Introduction to V2G Use Cases

In the last activity we looked at how V2G works.  Now we’re going to look at what V2G can do.   We’ll do this by looking at the different use  cases for V2G but what is a use case? This can   often be a loosely defined term but here we’re  going to define it as a specific application   of the technology with a type of customer or  site in mind.

There are three main cases that   we will look at which in broad terms should  cover almost every type of V2G installation.   So the first use case is V2G so far in this  course we’ve used V2G to refer to any kind   of bi-directional charging but here we will use  it more specifically as vehicle to grid or V-to-G the use case where energy discharged  from the ev enters the electricity grid.

The next use case we’ll look at is vehicle to  home and vehicle to building so V-to-H or V-to-B   where energy energy discharged from the EV flows  into a home or building but not into the grid.   And finally the use case vehicle to load or V-to-L  where energy from an EV provides auxiliary power   whilst not connected to the grid. Now for each  of these use cases we will explain what it is   why it is useful, how it is controlled  and give an example but before we launch   into the use cases we’re going to cover the  important point of grid connections for V2G  

In any V2G use case where the vehicle is to be  connected to the electricity network a connection   request must be made to the local network operator  from the perspective of the DNO V2G is a source of   generation and therefore in order to be allowed  to connect a number of requirements will apply   it’s important to note that these  requirements will apply for V2G   V2B and V2H regardless of whether the use case  actually intends to discharge to the grid or not   there are three reasons for these requirements

number one the DNO needs to keep a record of  the sources of generation on their network   to understand the impact on  their network’s infrastructure   in some locations there may be constraints on  generation at low voltage levels that can even   prohibit additional generation being added to  the system without the network being reinforced   number two the DNO is obligated to operate  their network within a strict set of limits   therefore there are electrical  requirements for the V2G systems   output in normal conditions including voltage  frequency and power quality and number three   the DNO needs to have assurance as to how  the V2G system will respond in a fault event   for example if maintenance is necessary on  part of their network then the DNO can switch   off power for a short period of time unless  additional control is added to the switch   Unless the additional control is  added to switch the V2G system into islanded   mode then the system must be designed to respond  to the loss of mains power to prevent discharging   the vehicle and therefore protect the maintenance  personnel at risk of electric shock.

The exact   requirements will depend on the location where the  V2G system is to be connected this is irrespective   of whether the system is ever intended to  be used to export energy to the network   and therefore applies to both V-to-B and V-to-H where there is an electricity network connection   as well as V2G. For further reading on this  check out the links provided below this video