Electricity Bills and Load Profiles: What Solar Buyers Should Prepare

An electricity bill is a useful starting point for a solar assessment, but the amount payable does not describe when a factory uses power. A daytime production unit, a night-shift operation and a seasonal facility can have different requirements even when their annual electricity expenditure is similar.

Preparing a clear data pack helps the assessment team distinguish measured consumption from assumptions. It also makes later design discussions easier: everyone can refer to the same meter, period and operating conditions.

Keep energy, demand and cost separate

Electricity consumed over a period is commonly recorded in kilowatt-hours, or kWh. Power at a particular time is expressed in kilowatts, or kW. Bills may also include demand values expressed in kVA and other charges. Copy the units exactly rather than treating these measures as interchangeable.

A rupee total combines the consumption pattern with the applicable billing structure. Dividing that total by an assumed tariff is not a substitute for collecting the actual billed units and demand information. Ask your electrical or commercial team to explain unfamiliar bill entries.

Build one organised information pack

As a practical starting request, gather a complete recent year of available bills and interval data, if accessible. A year can reveal seasonal operations, although the assessor may need a different or longer period. Keep gaps visible and explain any recent change that makes the historical period unrepresentative.

Explain what the load profile represents

A load profile records electricity demand across time intervals. Before forwarding a spreadsheet, identify the facility and meter it represents. State whether the values are measured demand, energy within each interval or cumulative meter readings; these require different handling.

Confirm the time zone and whether timestamps mark the start or end of an interval. Note missing records, duplicated timestamps and periods when the meter was changed. Preserve the original export alongside any cleaned version so that adjustments can be checked.

The REopt user manual distinguishes actual custom interval loads from modelled profiles. That distinction is useful beyond any one modelling tool: an assumed profile should remain labelled as assumed, rather than being presented as your facility’s measured behaviour.

Add the operational explanation numbers cannot supply

Ask production colleagues to annotate exceptional periods. A low-consumption month may reflect maintenance, a holiday shutdown or reduced orders. A recent increase could be temporary rather than a permanent baseline. The purpose is to give the assessor context, not to remove inconvenient observations.

For a campus with several meters, create a small meter map. Identify which buildings and processes sit behind each connection and where any existing generation is measured. Avoid combining meters into one total before the proposed electrical arrangement has been assessed.

Use a short data-quality review

• Check that filenames identify the site, meter and covered period.
• Compare monthly totals with the corresponding bills and flag unexplained differences.
• Identify whether gaps were left blank, estimated or replaced with another period.
• Separate confirmed expansion plans from possibilities under discussion.
• Share records through an agreed channel with the assessment team.

If interval records are unavailable, say so. A preliminary discussion can still identify the next information needed. The resulting assumptions should be documented and revisited before conclusions are treated as sufficiently detailed for a project decision.

Turn the pack into a better assessment brief

List the questions you need answered: which operating periods matter, what site constraints need inspection and what additional measurements are required. Avoid asking a preliminary data review to produce a guaranteed generation or savings figure.

Explore Deon’s solar solutions to identify the relevant project scope. You can then start an assessment discussion with the available records and a clear list of missing information.

Further reading

The Department of Energy’s renewable energy tools directory describes modelling resources. Estimates from any tool depend on inputs; they do not replace a site-specific assessment or the applicable Indian utility requirements.