The other side of the equation: how DOES the grid work ?

Astute readers will notice that I haven't written in my journal in quite some time. Life gets busy: a new job, family pressures, and a host of other things have occupied my time. But on a positive note, I have taken a long term contract as an IT Consultant at the Alberta Electric System Operator (AESO). This is an eye-opening experience, and I'd like to share a little about what I have learned so far.


The AESO is mandated by the Provincial Government of Alberta to operate "the Grid". The Grid is a mesh of components, including electricity producers, the transmission facilities and the retailers. Finally the retailers handle the "last mile" of connection to the homes & businesses in Alberta.

The AESO manages the supply and demand cycle of electricity on the grid. That means that it forecasts usage in advance, but tweaks the generation on a minute by minute basis. Electricity has to always be on, so imagine it's like a pipe full of water: water goes into the pipe, and flows to the far end of the pipe, which is open. If you opened a faucet in the middle of the pipe, the amount of water coming out the far end is diminished. In order to keep the flow and pressure up, the producer must monitor the flow and add more water when the faucet is open, and equally, reduce they need to reduce production when that faucet is closed again.


Behind the scenes is a lot of metering, and logic behind the estimation of the demand. Complex models are created which identify how to re-route the electricity should a segment of the grid become available, such as in severe whether when transmission lines get damaged.

The AESO monitors the demand, and as demand rises in the morning, or slows in the evening, must call for more power from the producers, or ask the producers to throttle back their production. Internally, it operates similar to a commodities market, buying electricity according to demand, and in turn selling it to the retailers.

Of course this is where things get interesting. With traditional electricity-generating methods, the aim is to create so-called "steady state" production, ramping up as demand rises, and ramping down as demand subsides. Producers which are able to adjust morequickly to demand changes have a higher "value" in the market, than those which react slower. Remember, we are measuring demand on a minute-by-minute basis !


But how do you do that with some of the renewable energy sources ? Wind and solar generation schemes are fickle. It's either windy or it's not. It's either sunny or it's not. From the AESO's point of view, renewable energy is usable, but has ZERO value on the Grid, due to the fact that it cannot ramp up or down according to demand.

When it is available to the Grid, it is added at a net-zero cost, which effectively lowers the market price over a long period of time. In effect, sunny and windy days CAN help lower your power bills ! BUT we also can't count on them, as their production tapers off as the sun ducks behind a cloud, or the wind dies down.

So while we value the electricity generated by non-traditional, renewable energy sources, there are some drawbacks. The Grid wasn't really built to support non-"steady state" producers, so the "value" is zero. But we can all rest assured that at least some of our power is generated from non-polluting sources, and that is worth being proud of.

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 !