What You Should Know About Stand-Alone PV System
Disconnecting from the local grid gives you energy independence. It’s the freedom to live remotely away from overpopulated areas and stop handing your hard-earned money over to utility providers.
Whether you’re looking to save money, live remotely, or travel cross-country, off-grid solar systems are strongly worth considering.
Going off-grid doesn’t have to be complicated.
We’ve distilled the essentials of off-grid solar systems. Here’s everything you need to know to build an independent DIY off-grid solar power system and whether going off-grid or staying grid-tied is the right solution for your energy needs and budget.
What Is an Off-Grid Solar System?
An off-grid solar system satisfies your electrical requirements by harnessing the sun’s power without relying on the electrical grid. Without a direct connection to a utility grid, your off-grid solar system provides an independent power supply to your home, RV or trailer.
The off-grid solar system comprises the following components:
- Solar panels
- Charge controllers
- Battery banks (sometimes called portable power stations or, when combined with solar panels, portable solar generators)
These components all work together to provide energy for your home’s electrical appliances and devices.
- Solar panels capture sunlight. Most homeowners and businesses set up these panels on a rooftop system or an open yard for direct sunlight.
- The solar panels transfer the captured sunlight to the charge controllers.
- Charge controllers act as the ‘delivery man’ between the solar panels, the battery bank, and the inverters. The charge controller regulates the amount of power received, preventing battery overload. It keeps the battery fully charged and tops off the power levels when needed.
- The energy passes through the charge controllers to the solar battery bank, the heart of the off-grid solar system.
- The battery bank stores energy until it comes time for you to use it.
- Inverters convert the direct current (DC) energy into alternate current (AC) power to power your appliances.
Grid-Tied vs. Off-Grid Solar Systems
Grid-tied solar systems connect to the utility grid, while off-grid systems don’t. The difference between grid-tied and off-grid solar power systems centers around where you store the energy you generate.
Every system requires a place to store energy. Solar panels only capture energy when the sun is out, but you’ll still need a way to power your home in the evening.
With grid-tied systems, your panels transport the electricity generated to the utility grid. The utility provider distributes this energy to other residents in the community. In return, you can earn credits for the excess energy you generate through a net-metering program.
Off-grid power is different. Without the utility grid to keep your energy in reserve, you’ll need to find alternative storage. A solar battery or portable power station offers dedicated energy storage, allowing you to access stored energy during cloudy weather, nights, or blackouts.
Pros and Cons of Solar-Powered Off-Grid Systems
A solar-powered off-grid system has numerous benefits, but it’s not without its challenges. Here are the factors to consider:
Pros of solar-powered off-grid systems:
- Energy independence: Going off-grid gives you complete freedom from the utility company. You’re no longer subject to their terms and conditions, and rising utility costs won’t affect you.
- Power remote locations: Off-grid solar lets you access power in remote areas where utility power might be too expensive to run power lines or otherwise unavailable.
- Energy-conscious: Off-grid systems reduce carbon footprint and pollution for cleaner air quality and a healthier environment.
- No more blackouts: Off-grid solar means your power stays on even when the rest of your neighborhood experiences a blackout.
- Saving money long-term: While initial costs for an off-grid solar system are high, it pays itself off eventually, letting you live with zero electricity bills. Some people offset their costs in as little as five years.
Cons of solar-powered off-grid systems:
- Higher initial investment: Off-grid solar requires a more substantial initial investment to purchase and install the equipment. While solar energy eliminates your monthly electricity bill, it’ll take some time before the savings offset the cost in full.
- Limited energy storage: Off-grid solutions have a limited storage capacity, which depends on solar battery capacity. Knowing how much energy storage you need to meet your electricity requirements is essential when choosing your solar-powered system.
- Battery maintenance: Batteries have a costly initial investment and require maintenance. Batteries also eventually need to be replaced, but newer battery technologies like LiFePO4 last for many years.
How to Build a DIY Off-Grid Solar Power System
Installation costs for off-grid power solutions can increase the upfront investment. The good news is that you can get around paying labor and installation fees by doing it yourself. It’s a multi-step process but feasible for DIY enthusiasts.
Follow these steps to build your simple off-grid solar power system and save.
Determining How Much Power You Will Need
Start by calculating your daily power consumption for running your appliances and devices. Knowing your power consumption will let you determine your solar panel and battery storage requirements.
You can calculate your energy requirement using the following steps:
- Check the power rating for each appliance and device.
- Estimate the runtime for each appliance and device.
- Calculate the Watt Hour (Wh) by multiplying the power rating in watts (W) by the time you plan on running the appliance in hours (h).
