Selected-load solar backup blueprint

Will Prowse 2026 budget path.

A practical split-phase backup model for selected house loads: a 900W bifacial panel pair, one 16kWh 48V DIY battery, and a clear read on how much of the Barn we can cover in Tinicum, PA 18947. The 2-kit Callsun upgrade shows what changes if we double the panels.

Hardware cost

$4,889

Base electrical stack, before racking, tax, shipping, labor, and final breaker hardware.

Best version

2 kits

The 1.8kW Callsun version is the first one that feels meaningfully useful.

Practical target

~5.8 kWh/day

Radon, fridge/outlets, network, well, and basic lights from Emporia data.

Stretch goal

Heat pump

Not supported by this build; needs a larger solar/storage plan or load-shed strategy.

Plain-English readout

This is a critical-load battery system, not a heat-pump offset system.

The useful version is the 2-kit Callsun build. It gives enough solar to support the small daily loads and recover the battery on good days, but it does not make the Barn's heat pump, water heater, dryer, or electric cooking feel solar-backed.

Question	Answer	Why it matters
What should I expect?	A selected-circuit backup panel for fridge/outlets, radon, internet, well pump, and basic lighting.	Those loads average about 5.8 kWh/day in the Emporia model.
Is the 2-kit upgrade worth modeling?	Yes. It moves the array from ~1.7-4.0 to ~3.4-8.0 kWh/day.	That changes the system from "slows discharge" to "can recover on decent sun days."
Can it cover the heat pump?	Maybe as a managed recent-weather stretch, not as guaranteed backup.	May+June heat-pump use is ~7.65 kWh/day, but winter stress-test days are much larger.
What about a 58.4V 20A charger?	Possible as a rescue/top-off charger.	It is about 1.17kW DC, so it is useful as a rescue charger when solar is weak and comfort loads matter.
Can the GM2200i help in a full outage?	Yes, as the AC source for the 58.4V charger.	The generator is rated 1800W running, so it has headroom for the charger if we avoid stacking other loads.

Design decision

Build for selected 120V loads first.

Your Emporia data says the measured mains average about 55.2 kWh/day. The useful Prowse target is not "the house." It is a critical-load island around roughly 5.8 kWh/day: radon, fridge/kitchen outlets, internet, well pump, and basic lighting. The broader 12.2 kWh/day version starts to include questionable outlet circuits and needs more care.

Measured average

55.2 kWh/day

Emporia mains A + B daily average.

Removed loads

~79.0%

The heavy loads stay off this backup panel in the sane version.

Remaining target

~5.8-12.2 kWh/day

Narrow critical-load set to broader critical circuits.

Modeled circuits

Priority-first

Fridge, network, lights, well, and radon before comfort loads.

System output

What this system actually gives you.

The updated model is the 900W bifacial pair you sent: two 450W panels, about 1.7-4.0 kWh/day depending on season in Tinicum, and a realistic off-grid test path. The better version doubles the panel count to two 900W pairs, which raises solar to about 1.8 kW DC and roughly 3.4-8.0 kWh/day seasonal. With no solar contribution, the DIY battery gives about 11.6 kWh usable AC, or about 2 days for the narrow 5.8 kWh/day priority set.

Solar generation

~1.7-4.0 kWh/day

The minimum learning build. It helps, but it is not enough to confidently refill daily usage in winter.

Doubled solar

~3.4-8.0 kWh/day

The recommended Prowse version. It can cover most or all of the priority-load day on decent sun.

No-solar outage

~1-2 days

Battery-only runtime from broader selected circuits to the narrow priority load set.

Typical night

~5.8 kWh

The current critical subtotal from the Emporia circuit mix. The DIY battery can cover this with margin.

Daily gap

~1.8 to 8.8 kWh/day

A single 900W pair can nearly cover the narrow load set in summer, but it remains short on winter days and broader circuits.

Heat-pump gap

~7.65 kWh/day recent

May+June usage is closer to the 2-kit solar range, but winter is a different story.

Rack area

~48 sq ft panel face

Using the listed panel size of about 51.3 x 30.3 in, the 2-panel pair is just under 48 sq ft before mounting clearance and setbacks.

Doubled rack area

~96 sq ft panel face

Doubling the 450W pair to two matched pairs roughly doubles the array footprint, which helps daily production but asks for more rack, space, and wiring.

