One big grid is the solution to secure electricity

Professor Michael D. Mehta of Thompson Rivers University makes a number of good points in his article regarding a secure electrical system (Armchairmayor.ca, March 6, 2021).

However, he’s thinking in the wrong direction when he suggests that the solution is microgrids.

image: Student Energy

The recent electrical blackouts in Texas have focused the problem of electricity security. In a state that prides itself on independence and abundance of energy, it was the height of irony that they should suffer from an electricity shortage that left people freezing in the dark.

Texas’ problem was that its electrical grid was too small. In an attempt to avoid federal regulation, Texas constructed a grid that is a virtual island.  So when the cold snap hit, when wind turbines froze and natural gas generators quit, they had only themselves to rely on.

But not so for all of Texas. El Paso in eastern Texas did just fine, thank you. That’s because they were not connected to the Texas grid but rather to the much larger Western grid.

You see, there are three major electrical grids in North America: the Eastern Grid, the Western Grid and the Texas (ERCOT) Grid, El Paso picked a winner.

The big problem facing green energy is storage. Wind turbines and solar panels are great when the wind blows and the sun shines. But they usually produce too much power when we don’t need it and too little when we do. Storage seems like the answer.

However, as Professor Mehta mentions, no affordable storage system exists with the capacity needed. A number have been proposed; batteries, small-scale pumped hydro, compressed air, and flywheel technology.

Mehta suggests that the solution is not a bigger grid but smaller microgrids: “A microgrid is a local network of generators, often combined with energy storage.”

“Such systems can increase reliability and drive down carbon emissions when renewable energy is used,” says Mehta. “When combined with smart meters that reconcile inflows and outflows of electricity, microgrids provide real-time energy data. When a microgrid goes down, it only affects the local region and not an entire state or province.”

With one big continental grid, there is no storage problem and no one has to go without electricity.

One big grid solves the storage problem by virtue of its size.

The demands on one big grid are predictable. Cold snaps can be are forecast. In that case, thousands of generators, from big hydro dams to small run-of-river, solar and wind generators can be activated.

On an ordinary day, demands on one big grid are even more predictable. As people rise and shine on the Atlantic coast and turn on toasters, heaters, air conditioners in the summer, the demands on the West coast are minimal.

As the sun rises across the four and one-half time zones of our continent, the demand follows the sun. While the demands are not exactly constant they are predictable.

Of course, Canada doesn’t have a cross-country grid and neither does the U.S. Most of our connections are oriented in the worst way: they are North-South, in the same time zone where demands occur at the same time.

As Professor Mehta says, transmission lines are costly to build and lose power. The power loss can be minimized through use of High Voltage Direct Current transmission lines.

The construction of lines is a political problem, not one of cost. When the Trudeau government decided that the Trans Mountain Pipeline was in the national interest, he bought it and built it.

One power grid solves the green energy problem

Solar and wind energy suffer from a storage problem. They produce in abundance, often too much, when the wind blows and the sun shines. Storage of that abundance is one solution but it’s expensive and inefficient. You don’t get as much out as what you put in; like a bank account that gives you negative interest.

image: HowStuffWorks

The sun takes a long time to cross the four and one-half time zones of our big country. The advantage of that is when the sun shines on Canada’s largest solar farms in Ontario at ten o’clock, surplus electricity could be used to make breakfast in B.C. and lunch in Newfoundland.

Great idea, except that we have no way to get the excess power across Canada.  B.C. is connected to western Alberta by a major (345 Kilovolt) line and stops. There is nothing between Alberta, Saskatchewan, Manitoba and Ontario. One connects Ontario, Quebec, and the Maritime Provinces; none connects Newfoundland.

While there are few east-to-west Canadian connections, there are 34 lines connecting Canada to the U.S. The problem with north-south connections is that the sun shines on all solar panels in the same time zone at once.

Those gaps in Canada’s transmission lines create a challenge for green energy sources -wind even more than solar. Whereas solar power is fairly predictable, wind can be a problem. Sudden storms can wreak havoc with a power grid, dumping huge amounts of power into the system with nowhere for it to go. Some power utilities, such as in Germany and Texas, pay customers to consume electricity just to rid of it.

Climate change is creating increased demand on air conditioners in some areas of North America, while creating storms and wind in other parts. One big grid would link the wind power to where it’s needed.

The fragmentation of power grids is a problem says science writer Peter Fairley of Victoria:

“This balkanization means each region must manage weather variability on its own (Scientific American, July, 2018).”

Since we are already connected to the U.S., if the States were connected, so would Canada. It would be one big continental grid -something like the internet. The U.S. solution is simpler because they have only three major grids, the Western Interconnection, the Eastern Interconnection and the ERCOT Interconnection in Texas.

A big grid would soak up all the power you can pump into it but it requires weather reports. We need to know where the sun is shining and where the wind is blowing to determine where sources are. We already have that. The U.S. Department of Energy and National Renewable Energy Laboratory maps the potential energy areas of four kilometre squares, updated every five minutes throughout the year. Couple that weather information with a huge single grid and you can send surplus power to where it’s needed.

Fairley continues:

“What we need is a weather-smart grid design, directed by meteorology and built on long-distance transmission lines that can manage the weather’s inconsistencies. Such a system could ship gobs of renewable power across North America to link supply with demand, whatever the weather throws at it.”

Just think, the tidal power generated in the Bay of Fundy could heat a toaster in Moose Jaw faster than the rate at which photos of kittens are shared on Facebook.