Methodology Change History

2026-08-04

Major methodology overhaul: the comparison tool was replaced by a ground-up rewrite. The previous methodology page is archived verbatim at Electricity Price Comparison Methodology (Archived). Headline changes:

• Tariff-dependent load shifting. The choice of tariff now affects when flexible loads (battery, EV charging, other large shiftable loads) are scheduled: for each tariff structure, movable load is placed into that tariff's cheapest hours before pricing, rather than pricing every tariff against one fixed schedule. This makes comparisons fairer for households with batteries, EVs, solar panels and heat pumps — these households will see the largest changes versus the old tool.
• New synthetic load shape for annual-kWh comparisons. Estimated-consumption comparisons now use a half-hourly load shape built from the Irish 2026 RMDS standard load profile (daily shape and seasonality) combined with UK Power Networks 2011–2014 household data (half-hourly texture and day-to-day volatility), replacing the old flat day/night/peak split (54%/36%/10%). The band-allocation slider was removed as a consequence: you can no longer override the time-of-day split, because the model now derives a full half-hourly shape instead.
• More conservative solar savings. Solar self-consumption is now modelled at sub-half-hour resolution: within a single half-hour you can import a little and export a little at the same time, and the residual export is worth less than avoided imports. The old model assumed all solar produced within a half-hour offset imports, so modelled solar savings are now lower (and more realistic). Inverter clipping is still applied and is now variance-aware; the inverter capacity (default 5.5 kW) is now user-editable under the solar Advanced options.
• Maximum import capacity default changed from 16 kW to 12 kW (the standard domestic connection), with an "Enhanced supply (16 kW MIC)" toggle for homes with an enhanced connection. Households that would previously have been modelled at 16 kW may see reduced modelled battery/EV stacking unless they tick the box.
• Some legacy-only advanced controls were retired (e.g. the current-supplier field and user-set battery/EV schedules) — scheduling is now decided per tariff inside the comparison.

2026-02-21

Added Maximum Import Capacity 12 kW option for throttling EV charging to a total import rate of 12 kW rather than the default 16 kW. Available under "Advanced Options" when the EV slider is set to a non-zero value.