As renewables increase, so will the need for a supergrid



The rapid rise of variable renewable generation is increasingly challenging both market and grid operators as the real-time balancing of load and generation becomes more difficult. Demand response, pumped storage and more flexible generation with fast ramping features are among the solutions.

Another solution, however, is more transmission and larger integrated grids which allow for better management of variable generation with load. This explains why many organised wholesale markets in North America, notably MISO and SPP, have grown so much in the past few years, now expanding from the Canadian provinces to the Gulf of Mexico (Fig. 1).

Fig. 1: Existing North American RTOs/ISOs (FERC).

Far more can be done where existing networks can be expanded and interconnected, allowing more trading in energy imbalance markets (EIM). A 2016 Pan-Canadian Wind Integration Study (PCWIS), co-funded by Natural Resources Canada and the Canadian Wind Energy Association, for example, identified that a myriad of benefits can be achieved by the TransCanada grid if it were extended and integrated with its counterpart in the US in a supergrid or macrogrid (Fig. 2).

Among the many expected benefits are increased and profitable penetration of wind energy with increased inter-provincial electric transmission, according to Dennis Woodford, the president of Electranix Corporation. In a paper describing the benefits of the proposed supergrid [1], Woodford says a larger, more integrated wide area electric energy market would be established for all interconnected regional utilities.

Fig. 2: Conceptual map of TransCanada electric supergrid integrated with the US macrogrid (MISO and D. Woodford).

What is this market possibility?

It is not a capacity market. It is an Energy Imbalance Market (EIM). This is the most significant market now being developed in the western US where variable generation continues to develop. The advantage of this market is that the western US regions are trading across regional and state borders much more than they ever did before. This goes against today’s Alberta’s and western Canada’s balkanised attitude, Woodford says.

The balkanised attitude, Woodford says, refers to the autonomous nature of power systems among vast and distant Canadian provinces – many of which are sparsely populated with smallish population centres many miles from one another. For this and political reasons, the Canadian provinces tend to be better integrated to the US than they are with each other. In fact, most existing transmission lines in Canada run north-south, rather than east-west. Woodford says this is another reason why a larger, better integrated supergrid makes perfect sense – at least when viewed from an electrical engineer’s perspective.

Politics, however, get in the way as do issues on how to attract the large investments to build long distance transmission lines. Woodford says that the Canadian electric east-west superhighway will be feasible, in fact profitable, if developed wisely and in stages, starting with the four western Canadian provinces first, most likely with merchant transmission investors. It can be extended over time.

Woodford says he participated, in 1970, in a study to electrically interconnect Britain with France which was justified on reduced reserve generation in both countries. Initially Britain rejected it, but France was partially inclined. In time, a substantial interconnection was built. Being a profitable venture, the two countries are increasing the grid connections between them. In the same way, Woodford says, profitability will happen with a TransCanada Electric Superhighway enabling east-west energy diversity, reduced generation margins, and an energy imbalance market for increasing penetration of variable generation.

The Alberta Electric System Operator is already engaged in a regional electricity cooperation and strategic infrastructure initiative, expected for completion this year. There are reasons for Woodford’s optimism including California’s huge appetite for renewable generation – currently 50% by 2030 and possibly increased to 100% by 2045 as proposed in a bill introduced by Kevin deLeon in California’s state senate.

If that were to happen, the justification for extending the California Independent System Operator’s (CAISO) Energy Imbalance Market to cover a much larger geographical footprint will become overwhelming, perhaps convincing politicians to go along with an expanded and better integrated western wholesale market.

Reference

[1] www.electranix.com/publication/how-a-transcanada-electric-superhighway-will-profitably-achieve-renewable-energy-objectives

Acknowledgement

This article was first published in EEnergy Informer’s November 2017 newsletter, and is republished here with permission.

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