Global Power Grids for Harnessing World Renewable Energy

Spyros ChatzivasileiadisTechnical University of Denmark (DTU)

Energy Security Summit 2016, Berlin

Towards a 100% Renewable Energy Future

Paris agreement on climate change:

•EU to reduce greenhouse gas emissions (GHG) at least 40% from 1990 levels in 2030

•US to reduce CO2 emissions by 32% from 2005 levels by 2030

•China committed to peak GHG by 2030, with the intention begin to cap even earlier (2020)

•Studies for a 100% RES* energy production

*RES: Renewable Energy SourcesJune 2, 20162

Interconnecting RES increases reliability in supply

June 2, 20163

§ Interconnection of19 wind farms in Midwest-US

§ Area of 850 x 850 km

§ “On average, 33% of yearly averaged wind power canbe used with the same reliability as a conventionalpower plant.”

(Archer and Jacobson, 2007)

Interconnections decrease the need for balancing power

• Fully renewable European system

• Interconnector capacities 5.7x larger reduce by 38% the need for balancing energy (~32 GW)

• 32 GW less balancing power (~32 nuclear power plants)

June 2, 20164

We define the Unconstrained layout as that in which all linkshave capacities equal to the maximum recorded exchange, so thatpower can flow unconstrained along the interconnectors. By con-struction, these give rise to the full benefit of cooperation, as theyallow the interactions between countries to be identical to one inwhich they are all aggregated. The sum of the transmissioncapacities

TC ¼XL

l¼1max

n!!!f"l!!!;!!!fþl

!!!o

(26)

over the larger NTC value of each interconnector in the presentlayout adds up to around 73 GW. With 840 GW the Unconstrained

layout capacities are 11.5 times larger. These unconstrained ca-pacities are determined by single, 1-h events over eight years ofdata. Therefore, we consider the 1% and 99% quantiles of the flowdistributions to define a reduced, directed capacity layout, whichwe call the 99% Quantile layout; see again Fig. 4. This means thatpower will flow unobstructed for 98% of the time. The remaining 2%corresponds to around one week per year. The 99% Quantile layoutcomes with 395 GW in total and is roughly half as large as theUnconstrained layout, but still 5.7 times larger than today’s inter-connector capacities. See Table 3.

3.3. Constrained power flow

To determine what fraction of the benefit of transmission isobtained with a non-ideal, limited transmission capacity, we dealwith constrained power flows as defined in (21). This allows thedetermination of a compromise between the reduction inbalancing energy and the increase in total transmission capacity.

As can be seen in Table 2, the 99% quantile capacities provide,with b ¼ 97.6%, most of the benefit of the Unconstrained layoutwith less than half of the total installed capacity. The layout definedby these 99% quantiles can be seen in Fig. 3(c). It is also noteworthythat today’s capacities already provide 35.5% of the benefit oftransmission, if applied to this scenario. In order to find out how thebenefit scales with increasing transmission capacities, ways ofinterpolating between today’s system and the larger layouts arenow defined.

Interpolation A is an upscaling of present capacities with a linearfactor a. That is, for a directed link l, the limits are defined by

f Al ¼ minnaf todayl ; f 99%Ql

o; (27)

where f todayl represents the NTC of the link as of 2012 and f 99%Qlthose of the 99% Quantile layout.

Interpolation B involves a linear reduction of the 99% quantilecapacities with factor b, that is

f Bl ¼ bf 99%Ql : (28)

Interpolation C defines the capacity layout

f Cl ¼ f cQl ; (29)

which allows unconstrained flow for a percentage c of time, asshown by the different quantiles in Fig. 4. Here, more capacity isallocated to more transited links than to less used ones.

Fig. 3. Transmission network topology and link capacity, with the links as of 2012[24e26]. (a) Present layout capacities. (b) Intermediate layout, with a total capacity 2.3times larger. (c) 99% Quantile layout, with 5.7 times the total capacity of (a). All threelayouts are described in detail in Table 3. Line thickness represents the larger NTC ofthe interconnector.

Fig. 4. Distribution of unconstrained, non-zero power flows between France andSpain, normalized to the mean load in France (see Table 1). Several low- and high-quantiles are marked for illustration. The dashed red lines represent current capac-ities. The solid red lines show capacities as defined by the Intermediate layout. Zero-flow events occur around 46% of the time, and are not shown. (For interpretation ofthe references to colour in this figure legend, the reader is referred to the web versionof this article.)

