This project is looking to develop a climate change impact assessment procedure which will be supplemented by a visualisation tool and technical information of the observed at-risk climate change hot-spots/assets and most up-to-date climate science (UKCP18 projections) so that adaptation measures are considered at the appropriate time and to an acceptable level.
Benefits
A climate change impact assessment procedure will provide a structured approach for WPD
to consider the risks posed by climate change in a short-, medium- and long-term so that
adaptation measures are proactively considered and put in place, when/if required. It is
envisaged that visualisation of at-risk locations will facilitate a streamlined adaptation
decision-making. The project will also allow for consideration of climate change impacts
within our network forecasting activities.
Learnings
Outcomes
The outcomes of ACCELERATED are listed below.
Heat maps have been generated.
These illustrate the weather-related hot spots and are incorporated into a GIS tool to show most at-risk location for a selection of weather variables and types of assets included in the analysis.
Fragility curves have been derived
These were produced for different assets and different climate variables.
A GIS tool has been developed and tested.
This allows users to visualize the data from the heat maps and fragility curves.
The demand / generation impact report has been compiled
A report providing details of the methodology and results of the analysis of the impact of climate change on demand and DG output profiles has been produced.
Climate change impact assessment procedure documented
The details of the analytical approaches developed in the project have been captured and documented.
The learning has been disseminated.
As well as publishing the various reports, a webinar was held in March 2023. Further detail on the information presented during the webinar is available here: www.nationalgrid.co.uk/downloads-view-reciteme/628697 . The project outputs have also been widely shared through presenting at the Utility Week 2023 and international conference CIRED (2023).
Overall the project has enabled improved analysis of the impact of climate change on our assets. This will enable informed and future-proof investment decisions to be made for network construction standards, policies, and of at-risk hotspots identification.
Lessons Learnt
Nature of historical weather related faults, and Fragility curves
Overall, wind is the main risk factor for unplanned weather-related power outages across NGED license areas (~80%). The South West region is particularly vulnerable to wind-related faults. Lightning is the second most prevalent fault, but this and the other categories result in far fewer faults than wind. Apart from wind, for some of the other climate variables there is not enough data to reliably create fragility curves. In these cases the data has been pooled for the regions and the different asset types to produce fragility curves. These fragility curves should be used with more caution as the relationships between climate intensity and fault probability are not strong.
Fragility curves are useful for two things: the first is to understand how likely it is for a fault to occur subject to a given intensity of weather variable and the second is to understand the range of likely faults that may occur for that given weather intensity value.
Projected climate impact
Climate change is likely to lead to an increase in the number of power outages in the NGED license areas, particularly in the South Wales and South West regions. This is due to more frequent and intense storms, hotter temperatures, and more extreme rainfall events. The projections, however, differ from one licence area to the other so the caution should be applied when utilising the results of the analysis. It is recommended to enhance the analysis for wind related faults by adding further variables such as wind direction, soil saturation and topography data.
Demand for electricity
Historical datalogger measurements have been used to obtain the best approximation of the underlying “unmasked” demand and DG output profiles. However, the following limitations should be noted:
- Actual demand measurements include the effect of some technologies, e.g. overnight storage heating. There is no established method to cleanse the underlying demand, but more information about the nature of demand may be available in future; and
- Profile data for the aggregate output from small behind-the-meter generators is not generally available. This means that it is difficult to determine the true “unmasked” demand.
The greatest reductions in demand are seen in the periods of the year when intermediate temperatures are observed. This results from the historical relationships showing that the underlying demand converged on a finite maximum value at low temperatures and a finite minimum value at high temperatures (represented by sigmoid functions).
ENA report
The ENA third round report largely disregards the impact of wind, but wind is responsible for most historical weather-related faults. The Geographical Information System (GIS) tool allows users to filter the fault causes, so that wind-related faults may be included or excluded from the visualisations depending on the requirements of the assessment.
Application of the project outputs:
The following applications have been demonstrated to be legitimate uses of the new analytical approaches, and examples of suitable analyses have been prepared:
- ED3 Business Plan – consideration for additional climate resilience expenditure;
- ED2 expenditure – prioritise locations for Capex and Opex schemes;
- Feedback to Policy team – suitability of equipment specifications / selection of specifications under different conditions; and
DFES preparation - generation and demand profile adjustment.
