Battery Storage FAQ
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Our commercial battery storage FAQ page answers some of the questions we get asked about how they work, how they benefit and how they are installed.
What is the difference between a grid connected battery and a ‘behind the meter’ battery?
A grid connected battery is one that is connected straight to the electricity grid and derives its income solely from providing grid services to the National Grid. A “behind the meter” battery is a battery that is connected to a private electrical infrastructure, often within a factory or warehouse. In this scenario a battery can provide grid services, as a grid connected battery, and also support the occupier with load shifting, electrical storage and peak shaving services.
What technology does Greensphere use for its battery storage systems?
Greensphere use Lithium Ion batteries, which are a common and understood battery technology. However, Greensphere is not tied to any manufacturer or technology and keeps abreast of new and developing technologies as they appear. Our challenge is to identify the best technology for our customers and to explain the risks associated with any decision.
What are Grid Services and how can they fund a battery installation?
Grid services are the portion of services that are devoted to supporting the National Grid. They change from time to time as the National Grid seek to manage their network more effectively. They appear as short term markets with bidding opportunities, barriers to entry and licences. These services can be accessed from inside an occupier’s property as well as connected directly to the grid. The services typically are designed to provide additional grid stability at short notice; should an unexpected event occur on the network outside of normal operation. By allowing your battery to be entered into these network managed markets – making your asset available to the network operator – additional revenues can be earned.
What are the benefits of a battery storage installation to an occupier?
There are many benefits of installing a battery. The economic benefits include load shifting, where an organisation can draw battery power during times of high Triad (TNUOS) charges between 4pm and 7pm during winter rather than drawing expensive grid energy. A company can also reduce the peak load that it may draw, in order to stay below a physical or financial threshold that may be imposed by their supplier. Large pieces of industrial machinery may have this effect. A pre-charged battery can provide this energy to smooth out the spikes, without drawing high peaks from the local network. The third benefit is to act as a store for renewable energy generated on site as the battery could be charged off free solar electricity. This energy could be sold back to the grid for a nominal sum, or retained to replace future demand.
How much space does a battery installation take?
There is no such thing as a typical installation, however, most batteries up to 2MW could occupy the footprint of a shipping container and the battery units can be laid out to suit the location, provided that the battery packs can be accessed for maintenance.
Do I have to own a battery to get the benefits?
Greensphere can arrange finance for many battery installations, however, there are a number of minimum requirements around battery size, use and covenant strength of the occupier.
What is an Aggregator and do I need one?
An aggregator is an organisation that supports the income from a battery through interfacing with the National Grid’s markets or Grid Services to allow the battery to be used within the pre-defined parameters. All Greensphere battery installations that hope to generate revenue from the National Grid will require an aggregator.
Do batteries need to be maintained?
Batteries, like any other sophisticated piece of equipment, require an amount of maintenance to ensure that they are running effectively. Greensphere has trained engineers who provide this service, which includes monitoring, to ensure that any issues are picked up quickly and dealt with.
How long will a battery last?
Batteries are a way of storing electrical energy in a chemical manner and as such it depends on how often the batteries are charged and discharged and the conditions they are charged and discharged in.
Most manufacturers will talk about the number of complete charges and discharges, or complete cycles, that a battery can perform and give a percentage of original energy capacity that they will retain after those cycles. For example, 60% of original capacity after 10,000 cycles, for a Li-Ion battery.
Ultimately the lifespan of a battery will depend on how it is used. For C&I ‘behind the meter’ batteries, performing relatively light frequency response and TRIAD avoidance functions, 15 years could be an achievable length of time for the battery to last.
How do you connect battery storage to an organisation’s infrastructure?
Connecting a battery to an organisation’s electrical infrastructure is done in the same way as Greensphere connects a large solar PV array. We generally connect the battery to the primary distribution network and ensure that the organisation’s protection systems are up to date and will behave in a known way in the event of a problem. The batteries deliver a direct current (DC) and this is passed through an inverter to create alternating current (AC) which is suitable for general use. In addition to the battery and inverters, Greensphere will also install a G59 relay and cut-out to protect the site in the event of an electrical failure, in addition to a series of meters to ensure that the billing and flow of energy is understood. This generally requires significant design and customers can ask Greensphere to investigate old infrastructure thoroughly to give them a better understanding of the risks within their systems.
For more information, visit our commercial battery storage page.
