Are you thinking about going off-grid but worried about the cost of setting up a solar power system? You’re not alone! Many people assume that going solar is expensive, but with a little creativity and smart planning, you can build an affordable and efficient solar power system without breaking the bank. In this post, I’ll walk you through how to create a low-cost solar setup for your off-grid living scenario step by step.
Why Go Solar?
First, let’s talk about why solar power is such a great choice for off-grid living. Solar energy is renewable, environmentally friendly, portable (in many cases), and once you’ve set it up, it’s virtually free! Sure, there are some upfront costs, but they can be minimized, and in the long run, you’ll save tons on energy bills. Plus, solar power offers peace of mind — no more worrying about power outages or rising electricity costs. Ready to dive in? Let’s go!
Step 1: Figure Out Your Basic Power Needs
The first step to building a low-cost solar power system is knowing exactly what you need to power. Keep it simple, especially if you’re working with a tight budget.
Here’s a quick list of the essentials:
• Lighting (LED bulbs are the best for saving energy)
• Charging phones and laptops
• A small refrigerator or cooler
• Maybe a water pump, if needed
The fewer devices and appliances you plan to use, the less power you’ll need. Start by listing everything you plan to run and figure out how much electricity each device uses in watts (you can usually find this info on a label or in the manual). Then, multiply the wattage by the number of hours you plan to use each device per day. This will give you a rough idea of your daily energy needs.
Example:
• LED lights: 10 watts x 5 hours = 50 watt-hours (Wh)
• Phone charger: 5 watts x 3 hours = 15 Wh
• Small fridge: 100 watts x 24 hours = 2,400 Wh
As you can see, fridges and similar appliances use the most power. If you really feel the need to have a fridge as many people do, consider giving it extra thermal insulation to increase its efficiency and thereby reducing daily power usage. Cooking with electric cookers is also power-hungry, so you will want to avoid these for an off-grid situation. Stick to cooking with gas or wood-fired stoves.
Whatever you decide is a must-have is up to you. Just remember that your overall power capacity will have its limits and you may need to compromise in certain areas.
If you keep your total energy use under 3,000 watt-hours per day, you can build a smaller, cheaper system.
Step 2: Find Affordable Solar Panels
Solar panels can be one of the biggest costs, but don’t worry, you’ve got options! If you’re on a budget, check for used or refurbished solar panels online. Sometimes, people upgrade their systems and sell perfectly good panels for cheap.
You don’t need the latest high-efficiency panels to get started. Look for polycrystalline panels, which are often more affordable than monocrystalline ones. Polycrystalline panels aren’t quite as efficient, but they still get the job done.
Let’s say your energy needs come out to about 3,000 watt-hours per day. If you get about 5 hours of sunlight daily, you’ll need around 600 watts of solar panels (3,000 Wh ÷ 5 hours). You can easily find smaller, budget-friendly solar panel kits that can generate this amount of power.
I recommend checking out sites like aliexpress and ebay for good deals on imported solar panels and controllers. When shopping online, keep in mind that many of the products listed for sale on ebay originated in China anyway, and are being sold by drop-shippers who buy from aliexpress themselves. Save yourself a few extra bucks by cutting out the middlemen wherever you can. Most aliexpress sellers have great return and refund policies these ways although you won’t get (and probably can live without) things like “12-month warranties”.
Step 3: Use a Budget-Friendly Charge Controller
A solar charge controller is essential to keep your batteries from overcharging. There are two main types: MPPT (more expensive but efficient) and PWM (cheaper but still works fine for smaller systems).
For a low-cost setup, go for a PWM charge controller. You can always upgrade to an MPPT controller later when you expand your system. For now, stick with the PWM model to save money upfront. You’ll buy these much cheaper online than in your local physical retail store. The price difference between a 10 amp unit and a 20 or 30 amp one is minimal, so go for higher spec’d ones where the price is right.
Step 4: Affordable Battery Options
Batteries are another major expense in any solar system. While lithium-ion batteries are highly efficient, they can be expensive. To keep costs down, consider lead-acid deep cycle batteries — they’re much more affordable and widely available.
You can even look for used batteries that still have a decent lifespan left. Some stores offer refurbished options at a fraction of the cost. When sizing your battery bank, think about how much power you’ll need during the night or on cloudy days. If you’re only running essentials, you don’t need a massive battery bank.