For example, a TV may require 80W. If you plan on using your TV for five hours daily, the total energy consumption required for running your TV is 400 Wh.
Add up all of your appliances and devices. Examples include refrigerators, lights, water heaters, electric fans, grills, coffee makers, power tools, laptops, Wi-Fi routers… anything in your home that requires electricity.
You can also look at your previous electric bills, which should list your monthly kilowatt-hour (kWh) output. Divide the monthly kWh by 30 days to estimate your daily electricity usage.
Calculating the Amount of Battery Storage Required
Your battery storage should have at least enough capacity to accommodate your daily energy usage in kilowatt-hours. However, that’s only part of the equation.
You also have to estimate how many days your system will be without the sun. You can search for your area’s annual average of cloudy or sunny days online. A smaller solar battery capacity may be sufficient in areas with lots of sunlight, while larger solar battery banks are best in regions with more cloudy days. When in doubt, it’s best to size up rather than down.
Each battery has a Depth of Discharge (DoD) rate, meaning you can’t take all the power from the battery. Lead acid gel batteries typically give around 50% of the total rated power, meaning a 100Ah battery delivers 50Ah of usable energy. LiFePO4 batteries distribute 80% of the rated power capacity.
Let’s say you’re total daily energy consumption is 3,000 Wh, and you need two days of backup for potentially cloudy days. And assuming that you use LiFePO4 batteries, it has a DoD of 80%.
Here’s the formula for calculating battery storage capacity taking into account times when you may not be able to generate much solar power due to Cloud cover:
Daily Energy Consumption x Number of Cloudy Days / Depth of Discharge = Solar Battery Storage Capacity
3,000 Wh x 2 (backup cloudy days) / 0.8 (DoD) = 7,500 Wh of battery storage capacity.
You can be extra cautious by accounting for the annual correction factor. Batteries lose their capacity over time, meaning they won’t hold the same amount of power after a certain number of life cycles.
Here’s what it would look like in the above example:
3,000 Wh x 2 (backup cloudy days) x 1.15 (annual correction factor) / 0.8 (DoD) = 8,625 Wh of battery storage capacity.
Calculating the Number of Solar Panels Needed for Your Location
Before rushing out and purchasing solar panels, find out if your location can accommodate solar. You’ll need to calculate your energy usage and find the solar panels with the best conversion efficiency rating.
First, you need to understand the number of peak hours of sunlight your area receives every month. Then divide your monthly electrical usage by your monthly sunlight hours.
If you’re installing solar panels on the roof, you’ll need to account for the roof direction and shading, in which case, a solar calculator can provide a more accurate estimate.
Also, the number of solar panels depends on the panel’s power output. Most solar panels produce between 100 and 400 watts of power.
Let’s say you use 3,000 watts of power per day and receive five peak sunlight hours daily.
If you’re buying a 250W panel, each panel produces approximately 1,250 watts daily (250W panel x 5 peak sunlight hours).
As a result, you need at least three 250W panels to generate 3,000 watts of power per day. Three panels will give you approximately 3,750W of power. Excess stored energy can help prepare you for cloudy days when you may not receive maximum output from your solar panels.
Identifying a Solar Charge Controller
Solar charge controllers prevent batteries from overcharging. If the current is too high, it can damage the battery and potentially start a fire. If the battery is running at a dangerously low level, the control disconnects it to prevent harmful usage.
Pulse With Modulation (PWM) and Maximum Power Point Tracking (MPPT) regulars are the two most common types of solar charge controllers. MPPT controllers are more efficient than PWM controllers since they compare the panel’s voltage against the battery’s voltage.
PWM controllers send pulses of power by switching the power flow on and off continuously. It establishes a direct connection between your panels and the bank, making it the most straightforward and affordable option.
MPPT regulators optimize the voltage between the panel and the battery to extract maximum voltage, especially during rough weather conditions. While MPPT controllers are more expensive, they’re also 20% to 30% more efficient. Also, they’re best for high-voltage PV systems like your home.
PWM controllers are ideal when you have a small system and won’t need to maximize efficiency, such as powering an RV.
MPPT controllers are essential for a large-scale system such as powering your home since maximum efficiency is a priority.
Ideally, look for charge controllers that let you monitor and customize the regulator via an app on your mobile device. If you’re living in a rainy region, consider getting a waterproof control to ensure the controller’s safety.
Selecting an Inverter
The inverter manages the power flow between DC and AC energy. It takes the DC power from your panels or batteries and converts it into standard household AC electricity. After conversion, you can use it for your lights, TV, fridge, and other household appliances.