Outage condition	Solar input	Net battery draw	Expected runtime
No sun / overnight	0 kWh/day	~5.8 kWh/day	~2 days from full battery
Average solar day	~3.4 kWh/day with 1 kit	~2.4 kWh/day against the narrow set	~4-5 days from full battery plus same-day solar
Average solar day, 2 kits	~6.8 kWh/day planning	Near break-even against the narrow set	Can run indefinitely on many decent days if loads stay disciplined
Poor solar day	~1.0-1.6 kWh/day	~4.2-4.8 kWh/day	~2-3 days from full battery plus weak solar
Lower actual load	Any condition	Depends what is turned off	Runtime improves directly as load drops

Upgrade option

Two Callsun kits is the version I would actually model.

If you want the array to do more than recharge the battery slowly, model the Callsun 450W bifacial 2-pack as two kits instead of one. That gives you 1.8 kW of PV, roughly doubles daytime harvest, and makes the battery bank much easier to recover after an overnight outage. It still is not a whole-house solar system, but it is the point where the Prowse option starts to make intuitive sense.

1 kit / 2 panels

~1.7-4.0 kWh/day

Enough to slow discharge and support critical loads on good days.

2 kits / 4 panels

~3.4-8.0 kWh/day

Better daytime coverage and much faster battery recovery.

Array cost

$1,399.98

2 panel kits at the current $699.99 coupon price each, before extra rack and wiring.

Battery recharge

~1.5-3.4 days

From empty to full on 2-kit solar, before losses and load overlap.

Practical recommendation

Buy-list base + 1 extra Callsun kit

The current spreadsheet keeps the 1-kit MVP price visible. The planning recommendation is to treat the second kit as the first upgrade because it materially changes daily recovery.

Panel alternative

Aptos 460W is the stronger long-term panel path.

The Aptos DNA-120-MF10-460W set is supported by the same overall design. It keeps the same inverter, battery, and load-center architecture, but it reads more like a settled permanent install than the bargain 2-pack path. The only real design gate is the same one we use everywhere else: verify cold-weather string voltage, MPPT window, and final stringing before purchase.

Panel price

$186.88 each

Your 4-panel cart example is $747.52 before tax and shipping.

Array size

1.84 kW

4 x 460W panels, which is a meaningful bump over the 900W Callsun MVP.

Fit

Supported

Same Prowse-style power flow, same critical-load philosophy.

Tradeoff

More settled

Better durability/support story than the cheaper backup panel option.

Per-circuit fit

What the 2-kit Callsun upgrade actually runs.

The "Yes" rows are the circuits the doubled array can support in normal use if the battery is doing the buffering. The "Investigate" rows are not automatically bad, but they need appliance-level truth before we put them on the backup panel. The "No" rows are the heavy loads that still belong on grid, generator, or a much larger system.

Circuit	kWh/day	Peak kW	Fit	Readout
Radon fan	2.26	0.49	Yes	Always-on load. It is a real daily draw, but easy electrically.
Kitchen outlets / fridge	2.14	1.66	Yes	Likely the highest-value circuit because it includes refrigeration and normal kitchen outlet needs.
Internet / router / phones	0.30	0.05	Yes	Negligible load relative to the array.
Well pump	0.59	0.28	Yes*	Daily energy is small, but pump startup must be confirmed by the electrician.
LED lighting	0.50	0.10	Yes	Easy fit even on weak solar days.
Critical subtotal	~5.8	~2.6	Yes	This is the target load set the doubled array is built to support.
Master bedroom	5.23 avg / 1.02 median	1.76	Investigate	The median is small but the average is high, so something intermittent may be hiding here.
Toaster / countertop appliance	Unknown	Often 1-1.8	Short bursts	Possible if it is on a supported outlet circuit and not stacked with other big loads.
Kitchen stove	0.31	1.20	Unlikely	Small measured average, but cooking loads are the kind we should avoid backing up.
Clothes dryer	0.87	4.44	No	Still too spiky and too large for this class of system.
Water heater	10.10	4.64	No	Consumes too much daily energy even with double solar.
Heat pump, recent May+June	~7.65	3.13	Managed stretch	Possible to offset on good sun days if other loads stay disciplined, but not guaranteed backup.
Heat pump, full winter-weighted file	23.35	7.63	No	Useful as a stress test, not the normal-weather expectation.

