Why an EU-wide supergrid has the wind in its sails
18 September 2018
The supergrid can be thought of as an EU-wide hub networked transmission grid which extends existing national island systems into a continental system, write Marcos Byrne and Eddie O'Connor
Figure 5: Potential locations for SuperNodes around Europe
In order for Europe to meet its COP 21 Paris commitments, it will be a requirement that all electricity be generated from renewables by 2050.
European electricity demand peaked between 2005 and 2007 at roughly 3,500 TWh. However, since this peak, demand has actually fallen back to about 3,100 TWh (10 per cent decrease).
Fall in electricity demand down to energy efficiency measures
This fall over the previous 10 years can be attributed, in large part, to energy efficiency measures incorporated mainly at a domestic level. During the same period in time, there has been a large increase in the power generated from renewable sources in Europe.
Figure 1 shows the split by technology of renewable power generated in 2015. Further to this figure, in 2015 renewable sources accounted for 77 per cent of new EU electrical generating capacity. In 2016, 86 per cent of new EU generating capacity came from renewable sources.
This shows the significant level of investment and commitment to renewable energy over the past few years. There is a clear trend of growing interest in the renewable sector in Europe.
Part of the explanation for this increased renewable penetration is that the cost of wind power has fallen by about 67 per cent since 2009. Solar PV during the same period has fallen by about 86 per cent.
Coal can no longer compete with wind or solar. According to CIA projections, the average price per kWh of new coal is $9.2 cents, without any carbon mitigation measures. The latest price for offshore wind awarded as a result of competitive tenders in the North Sea is $8.1 cents per kWh.
It was important for this research to quantify what European demand would look like in 2050 and how renewables can meet this demand. It is assumed that 1,335 TWh of demand will be met by rooftop PV installations on 232 million roofs across Europe (both residential and commercial sectors).
Annual demand expected for private electric cars is 522 TWh of electricity
The annual demand expected for private electric cars is 522 TWh of electricity, assuming car ownership profiles remain the same. In the commercial road transport sector, the annual demand is expected to be about 863TWh of electricity.
Figure 2a shows the baseline trend in annual demand. This was calculated assuming an annual growth in GDP of 1.8 per cent, leading to an increase in demand by about 1.3 per cent per annum. Figure 2b shows the estimated annual demand trend when factoring in the previously mentioned factors. This leads to a calculated figure of 4,360TWh annual demand for Europe.
Taking the European demand figure, it was assumed that the difference between current renewable generating capacities and overall demand would be met using only wind and solar resources, and that all other forms of renewable capacities would remain at current levels.
It was noted that an extra 421 GW of wind capacity and 398 GW of solar capacity would be required to meet this estimated extra European demand.
100% future renewable scenario and cost of electricity storage
Of equal importance in considering a 100 per cent future renewable scenario is the cost of electricity storage. Lithium ion batteries have fallen in cost by 75% since 2010, and stand at circa USD 209 per kWh currently. Elon Musk has stated that cost of lithium ion batteries could fall to approximately $100 per kWh by 2020.
The next important question is where the required wind and solar capacity will be located. Figure 4a and b show the available wind and solar resources in Europe. Figure 4a clearly shows that the North Sea, and Atlantic coast off the west of France, and Ireland offer excellent locations for offshore wind farms.
The introduction of floating turbine technology will lead the growth of offshore wind in these areas. It will be impossible to install wind on land in sufficient quantity to meet future demand. Low average wind speeds and community resistance are the reasons for this assumption.
Higher capacity being experienced for offshore wind farms built today
In the calculation leading to the 398 GW figure mentioned above, a capacity factor of 50 per cent was assumed. This is conservative as higher capacity factors are already being experienced for offshore wind farms being built today.
Figure 4b identifies the south of Spain, Italy, and Greece as key areas for the installation of new solar capacity. It was assumed that solar PV would have a conversion efficiency of 30 per cent.
The big question is how to link these areas of generation to the rest of Europe. An EU-wide supergrid is needed to accomplish this. The supergrid is defined as an overlay transmission system, constructed largely in DC.
It will link zones where renewable energy is optimally produced to one another, and to existing national grid AC transmission points. The supergrid can be thought of as an EU-wide hub networked transmission grid which extends existing national island systems into a continental system.
The great enabler of the supergrid is the SuperNodeTM. Figure 5, the main image, shows a map of Europe including possible locations for SuperNodesTM, which will act as a distribution hub, distributing the energy from generation sites to areas of significant demand in Europe, with low loss.
Enable electricity to be collected from where it is generated and intelligently routed
The SuperNodeTM will enable electricity to be collected from where it is generated and intelligently routed over long distances to where consumers need it. The various SuperNodesTM to be located around Europe will be of varying size.
It will enable the transmission of solar from southern Europe and wind from northern Europe to homes all around member states, allowing the EU to meet 100 per cent renewable energy by 2050.
Authors: Marcos Byrne and Eddie O’Connor, Mainstream Renewable Powerhttp://www.engineersjournal.ie/2018/09/18/eu-wide-supergrid-wind-sails/http://www.engineersjournal.ie/wp-content/uploads/2018/09/a-aed5.pnghttp://www.engineersjournal.ie/wp-content/uploads/2018/09/a-aed5-300x300.pngElecenergy,renewables,solar,wind farms