Worked method / Compare
Use the comparison model to explain your energy buying choice
A completed comparison should show where every pound comes from, which assumptions are uncertain and why the recommendation remains suitable. Follow the fictional dated example, then replace its inputs with your own evidence.
Begin with one consistent requirement
The online comparison model and editable Excel workbook begin with two offers for a fictional school. Each covers the same two meters, demand and dates. The requirement is 100,000 kWh in each model year, allocated 60% to Meter 1 and 40% to Meter 2. For illustration, 2027 consumption is split equally between January–June and July–December. This is an invented demand profile, not a recommended assumption for a real school.
Separate periods matter. The model derives 181 days for January–June 2027, 184 for July–December and 366 for the full 2028 leap year. It multiplies daily charges by the actual inclusive days and uses the kWh entered for each period. It does not automatically allocate annual demand across shorter periods. A school should use its measured profile or a justified forecast.
Translate the offer into component costs
Every rate and tax assumption in this example is a teaching input. Actual VAT depends on the supply, use, customer, dates and relevant rules. The model does not decide relief or recovery eligibility. A direct advisory fee has its own VAT field. Its VAT treatment is entered separately from that of the electricity supply. Charges needing a different treatment or recovery allocation can be entered on separate zero-consumption lines.
| Entered component | Fictional offer A | Fictional offer B |
|---|---|---|
| Quoted unit rate | 25.0p/kWh | 24.0p/kWh |
| Broker uplift | 0.2p/kWh, already in rate | 0.3p/kWh, additional to rate |
| Total daily standing charges across both meters | £2/day | £4/day |
| Direct TPI service fee | £300 per model year | £500 per model year |
| Variable-charge exposure | None in the starting illustration | Marked as exposed; base increment is zero |
| Supply VAT assumption | 0% for first half of 2027; 5% afterwards | Same assumption |
| Direct TPI fee VAT assumption | 20% | 20% |
Reconcile the starting result
The gross difference is £544.50 under these inputs. The model does not then add the disclosed remuneration again. For A, its uplift is inside the rate and its direct fee is already inside the period charges. For B, the uplift is added once to the quoted rate and the direct fee is included once. Full remuneration is visible without inflating the bill.
The worked maintained-school dossier uses two normalised 365-day years and a constant illustrative 5% supply VAT rate, with 20% on direct TPI fees. Its figures therefore differ from this dated model. Both examples state their assumptions. Do not take a difference produced by different dates and tax schedules to be a supplier saving.
| Two-year dated result | A | B |
|---|---|---|
| Pre-VAT cost | £52,062.00 | £52,524.00 |
| VAT under the entered component assumptions | £2,050.00 | £2,132.50 |
| Gross modelled cost | £54,112.00 | £54,656.50 |
| Broker commission disclosed within those costs | £400.00 | £600.00 |
| Direct TPI service fees already included | £600.00 | £1,000.00 |
| Total disclosed TPI remuneration before VAT | £1,000.00 | £1,600.00 |
Run a sensitivity test, then explain it
Select the higher-use scenario to increase all entered consumption by 20% and add 1.5p/kWh only to lines marked as variable. Standing charges and fixed period fees remain unchanged. The result illustrates exposure to two stated changes; it is not a forecast or a statistical worst case.
The lower-use scenario reduces consumption by 20% while retaining the same additional variable-charge assumption. This can help identify the share of cost that does not fall with consumption. The separate clause playbook and school dossiers show why a volume-tolerance or take-or-pay condition can create an additional liability. Those supplier-specific clauses are not automatically priced by the cost model.
If a quoted charge is missing, leave the field blank and mark the line incomplete. The tool reports a known subtotal and a gap; it should not suggest that an unknown cost is zero. If dates, meter coverage or entered demand differ between offers, the comparison is flagged. Resolve the difference or explain the normalisation in the decision paper.
For a linked climate or estate project, retain separately identified on-time, delayed and no-project demand cases from the approved requirement. Use the relevant meter and period rather than applying a blanket percentage where the project changes the demand profile. Check the actual supplier baseline, tolerance boundary, adjustment formula and change provisions against each case.
Record supplier-specific volume liabilities or agreed amendments alongside the model with their clause reference, calculation, owner and status. The model does not calculate those terms automatically. An unexplained formula remains unresolved; an unsupported zero would make the comparison misleading.
Keep cost, cash and valuation separate
- Gross payable cost shows the modelled bill before any assumed VAT recovery.
- Net economic cost subtracts only the recoverable share entered and justified by the finance team.
- A refundable deposit is displayed as an additional cash requirement. It is not automatically treated as an expense or added to procurement value.
- Whole-term procurement valuation needs a separately documented maximum expected amount, including VAT and relevant options or extensions. A scenario total does not by itself establish that amount.
- An offer covering fewer years leaves later replacement cost unknown. The model flags unequal periods rather than inventing a future renewal price.
Write the decision in four short parts
Use the notes alongside the model to record price, terms, service and risk. Identify the evidence behind each judgement: a supplier's written cost schedule, a clause, a named service commitment or a dated benchmark. Explain why a rejected offer is unsuitable or less attractive, including where it could become preferable under different assumptions.
Return the supply comparison to the project appraisal owner where a climate or estate measure affects demand. Identify which import charges are avoided, which standing, capacity or service costs continue, and any supported volume or change cost. Do not value every reduced kWh at the average whole-bill price. Explain whether the actual offer changes the project’s revenue benefit or timing and whether its separate appraisal and approval need refreshing.
For academy alternatives, retain the required approved-route comparison and governance evidence. For maintained schools, connect the recommendation to the actual LA scheme and authority. For independent schools, use the appropriate company or charity decision process. The editable transaction pack supplies completed specimens and blank documents; the route playbooks explain the procedural steps.
Save the input file, scenario, source offers, clause review and approval record together. The browser model exports its inputs and results locally. Its entries are not automatically stored or submitted. The Excel workbook provides a separate editable calculation record, with its own assumptions and verification notes.