The Half-Hourly Data You Need Before Requesting a Solar Quote

Why HH data matters

Most commercial solar quotes you receive in 2026 are built from annual kWh and sector rule-of-thumb assumptions. That approach gets within 25-40% of the right system size. Half-hourly consumption data — your actual electrical usage in 30-minute blocks across 12 months — gets within 3-5%. The difference matters because oversizing wastes capex on kWh that get exported at low SEG rates instead of self-consumed at full grid rate; undersizing leaves money on the table.

How to pull HH data

1. Confirm you are HH-metered — most UK commercial sites above 100kW peak demand are mandatorily HH-metered. Your bill should say "HH" or "Half Hourly" somewhere.
2. Request from your supplier — most large commercial suppliers (EDF Energy Business, npower Business, Drax, SSE Business, Engie) will email a CSV inside 48 hours of request.
3. Alternative — your Meter Operator (MOP) — your MOP holds raw HH data and can release it. Your bill lists the MOP code.
4. Let KMM pull it on your behalf — we have signed authority arrangements with most major commercial suppliers and can pull HH data inside a week.

What we model from HH data

• True annual self-consumption ratio for any proposed system size
• Battery sizing — exact capacity to lift self-consumption from baseline to 85%+
• Peak-shaving potential — DUoS/TNUoS reduction opportunity
• Time-of-use arbitrage if a relevant tariff is available
• Year-by-year cash model with realistic generation overlap (not averaged)

What if you don't have HH data

For smaller commercial sites that aren't HH-metered, we work from annual kWh and sector-typical load profiles. The sizing is less precise but within 8-15% of optimal for simple commercial operations. For complex operations (multi-shift, refrigeration, peak-driven), we strongly recommend a temporary clamp-meter logger for 4-6 weeks — costs around £200 and we credit it against your install.

Bottom line

If you can pull 12 months of HH data before your survey, do. It produces a materially better proposal. If you can't, that's fine — we have workarounds. But ask any installer giving you a commercial solar quote whether they've used your HH data or rule-of-thumb assumptions, and if they say rule of thumb, ask why.