- Introduction
- Two Customers, Two Visions
- The Power Equation: Why Voltage Matters
- When to Use Each Voltage
- Conclusion
Introduction
One thing I’ve learned over the years of designing and installing solar systems is that getting to know my customer is the most important part of what I do. Time and time again, it’s the key that opens the door to discovering what my customer truly wants and needs, often before they even know it themselves.
By asking questions, I learn more about them, and suddenly the real reasons and the real solutions become so clear that you can’t miss them. But without that back-and-forth, we’d never reach those goals.
Most large solar companies simply don’t have the time to engage on that level, and I understand that. Even I, when things get busy, sometimes miss those moments and later wish I could go back and have them again.
That’s why I always stress how important it is for you, the customer, to ask as many questions as you can. It shouldn’t always be me trying to find the perfect system for you, when you ask questions, we work together to get there.
I say it all the time: confidence comes with understanding, and understanding starts with asking questions.
Two Customers, Two Visions
This past week or so, I’ve been discussing a system with a new customer who, like many others, originally reached out asking for a solar system for her property. She wanted to power a small off-grid building and said she didn’t need much, just something small. My neighbor was asking for the exact same thing not long ago. “Something small,” he said. “We don’t really use much power at all, maybe some lights, phone charging, a TV, and some tools now and then.”
Being my neighbor, and someone who knows I work in solar, he trusted me to design a system for him. So, I asked my usual questions, and he gave me his answers. Together, we came up with a system that works for his needs.
His property is off an inlet on the ocean, only accessible by boat. It’s very remote, and like many such places, there's always the unfortunate risk of theft when no one is around. That’s just a reality of remote area living and recreation. It’s not where he lives full-time, but he spends a lot of time there fishing and relaxing. So, we went with a small 12-volt system. It’s simple, affordable, and does the job. And if anything were to get damaged or stolen, while it would be upsetting, the loss would be limited.
Now, back to my other customer. She has a small building on her land and had originally asked for a similar 12-volt system. But our second conversation took a different turn. I started explaining the differences between 12, 24, and 48-volt systems, and the implications of those differences.
She has 20 acres and two buildings, and she mentioned that someone else would soon be moving into the second building. That completely changed the picture for me. When I asked if this was a temporary setup or a place she might sell one day, the answer was no to both. This was a long-term dream of hers, and now, it was becoming a shared dream with family relocating to the property as well.
Right then, I knew a 12-volt system no longer made sense. Selling her something that technically works, but is inefficient, limited in capacity, and expensive to upgrade later would be a mistake. She would likely end up needing to buy new equipment as her needs grew over time.
This is exactly why I take the time to ask questions, to understand not just what you think you need right now, but where you’re headed. My job isn’t just to sell you a solar system. It’s to help you make the right decisions the first time, so your investment supports your goals for years to come. And that only happens when we talk things through and look at the big picture together.
The Power Equation: Why Voltage Matters
I want to explain why these conversations are key to finding the right fit for your solar system. If you're thinking about purchasing a system, whether now or in the future, it’s so important to do your research and ask the right questions. I always say it, and I’ll keep saying it: asking questions is where understanding begins.
Here’s one of the most crucial questions you should ask early on: What voltage will your system be based on? This decision sets the foundation for everything that follows. Once your system is built around a certain battery voltage, whether it’s 12, 24, or 48 volts, there’s no easy way to change it later without replacing major components, including the batteries themselves, to accommodate the new voltage. Let me explain why that voltage choice matters so much.
Power (in watts) is the product of voltage × current:
P=V×I
So if you're powering a 1,000-watt appliance:
System Voltage Amps Required
12V 83.3 A
24V 41.7 A
48V 20.8 A
Notice how current drops by half each time voltage doubles?
While 12-volt systems have been the "go-to" standard for small cabins, RVs, and boats for decades, many modern off-grid systems benefit greatly from stepping up to 24V or 48V.
In my years of designing off-grid systems, again, I’ve had many customers tell me:
“I don’t need a big system , just a couple of lights, a fridge, a TV, maybe a tool or two.”
They usually mean:
“I want to keep the cost low and I think a basic 12V setup will be enough.”