Per-circuit fit uses the Emporia 1-day file for daily kWh and the 1-hour file for planning peaks. The table is intentionally conservative because the final answer depends on which physical receptacles and appliances are actually on each breaker.

Stretch priority

Offloading the heat pump is a different project size.

I agree that the heat pump is the more interesting long-term target. Using the full January 14-June 14 file makes the heat pump look worse than recent reality because February and March include the rare cold-spell behavior. For a recent-weather planning view, May plus June averages about 7.65 kWh/day with a 3.13 kW hourly max. That is much closer to the 2-kit Callsun range, but it still should be treated as managed offset, not guaranteed backup.

Recent avg

7.65 kWh/day

May+June heat-pump average from the daily Emporia file.

Recent peak

3.13 kW

May+June hourly max, with p95 around 1.43 kW.

Winter stress

23.35 kWh/day

Full-file average stays visible as a cold-weather caution, not the headline case.

Mounting angle

Set the rack to match the season, or pick a fixed compromise.

For the Barn, a fixed array is simplest, but adjustable ground-mount hardware gives us a better seasonal fit. Signature Solar lists the IntegraRack IR-30 BallastRack as a fixed 30° frame at $129.99 per panel frame, and the IR EarthScrews 10-pack at $129.99 as the concrete-free mounting kit. Face panels true south for best performance in the Northern Hemisphere.

Season	Recommended tilt	Why
Summer	15°-25°	Sun is high, so flatter panels catch more light.
Winter	55°-60°	Sun is low, so steeper panels face it better.
Year-round fixed	30°-40°	A practical compromise if we do not want seasonal adjustments.

Fixed-angle option: IntegraRack IR-30 BallastRack. Mounting kit: IR EarthScrews 10-pack. If we follow the 2-anchors-per-frame pattern, the 10-pack should cover about 5 frames.

Hardware path

Buy list for the 900W Tinicum model.

Hardware prices checked May 23, 2026. Totals exclude critical-load panel, breakers, disconnects, labels, permits, shipping, tax, and labor.

Recommended build

10kW split-phase critical-load stack

$4,889.39

Use this if you want a realistic Tinicum test path with the 900W solar pair, the more conservative 16 EVE 314Ah battery kit, and a proper load center for the house-side output. The lower-cost JK 200A kit brings this to $4,629.39 if you prefer a lower entry point.

Cost scenarios

Scenario	Modeled cost	Monthly read	What changes
1-kit electrical MVP	$4,889.39	~$407/mo over 12 months	Good learning build, but solar recovery is modest.
2-kit electrical upgrade	~$5,589.38	~$466/mo over 12 months	Adds one more Callsun kit and doubles daily solar harvest.
2-kit with IR-30 racks	~$6,239.33	~$520/mo over 12 months	Adds 4 panel frames plus one EarthScrews 10-pack for the cleaner ground-mount model.
48V rescue charger add-on	+$76.99	~$6/mo over 12 months	Adds a possible 58.4V 20A LiFePO4 rescue/top-off path, pending BMS and wiring review.

Spreadsheet

Item	Qty	Unit	Total	Share	Purpose
SUNGOLDPOWER 10kW split-phase inverter	1	$1,635.44	$1,635.44	33.4%	Primary 120/240V inverter.
Yixiang Vertical JK BMS DIY battery kit with 16 EVE 314Ah cells	1	$2,249.00	$2,249.00	46.0%	16.1 kWh nominal battery, the more conservative long-term option.
No heating pad	0	$0.00	$0.00	0.0%	Batteries are in a heat-controlled space, so the pad is unnecessary.
Shirbly 4/0 AWG battery-to-inverter cables	1 pair	$181.99	$181.99	3.7%	Battery-to-inverter connection.
Pjerjzn 1000V 60A PV disconnect switch	1	$39.99	$39.99	0.4%	PV isolation and service disconnect for the Callsun-focused solar side.
Callsun 450W bifacial 2-pack	1 kit	$699.99	$699.99	14.3%	900W total, about 48 sq ft of panel face.
JINDOUZI outlet / breaker box	0	$0.00	$0.00	0.0%	Moved to a note because the proper load center is the preferred house-side panel.
Square D QO 125A load center	1	$82.98	$82.98	1.7%	Preferred house-side panel for breakers, transfers, and safer circuit organization.
Modeled hardware subtotal			$4,889.39	100%	Before breaker, disconnects, labels, permits, shipping, tax, and labor.

