From study to signed project: a sales sequence for installers

Why storage is the line that gets cut

A UK installer writing in POWER Magazine in September 2026 describes solar clearing the client's hurdle rate on its own while storage is removed to make the numbers work; in his order book 2 of 16 jobs above £30,000 included storage, a small sample as he notes. His advice: size the battery against the site's half-hourly demand and quote it as a separate line with its own business case (POWER, 23 Sep 2026). SolarPower Europe names the lack of standard business models — every site a bespoke case, with higher transaction costs — as a structural barrier for C&I storage (SolarPower Europe 2026).

1. Screen the site on its invoices

• Triggers worth a study: a high charge per kW (Germany above 2,500 full-load hours), a connection on a waiting list or close to its limit (the Netherlands), solar export with evening imports, new EV chargers or heat pumps, a dynamic contract.
• A first number from four invoice values in the free peak-shaving calculator tells you whether it is worth asking for data. Say it is a screen, not a result.

2. Ask for the data early

Interval data can take longer to get than the study takes to run, and gathering 12 months of bills can be daunting for the client, as one software vendor puts it (Energy Toolbase blog, 2018). Send the request in What to ask your client for before a battery study on the first call.

3. Check the data and rebuild the bill

Run the file through the free meter data checker, then rebuild the bill and reconcile it with the invoices. A billing error found here is a finding that earns the client's attention before the battery is discussed — and a baseline the finance reader can trust. See Reading the C&I bill and rebuilding it from the meter data.

4. Size on the client's demand, with the expected case

• Size on the 15-minute load and the solar together, not on the solar export alone.
• Headline the rule-based expected case; show the perfect-foresight result only as the upper bound.
• If the battery does not pay, say so, and say what would have to change. See Rule-based vs optimal dispatch.

5. Quote the battery as its own line

Bundled into a solar quote, a weak battery hides until the CFO removes it. Quoted separately — size in usable kWh, AC power and efficiency, cost and scope, savings by bill line, payback and NPV, warranty terms — it either stands or it does not.

6. Present the sensitivities before they are asked for

• The two or three changes that would make the case fail — installed cost, savings, discount rate — and the break-even values. In the illustrative example in NPV, IRR and payback for a C&I battery, raising the cost from €450 to €536 per kWh turns an NPV of about +€25,550 into about −€10,953.
• The tariff changes ahead, as scenarios: the Dutch 2028 draft, the German 2029 reform.
• The one-page summary a finance reader expects is in What makes a battery report survive the CFO.

7. After signing: check the first year

• Compare each month's invoice after commissioning with the study's battery case. Differences have the same causes as in step 3: tariff version, data, dispatch.
• Feed what you learn back into the next study: the controller's real threshold and reserve, the auxiliary load, the real efficiency.
• A client who sees the first year match the study is the reference for the next site.

How many studies per signed project?

No data was found. Zorowatt's market research assumed 3–5 feasibility studies per signed project for its own market sizing, and flagged the assumption as unvalidated. Track your own ratio; it is the number that tells you what a study is worth to your business.

The Workspace produces the pieces of this sequence — data check, rebuilt bill, sizing, expected case and upper bound, sensitivities and the report. Your first site analysis is free.

Related guides

• What makes a battery report survive the CFO
• Pricing a battery feasibility study
• Why your study and the vendor's quote disagree

Sources

• POWER Magazine, The commercial storage gap is not technical, it is what survives capital approval, 23 Sep 2026
• SolarPower Europe, European Battery Market Outlook 2026–2030
• Energy Toolbase, keeping up with utility rates (vendor blog, 2018)

Last checked: 2026-10-30. Every figure in this guide comes from the source linked next to it, with the retrieval date Zorowatt's research recorded (28–30 October 2026), or from arithmetic shown step by step. The NPV figures are from the illustrative example in the NPV guide; the 3–5 studies per project is an unvalidated assumption.