Client Success Story: A Minimum-Viable Solar Power System For $600 in Material Costs
What is the minimum cost to get a small solar power system going?
CP called two solar installers before talking to us. One quoted her $18k, and the other one, $30k. Neither could answer her simple question, “Why is the amount so different?”
Two weeks after our first onsite visit, CP has her minimum-viable solar system running for around $600 in material costs.
Let’s start from the beginning.
The situation
CP lives in a fifth-wheel RV on a mountaintop with a beautiful view. Although the utility meter box was just a couple hundred feet away from her RV, she could not get the county and SCE to play nice and pull a line to her RV.
She has a generator for most of her power needs, which are sporadic and could be batched so she doesn’t need to run the generator continuously (which is noisy and expensive). However, that doesn’t work for a fridge.
CP tried many things to keep her fridge running. She had an old-school propane fridge that could also run on electricity. It wasn’t working well with the propane, so she tried to use a small, folding solar panel (5W) and borrowed a couple of used lead-acid batteries.
[ Side note: We don’t recommend using lead-acid batteries because they’re more expensive, have a shorter lifespan, and are less safe. ]
Unfortunately, that didn’t work either. The solar panel was too small to run the fridge, let alone charge the batteries, which became drained — affecting performance and longevity.
Instead of more patchwork fixes (and spending $$$ on ice cubes), CP gave us a shout.
The solution
After assessing the problem, we convinced CP to stop throwing good money after bad with stopgap measures. We urged her to “do it right” by investing in equipment that will work today to power the fridge and form the foundation of a solar power system for the entire RV when she has the resources to upgrade.
The biggest offender in the equation was the old-school propane fridge. It’s extremely energy inefficient, while the ammonia-based refrigerant is highly toxic and hazardous if it leaks.
Throwing the propane fridge out might seem like a waste, but it’d be worse to keep it. The amount of solar panels and battery capacity CP would need to run the old fridge would be way more than buying a small, brand-new, energy-efficient fridge for under $200.
[ We often go through a similar process with other clients by identifying power-hungry appliances and evaluating if an upgrade to a modern, energy-efficient version would save them money. Yes, looking at you, the 25-year-old fridge hiding in the basement! ]
Work in progress as we experimented with panel positioning and angle to maximize the solar yield.
The result
Life without a fridge in July is no fun in Caliente, so we got to work immediately.
The system design is simple: It consists of 4 refurbished utility-grade solar panels (250W each), a good-quality medium-sized inverter (1500W, sufficient for expanding the system), and a high-quality solar charge controller (SCC). The total cost was around $600.
(CP is able to keep the lead-acid batteries she borrowed, bringing the initial setup cost down to suit her budget.)
CP bought her new fridge, and we ordered the materials. The implementation took a few hours, and the fridge was humming along nicely by the end of the day.
While CP still uses the lead-acid batteries to store power for nighttime use (until she has the resources to upgrade to a lithium battery pack), the solar panels generate enough power to charge them up and top them off, which is essential for extending their lifespan.
CP plans to expand her system to 8 panels with a lithium battery pack. We selected the components, i.e., the inverter and SCC, with sufficient capacity to accommodate the upgrade. Meanwhile, the modular and expandable system design will allow us to add solar panels and batteries without overhauling the system or causing hours-long disruptions.
Learn more about our off-grid solar solutions and get in touch to see what’s possible.
