Off-Peak Usage | Guernsey Electricity

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Powering Life in Off-Peak

Use, run and charge electrical appliances between 11pm and 5am to use imported 100% lower-carbon energy. 

Guernsey's electricity load profile

What is 'Peak Demand'?

Peak demand is the time when consumer demand for electricity is at its highest. This is usually around breakfast, lunch and dinner, and is simply because more people are indoors and using electrical equipment to power their lives.

In Guernsey, we import around 60MW of renewable energy from low-carbon sources in Europe. When customers demand more than 60MW of electricity, this must be topped up using diesel generators at the Vale power station. 

Using electricity during these peak times can cause higher greenhouse gas emissions - especially during the colder, darker months - plus increased wear and tear on equipment. Less pressure on the power station means less emissions and less costly maintenance and repair.  

An aerial shot of the vale power station

Want some help reducing your reliance on fossil-fuels? Find out more about our services designed to help islanders get energy smart. 


Home Energy Audits

Here's an example 

In January 2024, the highest demand in Guernsey was reached at 94.2MW in response to the cold winter weather that week. 

As mentioned in the news, Jon Sexton, Head of Engineering and Design at Guernsey Electricity, said: “The maximum energy we can import through the subsea cable is 60MW, which means that generators at the Vale Power Station were required to meet the additional demand."

This means we needed to use fossil-fuels at the power station to meet the additional demand, and for ease of reference the 60MW importation capacity has been marked up below. It's only natural to use more electricity during colder, darker months - and even more important to be mindful of the electricity we're using and move what we can to the cleaner off-peak periods between 11pm and 5am.


Peak Demand Guernsey January 2024

How can I use low-carbon electricity? 

Where possible, move as much electricity usage as you can to between 11pm and 5am.

The best appliances to use 'off peak' are those with in-built time delays, such as:

  • Washing machines
  • Tumble dryers
  • Dishwashers
  • Hot water cylinders
  • Electric vehicle charging points
  • Slow cookers 

Don’t have built-in timers?

Hold off on using these appliances during the busy 'peak' times, like dinnertimes, until later. Any time from 9pm works well, provided this is on or before your Super Economy 12 low-rate time band.

Here’s an example:

A quick 1-hour cycle of a washing machine at 6 or 7pm, especially during winter, means the power station has to help supply the electricity. This power is generated using fossil-fuels.

In other words, you’re using diesel to clean your clothes at peak times. 

But if you set a time delay to start between 11pm and 5am, instead of fossil-fuels you can get the clothes clean using low-carbon energy, as electricity demand is so low during this overnight period.

Plus, using a longer 'EcoMode' will save you money too as it actually uses less electricity and less water, especially if you’re on the Super Economy 12 tariff which offers low-rate electricity over 50% cheaper than earlier in the day. Over time, it all adds up!

Washing machine timer



How can I spend less money? 

Bad habits cost you money, and when it comes to electricity there are so many ways people can reduce their bills. Why pay for electricity you aren't using? 

First, a few things to check. 

  1. Are you on the Super Economy 12 Tariff? If not, sign up today 
  2. What are your low-rate times? If you're not sure, check the back of your electricity statement

Once you're all set with your low-rate times, simply use your electrical appliances as much as possible as it's over 50% cheaper to use. 

It's a win-win for your wallet and the planet. 

Discover more about saving money on your electricity bill in our energy saving hub. 

Or if you'd prefer someone to visit your home and help save energy for you, why not book in a home visit with one of our Energy Savers. 

Home Energy Saving Audit 


Book in one of our Energy Savers to help you save energy

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