We have a seasonal off-grid cabin in a remote part of Ontario, Canada, with an existing solar system that was “professionally” installed about 5 years ago. However, I’ve come to understand that it was installed incorrectly (undersized and wiring issues), which I’m now looking to correct.

Finding installers willing to come into the cabin is difficult, so I would love your guidance as I’m trying to determine if this is a project I can/should take on myself or if I should just leave it to a professional.

The Cabin

1. It’s not winterized, so it’s only used from May to October, mainly on weekends with occasional week-long stints when possible.
2. It’s located at 44.880156,-78.982344, and is south-east facing.
3. I did a load audit, which can be found here. If my calculations are correct, we need an average of 14.12 kWh of power daily. This includes adding a fridge and microwave, which we don’t currently have.
4. We have a few DC loads (a fan and a few lights), but everything else is AC.

The Current Equipment

1. Schneider Electric SW4024 Inverter/Charger (3400 W, 7000 W surge).
2. Schneider Electric MPPT 60-150 Solar Charge Controller
3. Schneider Electric Control Panel, DC breaker panel, Battery Monitor, and ComBox
4. 6 x Canadian Solar CS6P-255P 255 Watt Solar Modules (1.53 kW)
5. 4 x Discover Energy 6VRE5-3400TG Tubular Gel Batteries (11.6 kWh) . Note: these are damaged and need to be replaced as they no longer efficiently hold a charge.
6. Honda EM 3500S Generator

The Plan

1. Reuse the existing Schneider Electric equipment (inverter, MPPT charge controller, etc.)
2. Replace the existing solar panels with new 8 x 430 W, for a total of 3.44 kW (and use a few of the existing panels vertically mounted for winter trickle charging)
3. Replace batteries with 8 x 6V FLA batteries, for a total of 20.5 kWh

Questions

1. I have basic electrical skills, and while I’m confident I could do this job with a bit of guidance & YouTube… I’m not sure if I should. How crazy am I to even contemplate attempting this?
2. The load audit I did seems high. Or, at least we don’t seem to consume as much power today as my calculations suggest. I have actual consumption data stored in the ComBox… but it’s at the cabin.
3. Given the location and seasonality of the cabin, plus the projected loads, will 3.44 kW of generation and 20.5 kWh of storage be suitable?
4. If I do attempt this, can you recommend any panel and battery resellers in Ontario (near Toronto or Kawartha Lakes/Haliburton/Bracebridge?)
5. Given the remote location of the cabin, we’ve struggled to find reliable contractors over the years. However, we did find a reputable company to quote an upgrade a few years ago, but I thought it was too expensive at the time (as we were reusing so much of our existing equipment). Their proposal was similar “the plan” outlined above, and they quoted $25K (CAD) for the batteries, panels, and installation. Does that sound reasonable?

​

For additional context, this was their analysis of the electrical wiring issues with the current system:

“The system has numerous code issues of concern. The first and foremost is the lack of overcurrent protection on the incoming PV. It is currently tied into an AC circuit breaker before feeding into the charge controller. An AC circuit breaker protecting a DC circuit is only a glorified switch and offers no fault current protection. The cottage also has wiring for 2 DC lighting systems, again utilizing AC breakers to distribute DC power. A breaker for the PV can be added to the Schneider Conext DC Breaker Panel, however it offers no additional room for DC load breakers. The existing PV utilizes a junction box. There is no combiner box present. There is no RSD for the existing system. As connected, the system is only utilizing half of the capacity of the inverter as the load panel is connected for 120V. The cable feeding from the Inverter to the load panel will need to be changed to feed the Load panel with 120/240V. There is also no lightning arrestor installed on the DC portion of the system. The batteries are in poor condition due to constantly being in an undercharged state. Cell-to-cell voltage is unbalanced ranging from 2.2V ot1.4V(!)