Direct answer

A usable residential energy-storage quote requires more than the requested number of kilowatt-hours. The supplier needs the destination market, grid topology, electrical service, load profile, backup scope, peak and motor-starting demand, PV and inverter details, site conditions, operating objectives, approval requirements, quantity and schedule.

With only “I need a 20 kWh battery,” a supplier can provide a budgetary hardware price. It cannot responsibly confirm runtime, whole-home capability, inverter compatibility, permit readiness or final installed scope.

What is a residential ESS RFQ?

A residential energy storage system request for quotation, or RFQ, is a structured project package used to obtain a technical and commercial proposal from a battery manufacturer, inverter supplier or system provider.

The RFQ should allow the supplier to answer four separate questions:

1. How much energy is required?

2. How much continuous and starting power is required?

3. What system architecture fits the existing electrical and solar equipment?

4. What documentation, approvals, services and commercial terms are required for the target market?

The minimum project dataset

1. Market and application

Provide:

• installation country and state/province or island;

• residential use case: backup, self-consumption, time-of-use, off-grid or hybrid;

• new solar-plus-storage project or retrofit;

• end-customer project, installer standard offering or distributor stocking program.

The market determines voltage, frequency, code, utility, documentation and commercial requirements. A configuration suitable for one country should not be assumed suitable for another.

2. Grid and electrical service

Provide:

• nominal grid voltage;

• frequency;

• single-phase, split-phase or three-phase service;

• main-service rating;

• main-panel and subpanel information;

• neutral and grounding arrangement where relevant;

• generator connection, if any;

• utility interconnection or zero-export requirement.

Include a one-line diagram for any project beyond an early budgetary request. Photos of labels and panels can support the review, but they do not replace electrical documentation.

3. Energy consumption and load profile

Provide at least 12 months of electricity bills when available. Interval data at 15-, 30- or 60-minute resolution is more useful because monthly totals do not show simultaneous demand.

Record:

• average daily consumption in kWh;

• seasonal high and low usage;

• maximum measured demand where available;

• daytime and nighttime consumption;

• expected future loads such as EV charging, heat pumps or additional air conditioning.

Tesla's public ordering process provides a recognizable example: the customer supplies a utility bill, then site-assessment information is used to develop the system design. See How to Order Powerwall and Powerwall Pre-Installation.

4. Backup-load schedule

Do not write “whole home” without listing the circuits. Divide loads into:

• essential: refrigeration, lighting, communications, controls, medical or security equipment;

• comfort: selected air conditioning, fans, bedroom or living-area circuits;

• deferrable: water heating, laundry, cooking appliances, pumps, pool equipment and EV charging, depending on the project;

• non-backup: loads intentionally excluded during an outage.

For every major load, record rated power, measured running power when available, starting demand, operating hours and whether it can run at the same time as other high-power equipment.

5. Backup objective

State the requirement in operational terms:

• target outage duration;

• minimum loads that must remain available;

• expected starting SOC;

• minimum SOC or reserve policy;

• whether solar is expected to operate and recharge the battery while islanded;

• whether the customer accepts load shedding or scheduling;

• maximum acceptable generator use, if a generator is part of the design.

“Eight hours of backup” is incomplete without the corresponding average load and SOC assumptions.

6. Solar and inverter information

For an existing PV system, provide:

• PV array size in kWp;

• module quantity and model;

• string arrangement where DC coupling is considered;

• inverter manufacturer, exact model and firmware;

• AC- or DC-coupled architecture;

• available battery communication interface;

• export-limit or meter/CT configuration;

• whether the current inverter is intended to remain.

MERITSUN publishes a general multi-brand inverter-compatibility overview, but a project decision must use the current compatibility documentation for the exact battery, inverter and firmware combination.

7. Installation environment

Provide:

• indoor or outdoor location;

• minimum and maximum ambient temperature;

• humidity, salt-air, flood, dust or direct-sun exposure;

• wall or floor construction;

• equipment clearances and available footprint;

• cable-route lengths;

• network availability;

• delivery access and lifting constraints;

• photographs of the proposed battery, inverter and panel locations.

Site conditions can change enclosure, thermal, mounting, routing and labor requirements. The final location must comply with the equipment instructions and local requirements.

8. Approval and documentation requirements

List the exact documents required by the installer, utility or authority having jurisdiction:

• product datasheets and manuals;

• single-line and wiring diagrams;

• model-specific certificates or listings;

• test reports where required;

• labels and warning documentation;

• battery shipping documents;

• commissioning records;

• warranty and service documents.

