Multiple Small-Scale Renewable Power Sources Can Lead to Power Failures: UK Study

According to a study published in Science Advances, mathematicians from the University of Nottingham have found that small scale multiple renewable power sources can lead to power failures.

The researchers used data emanating from smart meters in the United Kingdom and have come to the conclusion that grid behaviour changed over time and the resilience of the grid changed in different times of the day. They discovered that high uptake of solar panels can cause failures in the grid systems.

Domestic renewable installations are highly democratized in the United Kingdom and continue to grow each passing day. There are more than a million small scale solar PV systems in the country. The net outcome is that low output of renewable power and intermittent supply puts the grid systems at risk, claim researchers.

Renewable power generation in the UK relies heavily on household solar PV generation. Under the feed-in tariff system the households are paid for supplying their stored power back upstream to the grid.

Researchers say that the renewable power is unpredictable as the household generators come on and offline intermittently. The seasonal usage of the households and daily changing meteorological conditions also cause intermittency.

Oliver Smith, who led the research at the University of Nottingham, said, “The increasing proliferation of small, intermittent renewable power sources is causing a rapid change in the structure and composition of the power grid. Indeed, the grid’s effective structure can change over the course of a day as consumers and small-scale generators come on- and off-line. Using data from smart meters in UK households we tracked how grid composition varies over time.”

“We then used a dynamical model to assess how these changes impact the resilience of power grids to catastrophic failures. We found that resilience varies over the course of a day and that a high uptake of solar panels can leave the grid more susceptible to failure,” added Smith.

During the research, the mathematicians changed the size and proportion of solar PV generators in the network and found that the grid has to be more robust for this uptake than taking power from one source. They found that the grid doesn’t reach the optimum levels when too many small scale renewable power systems operate at different times of the day.

They also discovered that the household batteries meant for renewable power storage reduced the household power costs only. These batteries didn’t help to reduce the grid failure risks.

“The main problem is the amount of fluctuation there is in small-scale renewable energy supply. A cost-effective way to overcome this would be to intelligently schedule the release of stored PV energy from household batteries at specified times. This would provide much greater control and reduce the risk of system failures,” explained Smith.