Generac Grid Services Blog

For more than 100 years utilities have supplied electrical power to their customers and have achieved this with good reliability. The principle is simple. Loads may do as they wish, but generation — the supply — MUST be both dispatchable and monitorable. An operator must be able to start or stop a generator or to change capacity at the touch of a button to maintain a continuous balance between supply and demand.  On the other hand, the loads that use the electric power can be intermittent, unmonitored and subject to starting and stopping at what the system operator would see as near random times. 

Suddenly, the world is faced with a need to reduce or even eliminate emissions.

Introduction

Science has told us that we must reduce carbon emissions if climate change is to be kept below acceptable limits. The transition has led us in many new directions. Most politicians outside the US believe that our energy supply must be based entirely on renewable energy. This alone creates a large issue, in that the electric grid supplies less than 20% of total energy needs. The proposal to replace all fossil fuel with renewable capacity would require a potentially large increase in grid capacity. Ironically, many politicians typically include nuclear generation among the sources to be eliminated. The one bit of good news is that the efficiency of electrical devices is often better than fossil fuel, and the existing grid operation using a generation following load approach results in a system that can deliver more energy.

The results to date have been frustrating, both in costs and performance, and there are many serious problems that may make a complete conversion very difficult. These challenges include a lack of grid and generation capacity to handle the added electrical load, as well as the operation of the existing grid with extensive distributed devices. 

Distributed energy resources (DERs) give us big opportunities to build cleaner and more reliable power grids, but to be optimally effective, those resources need to orchestrated so that they are aggregated, optimized and controlled for the grid services that are needed – precisely when and where they are needed.

The platforms for achieving this orchestration encompass both Virtual Power Plants (VPPs) and Distributed Energy Resource Management Systems (DERMS). Many who talk and write about these platforms use the terms interchangeably, as if one is a synonym for the other. For those of us at Enbala who have made harnessing the power of distributed energy our life’s work, we respectfully disagree. There are foundational differences that significantly impact what can – and what can’t – be done with the DERs being harnessed.

What’s the difference – and why should you care?

There are a lot of acronyms floating around the energy world these days. It’s a veritable alphabet soup of evolving terms that are often hard to distinguish from one another.  This is especially true when it comes to distributed energy – it’s a relatively new concept in and of itself, and when the terms that define this evolving move to the grid edge aren’t inherently self-defining, the ensuing confusion complicates the equation. What’s the difference between DERs and a DERMS?  And what’s the definition of a DERMS versus a VPP?  Just as important what difference does it make? 

Here’s a little something you can chew on if you are sitting 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, the average U.S. home used 10,766 kWh in 2016. That means all that thermal storage in Thanksgiving’s main-dish favorite could power some 400 homes for an entire year.

So, how do you tap that energy? You can’t exactly roll into your garage and plug a hybrid vehicle into a turkey. But, you can use a turkey’s thermal storage capacity the same way you tap the thermal energy in the cooler that’s chilling the beer you might drink during a holiday football game. The mass of the turkey allows the grid to utilize a cold storage facility as an energy storage system.

I read Milton Caplan's post entitled "An Inconvenient Reality: Nuclear Power is Needed to Achieve Climate Goals." I can certainly support much of the article, but it seems to miss one very key point and that is the need.

Science has told us that we need to reduce carbon emissions. The trouble starts when the political masters translated that to mean that we need to fully get rid of fossil fuels and switch entirely to renewables – and while at it, we need to get rid of nuclear as well. I wonder where that latter part came from? Nuclear is clean. Why was it lumped in with fossil fuel? Much of the opposition was based on past fears. The movie Pandora’s Promise shows how many of the opponents have, after a careful look, reversed their views..

REDEFINING SUCCESS FOR A DISTRIBUTED ENERGY GRID: THE THREE TENETS

In our first “Three Tenets” blog we talked about the importance of speed when it comes to effectively leveraging distributed energy resources (DERs), and in the second one we wrote about the importance of accuracy. In this one we add a third dimension of criticality – scalability. From our perspective, these are by far the top three critical success factors today when it comes to successful DERMS and VPP projects and the determining factors for the long-term viability of these projects as increasingly larger numbers of distributed energy assets find their way onto the grid. There are, of course, other important factors, but many that topped the criteria list during the early phases of DER adoption have been far overshadowed in today’s world by the need for the triumvirate combination of speed, accuracy and scalability.

It’s been said that analogy is a powerful force when it comes to innovation. It creates an environment where it’s easier for people to apply knowledge from one domain that they already understand to another that they don’t understand quite as well – and thus make it, too, easier to grasp. 

Uber is a prime example of analogy taken, perhaps, to the extreme. It would be tough to estimate the number of companies that have come into being recently aiming or claiming – to be the “Uber for ....” – you fill in the blank. There’s an “Uber for errand running,” an “Uber for pet care,” an “Uber for tool rental,” an “Uber for grocery (and alcohol) delivery,” an “Uber for finding parking spaces…”  You get the picture.

I have posted several blogs in the past few weeks, focused on the potential to improve the operation of the electric power grid, reducing losses, and driving the overall efficiency up. Some of the thoughtful comments that have been posted by readers have provided food for thought. One comment was particularly important to this discussion…

“What’s best for players individually is not what’s best for the public and for the system as a whole.”

This comment reveals an issue that may soon be a problem.

For most of the 130-year history of the electric grid, utilities have charged residential customers for energy used and have NOT charged for peak power demand, as they do for commercial and industrial accounts.

REDEFINING SUCCESS FOR A DISTRIBUTED ENERGY GRID: THE THREE TENETS

When it comes to effectively leveraging distributed energy resources (DERs), there are three critical success factors that any DER management system or Virtual Power Plant (VPP) must embody. In a previous blog we focused on Tenet #1: the importance of speed.  

In today’s blog, we address another of the top three criteria: accuracy. Just as the question “how fast is fast enough” was answered with “it depends,” so too does the question “how accurate is accurate enough” have the same response. The criticality of accuracy depends on what the distributed energy resources are being dispatched to do.