Battery storage installations: Catering for energy demand and permitted development

What are these?

A battery storage installation is a type of energy storage system where batteries held in containers store electrical energy, deferring the consumption of the stored electricity to a later time. Battery storage is the fastest responding source of power on grids. Installations are proliferating globally as technology costs fall and demand for flexibility in electricity networks increases. Currently, battery storage is of relatively short duration, generally discharging for between one and several hours.

Standalone battery storage installations are often installed at, or close to, other active power stations or sub-stations, and may share the same grid connection to reduce costs.

The largest installations are located in the US, Japan and Australia. All have been developed in the last five years. Most use lithium-ion batteries.

Why are these important?

Electricity systems must be balanced in real-time, so supply must equal demand on a second-by-second basis. If power cannot be supplied to meet demand, the power quality will deteriorate and can lead to service interruption. It is the speed of response in turning the power on and off that is critical in maintaining reliable electricity supplies. Historically, generators have undertaken this grid balancing role, with fossil-fuelled power plants ramping production up or down to meet demand. Energy storage has a role to play in maintaining the system in balance, particularly due to its speed of response.

Another driver for electricity storage is the need to balance the system where electricity is supplied by a large volume of variable renewable energy sources such as solar and wind power. Solar and wind power are less predictable power sources than traditional fossil fuels, creating peaks and troughs in the supply of energy. Energy storage can help to maintain reliable energy supplies by using stored electricity to compensate for lows in output from intermittent renewables, or power plant outages. The greater predictability of energy that results from energy storage being integrated into the system enables more renewable capacity to be allowed into the grid, reducing dependency on fossil fuels, thereby reducing carbon emissions. To achieve this, the storage installation may be ‘standalone’ or ‘co-located’ on the same site with the renewable power plant. In both cases, there is a role for electricity storage in delivering the flexibility required for the electricity system in Great Britain through the provision of services to the system operator (so-called ancillary services).

In addition to providing ancillary services, some storage installations make money from electricity price arbitrage. These installations use cheaper, excess power generated at certain times of the day to charge the batteries, and then export it back to the National Grid during periods of increased demand when prices are high.

Another driver for energy storage is a need to meet increased electricity demand due to electrification of carbon intensive sectors such as heat and transport in the most efficient way possible. This increased demand places extra congestion on electricity networks and may trigger network upgrades. Energy storage can help avoid or defer costly upgrades to the electricity transmission and distribution networks, reducing bottle necks on the grid.

Battery storage installations are modest in size compared to traditional power stations, and can take up as little as 0.65 ha for 25 battery containers. These installations are also relatively low impact both in terms of height and environmental effects. There is, therefore, the opportunity to have many of these installations dotted around the UK, contributing to the UK’s energy security.

How are these consented?

Recent changes in legislation relating to the Nationally Significant Infrastructure Project (NSIP) regime means that the caps on battery storage capacity for planning applications in England and Wales (50 MW and 350 MW, respectively) has now been removed. This means a battery storage proposal which exceeds these thresholds will no longer be considered an NSIP, and all applications for battery storage, regardless of their size, will be determined by local planning authorities under the Town and Country Planning Act 1990 regime. The removal of battery storage installations from the NSIP regime is in the Infrastructure Planning (Electricity Storage Facilities) Order 2020.

Locational and planning considerations

There is a locational requirement for battery storage installations to be situated in close proximity to existing electrical substations and/or grid infrastructure, reducing grid connection costs. The initial challenge is to find substations with available grid capacity.

The following are the most important planning considerations:

• Protection of residential amenity – noise mitigation measures will be important if the facility is located near to sensitive noise receptors.
• Community safety – a secure boundary, usually a 4-metre high security fence, together with CCTV coverage is often required.
• Ecology – often battery storage facilities are located on green field sites, ecological mitigation measures may be required.
• Highways – connection to the highway network will be important for construction and maintenance; a s.278 Highways Act 1980 agreement may be required.
• Flood lighting /drainage / landscaping – high level security lighting may be required, as well as surface water drainage, and a landscaping scheme. All of these matters can be expected to be controlled by condition on a planning permission.
• Grid connection – sometimes a planning permission for a battery storage installation will not include the grid connection; sometimes this is the subject of a separate permission. This should be checked carefully and confirmation obtained that the connection can be established via permitted development rights if not expressly consented. Ensuring land rights are in place to establish the connection with also be important.
• Upgrades – it is expected that batteries will require replacement and upgrades during the life of the installation. Battery power is currently seeing huge leaps in technological advancement driven by the automotive industry, and it can reasonably be anticipated that more efficient batteries will be available in future than are available today. Planning permissions should be negotiated with local planning authorities to ensure that these are not unduly restrictive and that replacement can be undertaken without a separate planning permission being required.
• Permitted development – frequently the planning permission for a new battery storage installation does not show all the equipment associated with the facility, and required for the grid connection, and may only identify the number and location of the battery storage containers. The following are often not included in the approved plans: underground cabling works, switchgear and telecoms housing, harmonic filters, pre-insertion resistors, and transformers. It is necessary to carefully check that these works can be undertaken pursuant to permitted development rights, as explained further below.
• Restoration – since many of these installations are located on fertile agricultural land, many planning permissions provide that these installations will have a limited life span of approximately 25 years, after which the land will need to be returned to its former condition; a condition on a planning permission requiring a decommissioning and restoration scheme to be approved by the local planning authority can be expected.