Thursday, January 23, 2014

The Art of the Grid

It's Cold Out.  Everywhere.
Extremely cold weather is stressing the grid all over the United States.

Like the rest of the grid, the New England grid is stressed and the power is expensive.

The Art of the Grid

In the past few days, I have taken screenshots of various graphics on the ISO-NE (New England grid operator) website. These graphics are kind of like art.  The graphics are not the whole story of the grid in cold weather, but they are a start.

The graphics come from these two web sites: and  Each graphic includes the day and time it was taken.

January 23, 2014--today

Here's the grid at about 4:45 on Thursday afternoon.
Map of the spot prices in the ISO-NE region

Fuel mix in the ISO-NE region. Note the heavy use of oil

$360 per MWh is the same as 36 cents per kWh. The average price on the grid last year was around $36 per MWh or less than 4 cents per kWh.  The price of power right now is ten times the average price for last year.

Yesterday's Greatest Hits January 22

These are a few more pix.  The dates and times are on the graphics.

It seems that the grid operator winter reliability program is working as planned: look at the high percentage of oil! (ISO-NE made $75 million dollars capacity factor payment to oil generators because natural gas is less available in cold weather.  This payment was part of the Winter Reliability Program.)


Also: Infrastructure article

Cold weather stresses the grid infrastructure as well as stressing fuel availability. There's an excellent article today on grid infrastructure: Why Does the Power Go Out When It's Cold? by Eric Gunther at the National Geographic blog. 


Anonymous said...

Does every producer get this higher price or is this just the price of "extra" production? (Extra production might be the production above a previously contracted price.)

Meredith Angwin said...

Yes, you are right. Good question.

Basically, this is the "spot" price which the utilities must pay for electricity purchased on the spot market. Most utilities also have Power Purchase Agreements (PPAs) for a great deal of electricity at a lower price. But utilities would not purchase enough electricity with PPAs to fill all these peaks.

So, this is the price above a previously contracted price...but basically, the utility would have a contract for a contracted price with a single provider, and expect to buy more power, as needed, from the grid.

This is how the "grid" price is running.

But wait, there's more! It's even more complicated! Green Mountain Power made a PPA with HydroQuebec, but the price of that power moves with the market price! So some PPAs are also affected by this price.

Meredith Angwin said...

Here's an old post, but it is still relevant about power contracts.

Meredith Angwin said...
This comment has been removed by the author.
robdashu said...

I think the prices quoted are basically marginal prices - the price for the next unit of generation to be called on, or the cost of the last unit, which represents a floor for the next quote.