Wednesday, 02 March 2022
Renewable energy that feeds into the main power grid could destabilise the system and potentially cause power failures according to a new study.
Mathematicians from the University of Nottingham used data from smart meters to track how grid composition changes over time and found resilience varies over the course of a day and that a high uptake of solar panels can leave the grid more susceptible to failure. Their findings have been published today in Science Advances.
Domestic renewable energy generation is growing rapidly with just over one million small-scale solar Photo-Voltaic(PV) systems in the UK. These small-scale, renewable generators are low- output and intermittent and often distributed across and embedded within power grids in large numbers.
Household generation forms a key component of the integration of renewables and includes the ‘feed in tariff’ which pays the producer for supplying their stored power back upstream to the grid. This supply of power is unpredictable with generators coming on and off-line intermittently and households adopting the role of consumers or producers asdaily and seasonal usage, and meteorological conditions vary. These fluctuations can put the grid at risk of system failures.
Oliver Smith, researcher at the University of Nottingham led the study, he explains: "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.”
The first part of the research investigated the theory around changing the proportion and size of generators by modelling a system using many small-scale generators and in all cases it showed that the grid should be more robust than if using one power source. However, when the real-world smart meter data was incorporated the researchers found that the reality for a network with many small-scale generators operating at different times means the grid doesn’t reach optimum levels for this resilience to be achieved leaving it susceptible to failures.
The researchers found that renewable energy stored in household batteries is used only to minimise household power costs and does little to minimise the risk of network failure.
They recommend that the supply of power from these batteries should be scheduled to also optimise for power grid resilience.
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.
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More information is available from Oliver Smith at the University of Nottingham on Oliver.smith@nottingham.ac.uk
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About the University of Nottingham
Ranked 32 in Europe and 16th in the UK by the QS World University Rankings: Europe 2024, the University of Nottingham is a founding member of the Russell Group of research-intensive universities. Studying at the University of Nottingham is a life-changing experience, and we pride ourselves on unlocking the potential of our students. We have a pioneering spirit, expressed in the vision of our founder Sir Jesse Boot, which has seen us lead the way in establishing campuses in China and Malaysia - part of a globally connected network of education, research and industrial engagement.
Nottingham was crowned Sports University of the Year by The Times and Sunday Times Good University Guide 2024 – the third time it has been given the honour since 2018 – and by the Daily Mail University Guide 2024.
The university is among the best universities in the UK for the strength of our research, positioned seventh for research power in the UK according to REF 2021. The birthplace of discoveries such as MRI and ibuprofen, our innovations transform lives and tackle global problems such as sustainable food supplies, ending modern slavery, developing greener transport, and reducing reliance on fossil fuels.
The university is a major employer and industry partner - locally and globally - and our graduates are the second most targeted by the UK's top employers, according to The Graduate Market in 2022 report by High Fliers Research.
We lead the Universities for Nottingham initiative, in partnership with Nottingham Trent University, a pioneering collaboration between the city’s two world-class institutions to improve levels of prosperity, opportunity, sustainability, health and wellbeing for residents in the city and region we are proud to call home.
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