Battery swap option

$4,629.39 with JK kit

The JK 200A battery kit saves $260 if you are comfortable with a newer cell source. The EVE-based kit is the main modeled battery because it is the more conservative long-term choice.

Higher-capacity battery note

The Yixiang EVE MB56 32 kWh finished battery is still the cleaner more-power option. Adding it back in place of the DIY kit and heater raises the model by about $1,579, but usable AC storage rises from about 11.6 kWh to about 23 kWh. That is the better match if overnight margin matters more than lowest entry price.

The updated model is 1 linked 900W panel pair plus the battery, inverter, a DC disconnect, and a proper load center for selected house circuits. Before buying, verify panel Voc, cold-weather voltage rise, MPPT voltage range, conductor sizing, fusing, and disconnect requirements. The inverter supports split-phase 120/240V output and AC/grid charging modes, so a night-charge or utility-top-off path is possible in principle, but it should be built as a transfer-input or charge-input design that cannot backfeed the grid.

Grid rescue charger note

A 58.4V 20A LiFePO4 charger, like the BROODAY option, is a more plausible rescue/top-off charger because 58.4V matches a 16S LiFePO4 full-charge voltage. At 20A it is about 1.17kW DC, so expect roughly 10 hours to replace 11.6 kWh usable AC equivalent, or about 14 hours to refill a 16.1 kWh nominal battery before losses and taper. It still needs a fused DC connection, disconnect, BMS compatibility check, and a plan so it does not fight the inverter charger.

Generator fallback note

The GENMAX GM2200i is a useful full-outage fallback for charging the battery through the 58.4V 20A charger. The clean path is generator 120V AC outlet to the LiFePO4 charger, then charger DC output to the 48V battery through the proper fused/disconnect path. GENMAX lists the GM2200i at 1800 running watts / 2200 starting watts, so a roughly 1.17kW DC charger leaves some headroom after charger losses. Treat this as battery charging only: do not backfeed the house, do not plug the generator into the inverter output, and avoid running large extra loads from the generator while charging.

Inverter note

SRNE ASF48100U200-H is compatible enough to note.

Borick describes this SRNE unit as a 48V hybrid inverter with 110V/208V/240Vac split-phase output, mixed mains/PV charging, and remote monitoring. That makes it a believable lower-cost alternative in the same family as the current Prowse architecture. I cannot prove the exact SunGoldPower OEM chain from the public pages alone, but the overlap is strong enough that I would treat SunGoldPower as likely SRNE-style/white-label adjacent for planning. I would still keep the SRNE unit as a note instead of the main model until we verify the manual and charge behavior against the exact battery and load-center plan.

Listed price

$1,140

Borick’s retail price on the product page.

Fit

Supported, verify

Same 48V split-phase family, and likely the same OEM-style platform, but still a note-level option until we confirm the manual details.

Design caveat

This is a reasonable budget inverter note, not a drop-in replacement recommendation. The compatibility story is good enough to mention because it supports split-phase and mixed mains/PV charging, and it likely sits in the same SRNE/OEM family as the SunGoldPower unit. Even so, the page should keep SunGoldPower as the primary modeled inverter until we verify the SRNE commissioning details.

Compatibility check

What fits together, and what still needs verification.

Treat this as a blueprint for an electrician conversation. The broad architecture fits: PV into a 48V split-phase inverter, 48V battery on the DC side, and a critical-load panel on the AC output side. The exact wiring still needs a licensed review before buying because PV string voltage, transfer design, battery communication, and breaker assignments are where mistakes get expensive.

Item relationship	Status	Action before purchase
Callsun panels to SunGoldPower MPPT	Likely, verify stringing	Confirm panel Voc in cold weather, MPPT voltage window, max PV current, and whether 2S2P or another string layout is correct.
48V battery to inverter	Likely, verify BMS	Confirm charge/discharge current, low-temp protection, BMS communication expectations, fusing, and 4/0 cable length.
Inverter to Square D load center	Needs electrician	Design the transfer path so there is no grid backfeed and only selected circuits move to the backed-up panel.
58.4V 20A LiFePO4 charger to battery bank	Possible rescue option	Confirm 16S LiFePO4 profile, BMS charge-current limits, AC circuit capacity, fusing, connector, disconnect, and whether the inverter's AC input charger is cleaner.
GENMAX GM2200i to 58.4V charger	Good outage fallback	Use the generator as the charger AC source only. Keep it outdoors, avoid overload, and never connect it to house wiring without a legal transfer setup.
Heat pump to backed-up panel	Not this build	Model separately as a larger solar/storage project or controlled load-shed/comfort strategy.

