Before writing a BOQ: quantify the waste and processing scope
First confirm daily source-segregated organic waste in kg/day, peak-day variation, hours of operation, rejected material fraction and the required output pathway. A “100 kg/day” nameplate is not sufficient without feedstock assumptions and shift definitions.
- Record seven days of actual wet-waste weights, including highest day.
- Confirm whether shredder, collection bins, curing trays and ventilation are within supplier scope.
- Separate commissioning, unloading, electrical connection and civil platform responsibilities.
Technical OWC tender comparison sheet
Use the same field names for every vendor. Require model-specific declarations rather than a generic “fully automatic” claim.
| Tender field | What to request from each bidder |
|---|---|
| Input & throughput | Rated kg/day, working hours, acceptable feedstock and batch limits |
| Waste-contact material | Actual SS grade and sheet thickness for wetted parts |
| Shredder & drive | Motor power, gearbox reduction, blades and overload protection |
| Heating and controls | Connected load, heater configuration, control logic and protection |
| Power & utilities | Supply voltage, phase, connected/operating load, earthing |
| Output handling | Discharge, curing area, expected output characteristics |
| Site scope | Footprint, safe access, unloading, transport and civil interface |
| Service & acceptance | Installation, operator training, demonstration, warranty and exclusions |
Draft acceptance tests that can actually be witnessed
An acceptance plan should identify incoming waste weight and composition, pre-segregation, operating duration, run logs, safety trips, post-run observations and agreed operator training. Do not write an unverified “100% odour-free” or “instant mature compost” promise into the purchase specification.
- Inspect nameplate, electrical diagram and installed protections.
- Record a representative test feed and actual energy readings where agreed.
- Ask for signed installation/commissioning and training documentation.
- Document the difference between machine discharge and cured, usable compost.
Commercial BOQ: hidden exclusions to clarify
Separate machine supply price from GST, transport, loading/unloading, civil platform, shed, panel cabling, earthing, exhaust/ventilation, curing infrastructure, installation and service visits. Ask whether spare parts, labour and travel are included in the warranty/AMC.
Tender-grade specification should support functional comparability, not lock bidders to one proprietary dimension or controller.
Vendor evaluation and technical clarifications
Use a two-stage comparison: first mandatory functional compliance, then evaluated price and service scope. Seek documentary evidence of similar work where available and verify project claims with references. For model comparison, also see our 50 vs 100 kg OWC guide and installation requirements.
When the question becomes model-specific
This guide stays general. For exact figures on a particular machine, these published pages from the COMPOSTO range are the reference.
Want a second opinion on your site?
Send your site type, city and measured daily wet waste. The COMPOSTO technical team replies with the capacity and checks worth doing next.