UL Solutions notes that UL 9540 addresses the ESS as a system, including protection, controls and communications. For U.S. projects, confirm the exact certification scope and local acceptance requirements rather than relying on a generic logo list. See UL Solutions' ESS certification overview.

9. Commercial and channel information

Provide:

• required quantity for pilot and forecast volume;

• project or stocking-order schedule;

• destination and preferred Incoterm;

• packaging or labeling requirements;

• required spare-parts level;

• installer training needs;

• first-line and second-line support responsibilities;

• expected warranty-claim process;

• whether customization is required.

An installer ordering one system and a distributor launching a regional product line require different pricing, documentation and support structures.

Copy-and-paste RFQ template

Company and buyer type:
Installation country/region:
Project type: new build / retrofit / off-grid / grid-connected
Grid voltage, frequency and phase:
Main-service rating:
Average daily energy use:
Interval load data available: yes / no
Critical loads:
Largest continuous loads:
Motor/HVAC starting loads:
Target backup duration:
Expected starting SOC and minimum SOC:
Existing or planned PV capacity:
PV inverter brand, model and firmware:
Preferred architecture: battery-only / hybrid inverter / all-in-one / open
Existing generator or ATS:
Export-limit or utility requirement:
Installation location and temperature range:
Required certifications/approvals:
Quantity and forecast volume:
Delivery destination and target date:
Drawings, bills, panel photos and equipment labels attached:

What each project stage can legitimately produce

A preliminary quote should not be presented as a permit package or final installation design.

Manufacturer, distributor and installer responsibilities

Manufacturer or system supplier

• provide accurate model-specific documentation;

• state operating and expansion limits;

• identify supported communications and compatible configurations;

• provide the agreed battery or system scope;

• define commissioning and escalation channels;

• state warranty terms and evidence requirements.

Distributor

• maintain correct regional product and documentation versions;

• manage inventory, serial tracking and spares;

• coordinate installer access, training and first-line support;

• avoid extending compatibility or approval claims beyond manufacturer evidence.

Installer or EPC

• collect accurate site and load data;

• design the electrical integration and protection;

• confirm local code, permit, utility and AHJ requirements;

• install and commission within the approved documentation;

• record settings, tests, serial numbers and customer handover.

Responsibilities should be assigned in writing before equipment is shipped.

Frequently asked questions

Can I get a quote with only the desired kWh?

You can receive a budgetary battery price, but not a reliable system design or runtime commitment.

Are monthly electricity bills enough?

They are a useful start. Interval data and a circuit-level load schedule are needed to understand simultaneous power and backup behavior.

Why does the supplier need the inverter model and firmware?

Closed-loop communication, charging limits, alarms and commissioning may depend on the exact model and firmware combination.

What if the project does not yet have an inverter?

State that the architecture is open and provide grid, PV, load and backup requirements so the battery and inverter can be evaluated together.

Does “whole-home backup” define the system size?

No. The home service, simultaneous loads, motor starts, energy use, outage duration and load-control strategy still need to be defined.

Why are site photos requested?

They help identify space, access, panel, routing and environmental issues. They do not replace a site survey, one-line diagram or qualified electrical review.

When can a final BOM be issued?

After the architecture, exact models, electrical interfaces, site conditions, approval requirements and commercial scope have been resolved.

What should be recorded at commissioning?

At minimum: equipment models and serial numbers, firmware, communications, protection settings, SOC limits, operating mode, meter/CT direction, charge/discharge tests, outage-transfer behavior where applicable, alarms and customer handover.

Key takeaways

• A kWh request is not a complete residential ESS RFQ.

• Energy, power, integration, site and approval data must be reviewed together.

• A budgetary quote, technical proposal, final BOM and commissioned system are different project states.

• The exact battery/inverter/firmware combination must be verified.

• Clear responsibility boundaries reduce installation and after-sales risk.

Project CTA

Copy the RFQ template above and send the completed project inputs to MERITSUN. If some information is unavailable, mark it as “not yet confirmed.” MERITSUN can then separate the preliminary configuration from the unresolved engineering items and prepare a more useful discussion for your installer, EPC or distribution team.

Related MERITSUN resources

• Existing residential battery sizing guide

• MST-ESS 5000 stackable battery

• 15 kWh Multi-Function Integration Energy System

• Contact MERITSUN