Generac Grid Services Blog

I was recently invited to meet with a class of students studying energy and the future, and as a part of the session, I was asked to prepare a challenge for the students to work through. The result was interesting and showed a glimpse of what may lie ahead. It will certainly be a challenge that will require innovation, new concepts and a lot of hard work.

I showed a small area, powered by an electric utility (20% of total energy), natural gas (25% of local energy) and petroleum products (45% of total energy). The electric utility had capability to increase its energy delivered by about 25% in the next decade, and the students were asked to show how to minimize the emissions in that timeframe. They were free to add solar thermal or solar PV capacity to the system.

From mainstream media to social media, the world is abuzz with the topic of climate change.  A simple Google search on the phrase today yielded 1,100,000,00 results, and typing “gret” into Google is all it takes to bring up 107 million stories about Greta Thunberg.  This 16-year-old Swedish environmental activist whose lone mission to protest climate change outside the Swedish Parliament has ignited a flame within millions of young people from more than 100 countries who have joined her with demands for climate action and a cry to “listen to the scientists.”

Even those associated with the oil industry are taking up the charge. For example, the former CEO of BP, Lord John Browne, is speaking globally about the need to clean up the atmosphere and reduce reliance on fossil fuels. His new book “Make, Think, Imagine” considers whether our demand for energy has driven the Earth’s climate to the edge of catastrophe and suggests that the same spark that triggers innovation can be used to counter its negative consequences and that it is time to “listen to the engineers.”

Energy systems are changing. As variable renewable energy generation replaces retiring fossil fuel-run power plants, we see a shift from our century-old mindset of centralized supply following demand, to a more distributed grid with distributed energy resources (DERs) playing an essential role in a sustainable energy future. In order for renewable energy resources and DERs to replace conventional power plants, they need to be able to act like power plants – virtually at least.

At technology and innovation’s finest hour, we are able to aggregate disparate, geographically dispersed DERs and orchestrate them in such a way that they are able to respond to the grid’s needs at the same speed and accuracy as a traditional power plant. That’s where the Virtual Power Plant (or VPP for short) comes in. Navigant Research defines a VPP as:

“… a system that relies upon software and a smart grid to remotely and automatically dispatch retail DER services to a distribution or wholesale market via an aggregation and optimization platform”

VPPs are critical for the transition to more sustainable energy systems – so where is the technology at? Where can we find VPPs? And what can we expect in the future?

I recently reviewed an EPRI document that discussed storage, and by far the largest size storage systems were pumped storage plants.  I wondered why they did not include hydro (non-pumped) storage, as this form of storage is far larger than any other form of storage that is available on the grid now.

Parts of North America, but sadly not all of it, are blessed with mountainous territory that has many rivers and streams that run downhill, and many of these have been harnessed for electricity production. While not specifically intended as storage plants when built, the value of their storage may well turn out to be larger than the value of the electricity that they may produce.

Consider a hydro dam that is 35 M in height with a reservoir that is 10 km². Discharging the top 1 M of water through a generating station (90% efficient) would release almost 840 MWh of stored energy. This is a small hydro plant, with a small reservoir behind it, yet the storage is almost 840 MWh/M of depth that is drawn from the forebay.  That is in addition to the electrical energy generated for use.

So how does a utility that has no pumps manage to store and return energy?  The process is both simple and efficient.   

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. 

Our blog post this week was authored by our friends and fellow Coloradans at the Rocky Mountain Institute (RMI). We think it's one of the best posts we've read in a while, and RMI kindly gave us permission to share it. 

In April, U.S. Secretary of Energy Rick Perry announced a 60-day study on electricity market design and grid reliability, meant to assess to what extent current market designs fail to adequately compensate “baseload” (i.e., coal- and nuclear-fired) power plants.

The memo commissioning the study presents as “fact” a curious claim: “baseload power is necessary to a well-functioning electric grid.” This notion has been thoroughly disproven by a diverse community of utilities, system operators, economists, and other experts that moved on from this topic years ago. To these practitioners, this premise seems as backward as if President Eisenhower, instead of launching the interstate highway system, had called for restudy of the virtues of horse-drawn carriages.

Today, the grid needs flexibility from diverse resources, not baseload power plants. Leveraging market forces to help us decide between options offers the best chance of avoiding the multitrillion-dollar mistake—and gigatons of carbon emissions—of blindly reinvesting in the past century’s technologies.

Cities around the world, including 22 cities in the United States and a growing number in Canada have pledged to go 100% renewable. It’s a noble, collaborative effort to be the cleanest, most environmentally sustainable cities on the planet, with an ultimate and cumulative end goal of each city doing its part to reduce worldwide carbon emissions.

Many cities that have made the pledge don’t yet have a route to an all-renewables, carbon-free destination. Some don’t have ownership of their electricity providers and thus have little or no influence over power fuel sources. Others depend today on energy sources that are based almost entirely on fossil fuel, making the renewables transition particularly difficult.  Still others are dealing with high permitting costs for popular renewable options like rooftop solar, as well with other regulatory obstacles. Technologically, anyone switching to a renewables-based grid must, by default, deal with the intermittency and reliability issues imposed by wind and solar. Even hydro electric energy is generally limited by the amount of water flowing in rivers, a quantity that can vary significantly over time.

A broader question, however, is why a fully renewable grid is more desirable than any other combination of zero-carbon energy sources. And what the overall effort and cost would be to decarbonize via that pathway alone.

The U.S. election is finally over, leaving some elated and others terrified. The last several months have been polarizing and contentious, and many feel that a Trump presidency is destined to bring uncertainty to the energy industry and endanger the goal many of us share of a more sustainable energy future.

Here are my thoughts on the key reasons why I believe that the distributed energy resources (DERs) market will continue to thrive, along with the march towards an advanced energy economy. 

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.