And in the short term, sure, a 12V system can work. But what many don’t realize is that this approach often leads to:
- Higher inefficiencies
- Excess heat losses in wiring and components
- Very limited growth potential
In fact, running the same loads on a 24V system can be twice as efficient, and moving to 48V can improve that even more. That’s not just theory, it’s basic electrical math. A 12V system has to push double or even four times the current (amps) to deliver the same power, which means thicker cables, hotter wires, and more wasted energy.
The truth is:
Saving money upfront on a 12V system can end up costing more in the long run, in lost power, in system limits, and when you inevitably need to upgrade.
When to Use Each Voltage
12V Systems Ideal for RVs, small cabins, and basic setups with LED lighting.
A 12-volt system is simple and works well in applications where power needs are minimal. It’s especially practical for RVs and campers that already have many devices designed to run on 12 volts. In these cases, sticking with a 12V setup makes sense.
The limited roof space on RVs also plays a role, there's only so much room for small solar panels. That’s why keeping the system small and efficient is often the best approach. That said, I’ve designed motorhomes with additional large portable panels that are stored inside while driving, then set up once parked. These panels run on their own solar controller and can be positioned where the sunlight is strongest. Being able to move them throughout the day to follow the sun can make a big difference in the amount of power you generate.
24V Systems Great for medium off-grid homes, tool sheds, and cabins needing more power.
A 24-volt system offers a nice balance between simplicity and performance. I’ve installed many 24V systems over the years, and they’re a popular choice for good reason. They typically support systems in the 3000 to 4000-watt range, enough to power the basic appliances and devices most people need in an off-grid cabin or small home.
One of the key advantages of a 24V system is improved efficiency compared to 12V. Because the components draw less current, there's less energy lost as heat, which means your equipment doesn't have to work as hard. This not only reduces wear on the components but also makes better use of the energy you've generated. Plus, a 24V system leaves room to grow, making it a solid option for those who may want to expand their system later on.
48V Systems Best for full off-grid homes, workshops, and farms. Highly scalable, efficient, and cost-effective for larger power needs.
I’ve installed many 48-volt systems, and they’re by far the most efficient and scalable option for off-grid living. These setups typically start around 4000 watts and can scale up to 6kW, 8kW, 10kW, and 12kW systems. With the rise of new hybrid inverters, we’re now seeing commercial-grade systems reaching 30kW to 60kW or more, now using even higher voltages such as 300 volts or more.
For most off-grid homes or cabins aiming to match the comfort and power of a typical city home, a 48V system is the ideal choice. While they require more solar panels to properly charge the higher-capacity battery banks, this is easily managed and well worth the effort. The performance, flexibility, and long-term reliability are unmatched.
These systems can run virtually everything, and they often come with longer warranties, sometimes 10 years or more, similar to solar panels in the 25 year range. When paired with today’s lithium batteries, your entire system can last many years, far exceeding the lifespan of the smaller systems we used to install. It’s a future-ready solution for serious off-grid living.
Conclusion
Choosing the right solar system isn’t just about picking panels and batteries, it’s about understanding your goals, your property, and how your energy needs might grow over time. That’s why I always stress the importance of having real conversations and asking the right questions. Voltage choice, 12V, 24V, or 48V, is one of the first and most important decisions you’ll make, and it sets the foundation for everything else.
A small 12V system might work perfectly for an RV or a weekend cabin, while a 24V system covers the essentials for many off-grid homes. But when you're planning for long-term use, growing energy demands, or a lifestyle similar to what you're used to in the city, a 48V system is often the smartest investment.
The more we talk and explore your situation, the more we uncover what’s truly needed, sometimes even things you didn’t realize you needed. That’s why I do what I do. Because a well-designed solar system isn’t just about power, it’s about peace of mind, future-proofing, and helping make your dream life off the grid a reality.
There’s nothing like getting a message from a customer saying they love their system, that they can’t believe how much power it has, and how it’s changed their life. I never get tired of those messages and phone calls. They’re the reward I receive for focusing on education first, and then delivering a system that not only meets expectations but often exceeds them in ways the customer never imagined.
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