The New York Times says the pressure is on because Britain doesn’t have the infrastructure and the technology isn’t there for full reliance on renewables:
In the absence of new infrastructure and technology, the shift to more intermittent sources of power could leave the national grid more vulnerable to power cuts than it has been for decades. The last time Britain faced serious energy shortages and widespread power cuts was in the 1970s, when the government was locked in a battle with coal miners. The chaos contributed to a national emergency that took down the government. Today a majority of Britons are supportive of moving away from fossil fuels, but that could change in the event of such a crisis.
The pressure is on – if Britain gets it right, it might inspire other countries to follow:
Even so, it’s hard not to feel a little nervous about what, at its heart, is an experiment, one fraught with danger. Britain has turned itself into a test case for what happens when you take an industrial economy and rapidly wind down the use of fossil fuels. Already, there are consequences: higher power costs and a shrinking manufacturing base. The health of the country’s economy — and the willingness of other countries to follow — may very well ride on the experiment’s success.