first system before tariffs hit, maybe...

[rseech02]

Hey everyone, new to the forum and new to solar, jumping in the deep end, copying another poster's format, roughly, here's my proposed system, am I crazy?


SYSTEM & USAGE DESCRIPTION

System

• Inverter: 1x 12000XP
• Battery: 2x 14.3kWh batt (EG4-Wallmount Indoor)
• Solar PV: 15.3KW Gstar 425W Bifacial Panels – 3 strings, leaving 1 for future growth
• Grid Tied through inverter
• Critical Loads Panel
• Victron Lynx Power In
• 4 car solar carport over Pool, populating 36 panels, leaving 12 for future.

Phase One

Phase 1: I will install inverter, 2 batteries to Victron and solar PV panels with disconnects. Will connect to new 100 amp Critical load center (LC). Will move relevant circuits to LC from current main, both on interior, bonding the neutrals and grounds, so only hots will move, except for AHCI breakers, will move both in that case. There will be a 100 amp grid connection to LC from Inverter, and 100 amp breaker for that. Service Panel is 200 amps.

Relevant circuits, initially will be 2 refrigerators, stove, and depending on validation two inverter based HVAC systems Daikin 2 and 3 ton units, will be using Emporia sensor to validate if/when to migrate

Phase 2:

Additional panels to maximize space, and additional batteries, exploration/validation of TOU with power company FPL - South Florida based as additional cost saver

MAIN OPERATING MODE -OFF GRID

• Solar PV provide energy to non-battery LOADS --> store excess solar PV energy in batteries
• When no Solar PV energy, use batteries for non-battery LOADS – decision point – if TOU then save battery for use with peak rates? Unsure if TOU is valid to introduce…
• When no Solar PV and No Battery, energy draw energy from power company FPL to supply LOADS through inverter, again TOU complication if peak time for rates and no power for critical load LC

Why this setup and phased approach?

• Off Grid requires less complexity, possibility of issues with power company, lower cost entry point for effectively whole house backup and phased expansion.
• roughly 50kw usage daily, but hoping to decrease that over time as I look to expand system to maybe meet in middle with higher capacity system and lower energy usage via better insulation, change windows, etc. more of a DIY'er so will be gradual.

 

[BaylentheSky]

Not sure what your question is exactly, but if price is a concern, and you're looking for the most economical solution, it would have to be a battery-less system, since the battery is the most expensive component. If you're on the traditional tier-based pricing plan, this works out perfectly, even with an off-grid system, since you're effectively shaving half of your usage off, ensuring your bill to always be in the lower tiers. Going with this set up, you probably can get away with a 6kW PV system, a 12000XP inverter, this should allow you to run all your HVAC's comfortably, while minimizing cost, ensuring the shortest break even period.

If money is not an issue, go with your original proposed set up. It'll take longer to recoup your investment cost, but hey!

 

[rseech02]

Hey, appreciate your response and viable alternative, the question in a self deprecating way, am I crazy to consider this, does it make sense, can it work, or does it need improving? Keeping the costs down is important, kinda hesitating as I also expect prices to jump, so not really dipping toes, but jumping head first to start and preserve value for $$ and hoping things stabilize to expand later. Hope that explains my reasoning better!

 

[BaylentheSky]

Batteries are only going to be cheaper, so adding batteries later will be more economical, especially if you're looking to break even quickly. Your original proposal can work, but would be a bit expensive to implement if you're trying to keep costs down.