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Offgrid Solar Beginner Crash Course: How to Build a 10,000W System

By OffGrid Masterplan | March 2026 | Filed under: DIY Solar Guides

Viderpolate Offgrid Solar Beginner Crash Course — Essential knowledge for Australian off-grid living

Solar info online splits into two useless piles: the oversimplified drivel that tells you nothing, or the hyper-technical nonsense assuming you hold an electrical engineering degree. Will Prowse sits outside both. His crash course videos are the exception: practical, detailed, and genuinely useful for beginners who want to actually build something that works.

Building A 10kW Split Phase System

This article breaks down Will Prowse's crash course for a full 10,000W (10kW) split-phase system build. I've wired up enough sheds in central QLD to know that theory often crashes hard against reality, but if you want the video walkthrough, watch above. For the written guide with actual Australian pricing and component options to avoid the pitfalls of a failed installation, read on.

What Is a 10,000W Off-Grid Solar System?

A 10,000W (10kW) system is a serious power setup. It is not a weekend camping kit. This is a system capable of running an entire modest home off-grid: air conditioning, refrigerator, washing machine, power tools, the lot. The key word is off-grid — no grid connection, no reliance on the electricity retailer. Everything runs from solar panels and battery storage.

Will Prowse's beginner crash course breaks this system down piece by piece. The core architecture is:

• PV (solar panels) generating DC power from sunlight
• Inverter converting DC from panels and battery to usable AC (120V/240V split-phase)
• Battery bank storing excess solar for use at night or during cloudy weather
• AC breaker panel distributing power to your home circuits

The real beauty of a properly designed 48V system is that all the hard bits—the inverter, the charge controller, the BMS comms—come built into one or two boxes. I spent twenty-two years wiring solar, batteries and sheds in central QLD and never had to engineer anything from scratch. You're just wiring components together. It cuts the risk of a total system failure right down.

The Core Components

The Inverter

The heart of this build is a 10kW split-phase inverter pushing 120V/240V output. I've seen Will Prowse back a unit that takes high-voltage PV input, talks to a 48V battery bank, and delivers full split-phase power for Aussie or North American homes.

Key inverter specs to look for:

• Continuous output: 10,000W minimum
• PV input voltage window: 120V to 500V DC (higher gives efficiency benefits in cold weather)
• MPPT charge controller: integrated, so you do not need a separate unit
• Battery compatibility: 48V LiFePO4, with CAN or RS485 communication for BMS integration
• Split-phase output: 120V/240V for standard home circuits

The 10kW inverter paired with an EG4 server rack battery (covered below) is a combination Will has used and recommended extensively. It is reliable, well-supported, and scalable.

The Battery Bank: 16kWh

Storage is where most of your budget goes. The video features a 16kWh battery bank built from a 48V server rack system. In Australia, you have several good options:

• EG4 server rack batteries (available via Signature Solar and Current Connected) — the same units featured in the video
• Pylontech US5000 or RB5000 — widely available in Australia, proven reliability, integrated BMS
• Nissan Leaf EV modules — cheap per kWh from wreckers, requires external BMS, extremely capable when done right. See our battery sizing guide for full details on using EV packs.

Sixteen kilowatt-hours sounds like a lot, and it is, but a 10kW system running a household through an evening can easily consume 8 to 12kWh. Factor in a few cloudy days, and you want that headroom.

Wire Gauge and Cable Sizing

This is the bit most newbies get wrong, and it's the one Will Prowse bangs on about in his crash course. Getting cable sizing right isn't optional. I've seen undersized cables overheat and cause fires right here in central QLD after 22 years wiring solar and batteries.

The fundamental principle: your cable gauge must match the overcurrent protection (fuse or circuit breaker) rating. Every component in the circuit — the wire, the terminals, the breaker, the insulation — has a temperature rating. You size to the lowest of those ratings, not the highest.

For a 10kW inverter running on 48V, you are dealing with roughly 200A of current at full load. That means:

• Positive and negative battery cables need to be appropriately sized for 200A continuous. That is typically 2/O AWG (O gauge) cable or equivalent.
• Lugs must match the cable gauge and the terminal size they are attaching to.
• All connections must be crimped, never soldered, and checked tight.

Will shows the right way to crimp in the video. The short version: use a proper hydraulic crimper, not pliers or a vice. The crimp has to be tight and uniform, and you verify it by tugging on the connection.

PV Disconnect Switch

Every fixed solar rig in Central Queensland needs a DC disconnect between the panels and the inverter. This isn't optional, and it's not just for safety during maintenance; it is critical during operation. I've seen a live array arc burn out connectors and nearly injure a bloke when he tried to switch off the power in broad daylight without one.

Good news is most inverters now sport a built-in PV disconnect, but if you're stuck with a budget or older unit, you'll need a separate DC disconnect rated for your array's voltage and current. Expect to shell out between $30 and $60 AUD for a quality 2-pole DC breaker that clears your array's open-circuit voltage.

