Psychological research at MIT suggest human nature plus smart meters could equal grid oscillation if behavioural calming mechanisms are not added.
Smart meters are supposed to alter use behaviour: the price of electricity is displayed to the consumer so they move use from expensive peaks to cheaper troughs.
However, in an agile system where actual price based on actual grid load is frequently updated, the researchers found that price variations well within the normal range can cause oscillations in demand.
"For the system to work, supply and demand must match almost perfectly at each instant of time," said scientist Mardavij Roozbehani. "The generators have ramp constraints: They cannot ramp up their production arbitrarily fast, and they cannot ramp it down arbitrarily fast. If these oscillations become very wild, they'll have a hard time keeping track of the demand."
The MIT mathematical model assumes that every consumer has a 'utility function' describing how inconvenient it is to defer electricity usage.
While that function will vary from person to person, individual utility functions are pooled into a single collective function for an entire population.
"The researchers assumed that on average, consumers will seek to maximise the difference between the utility function and the cost of electricity," said MIT. "That is, they'll try to get as much convenience for as little money as possible."
While it predicts oscillations, it also indicates that partially shielding consumers from market volatility will tame those oscillations.
For instance, said Roozbehani, utilities could give consumers price updates every hour, instead of every five minutes.
Or, "if the prices in the wholesale market are varying very widely, I pass the consumer a price that reflects the wholesale market conditions but not to that extent", he said, "If the prices in the wholesale market just doubled, I don't give the consumer a price that is double the previous time interval but a price that is slightly higher."
To better tune the price presented to a consumer, customers could give utilities information about how they would respond to different prices at different times, said MIT.
Collecting that information would be difficult, but Roozbehani's hunch is that the benefits would outweigh the costs, and he is updating the model accordingly.