Variable rate electricity: how it works

Variable rate electricity tariffs mean the price you pay for energy can change over time. Unlike fixed tariffs, which lock in rates, variable rates fluctuate, offering both potential savings and increased unpredictability. Understanding how these tariffs work, including the role of the Ofgem Price Cap, is key to managing your household energy costs effectively.

Managing your variable rate electricity can be simpler with the right tools. Fuse Energy offers clear insights and support to help you navigate market changes and make informed decisions about your energy usage. Click here to see how Fuse can help you manage your energy.

Understanding variable rate electricity

A variable rate electricity tariff means the price you pay per unit of electricity can change. Unlike fixed tariffs, where your unit rate and standing charge remain constant for a set period, variable rates fluctuate. These changes are typically influenced by the wholesale cost of energy, which can rise or fall depending on market conditions, global events, and even the weather.

What defines a variable tariff?

A variable tariff is characterised by its fluctuating unit rates and standing charges. These rates are not locked in for a long period. Instead, they can change, usually reflecting the underlying costs of generating and supplying electricity. Most variable tariffs in the UK do not come with exit fees, offering customers the flexibility to switch to a different tariff or supplier without penalty if their circumstances or market conditions change.

The role of the Ofgem Price Cap

Crucially, for most households, these variable rates are not limitless. The energy price cap, set by the UK energy regulator Ofgem, limits the maximum amount suppliers can charge for each unit of electricity on a Standard Variable Tariff (SVT). This cap acts as a safety net, preventing prices from soaring uncontrollably and protecting consumers from excessive charges. It applies to most households on variable tariffs, ensuring that even as wholesale prices move, there's a ceiling on what you pay.

How variable rates fluctuate

Wholesale energy prices and market factors

The primary driver behind variable rate fluctuations is the wholesale cost of energy. This is the price energy suppliers pay to buy electricity from generators. Factors influencing these costs include global supply and demand, geopolitical events, the output from renewable sources (like wind and solar), and even weather conditions affecting energy usage. When wholesale prices are low, variable tariffs have the potential to offer cheaper rates to consumers. Conversely, when wholesale prices rise, so too can variable tariff rates, up to the Ofgem Price Cap.

Quarterly price cap reviews explained

The Ofgem energy price cap is reviewed and updated quarterly. These reviews take effect on specific dates: 1 January, 1 April, 1 July, and 1 October. This means your unit rates and standing charges on a variable tariff can change every three months, either increasing or decreasing, to reflect the updated cap. Ofgem calculates the cap based on a range of factors, including wholesale energy prices, network costs, operating costs, and environmental obligations. For more details on how the cap is calculated, you can read our Ofgem Price Cap explained article.

Advantages and disadvantages of variable tariffs

Benefits of choosing a variable rate

One of the main benefits of a variable tariff is flexibility. Most variable tariffs typically do not have exit fees, meaning you can switch to a different supplier or tariff at any time without incurring a penalty. This is particularly advantageous if you anticipate moving home, or if you want the freedom to switch to a fixed tariff should market conditions become more favourable. When wholesale energy prices drop, variable tariffs can quickly pass on these savings, potentially leading to lower bills.

Potential drawbacks to consider

The primary disadvantage of a variable tariff is its unpredictability. Your energy bills can increase if wholesale prices rise or if Ofgem raises the price cap. This can make budgeting more challenging compared to a fixed tariff, where your unit rates are guaranteed for a set period. While the price cap offers protection, it doesn't prevent increases altogether, and some households may find the uncertainty a source of anxiety.

Variable vs fixed tariffs: making the right choice

Key differences and comparisons

The fundamental difference between variable and fixed tariffs lies in price stability. A fixed tariff locks in your unit rate and standing charge for the duration of the contract, usually between 12 and 18 months. This offers predictability for budgeting but often comes with exit fees if you leave early. Variable tariffs, as discussed, fluctuate with the market and the Ofgem Price Cap, usually without exit fees.

When to consider a variable tariff

A variable tariff might be the right choice if you value flexibility and believe wholesale energy prices are likely to fall. It's also suitable if you don't want to be tied into a long-term contract or if you anticipate moving home in the near future. If you have a smart meter and are willing to adjust your energy usage to take advantage of lower prices during off-peak times, a variable tariff can be particularly beneficial.

When a fixed tariff might be better

A fixed tariff is generally preferred by those who prioritise budget certainty. If you want to know exactly what you'll pay per unit of energy for a set period, a fixed deal provides that peace of mind. This can be especially appealing during periods of high or volatile wholesale energy prices, as it protects you from potential increases, though you might miss out if prices drop significantly.

Managing your variable rate electricity

Monitoring market trends and your usage

Staying on top of your energy usage and market trends is key to managing a variable tariff effectively. Tools that provide detailed insights into your electricity consumption can help you understand where your energy goes and identify opportunities to reduce usage. Keeping an eye on energy news and Ofgem's price cap announcements can also help you anticipate potential changes to your bill. The average UK home uses around 2,700 kWh of electricity per year. Knowing your own usage against this benchmark can help you gauge your consumption.

The power of smart meters and time-of-use tariffs

Smart meters can significantly enhance the benefits of variable tariffs. They send automatic readings to your supplier, eliminating the need for manual submissions and enabling more accurate billing. More importantly, smart meters facilitate time-of-use (TOU) tariffs, which offer different rates at different times of the day. This allows you to shift high-energy activities, like charging an electric vehicle or running a washing machine, to off-peak hours when electricity is cheaper, maximising your savings. Discover more about the benefits of smart meters for your home.

What to do if you have an RTS meter

The Radio Teleswitch Service (RTS) is a legacy system that uses a longwave radio signal to switch between peak and off-peak electricity rates. This service is being phased out, with the industry-wide switch-off process having begun on 30 June 2025. If you have an RTS meter, your current supplier will need to replace it with a smart meter. This upgrade is free. Once your meter has been replaced, you'll be able to access the benefits of smart meter technology and a wider range of tariffs, including those that can help you manage your variable rate electricity more effectively. Fuse Energy does not install, convert, or upgrade RTS meters; this upgrade comes from your current supplier.

Frequently asked questions about variable rates

Can i switch from a variable to a fixed tariff at any time?

Yes, typically you can switch from a variable tariff to a fixed tariff at any time, as most variable tariffs do not have exit fees. This flexibility allows you to lock in a rate if you see a fixed deal that suits your needs, or if you prefer the stability it offers.

Are variable rates always more expensive?

No, variable rates are not always more expensive. While they carry the risk of price increases, they also offer the potential for lower costs when wholesale energy prices fall. During periods of low wholesale prices, a variable tariff can be cheaper than a fixed tariff. The Ofgem Price Cap also provides a ceiling on how high variable rates can go.

How does Fuse Energy help with variable tariffs?

Fuse Energy empowers customers to manage their variable tariffs effectively. Our app provides detailed insights into your energy usage, helping you make informed decisions and adapt to market changes. We offer 24/7 human customer support to demystify bills and market fluctuations, providing confidence. Our variable tariffs typically have no exit fees, aligning with a customer-centric approach to energy management and offering you flexibility without penalty.

Managing your energy bills should be clear and easy to understand. Fuse Energy focuses on straightforward pricing, so you can see exactly what you're paying without unnecessary complexity. If you have a smart meter, you can view detailed usage data through the app or website, helping you understand how you can lower your bills. If you don't have a smart meter, Fuse Energy can upgrade your non-smart meter, completely for free. Our 24/7 human support team is always on hand with fast response times whenever you need help. Click here to switch to Fuse Energy today. Find out about our mission by clicking here.