ESS buyer tools
Two quotes for the same 100 kWh system are rarely prices for the same thing. One supplier prices a battery rack, another prices a cabinet with PCS and fire suppression, and a third adds freight and commissioning. Comparing them on headline $/kWh produces the wrong answer before the technical review even starts. The tools here put supplier proposals onto one basis, using fields you can verify from the quotation documents.
Why a normalisation step is necessary
Six fields account for most of the apparent price gap between competing C&I battery offers. None of them is exotic, and all of them should be answerable in writing before a purchase order is raised.
| Field | How suppliers differ | Effect on headline price |
|---|---|---|
| Nameplate vs usable kWh | 100 kWh nameplate at 90% DoD is 90 kWh usable; some quote nameplate, some quote usable | 10% or more of apparent $/kWh |
| PCS / inverter | Included, excluded, or quoted as an optional line | Often the largest single omission |
| BOS, installation, commissioning | Cabling, transformer, HVAC, fire system, civil works, SAT | Soft costs can reach 15–30% of project cost |
| Round-trip efficiency boundary | Measured at the cell, DC terminals, or AC terminals | Changes modelled savings, not the equipment price |
| Warranty basis | Years vs throughput / cycle count; capacity-retention floor | Changes lifetime cost, not the initial quote |
| Incoterms, freight, duties | EXW vs FOB vs DDP; UN38.3 and hazardous-goods documentation | Can exceed the unit-price difference between bids |
Available tools
- Quote comparison sheet — enter up to five supplier quotes, normalise them to $/usable kWh, flag scope gaps, and export the result as CSV.
How these tools are used
Every tool on this site runs in your browser. No email address is required, no data is uploaded, and nothing is stored on our side. If you would rather send us the quotations and have an engineer return a normalised comparison with the assumptions written out, send a project brief instead.
VoltraSys is an engineering and sourcing operation, not a factory. We do not publish list prices or claim manufacturing capacity. These tools exist because the most useful thing an independent party can do at the procurement stage is make the numbers comparable — not add another brochure to the pile.
Related reading
- ESS resources and buyer guides
- ESS supplier RFQ checklist — the 12 items to specify before quotes arrive
- 50–100 kWh industrial battery storage
These tools give planning estimates only. Final configuration, certification documents and commercial scope must be confirmed per project with the supplier and the authority having jurisdiction at the installation site.
