My growing interest in Distributed Energy Resources (DER)

Image credit here.

First, a warning that this topic includes a number of related acronyms with ‘D’s and ‘E’s. I will mostly stick to the broad term DER.

The ‘E’ stands for Energy, which perhaps is the most obvious piece. Energy is used broadly in these conversations and can include familiar, established types of generation such as coal, natural gas or nuclear but the whole DER discussion has been elevated more because of the attention being paid to the viable alternatives to fossil fuel-based energy such as renewable solar & wind. I am all for that of course but here, I am more curious about the ‘D’ and the ‘R’ of DER.

“Resources” is always plural

I bought this BioLite solar home kit to test out off-grid home electricity. Read more about their cost-effective kit here.

In the DER context, Resources refers to the growing collection of available options for generating and storing power (i.e., electricity - different ‘E’ :-) at different scales.

For example, an inexpensive rooftop solar panel installation combined with a small battery might be sufficient to provide electricity for a rural home that is not located close to any municipal power grid.

In a medium-sized town just down the road, it might be more suitable to supplement the nearby hydro-electric power source with an existing diesel generator to reliably serve electricity to the community.

DER advocates look to combine multiple, appropriate Resources to both generate and store power in a way that best suits the needs of the consumers. And increasingly, they are favoring clean energy sources whenever possible.

Which brings us to ‘D’, for Distributed

To fully appreciate why there is so much interest and activity around Distributed Energy Resources, it is helpful to review the current state of our electric power infrastructure.

(This is where I start to get really interested because our national and global power story is changing - and large-scale change usually means new, exciting professional opportunities!)

Centralized grids are outdated

For more than a century, the United States has been operating a centralized grid using conventional power generation resources. It looks and works the way it does now for historical and generally, rational reasons.

For example, it was not always feasible to physically place large-scale power generation sites close to the communities that needed electricity. Efficient hydro-electric dams must be built next to the actual flowing water source, but they can generate enough power to serve hundreds of thousands of distant users.

In the case of coal-fired plants, the prevailing wisdom was to keep the resulting air pollution away from heavily populated areas. And nuclear power plants, which come with their own set of environmental risks are challenging to build near major cities.

What has resulted is a nation-wide electricity grid that links these relatively few power generation sources to millions of individual homes and buildings. Our bulk power system or BPS requires a massive transmission system to connect the various power plants to the end consumer.

But this network of long distance, high voltage power lines is quite susceptible to damage & failure as was just recently witnessed during the 2021 Texas Winter storm.

Centralized power stations are connected to cities and towns through a vast network of transmission lines. Image credit here.

With a relatively few number of (centralized) power sources, the Electric Grid is capable of supporting the immense power needs of a growing population, but it is also quite vulnerable to outages that can affect entire regions of the country.

The push for a decentralized electric grid

DER systems provide a compelling alternative. By decentralizing power generation and introducing many more, but smaller (i.e., 10 megawatt) installations, we are able to position them closer to the end consumers. That results in more overall power availability and less risk of unforeseen interruptions in electricity transmission.

And when we combine the flexibility of decentralized generation with additional distributed energy storage solutions such as advanced batteries, we increase the resiliency of the entire grid system.

But a single energy grid or even several connected energy grids are less likely to provide true energy security for any region or country.

The good news is that the same DER approaches that are helping increase the reliability of large national electric grids are also being utilized to create smaller and more independent microgrids that supply electricity to individual communities. These microgrids are less expensive to build and maintain and do not require high-voltage transmission lines. They can be deployed closer to the homes and buildings that need power and are less susceptible to weather or similar catastrophic events that disrupt lives and interfere with economic prosperity.

Meeting local needs with local generation

You can read more about concepts like islanding, microgrids and the future of distributed energy resources at Energy.gov.

While DER can be used to boost the resiliency of large electric grids, there is an additional advantage to having more microgrids, specifically that they can often run independently of the macro grids. The term islanding is used to describe how microgrids operate when they are disconnected from the larger electric grid system. This provides even greater energy security for communities and will likely become even more common in certain areas of the globe.

Microgrids can be created at different scales to meet various resiliency goals:

• single-customer - the BioLite SolarHome system I mentioned above consists of a small solar panel plus local battery storage that is sufficient to power 4 lights and a radio for a single home allowing those individuals to live off the “grid”

• nanogrids - these smart electricity systems operate on the scale of a single building and use advanced technology to better control when power is needed and where it will be generated and stored for maximum efficiency

• community-scale - these efforts use one or more solar & wind power generation installations (i.e., inexpensive and feasible energy production) plus neighborhood-located energy storage options (full-substations?) that can operate independently from the national distributed grid

The future needs clean, renewable and distributed energy

I am drawn to these topics for multiple reasons. Partly it’s because updating aging technology systems is what I’ve been doing my whole professional life and this would seem to be an opportunity to tackle familiar problems on a global scale - with no shortage of urgency. But part of my fascination is that microgrids and islanding just sound cool!

I fully intend to continue researching and learning about hybrid systems, smart grids, distributed energy storage systems (DESS), demand management, etc. and will certainly publish more articles about these along my path.

I am interested in DER because of how it looks to address known problems related to electric grid resiliency, environmental impacts of fossil fuels, growing global energy demand and energy security. I already see a tremendous amount of activity in a number of related spaces. That seems chaotic to me but again, that kind of chaos can create opportunities for innovation and building effective business models.