R.A. Rodríguez et al. / Renewable Energy 63 (2014) 467e476472

Becker et al (2014)

Tres Amigas

Cheap RES production over long transmission lines and Supergrids

Atlantic Wind Connection

[«Google» Project]

North-Sea Grid MedGrid

June 2, 20165

The Global Grid

June 2, 20166

June 2, 20167

Telegraph 1866-1901

1866: First successful submarine cable

1901: Global Telegraphy Network

June 2, 20168

A Possible First Step: Wind Farm in Greenland§ High winds ~9.0 m/s

Quebec City

New York City

London

North UK

Faroe Islands

§ Sell wind power always at peak prices§ Trade electricity with the remaining line capacity

June 2, 20169

§ Shallow waters

Wind Farm in Greenland

Quebec City

New York City

London

North UK

Faroe IslandsIceland

§ Greenland – North UK: 2066 km (81% Cable)§ Greenland – Quebec: 3269 km (32% Cable)

387 km (OHL)

550 km

June 2, 201610

Wind Farm in Greenland(3 GW)

*Assumption: off-peak-price/peak-price = 50%

Transmission Route: Europe – USA over GreenlandTotal Cable Energy Capacity: 20 TWh/year

Wind Production(sell at peak prices)

Electricity Trade**(USA ßà Europe)

Utilization (% of total time)

~10 TWh(40%)

~6 TWh(30%)

~10 TWh(50%)

Profits Increase 7% – 12%* 24% – 27% 39% – 42%

Both options result independently to a profitable operation

**Real Data for 2012: PJM (USA), EPEX (Germany)11 June 2, 2016

The Global Grid

June 2, 201612

Smoothing out electricity supply and demand

Load

Load

Wind

June 2, 201613

Electricity trade USA – Germany • Real price data for 2012

– EPEX in Germany – PJM in the USA

• Losses for an 8000 km route • Investing in the interconnection (5500 km long cable)

• Amortization period – 18-35 years for cable utilization 50% or more

• Costs per delivered kWh– Except for the most expensive RES generators, it is more economical for the

US to import RES power from Europe than operate its own conventional power plants

June 2, 201614

Additional Benefits

•Less need for bulk storage

•Lower volatility of electricity prices

•Enhance security of supply, by increasing the diversification of energy sources

•Boost developing economies and reduce their GHG emissions

June 2, 201615

Investments

•Costs are the biggest concern for the Global Grid

•Investment costs are estimated in the range of billions of dollars for each interconnection

•However: this is in line with the costs of other energy infrastructure projects

June 2, 201616

Olkiluoto, Finland: 4th Gen. Nuclear Power Plant; Cost: $4.1 US billion

Europe:

1 trillion Euros in investments forenergy infrastructurenecessary

Google Project:~ $5 US billion

North-Sea Grid

Estimated Costs:~ €70-90 billion until 2030

June 2, 201617

Operation

• Coupling regional markets to a Global Power Market

• Global Power Exchange

• Electricity as global commodity

• Increase competition within each region

• Establish competition among the lines

June 2, 201618

Global Grid in the News

• Articles in Newspapers and Magazines

June 2, 201619

• TEDx Talk by Prof. Damien Ernst

Eté 2013 l LIÈGEU l 27

à l’heure actuelle que des problèmes de congestion importants se créent entre les réseaux de distribution et le réseau de transmission, principalement à cause de l’énergie produite par les fermes éoliennes. Un autre exemple est celui des surtensions causées par les panneaux photovoltaïques. En effet, dans certains réseaux basse tension, ces panneaux ont fait grimper la tension jusqu’à 290 volts alors qu’ils sont sensés fonctionner à 230 volts.

Une grille pour la planète

Des chercheurs de l’université de Liège et de la Eidgenössische Technische Hochschule de Zürich (ETH) pensent que la prochaine étape de l’évolution de notre réseau électrique sera la constitution d’une grille qui couvrira la planète entière. Elle connectera la majorité des consommateurs et des sources d’énergie du globe. Ces chercheurs soulignent que la construction d’une telle grille est déjà technologiquement faisable et économiquement viable.

