  Virtual power plants, while being virtual, rely on a physical network for
operations. The portfolio of the virtual power plants is flexible in
facilitating a wide range of resources including the local heat pumps. The
power transmission network has the responsibility to ensure the security of
supply, reliability of operation, planning, and expansion. The power
transmission network and apparatus including lines and towers are also aging
with time. Furthermore, the transmission network covers a large geographical
area which is expensive to maintain. The objective of this paper is to
investigate the effect of power network conditions on power network expansion
planning. The condition of the power network is determined by the maintenance
cost of lines and a health index and a risk factor associated with the tower.
The investigation begins with answering how the inclusion of heat pump impacts
the decisions on network interventions. Thereafter, the condition network is
factored into the decision-making by better understanding the impact of the
network condition on the overall expansion planning. Furthermore, many
sensitivity analyses are conducted to evaluate the trade-offs between decision
variables such as cost of heat pump, coefficient of performance of heat pump,
risk factors, and line and tower costs.
