Generac Grid Services Blog

For anyone who worries about global warming and wants to see more renewables integrated into our grids because of it, demand-side management may be about the greenest choice there is. After all, carbon dioxide accounts for 82 percent of greenhouse gases, according to the U.S. Environmental Protection Agency. And utilities are the biggest carbon polluters, responsible for some 40 percent of carbon emission, says the same source.

Anyone who thinks distributed energy resources (DERs) can’t be used for time-sensitive applications like renewable firming should have a look at this article about how New Brunswick Power was able to do just that. The NB Power project was the first time load management provided renewable firming for a Canadian utility. Serving some 394,000 residential, commercial and industrial customers, NB Power is targeting 40 percent renewable generation by 2020. Firming for these variable energy resources must be in place quickly, and the project described in the article shows how the utility proved that demand-side resources could do the job.

When it comes to planning for distributed energy resources (DERs), the State of California is one to watch. In 2015, major electric utilities submitted extensive plans for integration of distributed energy resources (DERs), with special focus on how such technologies will change planning for the last-mile distribution system and what process changes will be necessary.

Not long ago, one of the largest electric utilities in California told me they have 180,000 generating sites, and they expect this to almost triple by 2025. That’s just one of many reasons I believe no grid optimization can truly occur without distributed intelligence and control in grid-edge devices.

Hybrid storage – the process that leverages the flexibility of behind-the-meter resources to support grid services – is dramatically less expensive than other generation or storage options, plus it has other benefits. On the price side, Enbala has found that our hybrid storage solution typically costs as much as six times less than peaker plants and more than a third less than utility-scale storage options. By the numbers, that means utilities would spend some $900 per kW for a peaker, $500 per kW for utility-scale battery storage and $150 per kW for Enbala.

Distributed energy resources (DERs) like household solar and battery storage could provide enormous support to large and small electric systems that are now threatened by rising penetration of these technologies. DERs bring new capabilities and value. But, here’s the problem. Few jurisdictions facilitate distributed energy participation in grid markets to promote grid reliability and power quality.

Here’s a little something you can chew on when you sit down to eat one of the 46 million turkeys Americans will roast this Thanksgiving. The latent thermal storage in all those turkeys could provide 4.32 gigawatt hours (GWh) of energy. According to the Energy Information Administration, theaverage U.S. home used 10,932 kWh in 2014. That means all that thermal storage in Thanksgiving’s main-dish favorite could power some 400 homes for an entire year.

Anyone who’s seen the California ISO “Duck Curve” knows south-facing roof-top solar is not particularly good for utilities. The problem, which appears so clearly in the eloquent graph below, is that daily peak continues to grow, so utilities still have to build out new generation, transmission and distribution facilities. But, household solar reduces overall energy sales, and this is where most of the money comes from to pay for the new capacity. Some utilities are referring to this as the “death spiral.”

Some people hear the word “storage,” and all they think of is batteries. Most utility people aren’t that short sighted. They’ll remember mechanical forms of storage, like flywheels or the water trapped behind a dam. But – and I admit I’m a little partial here – I think the most efficient storage is process storage, or the storage inherent in the flexibility of controlled loads.

A “mumuration” of starling is a remarkable thing. Huge numbers of birds — thousands and hundreds of thousands — fly together in unison and don’t collide. Scientists have found that each bird monitors the state of adjacent birds and responds to minute changes in direction from its neighbors. There is no control from any leadership, and yet the flock operates smoothly. This approach enables a large number of birds to fly successfully as a flock.

 A power system with a high penetration of distributed resources will need a similar autonomous yet distributed control system that can allow local measurements to be used to provide immediate local control. This will augment central management and coordination in order to maintain overall power system control.