How to Fix an Off-Grid Solar System Cost-Effectively
If you call a typical solar company to fix a failing off-grid solar system, you’d likely be quoted a $30k+ fee to toss out everything and plop in a brand new setup. Why? It’s the easiest and fastest way to get your money and off the hook.
Making equipment from different eras and brands work together isn’t always easy. If the service provider lacks the patience or expertise to troubleshoot, they sell you a new system to avoid trouble.
However, after diagnosing and upgrading many existing off-grid solar systems, we’ve learned a thing or two: More often than not, there are just one or two “weak links.” If you pinpoint the problem, you can address it surgically instead of tossing the baby out with the bathwater. The difference? Instead of a $30k+ bill, you may pay just a few thousand.
The good news is that we don’t have to make things too complicated. We start with two buckets in the off-grid solar equation: production and storage. Let’s examine how issues manifest and how we address them without overhauling the entire system.
Insufficient solar production
Back in the days, when solar panels were expensive, many installers used very few panels and put them on a swivel stick (“trackers”) to squeeze out an extra few percent of power. However, those trackers not only limit the number of panels people have in their systems. These mechanical systems also have a finite lifespan.
Fast forward 15 or 20 years: A screw loosens, something gets stuck, or the joints stop moving altogether. Moreover, when the panels are mounted high up, you can’t see if they have delaminated or if a cable/connector has detached.
The result? Not enough panels, coupled with them pointing in the wrong direction. You might have enough solar production during the bright summer months, but fall short when the clouds roll over in winter.
How can we tell that insufficient production might be the problem? Besides a relatively small solar field (in relation to the household usage), an “always hungry” battery bank is a telltale sign. It’s not uncommon for power to run out in the early morning when the batteries are depleted, but the sun is still low.
How we address this issue:
Examine existing panels for delamination, loose connections, or other signs of wear and deterioration.
Calculate if the total power the panels produce can support your consumption year-round.
Add solar panels to the system to boost production, if appropriate.
Solar charge controller (SCC) issues
SCCs turn power produced by solar panels into electricity you can use. For the most part, they don’t make much trouble. However, like anything else, they wear out. For example, older equipment often uses fans for cooling. However, if it’s stored in a pump house and not fully protected from the elements, dust can clog the moving parts over time.
When the SCC can’t cool itself and heats up, its ability to turn solar power into usable electricity diminishes. So, even if you have a sufficiently large solar field, you may still fail to generate enough power.
How we address this issue:
Examine the existing SCC. Rule out solar panel issues that hinder production.
Reconfigure the SCC settings, if applicable (e.g., different battery chemistries require different settings).
Replace the SCC if low production continues.
Insufficient storage capacity
Batteries deteriorate, especially poorly-maintained lead-acid ones (even pampered ones rarely last more than five years). Lithium batteries are more resilient, but they aren’t bulletproof. For example, lithium iron phosphate (LFP) cells can’t charge when the temperature drops under ~35 degrees. You destroy the cells if you charge a low-quality pack without a protective circuit in freezing conditions.
Batteries stored in extreme conditions, such as poorly insulated pump houses, experience more wear. Meanwhile, we’ve seen many technicians dialing up the depth of discharge (DoD) too aggressively when customers complain about lights going off at night — a questionable practice that may get them off the hook but drastically shortens battery lifespan.
Besides not having enough power to get through the night, insufficient battery storage capacity may manifest as trouble starting large tools and appliances. Without sufficient stored energy, your solar system may not be able to meet the surge power requirements to jolt a vacuum cleaner, table saw, or large well pump to life.
How we address this issue:
We measure your batteries to determine their capacity and how well they hold a charge. If you have our custom-built packs, we simply pull up the battery management system (BMS) app to review the data and troubleshoot.
We review battery settings (if available) to see if they’re configured appropriately.
We discuss your power usage pattern, such as nighttime or surge power requirements, to determine if your current storage capacity meets your needs.
We may suggest adding battery storage capacity and help you design a lead-acid-to-lithium transition plan, if appropriate.
We offer advice to help extend your battery pack’s lifespan.
The consumption side of the equation
In addition to verifying production and storage capacities, we may ask our clients questions about their consumption patterns. For example, changes like a newly installed electric water heater could push a system that used to work just fine over the edge.
We typically start with the usual suspects: Well pumps, electric water heaters, heat-generating appliances (e.g., hot plates, hair dryers, space heaters), and monster power tools. We also look for “phantom drains” — mystery power draws that continue even when everything is off.
After understanding your consumption, we calculate if your production or storage capacity may fall short and provide informed recommendations.
Enhance your off-grid solar system without a costly overhaul
Many existing off-grid systems can be enhanced to meet the owners’ energy demand without an expensive overhaul. We employ a surgical, personalized approach to help clients fine-tune their equipment, fill gaps, meet their needs, and achieve energy independence.
Learn more about our off-grid solar improvement services and get in touch to schedule an on-site consultation.