First, consider your off-grid solar inverter size. The size depends on your energy output. Here are general recommendations to help you pick out the proper inverter size:
Next, look at the technical specs of the inverter. We’ve laid out the standard specs and given you metrics to consider:
- Efficiency: Conversion efficiency determines the amount of current lost in converting DC into AC. Aim for a system with a higher conversion efficiency.
- Parameters: Pay attention to the output power, output voltage, and overload capacity. It should be compatible with your electronics and appliances. For example, everyday electronics use 120V, and some major appliances like ovens require 240V.
- Warranty: Warranties range between 1 and 10 years. Most inverters range between 3 and 5 years.
Balance of System (BoS)
The Balance of System (BOS) is all the photovoltaic components except for the module and solar panels. BOS primarily includes charge controllers, batteries, inverters, wiring, switching, junction boxes, and power conditioners.
Other elements within the BOS cover mounting systems, battery chargers, sensors, safety devices, solar concentrators, solar trackers, and lens reflectors.
You’ll have to purchase all these BOS components if you’re putting together your own DIY off-grid solar system. For example, wiring connects the solar panels to all other electrical parts of the off-grid solar system. Opting for dedicated solar cables means they can withstand UV radiation, temperature, and weather variations.
Mounting systems support solar panels. Whether ground-mounted or on the roof, you need to secure the solar panels. A solid mounting system keeps solar panels upright to withstand wind and secures them from physical damage.
Once you’ve calculated your energy use, battery storage, solar panels, and hardware needs, you’re ready to build your DIY off-grid solar system!
Introducing EcoFlow Power Kits
A power kit is a convenient way to switch to off-grid power if you want to skip the complicated installation and save money by bundling the BOS components. The EcoFlow Power Kit is a hassle-free plug-and-play modular power system. It requires less wiring, meaning fewer mistakes, and lets you instantly deploy and use off-grid power.
The power kit contains four components: the power hub, Smart console, solar battery, and Smart AC/DC distribution panel.
Unlike traditional power kits, Ecoflow Power Hub conceals the components in one box, saving space, and is easy to set up. The Power Hub includes:
- Inverter charger
- Two MPPT solar charge controllers
- DC-DC step-down converter
- DC-DC battery charger with MPPT
The console allows you to monitor and control your energy consumption, while the LFP battery (or batteries) stores your energy. The Smart distribution panel regulates your AC and DC loads.
The EcoFlow Power Kits feature stackable batteries, allowing you to add up to three batteries of the same size. The batteries come in two battery sizes: 2kwH and 5kWh. If you’re unsure about your backup power needs, you can start with one or two batteries and add more later.
How Are Power Kits Installed?
EcoFlow Power Kits are designed to be plug-and-play and require no specialist knowledge to install. You or your installer of choice should have no problem installing the Power Kit. If you run into problems, EcoFlow has your back with live chat on EcoFlow App, tutorial videos, and a quick start guide to help you during the installation process.
Here are the basic steps required to install an EcoFlow power kit:
- Mount your solar panels: Choose a good place to mount your solar panels where there won’t be any obstruction to sunlight. Rigid panels work best for solid structures like tiny homes and standard residences, while flexible solar panels work best for RVs, campers, and vans. With the EcoFlow Power Kit, you can mix and match rigid and flexible solar panels to create the most efficient configuration for your build.
- Install the power hub, console, LFP battery, and AC/DC Smart distribution panel: Select the appropriate place to install these components in your home. You’ll need to connect the solar panels to the power hub, so installing the hub on the wall close to the roof is probably best. You’ll also need to charge the power hub to make it entirely off-grid. Investing in an EcoFlow Smart Generator (Dual Fuel) can give you a last line of defense when you’re unable to generate enough power from solar.
- Wire up off-grid solar: Connect all components to your power hub, including the solar panel(s), LFP battery, console, and Smart distribution panel. You’ll also need to connect a power strip to use the electricity with regular plugs.
- Test your solar system: Turn the power on and test your installed solar system. Check your EF Smart app to read the console and monitor charge levels.
Best Off-Grid Solar Systems and Their Costs
The best off-grid solar system for you depends on your energy needs, which often come down to your household size and whether your installation is at a fixed location, like a tiny home, or mobile, like an RV.
EcoFlow’s Power Kit calculator makes it easy to design a custom off-grid solar system that meets your needs.
For reference, here are some common use cases:
Best Solar Power Kits for Vans/Rvs/Trailers
The best solar power kit for vans, RVs, and trailers is EcoFlow’s Get Set 5kWh Kit, a space-saving, plug-and-play system.
