I am by trade a designer of aircraft electrical power systems (among other things including laptops). The amount of electrical power on an aircraft is strictly limited. So what does an aircraft system do (formerly there were engineers aboard all aircraft to handle the job, that task is now fully automated) to keep the power flowing? The system switches off expendable loads. First to get dropped are the food preparation loads like refrigerators, ovens, and coffee makers - which may delay food service a little, but otherwise passengers hardly notice. Then comes cabin loads like laptop charger outlets. Entertainment systems would be next. Cabin lighting. And, so forth.

The aircraft electrical system does not need to be designed for the maximum possible load, because loads can be controlled.

Our current terrestrial power systems are not so well controlled. You turn on a switch and you expect the lights to come on. Your refrigerator says it needs a cooling cycle and it turns on without asking permission and stays on until the end of its cycle.

We already have the beginning of a more integrated load management systems with what are called interruptable contracts for electrical delivery. During peak load time those loads are shut off for short intervals in order to match demand with supply. These loads are usually in the megawatt range and often in the multi-megawatts, the transactions are normally handled by phone so the plant engineers involved can make the desired changes in demand.

Sietze van der Sluis, an engineer in the Netherlands, wants to expand that idea.

Refrigerated warehouses might soon be used to store not just food, but gigawatts of electricity. A plan dreamt up in the Netherlands could see the giant fridges acting as massive batteries. They would buffer swings in supply and demand from electricity created from renewable sources.

The idea seems simple. Say you lowered the temperature of all large coldstores in Europe by just 1°C during the night when electricity demand is low, then let it rise 1°C by switching them off during the day when demand is at peak. The net effect would be that the warehouses would act as as batteries -- potentially storing 50,000 megawatt-hours of energy -- and the food wouldn't melt.

That's the calculation of Sietze van derSluis, head of refrigeration and heating technology at The Netherlands Organization for Applied Scientific Research (TNO) in Delft.

Such a system would make it possible for smaller discrete loads (such as large cold storage plants) to take advantage of their interruptable nature to balance supply and demand. Also feasible is cooling a few degrees colder at night than normal and letting the system warm up during the day. Thus shifting at least part of the load from daytime when usage is high to night when the utilities would actually prefer a larger load (it makes the system easier to control).

Then add in variable sources like wind and solar voltaic and we have a real winner.

Automated integrated electrical power systems were pioneered on aircraft. That technology is now in the process of being applied to our power grid. It will increase capacity without adding any new wires or generating plants by better matching of supply and demand. Automatically.

H/T Instapundit

Cross Posted at Power and Control