The Handtruck System: Portable Power

One of the standout ideas in this video is the handtruck (platform cart) system. Rather than mounting everything permanently to a wall, you build the system on a rolling frame. This gives you:

• Portability — roll the system into a van, move it between properties, take it to a job site
• Modularity — add or remove batteries as needed
• Simplicity — the system shown in the video goes together in about an hour with basic tools

Will has a full parts list and wiring blueprint for the handtruck system on his website, Mobile Solar Power. This includes the specific inverter settings, cable specifications, and component links.

Ground Mount Arrays

If you are not mounting on a roof, ground mounting is often the better choice for off-grid systems. Advantages:

• Easier to clean and maintain panels
• Can be angled optimally for maximum sun exposure
• No roof penetrations or structural concerns
• Simple to expand later

Ground mount racking is widely available in Australia. For a 10kW array (roughly 20 to 25 x 400W to 500W panels), you need decent space — around 40 to 50 square metres of unshaded ground area. Use the solar calculator to size your array for your specific location and load requirements.

What Can a 10kW System Run?

A properly configured 10kW off-grid system handles essentially everything in a typical Australian home:

• Refrigerator and freezer (150–300W running)
• Air conditioning (2,000–4,000W, the biggest load for most homes)
• Electric hot water (if timed to solar hours)
• Washing machine, dryer, dishwasher
• Electric oven and cooktop
• Power tools at full load
• EV charging (with the right setup — talk to your installer)

The key is battery bank sizing and solar array sizing. A 10kW inverter is only half the equation. You need enough panels to recharge the batteries each day, and enough battery capacity to get through the night and cloudy periods. For Melbourne or other southern Australian locations, winter sun hours drop significantly — factor this into your design using our solar calculator.

Recommended Products (Amazon AU)

If you are ready to start sourcing parts, here are direct search links with the offgridmast09-22 affiliate tag. These support the channel at no extra cost to you:

Australian Pricing Guide

Here is a rough cost guide for a 10kW off-grid system in Australian dollars:

• 10kW split-phase inverter (e.g., EG4 or equivalent): $1,800–$2,800 AUD
• 16kWh battery bank (EG4 or Pylontech): $2,000–$3,500 AUD
• Solar panels (20× 500W monocrystalline): $2,000–$4,000 AUD
• Ground mount racking: $500–$1,200 AUD
• Cables, fuses, PV disconnect, breaker panel: $400–$800 AUD
• Miscellaneous (connectors, tools, mounting hardware): $200–$400 AUD

Total: approximately $7,000 to $12,500 AUD for a complete 10kW off-grid capable system, fully installed. Compare that to a grid-connected solar-plus-battery system of similar capacity at $15,000 to $25,000+ installed, and the off-grid DIY path looks very attractive for remote properties.

Safety Rules to Never Forget

Will Prowse is blunt about this in the video, and we will be too:

• Always verify zero volts with a multimeter before touching any conductor, even after switching off a breaker. Capacitors hold charge.
• Wear safety glasses whenever working near batteries. Batteries can vent, arc, or explode under fault conditions.
• Never solder battery cable lugs — vibration over time causes solder to crack. Crimp only.
• Do not exceed PV input voltage — know your open-circuit voltage in cold conditions before wiring panels in series.
• Use T-class fuses when connecting multiple battery banks or bus bars. DC arcs are much harder to extinguish than AC arcs.
• Metal enclosures contain fires — if you are building a DIY battery pack, use a metal enclosure.

Expansion and Scalability

A well-designed 48V system is inherently scalable. Starting with a 10kW inverter and 16kWh of battery:

• Add more solar panels up to the inverter's PV maximum
• Stack additional battery units in parallel for more storage
• Parallel a second inverter unit for 20kW of output (with correct configuration)
• Add alternator charging for vehicle-based or remote installations

The EG4 and similar platforms are purpose-built for this kind of incremental expansion. You do not need to build your whole system on day one.

Final Thoughts

Will Prowse's beginner crash course is exactly what it claims to be: a place to start. It does not cover everything, but it covers the most important things—the parts list, the cable sizing, the safety rules, the grounding approach—with the kind of detail that lets you actually go and do it.

For Australian conditions, you need to source components locally since Signatures Solar and Current Connected ship internationally, while Boss Audio and some local distributors carry EG4 and Pylontech stock. You also have to account for Melbourne's lower winter solar yield compared to Brisbane or Perth, and ensure any fixed installation meets local council and electrical regulations.

Start With Mobile Solar Power

The video and the full parts list on Mobile Solar Power are the best starting points. From there, use our solar calculator to size your system for your actual load, and read our battery sizing guide before committing to a battery chemistry.

Original video and system design by DIY Solar Power with Will Prowse. OffGrid Masterplan is a participant in the Amazon Services LLC Associates Program. Affiliate links may earn us a commission at no extra cost to you.