Watts Worth It guide

Whole-home backup vs essential-load backup

UK guide to whole-home backup vs essential-load backup, with current official figures, a worked example, practical checks, rules and installer questions.

Illustration showing a split power-cut scene comparing an entire lit house with a house where only lights, fridge and router remain powered

At a glance

Short answer

Whole-home backup vs essential-load backup cannot be judged from one national average; use the figures below as context and rely on a property survey, an itemised quotation and the rules that apply where you live.

What this guide covers

This page brings together whole-home backup vs essential-load backup, solar panels power cut, preparing you to compare written proposals without treating general guidance as a site-specific design.

For whole-home backup vs essential-load backup, separate energy capacity in kWh from power in kW; The first affects how long stored energy may last; the second affects which appliances can run together.

Current reference figures

  • 5 kWh: For whole-home backup vs essential-load backup, energy Saving Trust uses 5 kWh as a typical home-battery example. Official context (accessed 27 September 2026).
  • £4,600: For whole-home backup vs essential-load backup, its September 2026 example price for that battery is about £4,600. Official context (accessed 27 September 2026).
  • 10–12 years: For whole-home backup vs essential-load backup, the same guidance gives a typical battery lifespan of 10 to 12 years. Official context (accessed 27 September 2026).

For whole-home backup vs essential-load backup, these numbers are comparison anchors rather than promised costs, savings or performance; confirm the date, eligibility conditions and property assumptions behind every figure in a quotation.

How to compare proposals

For whole-home backup vs essential-load backup, compare usable capacity, expected losses, operating temperature, warranty throughput, compatible inverters and backup behaviour; A large nominal figure alone does not establish value.

For whole-home backup vs essential-load backup, model at least a winter and summer day using the household’s interval data where available; Check when the battery charges, what demand it can meet and how much energy is likely to remain unused.

Worked household example

A three-bedroom semi-detached household in Leeds is assessing whole-home backup vs essential-load backup, so it records present energy use and asks three suppliers to quote the same scope; one quotation is set aside because access work and commissioning are omitted, a second gives a plausible headline result without its supporting calculation, and the third progresses because its survey, assumptions, exclusions, warranties and responsibilities can be checked line by line.

This whole-home backup vs essential-load backup example does not identify a universally best product; it demonstrates why comparable evidence should influence the decision before the equipment choice does.

UK rules and responsibilities

For whole-home backup vs essential-load backup, check which planning, network, consumer-protection and funding requirements apply in the relevant UK nation; confirm the council, network operator and scheme administrator before signing, and request written cancellation information for a distance or off-premises contract.

Questions to ask

  • What property evidence supports this recommendation?
  • Which calculations determine the proposed specification?
  • What work and permissions are excluded?
  • Which warranties apply, and who handles claims?
  • What commissioning evidence will I receive?
  • Which current standards govern the work?

Independent sources

Last updated .