White paper: voltage optimisation

Voltage Optimisation: Worth a Look, but Not Always a Silver Bullet

Voltage optimisation (VO) often gets talked about as an easy win for energy efficiency – install a unit, save 10%, job done.

In reality, the results can vary quite a lot depending on the site, the electrical load, and how the system is managed.

Most UK sites receive supply voltages of 240-250 V, while much of our equipment is designed to run best around 220-230 V. In principle, VO reduces that excess, cutting waste and lowering consumption. But the impact depends on what’s actually connected.

When it works well

Older or overvolted equipment (e.g. fluorescent lighting, induction motors, refrigeration compressors) can show meaningful savings – often 5-10 %.
Sites with consistent base loads and long operating hours tend to benefit most.
It can also help extend equipment life by reducing electrical stress and heat buildup.

When it may not deliver much

Modern equipment with switch-mode power supplies (LED lighting, IT, variable-speed drives) already regulates its own voltage.
In these cases, VO might show very little reduction – sometimes just 1-2 %, or none at all.
If voltage at the point of connection is already close to 230 V, there’s little excess to trim.

A tool, not a guarantee

Voltage optimisation can absolutely be a useful part of a broader efficiency plan – but it’s not a universal fix.

A quick voltage and load profile assessment usually reveals whether there’s genuine potential. For some sites, it’s a solid investment with measurable savings; for others, the business case just isn’t there.

Like many efficiency technologies, it works best when applied thoughtfully, not automatically.

Is R2G good for your organisation?

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With an average cost-reduction of 26%, we consistently identify substantial savings opportunities for clients.

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From property data and staff insights to business goals and regulatory requirements, we consider every angle to build a plan that truly works for your organisation.