When he was in school, Joe Corbett recalls, his physics teacher described the three laws of thermodynamics as: you can’t win; you must lose; and there’s no way out of the game. While there is no way out of the power game, he states, the first two rules can be eliminated if we change the way we do things. For Corbett and Friends of the Supergrid, there is a way to move on.
The group of companies and organisations of which he is a member wants to see a pan-European transmission network facilitating large-scale renewable energy and transportation of electricity. It would not be an extension of interconnection, but the creation of supernodes to collect, integrate and route renewable energy to the best available markets. The first of three phases that it envisages is centred around the North Sea (UK, Germany and Belgium).
To make it happen, Corbett says that we need a vision. There has been “some political movement in the area but some governments are better than others at it,” he states. “But there’s no European vision.” This is despite various initiatives: the North Seas Countries’ Offshore Grid Initiative (NSCOGI), the European offshore grid study, ENTSO-E’s plan for electricity highways, the ISLES project and the Adamowitsch Working Group.
“My view is you start with the portfolio,” he explains. “If we try to live with our values, reducing greenhouse gases, we can’t be burning fossil fuels for generating electricity.”
Once a portfolio is agreed, we must identify a source. “They have to be secure so it’ll have to be indigenous,” he states. “Our argument is a huge amount of that is going to be wind and quite a lot is going to be offshore wind. So we can build at scale today, so we can start now,” he states.
While there is “no doubt” that solar will come from northern Africa and southern Europe, “the scale of that is not the same as wind.” Corbett explains: “We talk of hundreds of megawatts of PV, we talk about gigawatts of wind.”
Location is the next decision: “you create a vision of how you transport that electricity.” Rather than everyone “do their own thing and then putting it together,” somebody must provide leadership. “Show the people and say: ‘that’s our plan, what do you think?’ Let them comment or not, and then agree on what this vision is going to be.”
Mainstream’s head of technical services says that “everybody says to you when you start talking about these things: ‘it’s too expensive, surely that’s too expensive’.” Corbett has been focused on the economics of phase one. He and a colleague have run financial models on nine cases: from a small grid with high wind curtailment to a full supergrid with zero curtailment.
Based on a set of assumptions (e.g. a debt:equity ratio of 85:15, a ten year construction time and a life span of
40 years), Corbett predicts that the final cost could be “down to about
€0.02 per kilowatt hour” for the wholesale electricity user. “Ultimately the customer pays of course, but what the customer pays is only a very small bit,” he states. If the costs were included in the rate base, the supergrid’s first phase would cost consumers €0.23 per kilowatt hour, according to Corbett.
He cites the recent European offshore grid study (on building a grid in the North and Baltic seas) as supportive of his own conclusion. It found that the additional cost of creating a meshed offshore grid would be €0.01 per kilowatt hour.
As wind capacity factor is low (approximately 44 per cent in the North Sea), “we increase capacity by letting other people use it for trading,” says Corbett of phase one. Without this provision, the transmission use of system (TUOS) charge rises. Even with 100 per cent capacity for offshore wind, the TUOS charge would be lower than that forecasted for CCGT-generated electricity on the system (€40 per MWh in 2015 and €47 per MWh in 2020 based on Pöyry forecasts in November 2011).
The power grid Corbett envisages is also “going to be a data centre.” Beneath the supergrid of “a high voltage DC network with big links, connecting renewable resources to big load centres” will be existing transmission systems, distribution systems and residential and retail networks.
“Each layer of that, in the future, will have controllers. Between each layer there will be certain data requirements, so whoever is controlling the supergrid has to somehow know what’s happening at ground level and know what’s happening at the generation side,” he says.
“Because the generation will be variable you need two-way communication. So the generation needs to know what the supply is doing, and the supply needs to know what the generation is doing. And in between all of these areas you can have things like price signals.”
The supergrid will require market software for “huge amounts of data going up and down this chain, individual controllers at each level and certain levels of autonomous control”.
Between nodes on the supergrid and existing transmission systems, controllers will have to work “in harmony”, with the necessary software: autonomous support systems and simulation systems. Ireland, whilst not envisaged in phase one, could benefit by delivering some of the innovations, in particular regarding control strategy, software and design studies.
Grid not interconnector
In conceptualising a supergrid, Corbett considers the profitable Norway-Holland interconnector Norned. At night, European utilities export to Norway, which suspends hydro generation. Though energy is cheap, transmission capacity is expensive because of strong competition.
During the day, Norwegian generator Hydro is the only customer on the interconnector. It can get high electricity prices on the European continent at low transmission costs due to the absence of other bids for transmission.
Two features of this profitable pipe are notable. Firstly, the 700MW connector is “a relatively small pipe in comparison to the European market”.
Secondly, the connected markets are so different. “If the pipe is small in comparison to one of the markets, the interconnector makes money.” If the pipe between these disparate markets was large, prices would simply equalise.
“When you get into the realm of supergrids,” he adds, “you have to stop thinking about them as just interconnectors. This is just part of the transmission grid, it just happens to be a European transmission grid.”
Corbett believes that a phase one will be built. “Will it be the Friends of the Supergrid one? I don’t know.” While the Friends of the Supergrid plan is championed by industry, the NSCOGI is politically driven. “We need both.”