Both Britain and Ireland have a similar power grid set-up, being stand-alone islands with limited interconnection with neighbouring European grids and attempting to support bold targets for renewable energy. On 4 December 2004, the Irish electricity regulator placed a moratorium on new connection licences for wind generators with immediate effect. The moratorium was placed following urgent warnings from the Irish grid operator, ESB National Grid, that a recent rapid rise in the amount of wind generation proposed for connection to the power system posed an increased risk to the security and stability of the power system which exceeds the level normally likely to be accepted by a prudent system operator. ESB wants a number of technical issues resolved, such as the intermittent nature of wind as an energy source. Potential problems have arisen earlier in Ireland than in Britain because of the small size of the Irish power generation.