La nature très diffuse des énergies renouvelables explique la nécessité d’exploiter ses gisements de plus en plus loin des centres de consommation majeurs pour pouvoir continuer d’augmenter leur part dans l’approvisionnement en énergie de nos sociétés. A cet égard, l’Europe est en train de construire l’infrastructure nécessaire pour pouvoir exploiter le potentiel éolien de la mer du Nord et de la mer Baltique. Elle a également des projets pour l’immense

potentiel solaire d’Afrique du Nord, notamment grâce à l’initiative Desertec (www.desertec.org). Des initiatives similaires ont également été lancées en Asie où l’on s’intéresse à l’énergie solaire qui pourrait être récoltée dans le désert de Gobi (www.gobitec.org). Dans cette course aux énergies renouvelables, les Etats-Unis ne sont pas en reste puisqu’ils ont par exemple des plans ambitieux pour exploiter l’énergie éolienne de l’océan Atlantique.

Spyros Chatzivasileiadis et Göran Andersson de l’ETH ainsi que Damien Ernst de l’ULg – l’auteur de cette carte blanche – ont récemment publié dans Renewable Energyun article intitulé “The Global Grid”, lequel démontre l’intérêt de l’interconnexion des principaux réseaux électriques du monde. Avec comme conséquence que, comme le pétrole, l’électricité deviendra une commodité qui pourra s’acheter et se vendre à l’échelle planétaire.

Global Grid

L’énergie injectée dans la “Global Grid” proviendra de sources d’énergie renouvelable. Le potentiel de ces dernières est immense dans certains endroits de la planète et amplement suffisant pour pouvoir couvrir des centaines de fois tous nos besoins énergétiques. Beaucoup des sources exploitées seront localisées en des lieux peu ou non habités qui possèdent un très grand potentiel éolien, solaire ou hydraulique. Le squelette de cette “Global Grid” sera constitué de liaisons HVDC (High-Voltage Direct Current) qui utilisent le

A l’ULg et ETH (Zurich) des chercheurs parient sur un futur réseau électrique sous forme de grille couvrant toute la planète

• World Trade Forum on International Trade of Electricity, 2014

Sharing the Vision

• Zhenya Liu, CEO of the State Grid Corporation of China

– covers 88% of the Chinese national territory

• Book on “Global Energy Interconnection”, Elsevier 2015

June 2, 201620

• IEEE Spectrum, August 2015– Flagship magazine of the largest

techincal professional organization in the world

• “Let’s build a globe-spanning Supergrid”

188 CHAPTER 5 BUILDING GLOBAL ENERGY INTERCONNECTION

realization of grid interconnection and clean energy allocation at the global level to form a globally interconnected robust smart grid system.

1.2 GLOBAL ENERGY INTERCONNECTIONGlobal energy interconnection refers to the development of a globally interconnected, ubiquitous robust smart grid, supported by backbone UHV grids (channels), and dedicated primarily to the transmission of clean energy (Fig. 5.4). Comprising of transnational and transcontinental backbone grids and ubiquitous smart power grids in different countries covering the transmission/distribution of power at different voltage grades, the globally interconnected energy network is connected to large energy bases in the Arctic and equatorial regions, as well as different continents and countries. It can adapt to the need for grid access for distributed power sources with the capability to deliver wind, solar, ocean, and other renewables to different types of end users. Generally speaking, a global energy interconnection is in effect a combination of “UHV grids plus ubiquitous smart grids plus clean en-ergy,” forming a green, low-carbon platform for global allocation of energy with extensive coverage, strong allocation capability, and a high level of security and reliability. It can link up the grids on dif-ferent continents divided by time zones and seasons to remove resource bottlenecks, environmental constraints and spatio-temporal limitations, realizing mutual support and backup between wind and solar generation and across different regions. This will result in greater energy security, improved eco-nomic benefits and reduced environmental losses to effectively resolve issues of energy safety, clean development, efficiency improvement and sustainability. This development will turn the world into a

FIGURE 5.4 Illustration of Global Energy Interconnection

Challenges

Political and Regulatory

• Security of supply– Similar problems for gas and oil– But: electricity cannot be stored

• For importing country: no long-term reserves• For exporting country: RES not exported = economic loss

• Cost of electricity differs due to differing environmental policies

Technical• Power Systems Security Global Blackouts?

June 2, 201621

Conclusions• A Global Electricity Grid is technically feasible and can potentially be

economically competitive

• Several opportunities emerge:– Reduction of balancing power to more than 50%– International trade– Global Electricity Market

• Several challenges still exist

• Alternatives:– Global Power-to-Gas network– Microgrids

• Further need to examine in detail different aspects of the Global Grid

June 2, 201622

Thank you!

spchatz@elektro.dtu.dk

June 2, 201623