Why are you connecting the facility to the grid at Frome rather than locally in Westbury?

NREL applied to Scottish and Southern Energy (SSE), the local grid company, for a connection to the local grid. SSE determined the most suitable location for this connection was at Frome, which is a matter for them to determine as owners and operators of the local grid.

Grid connection is complex and can only take place where there is capacity available without needing to make unfeasible / unrealistic changes to the network. Thus, relatively distant grid connections are not an uncommon feature of many power generating facilities.