National Grid has outlined concerns over the likely technical challenges that would arise from integrating anything more than 10GW of solar electricity on the UK power grid.
In a solar PV briefing note published alongside the Renewable Obligation banding yesterday, the UK grid operator said that incorporating more than 10GW of solar would place excessive strain on the grid without the construction of new storage capacity.
The briefing note is intended to help inform the Department for Energy and Climate Change about the potential impact of significant solar capacity in the UK, modelling up to the minister’s oft-stated ambition of 22GW of solar by 2020.
In its modelling, the National Grid predicts that in the summer, 22GW of solar capacity combined with nuclear and the required level of combined cycle gas turbine (CCGT) generation would exceed the demand on the system (as seen in Figure 1).
Whilst the National Grid admits that the additional generation could be exported to the continent or diverted into storage, it warned: “It should not be assumed that all the interconnector capacity will be available or that other parties will be willing to buy electricity at the other end.
“If the required export capacity on the interconnectors was not available and the operator was not able to reduce output from solar generation, then nuclear generation would have to be curtailed or shut down."
As a result, the National Grid has recommended to DECC that the grid can only support 10GW of generation “without making the operation of the transmission system significantly more difficult”.
The grid operator added: “With 22GW of solar PV the system would require unacceptable dependence on the ability to export over the interconnectors, or the construction of additional storage.”
The Solar Trade Association (STA) expressed its surprise at National Grid’s claims about the balancing of more solar on the grid.
Commenting on the National Grid’s report, STA PV specialist Ray Noble said: “German grid engineers are overcoming the challenges of integrating considerably more solar than National Grid anticipate. We have every confidence in the competence of British engineers to accommodate new technologies.”
The National Grid’s concerns over the integration of significant solar capacity will cause concern to many in the industry, especially considering that the long-awaited revised renewables roadmap is yet to be published. It is expected that the revised roadmap will account for significant solar capacity in the future. However, the National Grid’s warning over problems balancing the grid could see ministers water down ambitions for solar in the UK.
The full National Grid briefing note on solar PV can be viewed here.
Do you agree with the National Grid? Are you concerned that the briefing note will have an adverse effect on the UK’s solar ambitions? Let us know in the comments.