Small wind / Buyer questions
Application integration
Should all electricity used during reverse-osmosis startup be counted as useful water production?
The short answer
Electricity consumed during startup remains real consumption, but it should not all be assigned to accepted water production. Flushing, pressurization and any required product diversion can consume energy before useful permeate is available. Compare complete operating sequences using the owner's accepted-water boundary, without inventing a water-quality criterion or assuming every litre produced is usable.
Identify the startup and release states
Obtain the RO plant's actual operating sequence and product-release requirements. DuPont's FilmTec manual includes startup and diversion considerations, illustrating why membrane operation and accepted water delivery are distinct. Apply only the selected plant's instructions. This page does not supply flushing settings, pressure ramps, chemical doses or permission to release water for any particular use.
Use accepted volume as the denominator
Hypothetically, a complete run uses 12 kWh and delivers 3 cubic metres accepted by the owner. Its input intensity is 4 kWh per accepted cubic metre. Counting a diverted startup volume in the denominator would misstate that accepted service. The numbers are illustrative and include no assumption about actual RO efficiency. Keep flush and rejected-water quantities visible in a separate water balance.
If the owner rejects part of a run's permeate, retain both its water quantity and energy. Removing unsuccessful production from both accounts can falsely improve the reported intensity of the remaining accepted output.
Evaluate repeated wind-related starts
A schedule with more starts can have a different accepted-water yield and auxiliary duty from one longer supported run. Model complete approved cycles rather than treating all input as immediate proportional product output. Include the supply needed to finish a required sequence when wind falls. The enquiry should contain startup states, accepted production windows and measured electrical input, with process acceptance remaining with the treatment owner. A wind package cannot guarantee water quality, membrane compatibility or a direct electrical connection from these general principles.
Sources
Examples are illustrative. Confirm product-specific performance, compatibility and supply scope in the applicable documents.