Off-Grid Solar Systems That Don’t Cost an Arm and a Leg

Most people don’t consider their power consumption habits when switching to solar. 

For instance, when the boiler turns on doesn’t make a whole lot of difference if you’re on the grid (maybe an extra dollar here and there because of higher electricity costs during peak hours.)

However, the equation changes when you’re on solar. If you heat all the water you need during the day when the sun shines, you don’t need to buy batteries (the most expensive part of a system) to store energy to heat water at night. After all, a boiler is a tank that stores hot water — a hot water battery!

Meanwhile, most solar solutions are cookie-cutter. They’re over-dimensioned to accommodate the 0.01% chance that you turn on every appliance in the house so the system can still handle the load. The added battery and inverter capacities could easily double the cost of materials, and you’re paying for things you won’t use 99.9% of the time.

A commonsense approach to dimensioning an off-grid solar system

Here’s what we do in our modest fully solar-powered motorhome (yes, we eat our own dog food):

We have a 5000W inverter, providing enough capacity to run two and a half power hogs (e.g., electric kettle, microwave, boiler, A/C) simultaneously on top of essentials like the fridge, computers, lights, and Starlink before a fuse blows or a circuit breaker trips. For the most part, we don’t turn on more than two power hogs at once. For example, we usually turn off the boiler when we use the kettle.

If we want to accommodate the few minutes every few days when we may turn on three power hogs simultaneously, we’d need to buy an even bigger inverter for over $1000. Ouch.

Flipping a switch or two to prevent a blown fuse isn't much trouble. But the problem is — how do we know the system is near capacity?

We developed Beep Beep — a little widget that goes BEEP BEEP when the system is close to its capacity. It gives us time to switch off a power hog, and everything is fine again. 

We also incorporate this handy lil’ guy into many off-grid solar systems we design for our clients to lower their material costs with minimum compromises. 

Beep Beep prototype v1

A customized system based on usage pattern

To ensure our clients get the capacity they require (plus some margins) without paying for things they don’t use, we start with an on-site consultation to understand what they need to run and how they use their appliances. 

We discuss sensible tradeoffs that will allow us to right-size the inverters and batteries to optimize costs. For clients who want to use solar to lower their SCE bills, the tradeoff may just be automatically switching to grid power temporarily until consumption falls back under the threshold.

When we design the system, we incorporate low-cost technologies like Beep Beep and timers based on the tradeoffs the client is willing to make. For example, we can set a timer for the boiler to turn on during the day so we don’t have to dimension substantial battery capacity to heat water at night. That could save you many thousands of dollars in batteries.

We can design an expandable system for clients on the grid to transition to off-grid or use solar to help lower their electricity bills. This approach enables them to add capacity over time to spread out the investment. They can also adjust their consumption habits, so they don’t have to purchase all the equipment upfront and realize they’ve bought more than they need.

If you’re considering an off-grid or hybrid solar system, let’s chat to see how we can get you started without paying $30k upfront.