Home systems & sample costs.

Battery-only planning runtime at a steady 2 kW load: approximately 6.0 hours using 80% of rated energy and 94% conversion efficiency, before standby consumption. This is a calculation assumption, not a promised runtime.

Battery-only planning runtime at a steady 2 kW load: approximately 12.0 hours using 80% of rated energy and 94% conversion efficiency, before standby consumption. This is a calculation assumption, not a promised runtime.

Battery-only planning runtime at a steady 2 kW load: approximately 24.1 hours using 80% of rated energy and 94% conversion efficiency, before standby consumption. This is a calculation assumption, not a promised runtime.

Battery-only planning runtime at a steady 2 kW load: approximately 27.8 hours using 80% of rated energy and 94% conversion efficiency, before standby consumption. This is a calculation assumption, not a promised runtime.

Design and price basis

Electrical checks

Mission 435 W modules: Vmp 33.31 V, Voc 39.56 V, Imp 13.07 A, Isc 13.79 A, Voc temperature coefficient −0.25%/°C. At an illustrative −10°C design temperature, an 11-module string has approximately 473.24 V open circuit, below Sol-Ark’s 500 V limit. A 12-module string would be approximately 516.26 V and is not used. Final string sizing must use the actual site minimum temperature and maximum cell temperature.

Two parallel Mission strings produce 26.14 A at maximum power, slightly above the 15K’s 26 A operating limit; that tracker may self-limit. Their STC short-circuit current is 27.58 A, below its 44 A limit. The 5 kW example has one string on each 12K tracker, avoiding its 20 A operating limit. EG4 uses single strings on its 15 A trackers; 13.07 A operating and 13.79 A short circuit are below its 15 A and 19 A limits.

Batteries and BMS

For V16 planning, use the manufacturer’s recommended 125 A charge and 150 A discharge per battery rather than treating the 200 A maximum as the normal setpoint. Apply the lower of bank allowance, inverter limit, cable/protection rating, and the BMS live limits. Two V16 batteries support the 15K’s 275 A battery current limit at no more than 137.5 A discharge per battery under ideal current sharing. Four eVault MAX batteries have 720 A combined continuous nameplate capability; two EG4 inverters are limited to 500 A total. Balanced branch wiring and protection are still required.

Closed-loop operation is required in all examples. Confirm battery firmware, CAN/RS485 protocol, cable pinout, master/slave settings, and the multi-inverter communication arrangement with the manufacturers. A built-in battery BMS alone does not establish successful inverter communication. The specific installed inverter/battery combination must have the required ESS listing and local approval.

MidNite and other accessories

Allow for MidNite MNSPD-600 protection on high-voltage PV circuits, MNSPD-300-AC on 120/240V circuits, and MNSPD-115 on battery circuits where suitable. Quantities and placement depend on independent PV circuits and the manufacturer wiring diagrams; the budget uses a lump-sum allowance. Use listed DC disconnects/branch protection and busbars rated for the actual fault current. No separate MidNite Classic charge controller is needed because these hybrid inverters already include MPPT charging.

What the price covers

Listed prices are a public-retail snapshot checked October 2, 2026. The equipment budgets include roof mounting, rapid shutdown, protected battery wiring/BMS links, AC distribution/bypass, wire/conduit, and grounding. Every row labeled “Allowance” is an estimate, not a verified supplier quote. EG4 18kPV is budgeted at $5,000 each and eVault MAX at $6,500 each pending current written quotes. One dealer marks eVault MAX unavailable; confirm stock, warranty and authorized sourcing before marketing a fixed price.

Installed planning ranges add the stated labor, design/permitting, freight and contingency allowances. They exclude sales tax, structural repairs, service upgrades, long trenching, ground-mount structures/foundations, generator purchase, unusual utility work, and financing. Smart North America’s final sales price should also incorporate its chosen overhead, margin and warranty/service obligations.

Runtime estimates use 80% of rated battery energy and 94% conversion efficiency, before idle draw. Solar yield, whole-home coverage and off-grid autonomy require the home’s load data and a site-specific solar model; no performance guarantee is implied.