It seems that every time we turn around, our electricity providers are extolling the virtues of going Green. By that they mean we should be using energy from renewable sources. Whether the sources are wind - like the experimental wind farm near Pincher Creek, in Southern Alberta, or Solar Panels that Enmax (the power retailer in Calgary) will install on your roof. It seems they all want to demonstrate how conscious they are of environmental issues.
Don't get me wrong, that's admirable and everything, but until the infrastructure changes, it is really little more than lip-service. "Why do you say that, Mark ?" you ask... Well, we have to remember that most Renewable Energy sources aren't steady-state. The wind goes calm, and the sun hides behind clouds. As such, we can't always predict how much power they will generate.
As I noted in my previous post, the Grid is like a pipe. When the demand for water at the output end changes, so must the call for water at the input end. In Alberta, the Grid is managed in a similar fashion - electrical demand is forecast and provided for in advance. When unplanned spikes or dips happen, the operators of the Grid call upon the producers to ramp up or slow down their production.
But the operator of the Grid can't ask to increase the wind or decrease the sun. It simply doesn't work that way. The generation "curve" from Renewable Energy sources would look very spiky, if you were to graph it on paper.
The problem is further exacerbated by simple physics - any electricity not consumed is simply wasted. Like the "water in the pipe" analogy, anything not used before it gets to the end flows out the far end, unusable and unrecoverable.
The State of California is desperate for electricity. Every summer, we read news articles about rolling blackouts, and brown-out conditions. So bad is the situation that Google built their own hydro-electric dam! But California struggles to use Renewable Energy from their neighbors in Oregon, because they can't manage it's production.
"So what's the solution, Mark ?" you ask... Well, I think if we could store any excess power when the Renewable Energy producers can over-generate, we could draw from that reserve to augment the production when the sun sneaks behind a cloud.
I'm quite sure we are all imagining a huge building full of truck batteries, in a quiet corner of the Province ! But we can store power in many different ways. Electricity is really a different form of energy potential. So that energy could be stored in other forms, such as heat or mechanical energy.
One power-storage means that I find intriguing stores potential energy in a huge fly-wheel. We use the excess electricity to drive a motor, which in turn spins up the fly wheel. It has lots & lots of mass, so once it is spinning, we need less energy to keep it spinning at the desired rate.
Then, when we need to draw power from the spinning mass, We simply attach or engage a generator - which turns the mechanical energy back into voltage. As long as the mass continues to spin, voltage is created. This is not a remarkably efficient means of storing energy, because as soon as the power input is removed, the flywheel's rate of spin begins to decrease, eventually stopping altogether.
Another, more efficient means of energy storage would pump water from a source in a lower basin UP a hill. The excess electricity powers the pump, and a reservoir at the top of the hill acts as the storage medium. When electricity is required, gates open up, channelling a flow of water through a hydro-electric generator. The trick is having large enough storage reservoirs to handle enough volume to provide power for a reasonable period of time.
So the solution is not in the creation of electricity from renewable sources,it's truly more of a question of how to manage it. Our current Grid is inelastic in that it is unable to cope with fluctuations in the production of electricity as well as it does with the consumption. Implementing some form (or many !) of energy storage would flatten the spiky generation curve, making it easier for the Grid operators to properly manage the load.
The opinions expressed in this post are purely those of the author. Opinions are like noses; everyone has one and they are entitled to it !
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