TABLE OF CONTENTS Building ever-larger and more complex networks to subdivide and deliver the electricity output to users did carry significant cost, and still does. What is more, it requires transmission lines to be installed across both public and private property. Building new lines is always contentious. But the overall effect of the increasing scale of electricity generation and interconnected systems steadily reduced the cost of electric light and motive power.
The National Grid was developed rapidly after the 1926 recommendations. By 1933 some 4 000 miles of transmission lines had been completed and by 1935 the grid was regarded as complete. Rated at 110kV, it was much smaller and operated at a lower voltage than the grid in operation today. But it signalled a radical shift in managing the electricity supply. The fact of the grid's existence meant that all electricity generators and electricity users were connected. For it to work successfully, power generators had to supply ('export') power to the network within strictly controlled current and voltage limits. What is more, the power stations could no longer operate entirely independently. Part of the intention of the grid was to allow electricity to be moved around the network to meet users' needs and to provide backup, for example for power stations that had to shut down. But, in return for access to supplies from the grid, power-plant operators had to accept that part of their own supply could be diverted to other parts of the network as required,...
