The astonishing collective impact of household energy shifts

At 1:12 am on a quiet March evening in 2030, a fox scrounges for snacks in a suburban street. Inside number 16, an electric car silently draws power from its battery while its occupants rest. The household's energy supplier detects low demand and offers cheaper electricity, prompting the car to begin charging. This seemingly simple action benefits the family and the broader grid.

By smoothing electricity demand, households help balance supply and demand, decrease carbon emissions, and lower neighbours' bills. While maintaining consistent power supply may seem effortless, it poses significant challenges for grid operators as demand fluctuates and power sources diversify. Building more generation capacity appears to be the obvious solution, but new research suggests that altering household behavior could make a substantial difference.

The issue lies in matching electricity demand and supply. Demand peaks in the evenings as people return home, switch on lights, boil water, and power appliances. Renewable energy generation, though increasing and cheaper than gas-based power, is intermittent and can strain the grid during peak demand. Grid flexibility is crucial to accommodate these fluctuations.

Existing flexible assets include gas peaker plants, grid-scale batteries, and pumped hydro. However, a 10% capacity gap is expected, requiring around 100 grid-scale batteries or 400 gas peaker plants. This would be costly, carbon-intensive, and necessitate additional grid upgrades.

Research by Cornwall Insight reveals that households have untapped potential to contribute significantly to grid flexibility. Encouraging consumers to adjust their usage or automating home energy use can help flatten peak demand and reduce the need for extra generation. Energy providers reward consumers for shifting energy use to off-peak or renewable periods, while automated systems for EV and home battery charging help shave peaks and avoid unnecessary generation.

Jacob Briggs, co-author of Cornwall Insight's study, notes that consumers can remain unaware of grid-side activities, yet their collective behavior can make a substantial impact.

To fill the capacity gap, one million fully smart homes equipped with EV smart chargers, heat pumps, solar PV with battery storage, all responding to flexibility signals, would suffice. Currently, 72% of Great Britain's household meters are smart or advanced, and 2.8% of consumers, or 835,000 households, are enrolled in time-of-use tariffs.

As more suppliers introduce flexible energy schemes, such as weekend discounts or peak-time rewards, the number of households participating in demand flexibility is expected to increase. With sufficient adoption of these tariffs and schemes, the potential impact on grid capacity and costs becomes evident.