Before the Nineties we had a very clear-cut industry,” says Richard Smith, head of National Grid’s networks business.Across the country, thermal power plants fired up by fossil fuels would send power via giant cables, strung up by pylons and criss-crossing the country. After spanning miles, cables meet substations which dim the power to a voltage which smaller distribution wires can carry into homes and companies.“It’s not as simple now,” Smith says.National Grid sits at the heart of this energy system. Now the £39bn company faces one of the country’s greatest challenges – delivering the energy system’s biggest shake-up since deregulation. The one-way relationship between power producer and power consumer has been skewed by the rise of technology which is handing energy users the power to make their own electricity. From suburban rooftop solar panels to the scaled-down generation units on site at major factories, Britain’s electricity chain has become more democratic. Where once National Grid was in near full control, now a wave of new technology is changing the rules of the game.“The big challenge that National Grid is facing is that we have 38GW of large thermal plant that are going to be closed by 2025 and they were traditionally what we would use to keep the system stable,” says Tim Rotheray, boss of the UK’s Association for Decentralised Energy.“At the same time we’re seeing a rise of variable, intermittent generation coming on to the system. The traditional tools that National Grid had are falling away so the challenge is to look at the new options which exist.” The UK is home to about 12GW of solar PV, the equivalent of more than three Hinkley Point C nuclear power projects or 24 gas-fired power plants. On a sunny day these panels can generate 9GW of power – much of which cannot be controlled by National Grid’s main control centre because it is connected directly to local grids. The impact is clear: a surge in this “decentralised” power is reflected as a sudden drop in demand on the main grid – and system controllers have seconds in which to react to avoid overpowering the system. Last spring a surge in solar and wind power during an ebb in demand meant power plants were forced to pay to have their generation volumes taken up. Without a redesign of the system negative market prices will increase. Already it expects to invest £20bn to ensure Britain’s energy system is ready for a low-carbon future, of which £9.5bn will be spent replacing and renewing network equipment. The company is also offering millions of pounds worth of contracts to generators and users who can guarantee to help the operator manage the ebb and flow of demand and generation volumes. This summer the group will launch a scheme which pays companies to use more electricity when wind and solar power surges past demand. This flips the winter-time challenge of securing enough supply to meet demand. During these times National Grid has resorted to paying power plants to remain on standby to ramp up power on demand.
Telegraph 13th May 2017 read more »