Secure and reliable electricity supplies

By David Brayshaw

Secure and reliable electricity supplies are an essential part of modern life. The networks and infrastructure that produce and supply this power are, however, changing rapidly across the world due to both socio-economic pressures (e.g., rising demand in the rapidly growing economies of Asia) and attempts to decarbonize energy in response to the challenge of climate change. The scale of this change is massive: the International Energy Agency estimates that investments of around $50tn are required to develop energy supplies[1] and networks in the next few decades.

Power systems are, however, highly sensitive to weather. Perhaps most immediately one thinks of extreme and damaging weather (flooding, windstorms and the like) but the influence of weather on the power system is far more pervasive than this.  It is well known, for example, that demand for electricity is strongly influenced by temperature (demand for heating on cold days, cooling on hot days), as is the supply of renewable energy (especially wind and solar). These individual “ingredients” are also interconnected through a power-grid – itself a highly complex system – which requires an almost instantaneous balance between power supply and power demand. Variations in weather thus not only influence individual resources, but also influence system-wide properties such as supply-demand balance and the wholesale electricity price.

The Energy-Meteorology research group at the University of Reading, working closely with industry partners and researchers from Engineering, seeks to understand these system-wide weather impacts better and to develop new ways for risk management in the power sector. A particular focus has been to identify “modes” of weather and climate variability that have the potential to cause extreme stress on power system. This is illustrated in a recent study examining the potential use of wind-power in India.

The demand for power in India is rapidly growing year-on-year and, looking forward, it is expected that the strongest demand each year will occur due to space cooling during the warm summer months. At the same time, India has plans to expand its use of wind-power generation. Day-to-day co-dependencies between wind and temperature during the summer are therefore likely to have a strong influence on the need for generation sources other than wind (i.e., the residual demand after the wind-generation has been deducted, the so-called “demand-net-wind” or DNW).

Our study, results from which have recently been published in Environmental Research Letters (Dunning et al 2015), shows that “monsoon-break” events during the summer period can be expected to produce both a significant reduction in wind-power and an increase in cooling (i.e., an increase in DNW) across much of peninsular India. This does not necessarily mean that wind-power cannot make a useful contribution to the Indian power system, but it does mean that these weather-induced changes in output should be anticipated when designing and operating power systems over the coming decades.

An introduction to some of our recent work (UK wind-power extremes, wind-power during-peak-demand, influences of future wind power) and the European power sector (multi-week weather forecasting for price and volumes, impacts of seasonal variability) can be found on our group website and in the references below. The website also provides free access to a reconstructed wind-power record for the UK covering more than 30 years (derived from weather data assuming that all of today’s wind-farms were present).

REFERENCES

Dunning, C.M., Turner A.G., Brayshaw, D.J., 2015. The impact of monsoon intraseasonal variability on renewable power generation in India. Environmental Research Letters, 10, 064002.

Cannon, D.J., Brayshaw, D.J., Methven, J., Coker, P.J. and Lenaghan, D., 2015. Using reanalysis data to quantify extreme wind power generation statistics : a 33 year case study in Great Britain. Renewable Energy, 75, pp. 767-778. ISSN 0960-1481 doi: 10.1016/j.renene.2014.10.024

Drew, D., Cannon, D., Brayshaw, D., Barlow, J. and Coker, P., 2015. The impact of future offshore wind farms on wind power generation in Great Britain. Resources Policy, 4 (1), pp. 155-171. ISSN 0301-4207 doi: 10.3390/resources4010155

Lynch, K. J., Brayshaw, D. J. and Charlton-Perez, A., 2014. Verification of European subseasonal wind speed forecasts. Monthly Weather Review, 142 (8), pp. 2978-2990. ISSN 1520-0493 doi: 10.1175/MWR-D-13-00341.1

Ely, C. R., Brayshaw, D. J., Methven, J., Cox, J. and Pearce, O., 2013. Implications of the North Atlantic Oscillation for a UK–Norway renewable power system. Energy Policy, 62, pp. 1420-1427. ISSN 0301-4215 doi: 10.1016/j.enpol.2013.06.037

Brayshaw, D., Dent, C. and Zachary, S., 2012. Wind generation’s contribution to supporting peak electricity demand: meteorological insights. Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability, 226 (1), pp. 44-50. ISSN 1748-0078 doi: 10.1177/1748006X11417503

[1] Please note this figure includes all forms of energy, not just electricity.  Figure taken from International Energy Agency, World Energy Investment Outlook Special Report, 2012.

 

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