A low unit rate can look attractive on an energy bill, but it is only half the story. Energy tariffs also include standing charges, contract terms and, increasingly, prices that change by the hour. Choosing the right energy tariff for your household can make a noticeable difference to what you pay, particularly if you have solar panels, a home battery, an EV charger or a heat pump.
The best option is not always the cheapest tariff advertised. It is the tariff that suits when and how your household uses electricity and gas, as well as the energy improvements you already have or are planning.
What makes up an energy tariff?
Most domestic energy tariffs are made up of two main costs. The unit rate is what you pay for each kilowatt-hour (kWh) of electricity or gas used. The standing charge is a fixed daily amount that contributes towards supplying energy to your property, maintaining the network and managing your account.
A tariff with a lower unit rate may have a higher standing charge. This can work well for a busy family home that uses a lot of energy, but may be less attractive for a smaller household with low consumption. The reverse can also be true. Looking at both figures is more useful than focusing on one headline price.
Your bill will also depend on your annual consumption, meter type, payment method and region. Electricity network costs vary around Great Britain, so the same supplier tariff can cost different amounts depending on where you live.
The main types of energy tariffs
Fixed tariffs
A fixed tariff keeps its unit rates and standing charge unchanged for an agreed period, commonly 12 months. It offers certainty, which can make household budgeting easier. You know what you will pay per unit, although your total bill can still rise if you use more energy.
The trade-off is flexibility. Some fixed deals charge an exit fee if you leave before the end of the contract. Before signing up, check the end date, exit terms and what happens when the tariff finishes. A fixed tariff can be a sensible choice for households that value predictable costs and do not want to monitor hourly prices.
Variable tariffs
Variable tariffs can go up or down when a supplier changes its rates. Many are linked to the Ofgem energy price cap, which limits the amount suppliers can charge per unit and standing charge for typical domestic customers on default tariffs. The cap is not a limit on your total bill, because that still depends on how much energy you use.
These tariffs are usually more flexible than fixed contracts and often have no exit fee. They may suit you if you expect to make changes to your home, such as installing solar or replacing an old boiler with an air source heat pump, and want to review your options afterwards.
Time-of-use tariffs
Time-of-use tariffs charge different electricity prices at different times of day. Electricity may cost less overnight or during periods when demand is lower, while peak evening hours can be more expensive. A smart meter is normally required because it records when electricity is used.
For the right home, this can be a practical route to lower electricity costs. Charging an EV overnight, running a dishwasher on a timer or heating a battery during cheaper hours can reduce the amount bought at peak rates. However, it is not automatically a saving. If most of your use happens during expensive periods and cannot be moved, a flat-rate tariff may be better.
Economy 7 and similar tariffs
Economy 7 offers a cheaper night rate and a higher day rate. It was designed for homes with storage heaters, but it can still suit some properties with electric heating, EV charging or battery storage. The key question is whether enough of your electricity use can move into the cheaper window.
Check the exact off-peak hours carefully. They are not identical everywhere, and clock changes can affect the times. A supplier can review your usage data and help show whether the tariff is working in your favour.
How solar panels change the tariff conversation
Solar panels reduce the electricity you need to buy from the grid when they are generating. In a typical household, generation is strongest during daylight hours, while consumption often rises in the morning and evening. That gap is where tariff choice and battery storage become particularly valuable.
Without a battery, unused solar electricity can be exported to the grid. You should receive payments through an export tariff for eligible exported electricity, but export rates vary between suppliers. A higher export payment may be useful for households that are out during the day and export a large share of their generation.
With a battery, you can store surplus solar power for later use. You may also be able to charge the battery from the grid during a cheaper off-peak period, then use that stored electricity when grid prices are higher. This approach needs careful system design and sensible controls. A battery should not be sized or operated purely around a tariff that could change next year.
For most homeowners, the first priority is reducing wasted energy and using more of their own solar generation. The right tariff can improve the returns, but it should support a well-designed system rather than drive every decision.
Heat pumps, electric heating and tariffs
An air source heat pump uses electricity, so a move away from gas changes how you should look at energy costs. Heat pumps are highly efficient: for every unit of electricity they use, they can produce several units of useful heat. Even so, your electricity consumption will increase while your gas consumption falls.
A heat pump performs best when the home is properly insulated and the system is designed for steady, efficient operation. Turning it off for long periods and forcing it to recover quickly is not usually the most economical approach. This means the cheapest tariff is not necessarily the one with the lowest overnight rate.
A time-of-use tariff can work well where heating controls, hot water schedules and battery storage are set up properly. But comfort comes first. Your home should stay warm when you need it to, without relying on complicated routines that are difficult to maintain. A property assessment can identify whether insulation improvements, radiator upgrades or a different heating schedule will have the greatest impact.
Eligible homeowners in England and Wales may also be able to use the Boiler Upgrade Scheme towards an air source heat pump installation. Grant availability and eligibility rules can change, so it is worth checking the current position before planning your budget.
How to compare energy tariffs properly
Start with a full year of usage if possible, rather than one winter bill or one summer bill. Your supplier account, annual statement or smart meter data can show electricity and gas use in kWh. This gives a more realistic basis for comparison.
Then consider what is likely to change. If you are adding solar panels, a battery, EV charger or heat pump, historical bills alone will not reflect your future energy use. Ask for projected running costs based on the proposed system and discuss which tariff type may suit it.
When reviewing tariffs, compare the unit rate, standing charge, contract length, exit fee and any conditions tied to smart meter data or direct debit payments. For time-of-use deals, look beyond the lowest off-peak rate. Check peak-time prices and whether your normal routine gives you enough flexibility to shift demand.
Be careful with estimated annual savings. They can be useful, but they rely on assumptions about your usage. A household with people working from home, young children, medical equipment or high daytime consumption may see a very different result from a standard illustration.
Practical ways to make your tariff work harder
Small changes can help, particularly when combined with efficient equipment. Run appliances when solar generation is available where practical, use timers for flexible loads, and avoid charging an EV at peak times if your tariff has expensive evening rates. Smart controls can help, but they should be set up around your routines rather than creating extra hassle.
It also pays to reduce demand before trying to optimise it. Loft insulation, draught reduction, heating controls and efficient appliances lower the number of units you need to buy regardless of tariff. For homes considering a heat pump, improving insulation and heat retention is often one of the most valuable steps.
If your property is within 100 miles of Nelson, Lancashire, Sunny Side Pro can assess how solar, battery storage, insulation and low-carbon heating could work together for your home. A tailored recommendation is more useful than choosing equipment from headline figures alone.
The right tariff should make your home energy system easier to run, not more complicated. Review it when your contract ends, after a major installation or when your household routine changes, and keep the focus on lower bills, reliable comfort and a plan that fits your property.