Why Norway should become the battery of Europe

This is an article that I am working on with my friend Tord Eide and a Norwegian professor from NTNU.

Why Norway should become the battery of Europe (This is based upon this prior unfinished document, Prepared by myself and Clay Taylor well we work at Alevo)

A debate rages at this very moment about whether Norway should connect strongly to the European electrical grid or use its abundant hydropower resources just for  Norwegians. We argue that using Norway's vast hydropower resources as the battery of Europe would make a vital contribution to the decarbonization of the world's future energy economy. This does not require Norway to sell its energy supply, but simply allow existing hydropower reservoirs to function as reversible batteries. This is Norway’s chance to think in scale and actually be a major contributor to affect the global climate. 

In order to actually become the battery of Europe, Norway needs a lot better electrical connection to the rest of Europe. The best way to accomplish such a connection is with a supergrid. A supergrid is a continental scale high-voltage DC (HVDC) grid, and this could be accomplished either with overhead powerlines or underground powerlines. Underground cables however are not up to the task because of their limited transfer capability per cable. This limitation is not likely to ever be overcome, because it is based on the simple fact that cables have to wrap on a reel in order to be transportable, and that limits the maximum diameter of both conductor and insulation per cable.

With presently proven technology we would have to build a lot of of new overhead power lines to make a European supergrid; this is precisely why the southern part of Germany is not strongly connected electrically to the northern part of Germany at present; large new overhead power lines are simply politically impossible in Europe today. 

Underground cables are not a solution either, as their capacity is typically limited to  about one gigawatt (1.0 GW) per cable. New technology is needed, capable of carrying more than 10 GW underground. 

There are four developmental technologies that could work for building an underground supergrid in Europe including two different flavors of superconducting lines (one which needs to be cooled with liquid hydrogen or helium, the other which may be cooled with liquid nitrogen), gas insulated lines (GIL), and the elpipe (the newest technology in this list). Figuring out which of these underground options is the best solution for creating a European supergrid should be a research priority in Europe, but that has not been the case. 

So far, the research has been driven by commercial entities with products they want to sell. Siemens has maintained a research program looking at GIL transmission of HVDC power, as well as AC, and ABB he was also active in this area up until 1999, when they sold their technology to US corporation AZZ.  ABB also has an active program for  HVDC cables.

Many companies are pursuing superconducting powerlines (one example is American Superconductor), and there have also been many research reports and studies from national labs and other similar entities looking at superconducting powerlines as well. Superconducting power lines of any design suffer from flaws that are uniquely a function of superconductivity per se. These  faults taken together are fatal to the practicality of a wide-ranging superconducting supergrid:
Transitioning to a non-superconducting state can be instantaneous and can be triggered by a current that  is over a limit even for a microsecond. This can lead to a catastrophic plasma explosion if the line is carrying a lot of current.
 the maximum practical voltage for a superconducting DC power line is around 130,000 V due to the difficulty of insulating under cryogenic conditions.  this is an unsuitably low voltage for conventional HVDC, so in a sense superconducting lines don't play well with the existing technologies.
Superconducting lines have no damping properties.  that means that resonances do not damp out. This is a critical threat to reliability.
every junction between the superconducting lines and the conventional grid is a high maintenance and difficult installation, the failure of any one of which could bring down the grid. Keeping the number of such junctions to a minimum is absolutely required.
It is very difficult to maintain cryogenic conditions reliably, and at all times (which might include times of national disasters such as widespread flooding or earthquakes).

Superconducting powerlines, which have often been proposed for long distance power transmission, are far from being practical at this point, and the other major industry sponsored powerline concept that could have adequate power transfer capability for a supergrid (GIL), has the fatal flaw of relying on an incredibly potent and practically immortal greenhouse gas for insulation, sulfur hexafluoride. Both superconducting powerlines and GIL powerlines suffer from poor repairability in terms of the time it would take to repair a major fault. (When something as important as a 10+ GW powerline fails, it is critical to be able to repair it in hours, not days.) Failure modes for both GIL  and superconducting lines are very difficult, potentially resulting in many days long outages.