Panel count

Two panel pairs is the better solar version.

If the goal is to support more daytime load, keep the same inverter and battery stack but double the panels. That does not turn this into a whole-house solar offset system, but it materially improves recharge speed, cloudy-day resilience, and the chance of supporting the well or HVAC-adjacent 120V loads while other circuits stay on.

Build	Solar / day	Annual solar	Bill offset / yr	Read
1x 900W pair	~1.7-4.0 kWh	~1,260 kWh	~$281	Best learning path and a solid critical-load starter.
2x 900W pairs	~3.4-8.0 kWh	~2,520 kWh	~$562	Better daytime coverage and faster recharge, still not full-home offset.
4x Aptos 460W	~3.5-8.1 kWh	~2,605 kWh	~$582	A stronger long-term panel family that still fits the same model.

System map

This is the wiring story in one view.

The cleaner MVP is PV into the inverter, inverter into a proper load center, and then breakers for the critical circuits. If we later want grid-top-off or utility assist, the first-choice path is the inverter's AC input or a licensed transfer design. A separate 58.4V LiFePO4 charger can be a rescue battery top-off path for poor solar windows, and the GM2200i can feed that charger during a full outage, but neither path is the main house power path. The Aptos 460W path fits that same architecture if we want the more durable panel option.

Sources

Amazon SUNGOLDPOWER 10kW inverter listing for ASIN B0F52FPVHD.
Refurbished SunGoldPower 10KW 48V split-phase inverter for the lower-cost inverter option.
Yixiang EVE MB56 32 kWh finished battery pack for the higher-capacity battery note.
Amazon 450W bifacial 2-pack (Callsun Store) for the 900W pair, N-Type 16BB / 25% efficiency / anti-shade dual-module specs, and the direct click path.
IntegraRack IR-30 BallastRack and IR EarthScrews 10-pack for the fixed 30-degree rack and ground-mount note.
Shirbly 4/0 AWG battery-to-inverter cables for the $181.99 black/red cable pair.
BROODAY 48V 20A LiFePO4 battery charger for the possible 58.4V rescue grid/shore top-off charger note.
GENMAX GM2200i product page for 1800 running watts, 2200 starting watts, 120V 20A duplex outlet, and 1-gallon fuel tank specs.
GENMAX GM2200i user manual PDF for operating, safety, maintenance, and storage documentation.
Borick SRNE ASF48100U200-H product page for the 48V split-phase hybrid inverter note, 110V/208V/240Vac output, mixed mains/PV charging, and remote monitoring claims.
JCP&L Energy Savings Rewards for the current smart-thermostat demand-response enrollment incentive.
JCP&L Energy Savings Rewards FAQ for eligibility, summer event season, and thermostat-adjustment behavior.
Sustainable Jersey utility demand response summary for the $75 enrollment and $25 annual JCP&L device incentive snapshot.
Tinicum Township community contacts for the local Met-Ed electric concern listing.
TubeTested 2026 Will Prowse approved products index for the referenced 2026 affiliate-list context.
YouTube reference video for additional budget-stack context.
SunGoldPower 10kW manual reference and related listings for AC input and 120/240V split-phase context.
Amazon 450W bifacial 2-pack (Callsun Store) for the $699.99 coupon price, N-Type 16BB / 25% efficiency / anti-shade dual-module specs, and 4.8-star sample size.
Aptos Solar 460W DNA-120-MF10-460W for the more durable panel alternative, 460W output, 21.26% efficiency, 1500V max system voltage, and 30-year product / power warranty note.
Pjerjzn 1000V 60A PV disconnect switch for the Callsun-focused PV service disconnect.
Emporia Barn 1-day circuit CSV (152 days) for measured per-circuit daily kWh averages, the May+June recent heat-pump view, and the critical-load subtotal used in the current model.
Emporia Barn 1-hour circuit CSV for measured hourly peak kW per circuit, including the May+June heat-pump peak of 3.13 kW and the full-file winter stress peak of 7.63 kW.
Emporia Barn 1-minute circuit CSV for the 121W median / 145W avg / 50W minimum phantom-load baseline used in the charge-under-load math.