Critique my plan

[Zymurgy]

Longish post.... Looking for feedback on my two step plan. I'm strongly considering installing two independent systems at my home - one totally off grid for "essentials" and one for grid tie. Yes, I know that it will cost more that way, but I'm looking to do some "layering" of two independent systems for multiple reasons. My education and work background is electrical engineering specializing in industrial automation so I'm good with the electrical aspects. Looking for feedback on the solar design aspects.

Off grid system (install in the next 4 - 8 weeks):
- Goal is to power the essentials via a new subpanel, 3 to 4 days battery capacity during poor conditions
- Loads: Well pump (240VAC), chest freezer, refrigerator, PROPANE high efficiency hot water heater (so the power is for the 120 VAC 3 amp combustion blower) and PROPANE fireplace (air circulation blower), a few low wattage 120 VAC LED lighting circuits. I have a wood burning stove to provide primary heat if the grid is down so no other heating loads.
- 48 volt hybrid inverter approx 4-6kw, need 240VAC for well pump
- I'm currently doing detailed daily kwh load monitoring for each of the loads so I will have high confidence in the sizing calculations.

Grid tie system (2023):
- 48 volt hybrid inverter - approx 15kw
- Goal is to offset/eliminate utility bill via net metering
- Large battery bank is not initially part of the install, but will be an option
- Taking delivery of an EV in 2023

I'm OK with spending a bit more for quality equipment. I've been on board with the "cheaper isn't always cheaper" philosophy for a long time.

For the 240VAC off grid system, I'm not finding a Victron hybrid that meets what I am looking for (I don't want to oversize and parasitic drain the batteries uncessarily), perhaps someone with more knowledge of Victron products can help out there? I see plenty of options from Sun Gold, Eg4, Schneider, etc. Two EG4 3000 EHV-48 (or similar) in split phase are cheaper than a Schneider 4048, and I need a separate charge controller with the Schneider. But what's the quality/reliability of the EG4 products? Any other reliable recommendations? Not looking for cheap Chinese stuff.

For the grid tie system, I'm looking the at the Sol-Ark 15k. My current annual usage runs around 16,000 kwh, averaging 800 in the summer and 2200 in the winter. Biggest load is the geothermal heat pump which consumes 43 Amps (compressor and fan) cooling or heating, plus a backup electric heat that runs at 80 amps when the heat pump can't keep up in very cold weather. Future battery expansion on this system could power the heat pump without the backup electric heat.

I'll be buying an EV in 2023 so that will add significantly to my consumption. In the future adding a second Sol-Ark and panels is a possibility.

Constructive comments welcome!

 

[42OhmsPA]

I'd start with understanding the inrush current of your well pump, that will likely deter you from the HF 3k. .. my 1hp is ~37a/leg.
I diy'd a grid supported system, main feed to primary panel to inverter to rest of house, using a 6kw LF AIO. It starts the well pump no problem but the idle consumption is excessive...
The next system I build will more than likely use the XW Pro 6048...
Good luck.

 

[MichaelK]

I definately recommend you look at Schneider, though I would try to steer you away from 4048. It only has a starting surge of 7000W, and depending on the size of your well-pump, may not be big enough.

I can tell you from experience though that my XW+6848 is easily up to the task of powering a well-pump up to 1hp in size. That's the size of the pump I have, and Schneider's 6848 is my primary home inverter. Since the new 6848Pro is also hybrid, it could be the single stand-alone inverter for both your off-grid, and grid-tie projects. It powers the whole place, the refrigerator, lights, TV, and everything else.

Be careful about the specifications claimed by Sol-Ark. They like to tout that their inverter can outperform the 6848, but in the real-world I see end users reporting the opposite.