For example, two or three lead-acid batteries with a combined capacity of around 5,000-7,000 watt-hours should be enough for basic needs like lights, phone charging, and a small fridge.
Step 5: DIY Installation to Save Money
The best way to save money on your solar setup? Install it yourself! Professional installation can cost hundreds or even thousands of dollars. But if you’re willing to learn and take your time, you can do most of the work yourself. Professional installers make big markups on all components then factor in their own time at exorbitant rates. You’ll save an absolute packet by learning how to do it yourself. You’ll also be well placed to do your own maintenance and upgrades on the system in the future.
Here’s a basic rundown of how to install your system:
1. Mount the Solar Panels: Find the sunniest spot you can, whether it’s on your roof or a ground mount, and make sure they’re facing south (if you’re in the Northern Hemisphere). For van-lifers, your roof is your solar real estate. And for boaties, you’ll need to do your best to find and make spaces. Lots of boaties install brackets over the transom… just a thought.
2. Connect the Charge Controller: Wire your solar panels to the charge controller, which regulates the energy flow to your batteries.
3. Set Up the Batteries: Place your batteries in a well-ventilated area, and connect them to the charge controller.
4. Wire the Inverter: Hook up the inverter to your battery bank so it can power your appliances.
Make sure to follow all safety precautions and consult online tutorials or community forums if you’re unsure about anything.
Step 6: Expand as You Go
The great thing about solar power is that you can start small and expand your system over time. Once you’ve got the basics covered, you can add more panels, batteries, or even upgrade to a better charge controller as your needs grow or as your budget allows.
For example, you might start with two 300-watt solar panels and two batteries. Later, when you have more funds, you can add another panel and battery to increase your system’s capacity.
Adding an Inverter for AC Power
Most off-grid LED lighting setups these days run directly off 12v power, so they can be connected to draw directly from your battery. However, the addition of a small AC inverter will allow you to run one or two appliances that require a traditional AC power supply. For example, one of my laptops runs from 12 volts provided by a cigarette lighter socket whereas the other needs 220 volts AC, so I run that one through an inverter.
An inverter turns the electricity stored in your batteries (DC power) into the type of electricity your appliances use (AC power). There’s no need to splurge on a fancy inverter. A modified sine wave inverter is much cheaper than the pure sine wave models, and it’ll work fine for most basic appliances like lights, chargers, and small fridges.
Make sure to get an inverter that’s rated slightly higher than the total wattage of the devices you’ll be running at the same time. I recommend never to run an inverter anywhere near the maximum wattage rating. In fact, I prefer a rating at least double of what I intend to run through an inverter to allow all kinds of safety margin. Fortunately, mass production means higher power inverters are easily within reach, and well under $100 when you buy online.
Connecting an Inverter into a Solar Power System
An inverter becomes part of the “load” in your system. While theoretically it would be connected via the charge controller, I personally think you are better off connecting an extra set of leads directly from your battery and run them through an isolator switch and then to the inverter. That way, you will minimise the risk of burning out your controller and you will have the benefit of the isolator so you can always remove the inverter from the circuit. As for the chance of discharging your battery too far: many inverters include a low-voltage cutoff, so they will switch themselves off if your battery voltage drops too low.
Money-Saving Tips for Solar on a Budget
• Buy Second-Hand: Used solar panels, batteries, and even inverters can be found online for a fraction of the price of new equipment.
• DIY Everything: From installation to maintenance, doing things yourself will save you hundreds, if not thousands, of dollars.
• Skip the Extras: You don’t need every fancy add-on right away. Start with the basics and upgrade when you can afford it.
Reach out for extra help
Don’t be afraid to contact me if you want help designing or setting up your own solar system. There can be small variations required depending on your situation and whether you’ll be in a fixed location such as in a tiny-home, or mobile on the road or water in a van-life or liveaboard setting.
Final Thoughts
Building a solar power system on a budget is totally doable. By focusing on your essential needs, hunting for deals, and doing some DIY work, you can have a low-cost solar setup that works for off-grid living. The beauty of solar power is that you can start small and grow your system as your needs or budget expand. Going off-grid doesn’t have to cost a fortune — and once you’re up and running, the freedom is priceless.