The elpipe has been successfully patented around the world, in spite of the fact that one has never been built.   This happened because the elpipe is so firmly based on well-established physics, that the patent examiners admitted it as new invention without ever having had a working model built. This is quite an achievement in itself, and it is a testament to the simplicity of the idea. It is a shame that such an innovative technology has not been able to find funding.

The elpipe has unique features related to repairability. Such technology can be utilized to build an underground European supergrid, and a European supergrid is absolutely required in order to have a renewable energy future for Europe.

Even if there were no bottlenecks in transmission, the installed hydroelectric power capacity of Norway (~30 GW) is not large enough to truly serve as the battery of Europe. Something on the order of 100 GW of energy storage power capacity will be required to allow for 100% renewable energy generation in the mix for Europe. However, if more turbines were installed, the energy storage in existing Norwegian reservoirs (80 TWh) could make a significant contribution to solve the European challenge. A proposal from the research center CEDREN described a step towards becoming the battery of Europe in the form of 20 GW of new pumped storage turbines to be installed on existing Norwegian reservoirs, combined with several new power lines and subsea power cables to European power nodes. These new power lines would cause most of the environmental and aesthetic damage to Norway, and would represent about half of the total cost. We recognize and understand the resistance of Norwegians to these new powerlines; indeed similar resistance throughout Europe to overhead power lines makes such schemes politically impossible. 

We propose a much larger concept for Norway becoming the battery of Europe than any prior proposal, based on HVDC loops, enabled by elpipes, and capable of exchanging much more stored energy with Europe than has previously been contemplated. This scheme however will produce far less environmental and aesthetic harm because it uses underground electric connections (elpipes and cables). We must get beyond the paradigm that power moves through power lines from node to node; continuing in that paradigm would mean that for Norway to become the battery of Europe, we would need at least 20 new power lines connecting us to our neighbors. Most such interconnecting power lines will become outmoded (stranded assets) in the future scenario of having a European supergrid.

If one compares the environmental impact and cost of installing more turbines on existing reservoirs to the environmental impact and cost of building new energy storage facilities, it is clear it would be far more desirable environmentally to use the existing reservoirs rather than flooding new valleys (in the case of hydroelectric energy storage), or mining the resources required for manufacturing and installation of batteries (for electrochemical energy storage).

Building new hydroelectric power capacity based on installing new reversible turbines on existing Norwegian reservoirs would create additional storage capacity without having to build any new reservoirs. The main unavoidable environmental impact for this scheme would be that the levels of the reservoirs would be changing more quickly than they are today. That makes it hard for many varieties of fish to reproduce. We propose floating structures in the Lakes to mitigate this. The tunnels, turbines and generators that would be required could all be installed underground. 

In order for Norwegian power to truly work as the battery of Europe, the power must be deliverable, and power flow must be controllable at many different connected power nodes inside Europe, ideally with millisecond level control of power flow into or out of each node. None of the currently proposed schemes, such as Figure 5, taken from the Nordic grid development plan 2017 which all involve point-to-point powerlines, would accomplish this. Figures 1 – 4 on the other hand do accomplish this.

Figure  1: Nordic grid development plan 2017
(See figure 3)...This could be copied and pasted here, or perhaps a few of these sorts of maps.

Although the Nordic grid development plan 2017 does enable increased power exchange with Europe, it uses the same old paradigm used for all such prior projects in which point-to-point power lines are used for purposes of transferring power. Any such point to point power line necessarily relies on the underlying AC grid to provide redundancy in case of a loss of a line.The ability to withstand the loss of any one power line or generator without a crash is a fundamental rule for electrical reliability of any large grid.This is the so-called “n-1 rule,” and strictly limits the maximum size of any power line in the grid. Following the current paradigm, it will be necessary to have about 20 new powerlines linking Europe to Norway just to get to the 20 GW capacity called for in the CEDREN plan (Figure 2).

