
In its flood risk review of national infrastructure assets, the Government identified 7000 locations or 14% of all substations were at risk in England.
This risk is directly transferable to battery storage, which may be highly susceptible to very localised flash flood and groundwater risks.
Leighton Buzzard Battery Storage Case Study
A proposal for a development site in Leighton Buzzard by UK Power Networks in 2013 shows how flood risk significantly affected the choice of materials and scheme.
The 6MW/10MWh battery facility is famed for being the UK’s first grid-scale battery storage facility and came to fruition under the Low Carbon Network Fund, helping to prove the technical and commercial viability of battery storage technologies.
A variety of sites were looked at using the sequential testing methodology. Once the site was agreed, it was then about how to mitigate the residual flood risk.
The proximity to Clipstone Brook, a small stream close to the proposed site meant some of this land was in a high-risk flood area, as designated by the Environment Agency
This would have had implications for safety hazards connected with the proposed technology. For UK Power Networks, this meant a move away from battery solutions based on liquid electrolytes, where there was some risk of hazardous liquids being released in a flood. Instead, Lithium Ion batteries have become increasingly preferred.
In order to mitigate flood risk, the following factors were required in the design:
Due to the flood risk at site, the design specified that the storage building was raised on stilts to ensure that any potential flood waters were not displaced, increasing the risk of flooding elsewhere.
The 100-year worst-case predicted flood levels were estimated at around 0.66m above the ground level of the development. However, health and safety policies within UK Power Networks meant that any void under the building less than 2m would be classed as a confined space. So the building was raised by 2m at the lowest ground level point. This mitigates against a predicted 1000-year flooding event.
A flood maintenance plan ensures that the clearance and removal of any debris happens after flood events. An alarm is also installed on site, which alerts UK Power Networks control engineers in the event of a flood.
The raised building design was balanced with the need to minimise the visual impact of the building and keep it below the levels of existing housing.
A sustainable drainage system (SuDS) was implemented to ensure flood risk is not increased to other areas surrounding the battery storage site. This included using shingle drainage around the building. Other measures to manage drainage include soakaways, swales, infiltration basins, permeable paving or retention ponds.
Get a Clearer Picture
Farmers and other rural landowners, faced with uncertainty over Brexit are also looking at battery storage facilities and the potential to accommodate them via the planning regime for income generation. So it is anticipated that the need to verify site suitability, especially to identify flood risk and how this impacts on the development opportunity, will be a key planning consideration.
GeoSmart understands how river, surface and groundwater flooding can affect infrastructure development sites. We work with utilities to map and alert asset managers on groundwater flood risk as well as identifying optimum locations and maintenance priorities.
Our expert flood risk consultants will advise on flood zones and constraints, as well as potential vulnerabilities that could impact on proposed energy infrastructure applications.