A optisizer alternative for European battery studies
If optisizer doesn't fit your sites or your budget: what Zorowatt does differently, what it costs per year and how to move a site over.
optisizer (Switzerland) is a web tool that sizes PV and batteries from a load profile, for peak shaving and self-consumption, licensed per project or per year, with white-label and an API as paid extras. Zorowatt sizes the battery against the site's rebuilt bill under sourced Dutch, German and Romanian tariffs. (optisizer.ch)
Five reasons consultants pick it.
- 01
The bill is checked against the invoices
Zorowatt rebuilds the bill from the meter data and sets it against each invoice, line by line, before it sizes anything. None of the tools we compared says it does this (checked 30 October 2026).
- 02
Dutch, German and Romanian tariffs, with sources
The 2026 tariffs of Liander, Stedin, Enexis, NEW Netz, Netze BW, RheinNetz and the Romanian ANRE zones are built in, each linked to its source. US tools leave European tariffs to you, in dollars.
- 03
Batteries from any maker
A database of 44 commercial products, every spec with its source. The free tools of Sungrow, SMA, Huawei and Victron size their own hardware only.
- 04
Prices on the page, from €0
A free analysis and free tools that need no account; Starter at €49 a month. Furo, Tibo, Gridcog and Energy Toolbase show no price before a call.
- 05
In the browser, in your language
A year of quarter-hours is simulated in about a second, with nothing to install, in English, Dutch, German and Romanian. HOMER, PVsyst and PV*SOL run on Windows.
Price per year
- optisizer
- Pro €1,900 a year for 10 projects; Basic €290 per project
- Zorowatt
- Starter €588 a year (€348 at the founding price) · Pro €1,788 a year for 3 seats · single analyses €15
As each vendor's page states it; prices in other currencies are not converted.
How to switch
Upload the load profile you used in optisizer as CSV or Excel.
- Upload the site's meter data to the free data checker or the Workspace: every assumption made reading the file is listed.
- Pick the site's tariff and enter the invoices: the bill check shows whether the baseline matches before anything is sized.
- Size the battery, compare it with your earlier study, and send the client the PDF report.
- When to pick optisizer
- Pick optisizer if you sell in Switzerland or Germany and want load modelling for EV fleets, priced per project.
- When to pick Zorowatt
- Pick Zorowatt if you want the white-label report included in Pro, the bill checked against the invoices, Dutch and Romanian tariffs, and a lower price per analysis.
Facts about the other tool read on 2026-10-30 from the pages linked in each cell. Prices and features change; check the vendor's page before you rely on one.
| Feature | Zorowatt | optisizer |
|---|---|---|
| Price | Free €0 · Starter €49 / month · Pro €149 / month · Enterprise on request | Basic €290 per project; Pro €1,900 a year (10 projects); Premium €5,900 a year (100); Enterprise €9,900 a year (unlimited); excl. VAT, billed annuallyoptisizer.ch · 2026-10-30 |
| Meter data import and checks | 15-minute or hourly data from CSV, Excel, German MSCONS or Green Button files, or a year of values with no dates; gaps, duplicates, daylight saving time and kW / kWh mix-ups flagged, never filled silently | The load profile is the basis of every calculation; a load-profile modeller adds EV charging and fleetsoptisizer.ch · 2026-10-30 |
| Tariffs | Versioned 2026 tariffs, each with its source: Netherlands (Liander, Stedin, Enexis, plus the ACM 2028 draft as a scenario), Germany (NEW Netz, Netze BW, RheinNetz, levies and Stromsteuer), Romania (ANRE zones). Any other country: a generic template where you enter the rates | Purchase and feed-in prices; Dutch and Romanian tariffs not mentionedoptisizer.ch · 2026-10-30 |
| Battery dispatch | Rule-based, with the optimal (LP) dispatch as the upper bound; every saving is billed by the same bill engine | Peak-shaving and self-consumption sizingoptisizer.ch · 2026-10-30 |
| Financials | NPV, IRR and payback, with degradation | Paybackoptisizer.ch · 2026-10-30 |
| Client report | PDF report for the client; white-label on Pro | PDF reports per module; a brand-free report costs €1,000 extra, custom colours €500optisizer.ch · 2026-10-30 |
| Try before buying | First site analysis free, no card | 30-day free trial and a free consultationoptisizer.ch · 2026-10-30 |
| Languages | Website, free tools, Workspace and PDF report in English, Dutch, German and Romanian | German (site)optisizer.ch · 2026-10-30 |
| API | No API for customers yet | Light API as an add-on, €6,000optisizer.ch · 2026-10-30 |
In short
optisizer prices by project volume and sells white-label (€500–1,000) and an API (€6,000) as extras. Zorowatt's Starter costs €588 a year for up to 36 analyses, single analyses cost €15, and Pro includes the white-label report. optisizer's load modeller for EV fleets goes further than Zorowatt's added-load block.
Try it on your own file first
Both tools run in the browser with no account; the file is not uploaded.
Meter data checker
Gaps, duplicates, daylight saving time, kW vs kWh and coverage in a meter export, before the study starts. No account, nothing uploaded.
Peak-shaving battery calculator
Battery size and payback for cutting a site's peak charges — from four numbers or your own load profile. No account, nothing uploaded.
Looking for a optisizer alternative?
Zorowatt runs in the browser, reads the site's own meter data and rebuilds its bill before it sizes anything.
Switching?
Bring a site you already studied: upload its meter data and bills, and set the result next to your old one.