Energy storage – Why do we need it?
Renewable energy is more sustainable, but it makes delivering power on demand a major challenge. Energy storage will be key.
Energy storage is not a new concept in itself. It has been an integral component of electricity generation, transmission and distribution systems for well over a century. Traditionally, energy has been stored in barrels of fossil fuel or pumped uphill for storage and then let it flow back down again, creating hydro energy when it’s needed.
Wind and solar power installations generate power intermittently and with variable output. When the wind is blowing or the sun is shining, excess power should be stored and made available during times of peak demand.
More renewable energy will require smart, efficient power transmission and distribution networks. Energy must be stored at appropriate times and locations in order to balance generation with consumption and to maintain grid stability.
Energy storage case studies
To provide additional power to the grid on demand, ABB supplied and installed a battery energy storage solution using Lithium-ion (Li-ion) batteries that can provide one megawatt of power during 15 minutes.
The storage facility is integrated into EKZ’s power distribution network and is being used to evaluate performance in key areas such as balancing peak loads and intermittent power supply, and the viability of the solution for grid optimization.
Falbygdens Energi is a Swedish utility with a significant portion of wind power connected to the grid in the Swedish city of Falköping.
Here, the storage solution to the unpredictable supply of energy from wind turbines was based on a new technology that uses a battery storage device to provide stability to the grid. The equipment is part of an existing substation in the city of Falköping and enables the storage of locally produced energy from wind turbines. It has a storage capacity of 75 kilowatts (kW) in cycles of up to 60 minutes.
This will help to balance peak loads during the day and enhance grid stability.
The UK Power Networks, which supplies power to over eight million homes and businesses in the UK, to develop a dynamic energy storage solution. The installation enables renewable energy generated by local wind power plant to be fed into the power network when needed. It also ensures that some of the energy is kept in reserve to regulate power flow to compensate for the intermittence of wind power and to support power quality in the event of a fault.
Together, these high-power density modules can store up to 200 kilowatt hours kWh of electrical energy.
The installation provides dynamic voltage control in the distribution system and, at the same time, enables dynamic storage of surplus energy from the wind power plant. This surplus energy is used to level out peaks in grid loading to provide grid stability.