Increasing connections for distributed generation (DG), and in particular, for wind generation, are being sought in power systems across the world. These increased applications present a significant challenge to the existing connection policies of distribution network operators. In particular, nonfirm access to the network has been proposed as a method to increase the penetration of DG. The impact of the connection policies arising from nonfirm access are investigated in detail here. The Irish system is used as a case study, and with reference to the available energy resource and network parameters, the costs and benefits of DG are determined under a number of planning policies. The costs and benefits assessed include connection and cycling costs along with emissions, capacity value, and fuel bill saving. It is shown that a significant increase in the net benefits of DG is gained if the appropriate connection policy is utilized from the outset, and conversely, significant costs are incurred if ad hoc policies are employed. Furthermore, it is shown that nonfirm access has the scope to facilitate a significant extra amount of DG capacity.