Grid connections

You can't generate electricity unless you can plug your powerstation into the same bit of wire as your customers - that way they can absorb the energy that you're pumping out and your power station won't break.

The problem is that, in this country, there have been quotes of a 10 year lag in requesting, and being served by, a grid connection.
The trouble is that, by their nature, most renewable energy sources are miles away from the nearest bit of the grid that can carry the vast amount of power they are generating. This is particularly the case in scotland, where the energy has to be shipped down to london.
Additionally the grid has to be routed through areas of outstanding natural beauty, which requires planning permission (etc. etc. etc.).

As such getting grid connections to renewables can be very time consuming and very expensive.

Coupled with the looming energy gap it therefore makes sense not to always give priority to renewables for their grid connection - something that the EU would like to see. Conventional (coal and gas) power stations tend to be closer to the consumers, and traditionally stronger sections of the grid (where their power can easily be absoped and fed to consumers).

The government is doing the right thing - whilst there is much essential work to be done to connect in the renewables we don't want to put all of our eggs in one basket.