Thursday, March 6, 2014

Electricity Load Profile....Is the Peak Being Shaved?

NRG Energy President David Crane frequently describes an apocalyptic future for conventional power generators where the daily load profile loses its distinct peak during high demand periods, and he claims that power producers won't make money in that world.  That is primarily because distributed generation and energy storage will increasingly shave that peak.  He says it will happen faster than anyone expects, due to the rapid pace of technology and affordability of distributed solar power and battery storage.

So NRG is planning for that kind of future (so they say).  On paper, we should be seeing this already in vanguard regions like California.  There is little battery storage yet but solar generation is expanding so quickly that summer afternoon peaks should decline relative to average daily generation.  

Right now it should not be visible because solar power generation falls to zero before 6 pm (sunset) and peak load is typically between 7 and 8 pm, as it was today:

But as spring waxes and California heats up, daytime generation demand rises and the sun sets later.  This causes the daily peak hour generation vs daily average generation ratio to decline.  Here is the 7 day average of that ratio last year and this year so far in Q1.  (It is worth noting that total generation is distinctly lower this year than last, on nearly ever day in 2014).

Meanwhile the EIA, in what is a true but perhaps backward looking analysis, draws attention to the heretofore rising ratio:

I think this summer will begin to test this sea change in California.  Battery installations will really be the key, but when the sun begins to shine through the daily peak, it will show in the data.  We will see both the institutional solar output on the grid, and should see the shadow of the missing demand, replaced by distributed solar (ie residential and commercial rooftop).  We should not have to wait long.