By Jason Deign
The potential for interconnections to minimise the need for storage across Europe looks vanishingly thin in the face of recent research.
Five future interconnection scenarios published last November as a result of a European Commission project called e-Highway2050 all accept the need for significant storage capacity in order to de-carbonise Europe’s energy system.
The 40-month-long project concluded it would be possible to achieve close to zero carbon emissions by 2050 with an investment of between €100bn and €400bn in electricity transmission infrastructure.
At the same time, however, all the models used in e-Highway2050’s research findings booklet also included an allowance of between 73GW and 113GW of energy storage, compared to 45GW in place in 2012.
“I suppose that the architects behind the project want to demonstrate the high shares of fluctuating energy can be handled,” consultant Paul-Frederik Bach told Energy Storage Report.
Energy savings, DSM and storage
“They have realised grid reinforcements cannot do it alone, so they have added energy savings, DSM [demand-side management] and storage in a necessary, but not necessarily optimal, extent.”
The research comes amid growing uncertainty over European grids’ ability to handle large quantities of non-dispatchable energy from the renewable generation being put in place to meet carbon reduction targets.
Last November, for example, the influential energy blogger Euan Mearns published an analysis of wind generation across Europe which appeared to disprove the notion that ‘it’s always windy somewhere.’
“On a regular basis the whole of Europe is becalmed,”Mearns observed. “Not only under Arctic high pressure in mid-winter, but also when high pressure is in charge during September and October.
“Near 100% back-up is required and interconnectors will not solve the wind intermittency problem.”
Intermittency grids can cope with
The exact level of intermittency that grids can cope with has always been open to question.
And a number of countries, such as Denmark and Germany, have already exceeded what might previously have been considered a ‘safe limit’ for renewables penetration.
However, some experts have argued that a sufficiently large grid would allow excesses in renewable energy production in some places to make up for practically all deficits elsewhere.
“There are only six countries but the smoothing result is already quite good,” he said. “There is no contradiction with my results. Wind and existing storage hydropower could cover almost all the annual need.
Rated power of existing storage
“Not included in this rudimentary idea are all contributions which could come from existing river run-off hydropower, biomass power plants, enlarging the rated power of the existing storage hydropower, or solar energy.”
In Czisch’s view, a European supergrid stretching as far south as Morocco would obviate the need for electrical storage, although up to an additional 24GW of pumped hydro storage might be needed to cover power deficits.
It is fair to say, however, that Czisch’s optimism over the potential of grids to support pan-regional wind power is not widely shared. “Sadly politics don’t seem to be able or want to translate the results into reality,” he admitted.
“I can’t answer the question how much electrochemical energy storage is necessary in the chaotic suboptimal and expensive system which we might get after all the bad decisions of our politicians and energy industry.”
But even if grid investments could potentially negate the need for non-pumped hydro storage, there is still a question over whether enough interconnection capacity can feasibly be installed to meet Europe’s decarbonisation aims.
Serving generation and demand scenarios
One thing that is clear from the e-Highway2050 research is that Europe’s existing grid, or even that forecast for 2030, cannot serve the generation and demand scenarios that the European Commission forecasts for 2050.
“Whatever the energy landscape will look like in 2050, it appears indispensable for the security and affordability of the power system to create North-South corridors and reinforce connections,” said an e-Highway2050 press release.
However, writes Bach: “It has always been difficult to achieve public acceptance of new transmission facilities, particularly for high-voltage overhead lines.
“It is hard to imagine how the assumed transfer capabilities could be established in densely populated European regions as AC overhead lines.
“On the other hand, it will be very expensive to install the same capacity as HVDC cables.”
Getting local communities on side
Furthermore, as anyone with experience in the European energy sector knows, the challenges in getting local communities on side pale into insignificance next to those involved in getting member states to agree on anything like a grid link.
In fairness, the European Commission has recognised this and is trying to tackle it, at least on a market level, through its Energy Union initiative.
Nevertheless, the likely difficulties that could arise in trying to build out Europe’s grid infrastructure contrast with the ease with which the continent appears to be embracing community energy trading models based on distributed generation.
These models, based on increasingly ubiquitous software platforms, promise to largely do away with the need for expensive grid infrastructure upgrades.
And the distributed generation and storage assets they rely on are largely paid for by energy consumers rather than taxpayers.
In the final analysis, it is almost certain that Europe needs both better grid connections and more storage. The issue is which could be put in place more quickly; and commercial viability might increasingly be on the side of the latter.