BESS quote comparison sheet
Enter up to five supplier quotations and this sheet converts each one to a comparable USD per usable kWh, then lists the scope items each quote leaves out. A low $/kWh is usually a scope difference, not a better price: the tool makes that difference visible before you shortlist anyone. It runs entirely in your browser; no data is sent or stored.
What the sheet normalises
Ask five suppliers for a 100 kWh cabinet and you will usually receive five documents that cannot be ranked. One includes the PCS, another assumes you already have an inverter, one quotes EXW and another DDP, and the capacities may be nameplate rather than usable. Procurement guides warn about this repeatedly, but a warning does not help when the quotes are already on your desk. The table below turns those warnings into fields you can fill in.
| Field | What to enter | Why it changes the comparison |
|---|---|---|
| Quoted price | Total USD figure from the commercial offer, before tax | Must be the same scope for every row, or the ranking is meaningless |
| Nameplate kWh | Capacity printed on the datasheet | Not the energy you can dispatch |
| Depth of discharge | DoD percentage the supplier guarantees, typically 90–95% for LFP | Usable kWh = nameplate x DoD |
| PCS included | Whether the bidirectional inverter is in the price | Frequently the largest single omission |
| BOS and installation | Cabling, protection, HVAC, fire suppression, commissioning, SAT | Soft costs can reach 15–30% of project cost |
| Freight and duties | Whether the price is DDP or excludes shipping, insurance and import | Can exceed the unit-price gap between two bids |
| Warranty | Years offered, plus the throughput or cycle cap in the small print | Determines lifetime cost, not the initial price |
Comparison sheet
Three example rows are pre-filled. Replace them with your own figures, add up to five suppliers, then press Normalise quotes. Use Download CSV to attach the result to an internal approval or send it with your enquiry.
| Supplier | Price (USD) | Nameplate kWh | DoD % | PCS incl. | BOS / install incl. | Freight / duties incl. | Warranty (y) |
|---|
All calculation happens locally in this page. Nothing is transmitted to VoltraSys or any third party.
How to read the result
In the pre-filled example, Supplier C shows the lowest USD per usable kWh because its 112 kWh nameplate figure is divided into a price that excludes the PCS and installation. Supplier B looks the most expensive but includes BOS and commissioning. The correct next step is not to pick the top row: it is to ask A and C for the missing scope priced as options, then re-run the sheet with all three on a DDP-equivalent basis. A ranking produced before that step is a ranking of documents, not of systems.
Note also what the sheet deliberately does not do. It does not model degradation, augmentation, round-trip efficiency losses, demand-charge savings or payback. Those belong in a financial model, and a financial model built on inconsistent scope inputs will be precisely wrong. Scope alignment comes first.
Use it before and after the RFQ
Use the field list above as a response template when you write the RFQ: ask every supplier to answer the same columns, with a guaranteed value, a test method and a supporting document for each. Then paste the returned numbers into this sheet. The usable versus nameplate explainer covers the capacity question in more detail, and the 50–100 kWh system guide sets out the configurations these quotes typically describe.
Frequently asked questions
Is USD per usable kWh a fair final ranking?
No. It is the first normalisation step, not a purchase decision. It removes capacity-definition differences, but it cannot price a missing PCS, a weaker warranty or a different Incoterm. Use the scope-gap column to decide what must be quoted as an option before any ranking is treated as final.
What if a supplier will not state usable capacity?
Treat that as a scope exception. Ask for the guaranteed usable energy at beginning of life and at the end of the warranty term, the DoD assumption behind each figure, and the test method. If the answer is unavailable in writing, the bid cannot be normalised and should not be shortlisted on price alone.
Does VoltraSys receive the figures I enter?
No. The calculation runs in your browser and no form submission is involved. The CSV is generated locally. If you want an engineer to review the quotations, send them through the project brief form and we will return a written comparison with every assumption listed.
This sheet provides a planning estimate only and is not engineering, financial, legal or fire-protection advice. Codes, grid-connection rules and certification requirements are set locally; the authority having jurisdiction and your grid operator determine what applies at your site. Final scope and documents must be confirmed per project with the supplier.