A 5kWh battery gives you ample capacity to satisfy the appliances in your RV. With the uncertainty of the weather conditions while on the road, it’s better to be safe than sorry if you run into extended Cloud cover.
Unlike some solar power kits, the Get Set Kit features an LFP or lithium-ion battery. It has a longer lifespan and greater efficiency than older battery technology, lasting up to 20 years. Furthermore, an LFP battery is safe and requires no maintenance.
Depending on your RV’s shape, we recommend combining rigid and flexible solar panels to maximize your solar energy generation potential. Both flexible and rigid solar panels are durable, lightweight, and can endure extreme weather.
For the EcoFlow Get Set 5kWh Kit and the two 100W rigid solar panels (mounting feet included), you could build this whole setup for 226 a month with financing or less than 8000.
Best Solar Power Kits for Tiny Houses
A tiny house is unlikely to have as many appliances as a normal-sized house. It’s why we recommend the EcoFlow 10kWh Prepared Kit. A 10kWh capacity provides substantial power to run your lights and appliances.
The compact size of the power kit lets you save space in your tiny house, and installation is a breeze. It uses a simple parallel connection, meaning you place all the battery units side by side and connect each wire to the Power Hub.
We recommend getting one or two 400W Rigid Solar Panels to give you enough daily electricity to power your tiny house. Rigid solar panels are highly durable under any weather condition and are easy to mount on a flat roof. If you have a slanted roof, flexible solar panels may be a more viable option — or you can consider a combination of the two.
For the EcoFlow 10kWh Prepared Kit along with the 400W Solar Panel, you could expect to pay approximately 14,000. Frequent discounts and sales at the EcoFlow online shop may make that price drop even lower.
Best Solar Power Kits for Full Off-Grid Powered Living
Living in a remote location requires homeowners to prepare for anything. Whether you’ve got tons of power-hungry appliances in your home or want backup power for consecutive cloudy days, choosing a system with sufficient capacity is vital.
We recommend EcoFlow’s 15kWh Independence Kit for DIY off-grid living. With three stackable 5kWh batteries and a Smart distribution panel, it’s a robust solution for fully independent off-grid living.
A 7-inch touchscreen lets you view all critical information and monitor the DC output and battery charging data in real-time. Additionally, you can customize the AC charging and discharging levels, AC input frequency, and 12/24 DC output voltage.
The EcoFlow app allows you to remotely monitor much of the Console’s data. Check the app to view the system’s health and update firmware anytime.
For a high-powered system like the 15kWh Independence Kit, we recommend at least two 400W Solar Panels. Depending on your home’s design, flexible solar panels can also help you maximize solar energy capture. The setup gives you enough power to supply your batteries and keep your home powered on demand.
The cost for the EcoFlow’s 15kWh Independence Kit and the two 400W rigid solar panels (mounting feet included) would average just under 500 a month with financing and less than 20,000 to purchase outright. With EcoFlow sales, you could even pay less than 15,000.
How to Calculate the Correct Size and Power Usage
To get the most out of your off-grid solar system, you must know how to size your system correctly to cover your energy usage.
Take a look at the following steps to size your solar system:
- Type of home: What do you plan on using your off-grid system to power? (RV, off-grid living, tiny house, etc.)
- Size of your home: How big is your home? Size is an essential consideration if you plan on mounting your panels on your roof.
- Appliances: What is your total daily energy consumption? Identify the appliances you need to power and the run time.
- Backup power: How long do you need backup power? If it’s common to experience consecutive days of cloudy weather, you’ll want to prepare accordingly. You may need to increase your storage capacity by adding extra batteries.
- Solar panels: What is the appropriate number of solar panels based on your daily energy consumption? A power-hungry household would need a higher solar panel power output, such as 400W. Take the panel’s watts and multiply that by the Peak Sun Hours in your area to estimate the total watts produced per day for each panel.
Using the EcoFlow Power Kit Calculator, you can accurately determine your usage and correctly size your solar power kit in minutes.
How Much Does an Off-Grid Solar System Cost?
The costs vary depending on the sizes and quality of each component. A significant share of expenses comes from the solar panel’s output, the number of panels you buy, and the solar battery storage capacity.
Here are estimated averages based on the rated power of the solar panels:
- 1kWh: 10,800 to 13,500
- 2kWh: 18,000 to 22,500
- 3kWh: 27,000 to 31,500
- 4kWh: 31,500 to 36,500
- 5kWh: 36,000 to 40,500
- 10kWh: 63,000 to 72,000
Know that the costs will likely be lower when you apply for the 26% federal tax credit and other available tax breaks and incentives.
