Estimate energy separately for every operating mode: average electrical input in kW multiplied by hours gives kWh. Add the modes, then apply the actual tariff and any demand or fixed charges. Installed motor ratings alone are not the electricity bill.
Collect the right inputs before calculating
List the equipment groups used in each mode: fountain pumps, lighting, filtration, treatment, control cabinets, audio and projection where present. Record their operating times. Include equipment that runs when the visible show is off; otherwise the estimate will omit part of the bill.
Use measured average electrical input for a representative mode where available. If a supplier provides a forecast instead, ask for its assumptions and label it as an estimate. A motor’s mechanical output rating is not necessarily the electrical input drawn at the supply.
Separate effects from their electrical demand
A photograph shows appearance, not consumption. Two displays with a similar footprint may use different jet heights, duty cycles and multimedia equipment. A variable-speed system also should not be assumed to consume the installed maximum continuously.
Worked example with explicitly assumed values
The following figures are arithmetic assumptions, not a Lishi project, equipment specification or local tariff. Replace all of them with your operating schedule and confirmed measurements.
| Mode | Assumed average input | Hours per day | Energy per day |
|---|---|---|---|
| Show mode, including equipment active in that mode | 18 kW | 2 h | 36 kWh |
| Remaining circulation-only period, not overlapping the show | 3 kW | 6 h | 18 kWh |
| Other standby period, not overlapping the modes above | 0.2 kW | 16 h | 3.2 kWh |
| Total | Different modes | 24 h | 57.2 kWh |
For 30 identical days: 57.2 × 30 = 1,716 kWh. At an assumed flat tariff of 0.15 currency units per kWh, the energy charge is 257.40 currency units. This excludes demand charges, taxes and fixed fees. Avoid double-counting filtration if it is already included in the show-mode input.
Match the calculation to the actual tariff
Obtain the site’s tariff and billing structure. If prices vary by time of use, split the energy into the relevant periods. Where a demand charge applies, obtain advice on how the site’s billed peak is determined rather than multiplying total installed power by an arbitrary monthly rate.
Keep the energy charge separate from water, treatment supplies, labour, servicing, repairs and software costs. The whole-project budget guide covers the wider quotation scope; this page focuses on electricity.
Compare two operating plans fairly
Keep the required audience experience and water-management duties visible when comparing alternatives. Consider show length, operating days, effect scheduling and lighting periods. Do not turn off essential treatment, protection or circulation functions solely to achieve a lower estimate.
- Ask for the input-power assumptions for each mode.
- Check whether auxiliary and standby consumption is included.
- Compare normal and seasonal operating schedules.
- Record the tariff, measurement period and items excluded.
Verify the forecast after handover
Ask a qualified person to arrange appropriate metering; do not open a panel to take measurements yourself. Compare a representative operating period with the forecast using the same programme and schedule. Investigate discrepancies alongside the equipment record rather than treating a single reading as a full annual estimate.
Reference for units: the US Department of Energy glossary distinguishes energy in kWh from power. Its definitions support the arithmetic, not the assumed equipment values or tariff above.