How can we reduce storage needs by managing our electricity consumption better?

It is possible, through incentives, to modulate the consumption of electricity in order to better adapt it to the production capacity. This strategy would reduce the need for storage and even avoid the need to store excess electricity from solar and wind power.

A country’s electricity consumption is constantly changing. Every time we turn an electrical device on or off, we change the demand. These constant changes require us to constantly adapt production, since electricity production and consumption must balance each other at all times on the grid [→ Q72]. Electricity consumption in Switzerland can vary considerably: up to 20% up or down in a matter of minutes; for example, when all electric cookers are switched on simultaneously at midday, or when a storm cloud passes in the late afternoon and everyone turns on the lights at the same time. Another demand peak expected in the next few years is for electric cars that will all be charged when they return from work in the evening…

Until now, variations in electricity consumption have been covered by power stations capable of adapting their production levels; in particular, hydroelectric storage power stations, which can open and close the injectors very quickly according to the demand for electricity and thus absorb peaks in consumption. But this traditional solution is no longer enough; with the growing share of coal-fired power plants with little flexibility, and solar and wind power that is difficult to predict precisely, balancing the grid becomes more delicate.

Demand side management (DSM) is a concrete solution to this problem. DSM consists of reversing the logic of network balancing; it is no longer only production that follows demand, but also consumption that adapts to production when necessary, when the production apparatus can no longer keep up with demand. This approach consists of bringing forward or deferring part of the national electricity consumption in order to make it more flexible, in line with fluctuations in production. This makes it possible to absorb peaks or power losses from solar and wind power, depending on the vagaries of the weather.

Rest assured, demand management will not be done on all electrical and electronic devices, nor on lighting. We will continue to turn on all of these devices on demand, whenever we want. The possibilities for modulating electricity consumption are found in equipment with heat or cold storage, such as refrigerators, freezers, water heaters and heat pumps. These appliances can easily be switched off for a certain period of time, especially if they have been able to accumulate excess cold or heat before being switched off. Similarly, the starting of dishwashers and washing machines, as well as the recharging of electric vehicles, can be slightly delayed in time. A certain potential for flexibility also exists in the field of industrial activities, particularly in large cold storage centres.

In practice, demand management is done in two ways: either through tariff incentives for consumers, or through remote control methods by the grid operator (which can remotely switch certain appliances on or off). There is therefore a close link between demand management and smart grid technologies and “smart” meters [→ Q69].

Some very basic functions to make consumption more flexible have already existed in Switzerland since the 1970s, through measures such as a differentiated electricity tariff between day and night, or the automatic switch-off of most domestic electric water heaters at times of high consumption. Today, this type of practice needs to be considerably refined, to make demand management much more dynamic and reactive (within a very short period of time) and remotely achievable (smart meters, etc.).