations. However, in others, there may be stringent rules in place that dictate how you can install and operate your solar system.

For instance, in some states in the U.S., like California and Texas, there are supportive regulations that make it easier to go off-grid- provided your system meets safety and efficiency standards. On the other hand, some localities may have more restrictive rules, especially in suburban or urban areas, where completely disconnecting from the grid might not be allowed or could require special approvals.

You will have to check with your local government and utility provider to understand the specific laws in your area. This includes everything from building codes and zoning laws to specific regulations around energy production and storage.

Most regions require you to obtain certain permits before you can install a stand alone solar system. These permits are in place to make sure that your installation meets local building codes and safety standards. In most cases, you will need a building permit and an electrical permit, both of which involve submitting detailed plans of your solar setup.

Once your system is installed, you will need to pass a series of inspections. These inspections are conducted by local authorities to verify that your system is installed correctly and safely. They will check everything from the structural integrity of your solar panel mounts to the wiring and connections in your electrical system. If you are using a battery storage system, that will also be inspected to check if they are properly ventilated and safely integrated with your other components.

The permitting and inspection process takes time, you should start early and factor this into your overall project timeline. Also, keep in mind that failing to obtain the necessary permits or passing inspections could result in fines or being required to remove or modify your system.

Zoning laws, building codes, and restrictions on off-grid living

Zoning laws and building codes are another important consideration. These laws govern how land can be used and what types of structures can be built on it. In some areas, zoning laws might restrict or even prohibit off-grid living, especially in regions that are heavily dependent on utility infrastructure.

For example, if you live in a residential neighborhood, local zoning laws might require that homes remain connected to the grid for safety reasons or because the area is zoned for specific types of energy use. In rural areas, zoning laws are often more lenient, but it is still important to check before you start building.

Building codes can also dictate specific aspects of your off-grid setup, such as the type of materials you can use, the placement of solar panels, and the installation of electrical systems. Some areas might have specific codes related to energy efficiency, fire safety, or environmental impact, which your off-grid system will need to comply with.

In addition to zoning and building codes, be aware of any homeowners association (HOA) rules if you live in a community governed by one. HOAs often have their own set of guidelines regarding the appearance and construction of homes, and these might include restrictions on solar panels or other visible components of an off-grid system.

Can off-grid solar power a house year-round?

The answer is yes, but it comes with some caveats. Solar energy production varies significantly with the seasons, so understanding these variations and planning accordingly is key to keep your home powered no matter the time of year. 

Solar energy production is heavily influenced by the amount of sunlight your panels receive, which varies with the seasons. During the summer months, longer days and a higher sun angle mean your solar panels will generate more electricity. In contrast, winter brings shorter days and a lower sun angle can reduce the amount of energy your system produces. Additionally, in some regions, snow accumulation on panels can further decrease energy production during the winter.

For example, in the northern United States, solar panels might produce 50% less energy in December compared to June. This seasonal dip in production is something every off-grid homeowner needs to plan for, especially in areas with harsh winters or extended periods of cloudy weather.

One of the most common strategies to make sure you substitute for the seasonal fluctuations is to oversize your solar system. This means installing more solar panels than you would typically need based on your average daily consumption. By doing so, you generate excess power during the summer, which can be stored in your battery bank for use during the winter. While this approach requires a larger initial investment, it provides greater energy security year-round.

Another strategy is to make seasonal adjustments to your energy usage and solar system setup. For example, you could angle your solar panels more steeply in the winter to capture the lower-angle sunlight better. By increasing the tilt angle of their panels, they can better align the panels with the sun’s lower path in the sky, maximizing solar exposure and energy production during the colder months. Solar panels in this case, need to be mounted on adjustable racks.

Additionally, being mindful of your energy consumption during the winter months – such as reducing the use of high-energy appliances like dishwashers or washing machines – can help you stretch your available power further. You need to schedule these activities for times when your battery storage is fully charged after a sunny day. 

Even in winter come favorable windows when the sun shines bright and temperature is quite pleasant. During these times, you can benefit from all the solar power your system gets, and wait during the forecast days. 

After all, even such a change of power using patterns is part of the off-grid living charm. Slowing down and respecting the cycles of nature a bit more.