Modelling embedded technologies in energy service networks - Modelling Distributed Energy Resources in Energy Service Networks - page 71

Naturally, the thermal power available to discharge from the storage facility is
closely related to the efficiency of the TES system. So, for all the thermal power
stored in a water tank the power available to discharge will rely on the performance
of the store units. Since the sensible storage units have the purpose of meeting the
daily thermal load requirements, it can be assumed that the discharging capacity of
the stores will be closely related to the energy they charge during the day; this concept
is related to (4.31) and can be defined as:
nβ nβ

ED store
k

EC store
k

= η ts · (4.36)

β = 1 β = 1

This concludes the formulation of the CHP and TES framework for the TCOPF
modelling tool. From this methodology it is clear that the presence of cogeneration
and TES systems in energy service networks can provide additional degrees of free-
dom in the consumption and delivery of energy, inherently impacting the operation of
the infrastructures. By introducing CHP equations into the TCOPF model, the effects
of a high presence of these small-scale generators on the performance of energy
service networks can be assessed and likewise optimal dispatch strategies can be
identified. This modelling capability allows engineers to begin devising the pathways
of a more sustainable way of heat provision to meet end-user needs.

4.4 Modelling PHEV technologies

4.4.1 Fundamentals of plug-in hybrid electric vehicles
Plug-in hybrid electric vehicles (PHEVs) are 'mobile agents that have the property
of operating either with an electrochemical battery, which runs on electric power
obtained from the grid or on an internal combustion engine (ICE) that uses petrol
as its main source of fuel'. This novel type of commodity has been gaining pub-
lic attention due to both the unstable prices of petrol and the high CO 2 emissions
conventional vehicles produce [194]. Nowadays, production of PHEVs is slowly
being rolled out into the market after much work in developing prototypes [195,196].
This progress has led the technology to receive attention from diverse sectors of the
population such as environmentalists, governments, academics and the energy indus-
try [197]. Due to the high interest, the auto industry is working relentlessly to market
PHEV models that appeal to the consumer both in their design and in their technical
performance [198-201]. Therefore, if technological progress is achieved and cou-
pled with sensible policy incentives, it could just be a matter of time for this 'green'
commodity to be massively deployed [202].
The plug-in type is the next generation of hybrid vehicles that bridge the gap
between present HEVs ( e.g. Toyota Prius) and the battery electric vehicles, also known
as BEVs ( e.g. Tesla Roadster) [112]. The vehicle configuration and components of
PHEVs can be very similar to conventional HEVs. This fact implies that both models
can easily couple an electric drive train with an internal combustion drive train. How-
ever, manufacturers have found there are complex trade-offs among different hybrid