Time-Varying Tariffs Could Lower Electricity Bills, UK Study

Electricity bills could fall if households are shifted onto flexible, time-varying tariffs by default, according to a major UK study released Friday, May 9, 2026. The report, produced by the Institute for Fiscal Studies (IFS) and the London School of Economics, suggests British policymakers could lower household energy costs without spending large sums of public money.

While wholesale electricity prices swing sharply with weather, time of day and location, most households pay a flat rate that ignores those swings. That leaves consumers paying high prices during evening peaks while cheap wind and solar power generated at other times is sometimes wasted. The new research argues that making time-of-use pricing the standard option would give households a direct financial reason to use electricity when it is abundant and cheap.

The problem is especially visible in the UK. On windy days, turbines in Scotland generate so much power that the grid operator often pays wind farms to shut down to avoid overloading the system. Meanwhile, in the south of England, costly gas-fired generators are switched on when demand spikes. Under a flat tariff, all customers share those costs equally, even if they are willing to shift their washing, charging or heating to cheaper hours.

The study, funded by the Nuffield Foundation and published as part of the IFS Green Budget, notes that the UK Government has ruled out localised electricity markets or zonal pricing. It points to other ways to align retail bills with generation costs. One option is to put households on time-varying tariffs by default rather than requiring them to opt in. Another is to offer larger subsidies for heat pumps in low-cost power regions and bigger solar incentives in areas where gas plants tend to set the marginal price.

The potential savings for consumers could be meaningful. Charging an electric car overnight, running a dishwasher after 9pm or shifting laundry to the middle of the day are all simple changes that become financially rewarding under a time-of-use design. As more homes adopt smart chargers, battery storage and automated appliances, those savings could grow without requiring much effort from residents.

The report also highlights a looming cost problem. Expenses tied to balancing electricity supply and demand are forecast to double in real terms by the end of the decade to £7 billion a year. Those costs eventually work their way into consumer bills. By allowing prices to send signals about scarcity and abundance, argues the report, the system could become more efficient and less dependent on expensive emergency interventions.

On the wider net zero strategy, the authors say a more balanced approach would lower the total cost of decarbonisation. Relying less on an extremely rapid electrification of the power grid over the next few years, they argue, would reduce strain on household finances while still keeping climate targets within reach.

Bobbie Upton, a research economist at the IFS and co-author of the report, said encouraging greater take-up of time-varying electricity prices could lower consumer bills at “minimal cost to the Government.” The scale of savings would depend on how willingly households adopt the contracts and adjust their consumption, she added. But the potential increases as more people buy electric vehicles and install technology that automatically moves demand to low-price periods.

“High electricity prices look set to be with us for many years to come,” Upton said. “Improving the efficiency of the electricity market would have a long-run pay-off.”

Mark Franks, director of welfare at the Nuffield Foundation, warned that energy costs weigh much more heavily on low-income households. “Energy bills account for a much higher proportion of spending among poorer households, and uncertainty about possible future price rises creates anxiety within families already operating with very little financial headroom,” he said. He urged the Government to seriously consider any credible option that reduces costs for vulnerable consumers.

The findings also carry clear lessons for the United States, where electricity regulation is split among regional operators, state commissions and competitive retailers. Time-of-use rates are not new there. California has moved most residential customers onto default time-of-use tariffs in recent years, and several other states offer optional plans. Yet many customers remain on flat rates, and adoption of dynamic pricing outside California has been slow.

Behavioral research on both sides of the Atlantic suggests that default enrollment dramatically increases participation compared with opt-in programs. People rarely switch from the status quo, even when the alternative would save them money. The UK report’s core recommendation—make time-varying tariffs the default—matches that evidence and could be applied directly to US utilities that want to boost demand flexibility.

For US grid operators, dynamic pricing also aligns with a broader push toward demand response. Wholesale markets have long paid large commercial users to cut load during emergencies. Extending the same logic to homes, through price signals rather than special payments, would turn millions of electric vehicle chargers, heat pumps and water heaters into distributed resources. Federal rules such as FERC Order 2222 already allow aggregated home devices to participate in wholesale markets, making residential flexibility increasingly valuable.

There are real obstacles. Time-of-use pricing works best with smart meters, clear billing information and strong consumer protections. Low-income households, retired residents and shift workers may not be able to move their electricity use easily. Without safeguards, critics say, a well-intended reform could push some vulnerable families onto plans they do not understand or cannot adapt to.

The report acknowledges those risks and pairs its tariff recommendation with targeted support. Heat pump subsidies in cheaper-generation regions and solar incentives in higher-priced gas-dependent regions would help reduce total system costs while spreading benefits unevenly across the country. That idea is particularly relevant for US states that still rely heavily on fossil generation during peak periods.

Overall, the study makes a simple but powerful point: electricity is not equally expensive at every moment, and consumer prices should reflect that. Encouraging households to shift their usage is one of the lowest-cost ways to lower bills, reduce emissions and ease pressure on the grid. The UK now has a clear road map; US policymakers will be watching closely to see whether following it can deliver the same promised savings.