LELABSINES
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Water reserve and
coverage of the need

Pumping follows the solar resource. The reserve stores the water produced and makes it possible to carry part of that production over to the less favourable days.

What the block measures

LE LAB simulates the production and the reserve level day by day over the weather history available for the site. The results describe that history and the configuration studied; they are not a guarantee for the years to come.

Covered dayThe daily need is served in full.
Incomplete dayPart of the need is not served.
Day below 20%The text of the block counts the days that “fall below 20 %” of the need.
Not modelled automatically. Leaks, evaporation, a consumption different from the need entered or another water inflow must be brought into the analysis of the project.
Three possible readings

The choice at step 6 determines the result

An existing reserve is entered

Ticking “I already have a water reserve” and entering its volume. The block assesses this capacity in the configuration studied.

Main indicatorAverage number of days covered over a year.
WarningFlags coverage insufficient for the criteria of the block.
Unfavourable episodeHistorical period during which the level of service is the most constrained.
Autonomy and water reserve block assessing an existing reserve with days covered, warning and monthly chart.

The reserve has to be sized PRO

Ticking “help me size it”. The result block is then titled “Size your water reserve” and offers two reference points:

  • Recommended volume: coverage target defined by the application on the simulated history.
  • Volume to cover everything: capacity that covers every day of the history studied.

These two volumes are sizing reference points. The final choice depends on the use, the space, the civil works, the water quality and the level of service sought.

Size your water reserve block with recommended volume, volume to cover the whole history and monthly chart.

No reserve is declared

The result block is titled “Coverage of the need”. It presents the coverage obtained at the pace of the sun, without water storage, states the number of days fully covered and shows the indicative effect of larger solar arrays. Its summary sentence states the number of days that “fall below 20 %” of the need.

This reading makes it possible to determine whether a reserve should be studied. It does not mean that a reserve volume has already been chosen.

Coverage of the need block without a reserve, with the number of days covered and a monthly chart of incomplete days.

Reading the incomplete days per month

Each bar represents the average number of incomplete days in the month. The decimals come from the average over several years: they do not describe a precise fraction of a day to come.

The associated table gives the figures. An identical annual total can hide two different situations: a few isolated days or one concentrated unfavourable period.

Chart and table of incomplete days month by month for a declared water reserve.

Checks before settling on a volume

  • The daily need and its seasonality are confirmed.
  • The usable volume is distinguished from the geometric volume of the structure.
  • Losses, additional uses and external inflows are examined.
  • The material, the water quality and the sanitary conditions are compatible.
  • The result is presented as a historical simulation, not as a guarantee.
Change the reserve at step 6Help centre