Figure 3 shows a first stage high-voltage DC loop–based transmission system map based on elpipes; this represents a logical first step towards a European supergrid. The nodes shown inside Norway and Europe are actual large transformer yards that already exist in the AC grid. The routes shown for the HVDC loop other then the portions of the loop that cross the Baltic Sea are all existing rights-of-way; some are power line rights-of-way, and others are gas, oil, railroad, roadway, or water pipeline rights-of-way. The nodes are mostly very large transformer yards near large power plants. 

Figures 1:  map showing the layout of HVDC loop that connects Norway to Germany. This example will show just a single loop,  enabling power exchanged between four nodes or so in Norway and 10 or so nodes in continental Europe. Pick the node points as the locations of very large transformers. The total sum of all of these transformers should have a capacity greater than 20 GW. Most of the big transformers will occur at large power plants, although there are a few crossing points where there are also a lot of transformers and there is not a Power plant.Try for Transformer yards with greater than 1 GW of capacity. Consult my paper suggesting a grid in Europe just within the boundaries of Germany. I drew that map based on the locations of nuclear power plantsIn Germany. By definition those power plants needs large transformer yards. The nodes in Norway conveniently located to access the largest pump storage reservoirs in the country. 

Figures 2:  map showing the layout of Figure 1 + additional features. HVDC loops would be added that went through Sweden and over to Denmark and making a logical return to the original loop somewhere in Germany,Possibly extending as far as the existing HVDC power line to Great Britain. Four Or so nodes would be added in Sweden, Several in Denmark… You get the idea. It really depends on the grid structure. I happen to know that several universities have posted the European grid in map format and it also includes power capacities and Transformer capacities. My former employee found all that stuff but never documented it for me then he quit and now I don't know where that information lies except it is in several different European universities. With that data I can ask my expert friend to figure out where the best points to put these nodes are. But I don't want to wait for that now I want to get something that looks reasonable and that is tied into real nodes and real rights-of-way that really would connect Scandinavia with Europe. I want to know the actual length of every segment of these maps.

The next example figure 3  Links to the loop through Denmark somewhere, and then travels in a manner through France as to tie in all of their nuclear power plants… or at least most of the ones in the north of France, and then it precedes to meet up with the German loop. 

figure 4  Links to the German loop And the Norwegian like this loop to extend into Russia, and access died Joe Power capacity of Northern Finland if there is any there actually I don't know that myself. 

Showing several levels of the concept would allow us to show the evolution of the elpipe–based supergrid starting from the very first HVDC loop up to a recognizable supergrid.

Figures 5 and 6 Show plans for connecting Norway to Europe that are on the books today or are being proposed by major utilities or European environmental groups. These figures show a series of a point to point connections That are dramatically less useful than if power from any point on a loop can be transferred to any other point of the loop as is the case in the HVDC loop systems of Yes. 

Contrast the plans of Figures 1 – 4 with the plans of Figure 5, which is taken from the Nordic Grid development plan 2014, or Figure 6, Which is taken from the  CEDREN Report.  Figures 1 – 4 are based on interconnecting HVDC loops; a loop is uniquely redundant  in that every node food on the loop is connected to every other node on the loop via at least two independent power lines, the clockwise and the counterclockwise.

The HVDC loop systems of Figures 1– 4 are comprised of large HVDC loops that are self redundant in the sense that power between any two points on the loop can be delivered either in the clockwise or the counter clockwise direction. (For this to work, one needs very high power HVDC circuit breakers between next–neighbor power taps on the main lines of the super grid.) Redundancy levels continue to improve as more interconnected loops are formed as in Figures 2– 4, for example. Point to point HVDC connections linking to large power nodes of the AC grid will never achieve this key property, that of being redundant strictly through the HVDC continental grid overlay.

