You know the world is changing when your electricity grid operator starts to take solar power seriously – even in a country more than 50 degrees of latitude above the equator.

Britain’s National Grid has just published its Summer Outlook Report, in which it shares its expert and informed view on how the electricity system will fare over the summer months. The grid operator forecasts another fall in electricity demand on the transmission network for this summer: ‘largely due to an increase in embedded generation, particularly solar photovoltaic (PV).’ That’s small-scale generation plant connected, not to the high-voltage transmission system, but to the local distribution system and thus ‘invisible’ to the transmission grid operator.

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National Grid’s role is to balance generation and demand, today and tomorrow, even as patterns of electricity generation and consumption are changing. And the operator certainly sees changing patterns; perhaps the most fundamental being incrementally reduced demand on the transmission system year-on-year. Consumers are both using less power, and relying more on on-site generators – PV and other technologies – and smaller, local generators, including CHP.

National Grid currently forecasts an increase in decentralized solar power generating capacity for the UK of 200 MW per month and, from its unique perspective, is clearly seeing the effects on the overall power system. And it is taking solar PV very seriously: ‘Embedded PV generation is a major contributor to the trend of decreasing transmission system demand.’

It’s one thing for decentralized energy (DE) enthusiasts to talk up the increased use of DE, here’s the grid operator from the cloudy UK reporting the same thing.

Globally, the solar PV market grew by a quarter during 2015 to reach an installed generating capacity of 227 GW, according to the International Energy Agency. A small proportion of this is large, sometimes utility-scale, ground-mounted arrays – modern power stations – but most is rather smaller, decentralized plant. Growth is taking place across the globe, with Asia leading the way. Italy, Greece and Germany each have enough PV capacity to generate 7-8% of their total electricity needs, says the IEA.

Electricity systems with a major decentralized component have arrived, with solar energy leading the charge.