A Solar Upgrade to Solve the Winter Blues
Brenda has a cabin with a small 12V off-grid solar system, producing sufficient energy to run an energy-efficient fridge and lights. She typically had enough power to keep the batteries charged until she added Starlink.
With the shorter daylight hours and changing sun angle, Brenda didn’t have enough power to charge the batteries to meet nighttime demand. They are often drained overnight.
Having done her homework, Brenda knows that constantly draining the batteries will shorten their lifespan. She also understands that she should not charge lithium iron phosphate (LFP) batteries when the temperature drops below ~35 degrees. Out of an abundance of caution, she manually shuts down the batteries during cold nights.
Having to watch her consumption all day, turning off Starlink after sunset, and not having power early in the morning isn’t sustainable. Brenda reached out to see how we can help her boost her system’s capacity cost-effectively to generate enough power for the winter.
Understanding current needs and future plans
Brenda is mindful of her usage pattern and appliances’ power consumption, which is a great start. We discussed her current needs and her plan for expanding her living space (e.g., she likes cooking and wants to build a full kitchen).
The 12V system is sufficient for her current requirements. However, there are some downsides. For example, the lower voltage puts more strain on the system, and components wear out faster because of the more intense thermal cycling.
Moreover, a 12V system would make it extremely challenging, if not impossible, to support high-power-draw kitchen appliances like a kettle and oven. The current would get very large, requiring expensive wires and parts while compounding inefficiencies.
However, Brenda’s timing and budget didn’t allow for an immediate upgrade to a 24V system. First and foremost, she wanted to have sufficient power output as quickly as possible to weather the long, sometimes grey(ish) winter days.
Setting the stage for growth with a two-phased approach
The good news was that we had everything in stock to perform a quick upgrade to boost power production. We designed a two-phased approach to more than double her current solar production within one week while paving the way for a future upgrade to a 24V system.
Phase 1
We kept the 12V setup as-is, added six 250W utility-grade refurb solar panels, and put the new array on a separate solar charge controller (SCC) for added redundancy. We also programmed the SCC to stop charging the LFP batteries under low-temperature conditions to prevent damage to her LFP batteries.
Since the added solar capacity would feed more power into the system, we revamped all the wiring and added safety measures. For example, when Brenda built the system, she did not have the tools to crimp the ends of the thick cables. While it may seem minor, the wires got hot — lowering efficiency and creating potential fire hazards.
We reoriented existing components to reduce power loss due to long wiring and replaced cables with bus bars to set the stage for handling high-current loads. Additionally, we rewired the diesel air heater (a cost-effective option for heating small spaces) to run off the solar DC instead of going through the inverter, eliminating fire risks in case the inverter malfunctions.
“Bert and Ling came over to discuss my solar setup's problems and future plans. They designed a system just for my needs and budget. I am so happy to be able to turn my lights and heater on whenever I want now. I can also use the internet after dark. These are things that were not always possible before. Thank you, Bert and Ling!” ~Brenda
Phase 2
When Brenda is ready to build her kitchen and a permanent mounting system for the solar panels, we’ll convert the system to 24V. We’ll also calculate the site’s solar trajectory and recommend the best orientation to maximize yield based on her usage pattern.
The new system will include a custom-built cold-temperature-tolerant lithium cobalt battery to ensure Brenda has an uninterrupted power supply even when the LFP shuts off during cold nights and early mornings.
We’ll rebuild her existing 12V LFP batteries and add a battery management system (BMS) to make them compatible with the 24V setup so she can keep using them. The BMS will include our proprietary software, enabling us to mix the LFP and lithium cobalt cells. Brenda will also have the option to program the BMS in a more conservative setting for added safety and longevity.
A solar solution that grows with you
Our expandable and flexible system design allows our clients to grow their off-grid solar systems to meet evolving needs.. Our off-grid solar solutions can fit smaller budgets and grow with you to support your big plans. Get in touch to see how we can help.
