Solar Power Vs Ontario's Electrical Grid: The Duck Curve

Ontario's electrical grid - indeed, all of North America's electrical grid - has a problem.

As we add more and more solar power to the grid, we are creating a surplus of available electricity during the middle of the day. While that energy is useful to the grid and does get used, it is actually the evening hours of the day where the electricity is most needed.

The evening hours are the time of day when most people come home and do a variety of activities, such as watching TV, using computers, making food in the stove/oven/microwave, and turn on their air conditioners.

When the sun sets energy demand peaks as more people turn on their lights just to see.

Then later in the evening their power consumption drops as they turn off the TV, the lights, and various other ways of using electricity and go to bed. So there is a sudden drop in the amount of electricity being consumed after 9 PM.

If you look at a chart of the day that shows the various hours with a comparison of power consumption and energy availability, the availability of solar energy has caused the chart to end up taking the shape of a duck. Hence why it is called a Duck Curve. See the video below to see what I mean.



For someone who wants to be off grid, this duck curve isn't so much a problem because the whole point of being off the grid is that you are no longer connected to the electricity grid at all.

The typical off gridder will store their electricity in a high capacity battery system so that they can use their electricity whenever they need to. They don't need to worry so much about what hour of the day it is, their primary worry is keeping their battery system full and balancing the amount of electricity going into the batteries with the amount of electricity being used.

For someone who wants to be attached to the electricity grid and sell their electricity to the Province of Ontario, this does become a problem however. It means that during the middle of the day when they are producing the most electricity that there is potentially a surplus of electricity, which means a drop in the value of that electricity.

In other words, too much electricity makes the electricity cheaper.

Meanwhile at the same time, the demand for electricity in the evening is actually getting worse. More people with tablets, phones and other electrical devices is putting an ever greater demand on the electrical grid in the evening. So the "head of the duck" is getting bigger, while the belly of the duck (the surplus of solar energy) is dipping way lower.

This means the electricity grid is completely reliant on nuclear, coal, hydro and wind power during the evening hours and overnight, but the system is becoming more and more stressed during evening hours as demand grows.

So what is the solution?

Ontario needs a way to store electricity.

Effectively what we need is a giant battery, or a series of batteries.

In the past Ontario Hydro has speculated about making a series giant water reservoirs that they fill up with water during times of the day when they have excess electricity to pump water into the reservoirs, and whenever they need that electricity during peak hours of the day they can just turn on the tap, let the water flow through the hydro turbines and then it creates electricity again.

Only problem with this system? The ratio of the amount electricity produced isn't economical. You pump water into the system but the amount of electricity produced by the turbines is only a fraction of what was put in.

But there is actually a better solution, a way to make a giant battery that stores energy, but in this case also provides a way to produce electricity.

GEOTHERMAL

Okay, so what happens with geothermal is that you still store water in giant tanks, but when you want to create electricity you then allow the water to flow down and it gets pumped into the earth's warm crust through pipes. The water then becomes superheated steam which rises up through different pipes and turns steam turbines super-fast.

The steam is then collected, turned back into water and stored once more. Sometimes the steam is released into the atmosphere, resulting in the need to pump more water into the tanks.

There are plenty of existing geothermal plants around the world which produce electricity, with the added cost that they have to pump water from a nearby lake or river to fill up their tanks. All the above solution does is allow the geothermal to do its normal routine of creating electricity, but with the added benefit of using excess solar energy from the grid to run the pumps.

It thus creates a more energy efficient electrical grid which can store and use electricity whenever needed. Because geothermal can be easily turned off and on, it can then be used during peak hours of the day, or even just let it run all day long to create a surplus of electricity which Ontario can then sell to other provinces or to the USA, while only pumping new water into the system during times when there is excess solar power.

Having that surplus of electricity also makes electricity cheaper for everyone in Ontario, and once successful geothermal plants could effectively replace coal plants.

Indeed, old coal plants (which also run on steam turbines) could be retrofitted and turned into geothermal plants.

So why is Ontario not doing this already?

Because the politicians lack vision or an understanding of how this creates a more flexible and economical grid.

Meanwhile, those of us who want to escape expensive electricity bills (in common parlance "hydro bills") are going off grid so we are only paying for the startup costs of our own private solar, wind and battery system.

To which you should also ask yourself when voting in the upcoming Ontario election, which party is most likely to build a geothermal plant?

The current answer?

None.

None of the political parties want to commit to building a geothermal plant (or retrofitting an old coal plant).

They all lack vision.

So if they all lack vision, the only true escape is go off grid yourself.