Also, we’ll break down the cost by the equipment you’ll need:
- Solar panels: Monocrystalline solar panels cost between 1 to 1.50 per watt. Solar panels can cost between 5,000 to 30,000 depending on composition, rated energy output, and the size of your off-grid build.
- Charge controllers: Charge controllers are affordable and range from 50 to 1,000.
- Inverter: Range significantly in price between 3000 to 13,000.
- Solar Batteries: It costs several thousand to 30,000, depending on the battery type and storage capacity.
If you have a tiny home, RV, or trailer or live a minimalistic lifestyle, there’s a good chance your costs will be lower.
How Many Solar Panels Do I Need to Be Fully off the Grid?
The number of solar panels largely depends on the following:
- Your daily electrical usage
- The wattage your solar panel generates
- The number of peak sunlight hours in your area
By following the steps above, you can calculate your daily energy usage. From there, look for rigid, flexible, or portable solar panels that suit your needs. Depending on your region, some areas will have more sunlight hours than others. States like Arizona, California, Nevada, and Mexico have the most sunshine, while states like Alaska, Washington, Ohio, Indiana, and Michigan have the least.
Maintaining Your Off-Grid Solar System
Maintaining your off-grid solar system extends its lifespan. The most critical maintenance aspect is taking great care of your solar batteries.
Follow these guidelines for maintaining your solar battery bank:
- Monitor the charge level: The Depth of Discharge refers to the battery’s discharge levels. A battery bank will gradually lower its depth of discharge, meaning its capacity will decrease over time.
- Don’t mix batteries: Mixing old and new batteries can limit performance since aging batteries can degrade the quality of the new ones.
Besides the batteries, you also want to take care of your solar panels. Keep solar panels clean of dirt, debris, and pollen build-up, which impact the amount of sunlight received. Also, clean your solar panels annually to prevent residue from reducing the amount of power they can produce.
Is Going Off-Grid Right for You?
If you’re still on the fence about off-grid living, let’s consider why most people choose this lifestyle.
As with any renewable energy, solar power is better for the environment than fossil fuel energy. Solar power lets you generate electricity without emitting greenhouse gases, thus reducing your carbon footprint by leveraging the sun’s power.
Going off-grid with solar benefits our planet and helps us reach a net-zero future.
An off-grid solar solution is a practical choice for those living in areas without access to traditional electricity provided by utilities. Off-grid solar systems don’t rely on outside electricity and function independently, making them perfect for remote regions or places prone to blackouts.
Being independent of the grid also is advantageous in areas prone to harsh weather conditions like tornadoes and hurricanes. Whether traveling in an RV or living in a tiny home to reduce living costs, energy independence is why many people switch to off-grid solar power.
Frequently Asked Questions
Below are some common questions about off-grid solar systems:
Yes, you’re typically required to have a permit for off-grid solar. Although you don’t have to submit an interconnection utility agreement, a building permit is still mandatory. Although you won’t connect the system to a local utility grid, it still needs to pass inspection to ensure sound structural engineering and fire safety. Your off-grid solar system must pass various building electrical codes to ensure the power is safe and sufficient. Standard off-grid systems should meet the following regulations: Solar panel placement guidelines Standard domestic wiring requirements Auxiliary power generation requirements Power storage and conversion guidelines DC minimum wiring requirements Code requirements will vary by county and state. Check with your city or county Building Inspector’s office for a complete checklist.
An off-grid cabin typically needs between 5,000 to 7,000 watts per hour of electricity to run optimally. However, you’ll need to add up the running hours on the appliances you use to get the right amount of solar power tailored to your needs.
The number of solar panels needed to run a house off-grid entirely depends on the following factors: Amount of electricity your household uses Amount of direct daily sunlight The type of solar panel you choose Amount of useable roof space (if roof-mounted) The average kilowatts used for a household is around 11,000 kilowatt-hours per year. A 1500 sq. ft. home needs about 20 to 25 300W panels to go entirely free of the grid. RVs and smaller homes require significantly less.
With more people going off-grid than ever before, there’s never been a better time to join the energy independence movement.
It all starts with calculating your energy needs and finding the right size power kit for your RV, tiny home, or home to achieve full-time off-grid living.
Check out the options at EcoFlow today.
EcoFlow is a portable power and renewable energy solutions company. Since its founding in 2017, EcoFlow has provided peace-of-mind power to customers in over 85 markets through its DELTA and RIVER product lines of portable power stations and eco-friendly accessories.