Off-Grid in Murrieta: When $100,000 for Utility Power Makes No Sense

Ground Mounted Solar System for Off-Grid Use

When Southern California Edison quoted a homeowner in Murrieta over $100,000 just to bring power to his brand-new home, it stopped him in his tracks. That number didn’t include building the house it was just for the privilege of running wires, dropping a new transformer, and making the connection.

Now, this wasn’t your average homeowner. He’s an engineer who had already installed his own solar system years ago using SMA America equipment. With that kind of background, he knew there had to be another way. And that’s where the idea of going off-grid came into play. Technology has changed dramatically in the last decade, and what was once a fringe option is becoming a viable solution for homes with unique challenges.

One of his contractors, someone I’ve worked with before, suggested he give me a call. I don’t brand myself as “the off-grid guy,” but I follow this technology closely—Fortress Power, EG4, Sol-Ark—and I’ve had the chance to interview some of the sharpest engineers in the industry. Shoutout to Alex, formerly with Fortress Power and now with Enphase Energy, who once had Fortress ship me a full system to test out. That experience stuck with me. And for this client, Fortress Power was the first company that came to mind, not least because they’re one of the few manufacturers that doesn’t punish you with a reduced warranty when you use their products off-grid.

But this homeowner is an engineer, and like any good engineer, he wanted options. He specifically asked me to explore EG4 alongside Fortress Power, so this turned into a full feasibility consultation.

Understanding the Challenge

This isn’t a little cabin tucked away in the woods. We’re talking about a 4,500 square foot home (not even counting the garage). Thankfully, an energy audit had already been done on the proposed build, which saved me some time and gave me a clear picture of what the house would consume.

The numbers were staggering:

• Winter average load: ~51 kWh per day

• Summer average load: ~148 kWh per day

For comparison, the average California home uses just 18 kWh per day. This house will consume almost eight times the state average thanks to heat pumps, zoned HVAC, induction cooking, appliances, lighting, and an electric vehicle. Designing an off-grid system to cover that kind of load isn’t for the faint of heart. It takes raw power, robust surge capacity, and serious storage.

Step One: Solar

The architect had designed space for 72 panels, but after accounting for modern panel dimensions, we could realistically fit 67 QCells Q.TRON 430W modules. These panels are high-performance, affordable, low-degradation, and U.S.-made.

That array delivers:

• 28.8 kW DC capacity

• ~40,000 kWh annually

• 83 kWh/day in December (lowest month)

In other words, the solar production alone was more than six times what a typical California household uses annually. Even in winter, the system would cover the home’s average consumption with the right storage design.

Option One: Fortress Power

Fortress Power’s Envy True 12kW hybrid inverter is built for off-grid. It supports parallel stacking and pairs with their batteries, including the powerhouse eForce 28.8 kWh stack.

My baseline design:

• 2 Envy True inverters

• 3 eForce stacks

This provided:

• 24 kW continuous AC power

• 86.4 kWh storage capacity (~1.5 days autonomy in winter)

But the LRA (locked-rotor amps) rating gave me pause: just 83 amps. For a system this size, that’s light. With multiple HVAC zones, I recommended adding a third inverter, which would bump it up to 36 kW continuous and 249 amps surge, far more comfortable for heavy startup loads.

The estimated installed cost? Around $137,000, climbing to $147,000 with the third inverter. Still, compared to Edison’s $100K just for wires, it was a serious contender.

Option Two: EG4

The homeowner was already researching EG4’s FlexBOSS21 and GridBOSS MID, but those weren’t the right fit here. Digging deeper, I discovered their LuxPower-based EG4 12000XP and that changed everything.

Highlights:

• 195A LRA rating (better than Tesla Powerwall 3 at 185A)

• Supports up to 16 units in parallel

• Shared DC bus across inverters, meaning all batteries and all inverters charge and discharge together

My recommended EG4 design:

• 3 × 12000XP inverters

• 6 × 14.3 kWh WallMount All Weather batteries

This provided:

• 36 kW continuous AC output

• 85.8 kWh usable storage

• Incredible surge capacity for large loads

The kicker? Installed cost came in around $90,000, that's $10,000 cheaper than Edison’s quote for just grid connection and nearly $50,000 less than the Fortress option.

The Bigger Picture

Designing and installing an off-grid system of this scale isn’t simple. Few contractors specialize in it. You need electricians, solar installers, sometimes even generator pros, all coordinated together. And that’s where I come in. I do the legwork, I call the manufacturers, I work out the design, and I help assemble the right team to make it happen.

Fortress Power vs. EG4. Reliability and warranty support vs. raw power and innovative design. At the end of the day, it’s not about picking a “winner.” It’s about tailoring the technology to the lifestyle and expectations of the homeowner.

Final Thoughts

This consultation is exactly what I offer homeowners: real numbers, real options, and real solutions, not the cookie-cutter packages that get pushed by most sales reps. If you’re exploring solar, storage, or even a full off-grid setup, I’d be happy to walk you through the process, review your bids, or design a system with you from scratch.

You can schedule a consultation through my website, request a quote through Axia by QCells, or simply reach out for a review of the proposals you already have. Because the more people understand what goes into these systems, the more empowered they are to make the right choices for their homes.