Only when the DC  continental grid provides its own redundancy will it be possible to trust an individual line with power flows in the tens of gigawatts, as will be required for the European supergrid to be a reality. 

Note that the proposed conventional HVDC power lines of Figures 5 and 6 will become outmoded in the scenario that there is a future European supergrid (as is actually planned), whereas the conceptual HVDC loops shown in Figure 1 would be a logical starting point for the European supergrid. 

Covering a large geographical area with a single grid capable of transmitting power from any point in the grid any other point, as can only be accomplished by a supergrid (continental scale DC grid). Such a continental scale grid is necessary in order to spread the weather risk of being cloudy or becalmed. This makes renewable energy more reliable in the aggregate than is feasible for any individual solar energy or wind power installation. There is a trade off between the size scale of the grid and the amount of energy storage actually required; the existence of a continental scale supergrid means that only a modest amount of energy storage capacity plus demand side management capacity is needed for a truly renewable energy future for Europe. 

One of the largest stumbling blocks to creating a European supergrid has been the necessity for using overhead power lines. Underground cables simply do not have enough power transfer capacity, and will never be economically feasible for this sort of task. 

There is however one sort of underground powerline that would be practical for the main conductors of the European supergrid, the elpipe. This is a type of polymer–insulated electric pipeline that is much thicker than a cable (capacity of any cable is limited by the fact that it must be manufactured so that it can wrap up on a reel). Because of its potentially much larger cross-sectional area for the conductor, an elpipe can carry the tens of gigawatts of electricity needed. The elpipe also solves the critical problem of the need for rapid repairability, by breaking up the overall elpipe into cars that are readily replaceable because they are on wheeled carriages, and roll inside of a pipeline. The elpipe is the invention of one of us (Roger Faulkner), but we all believe it is a critical innovation for enabling a European supergrid. 

If we are to base the European energy economy upon renewable energy, an underground power line capable of carrying tens of gigawatts of electric power is essential. That's because a European supergrid is absolutely needed in order to base our economy on renewable energy, and because it is not feasible to build a European supergrid based on overhead power lines. It is of course true that before backing the elpipe, an honest scientific evaluation of all the options including the other three is crucial; in fact it should've occurred years ago. We should've already selected the basic technology for the main conductors of the supergrid by now. 

Balancing power flow is the main task for batteries in the future renewables–based European grid. Energy storage is absolutely needed to balance variable loads with many non-dispatchable renewable energy sources (wind and solar primarily), if we are to balance the loads without using fossil fuel energy. Pumped storage and dispatchable hydroelectric power plants remain the gold standard for the very high energy end of this energy storage market. Very fast reacting energy storage, such as batteries, capacitors, or flywheels are also needed, but at present pumped storage is far more economical for storing many gigawatt hours of power, as will be needed to make it feasible for renewable energy to be the basis for Europe's energy economy. 

Pumped storage facilities also last much longer than batteries; about 50 years before major repairs will be needed, compared to typically 5 to 10 years of continuous service for electrochemical batteries before they need to be replaced. An optimal pumped storage plant can be as efficient as 83%; this is better than a lead acid battery and not quite as good as a lithium ion battery (~90% efficient); the longer life and lower cost means that pumped storage is much more cost-effective than any currently available electrochemical batteries.

Because the backup power is needed at different places at different times, Norway can serve as the battery backup for Europe only if it is strongly connected to many separated nodes within Europe. The technology to accomplish this, multiterminal HVDC, does exist and it is commercially available from all the HVDC equipment suppliers. The progress towards a European supergrid is painstakingly slow mainly because of the excessive conservatism of the industry and the lack of visionary funding. Given the extreme importance of a supergrid for decarbonizing the European energy economy, this is really a crisis. Perhaps Norway can lead the way by financing an introductory portion of the supergrid that would also enable us to monetize our vast hydropower–based energy storage potential for an environmentally important and renewable national income.

*(power nodes, major power plants or transformer yards) 

No comments:

Post a Comment