Wind energy storage technologies - Wind Power Generation and Wind Turbine Design - page 699

it is likely that economic incentives will be necessary to attract consumers to
purchase SEV and V2G vehicles.
4.11.4 Disadvantages of EV technology
The primary disadvantage with EVs is the initial investment to establish the required
infrastructure. Transmission lines will need to be upgraded to allow for high power
capacities to and (in the case of V2G) from the electric cars, battery banks or charg-
ing stations will be required to replace conventional refuelling stations, and main-
tenance services will need to be established as we transfer from conventional ICEs
to electric motors. In addition, travelling habits may need to be altered due to the
alternative limitations associated with EVs instead of conventional vehicles, such as
driving styles and time required for refuelling. Finally, the remaining issue with EVs
is the driving range that can be obtained. Currently, hydrogen vehicles have a much
larger range than EVs, although hydrogen vehicles are much less effi cient. There-
fore, depending on which of these factors is more important for different energy
systems will most likely decide which of these technologies is preferred.
4.11.5 Future of EV technology
Electric vehicles are most likely going to be a key component in a number of
future energy systems with large penetrations of intermittent renewable energy.
This is primarily due to the two advantages mentioned in the introduction to this
section: they reduce oil dependence and provide affordable large-scale energy
storage. However, as mentioned already, alternative options such as hydrogen
vehicles may reduce the attraction to EVs within energy systems which prioritise
range over energy effi ciency. However, steps are being taken in Europe, Japan
and elsewhere to improve battery technology to the point where a 500 km range
is standard. Key developments, e.g. in nanostructured lithium batteries may triple
the energy density which can be achieved if this technology can be proven and
manufactured cost effectively.
5 Energy storage applications
Energy storage devices can accommodate a number of network requirements.
These include as follows [2].
5.1 Load management
There are two different aspects to load management:
1. Load levelling : Using off-peak power to charge the energy storage device and
subsequently allowing it to discharge during peak demand. As a result, the
overall power production requirements becomes fl atter and thus cheaper base-
load power production can be increased.
2. Load following : Energy storage device acts as a sink when power required falls
below production levels and acts as a source when power required is above
production levels.