Jan . 10, 2024 14:25 Back to list

Energy storage technology

Ten energy storage technologies that want to change the world

As COP28 calls for a tripling of renewable energy, storage technologies beyond the lithium-ion battery will play key roles. Recharge rounds up 10 of the most innovative recently in the headlines

As the renewables revolution gathers pace, the role of energy storage for harnessing green power has never been more important. Ten breakthrough technologies – using gravity, concrete and even trees – claim they hold the key to revolutionising the energy ecosystem.

The rollout of wind and solar power is racing ahead at record levels as countries and companies try to hit challenging net zero targets to help avert climate catastrophe.

But while fossil fuel power stations can hit the on switch whenever needed to meet demand, the variable nature of the wind and sun means that green energy assets often generate too much (or too little) power at any given moment.

'Game changer' | US cleantech boom turbocharges energy storage revolution

Energy Storage Cabinet Self-Cooling-EN-215

Energy storage is therefore garnering increasing attention as the perhaps underappreciated backbone of the green energy ecosystem – helping save excess power for when it is needed.

Lithium-ion batteries have become the kingpin of the energy storage ecosystem due to their energy density – meaning they can pack a huge amount of power into a small space.

But lithium-ion batteries suffer from issues around their Chinese-cornered supply chain, sustainability and sometimes make headlines for going up in flames.

Perhaps unsurprisingly for a technology first commercialised by Sony in 1991 to power Walkmans, they are not always suitable for backing up an electric grid as they do not fare well storing energy for more than eight hours.

Lithium-ion battery fires 'will go up exponentially', warns energy storage chief

Two other stalwarts of the energy storage ecosystem, hydro storage and green hydrogen, are well suited to ultra-long energy storage but require hugely time-consuming and costly buildouts. Hydro storage is also hindered by requiring specific mountainous geographies to support it.

This has given rise to an array of alternative and highly creative energy storage solutions that are looking to step into the space left by that established trio. Below is a (non-exhaustive) list of ten technologies that have recently made headlines.

1. Gravity

Perhaps one of the most creative ideas to emerge in the sector is storing excess green energy by using it to haul custom-made bricks upwards by crane and release them down again for discharge.

Storing kinetic energy like this works in a similar way to hydropower, but it is not limited by requiring mountainous geographies to make it work.

Swiss company Energy Vault is a leader in this space, having recently won what it said amounted to $1bn in orders in China with its custom-built facilities. Scottish start-up Gravitricity is meanwhile eyeing US mineshafts as a home for its own similar concept.

Energy Vault recently commissioned this gravity energy storage facility in China Photo: Energy Vault

2. ‘No-water’ hydropower

Another idea for unshackling the huge potential of hydropower from its geographical chains is being pioneered by a UK company that says its technology can turn even gently undulating hills into green batteries.

RheEnergise says it has achieved this by developing a system to pump a patented fluid uphill when energy is cheap. Because its fluid is two and a half times denser than water, the incline needed for the system to work is claimed to be two and a half times shallower.

The upside is that the system can be used in far more places – RheEnergise claims to have already identified almost one million suitable sites around the world. For now, the company has inked a deal to roll out its tech in the British countryside.

3. Compressed air (anywhere)

Compressed air is another long-standing energy storage technology that has been historically encumbered by geography – often relying on large salt caverns and depleted oil or gas reservoirs.

Canadian developer Hydrostor says it has solved the problem by developing custom-built caverns it can build anywhere. The company uses excess or off-peak energy to produce heated compressed air. It then extracts the heat and pumps the air into a cavern part filled with water, which is pushed to the surface.

When energy is needed, water is allowed to rush back down the shaft, forcing up the air, which is recombined with the stored heat to power a turbine.

Hydrostor has received backing from the likes of Goldman Sachs for its concept, and is developing projects in the US, UK, Canada and, most recently, Australia.

A Hydrostor diagram of how its technology works. Photo: Hydrostor

4. Concrete batteries

A team at the Massachusetts Institute of Technology in the US has recently made a breakthrough it said could create homes that are powered from their foundations and roads that charge electric vehicles as they speed along.

Using cement and carbon black, a highly conductive material that looks like very fine charcoal, the team found that they could create a supercapacitor to store electricity. The abundance of these materials means that the supercapacitors could be easily manufactured anywhere on Earth.

Because the material is so strong, it could be used as part of the concrete foundations of buildings, or in roads, say the researchers, turning them into batteries that can power everything from a kettle to a car.

5. Superheated bricks

Microsoft and oil giant Saudi Aramco have thrown their weight behind a California start-up that wants to help industry slash its emissions by storing excess renewable energy in superheated bricks.

Chilean desert to host ‘world’s largest’ energy storage project

Rondo Energy is pioneering a system that uses electric heating elements, like those in a toaster or oven, to superheat thousands of tons of bricks. When power is wanted, air flows up through the brick stack before being delivered to the end point as superheated air or steam.

Rondo has already partnered with a Thai conglomerate to expand the production capacity for its system, creating a facility it says would be “larger than any current battery manufacturing facility worldwide.”

6. Metal blocks

Another oil giant, Shell, is backing another thermal energy storage technology that can pack power into shoebox-sized blocks of metal alloy particles.

Excess energy is used to heat the alloy particles until they melt, while a matrix material remains solid and keeps the molten particles in place. When the blocks are allowed to cool, the heat they give off can be used to power a downstream turbine.

The technology is being pioneered by Australia’s MGA Thermal, although it has had a rocky start after a demonstration unit in the country dangerously overheated, sparking an evacuation of the surrounding area due to fears of an explosion.

MGA Thermal workers during the commissioning of an automated production line for its metal blocks. Photo: MGA Thermal

7. Tree power

One of the biggest names in energy storage, Sweden’s Northvolt, is developing sustainable batteries using lignin-based hard carbon produced from wood from Nordic forests.

Northvolt eyes global storage markets with 'cost-effective' sodium-ion battery

Together with Finnish paper and pulp giant Stora Enso, Northvolt is aiming to create the world’s first industrial battery featuring anode sources entirely from European raw materials, lowering the carbon footprint and cost.

Lignin, a plant-derived polymer, makes up around 20–30% of trees. Stora Enso will provide the lignin from sustainably managed forests, while Northvolt plans to drive cell design, production process development and scale-up of the technology.

8. Iron-flow batteries

One of the next generation of battery technologies being developed, iron flow batteries circulate liquid electrolytes to charge and discharge electrons via a process called a redox reaction. Unlike in conventional batteries, the same electrolyte can be used on both the negative and positive sides of the equation.

One of the principal manufacturers of these batteries – US-based ESS Tech – says that this eliminates cross-contamination and degradation, meaning its batteries will last an expected 25 years. Conventional batteries typically last up to ten.

ESS, which has received backing from Bill Gates’ Breakthrough Energy Ventures (BEV) among others, claims its batteries are also safer than lithium-ion, reducing the need for safety equipment.

Lorries transporting ESS Tech's battery units. Photo: ESS Tech

9. Iron-air batteries

They also use iron. They are also backed by BEV. But the iron-air batteries being pioneered by Form Energy work on a very different principle – described by the US developer as reversible rusting”.

When charging, the application of an electrical current converts rust to iron and the battery – made up of cells including iron and air electrodes – breathes out oxygen. When discharging, the batteries breath in oxygen from the air and convert the iron back to rust.

Form Energy claims its batteries can store electricity for 100 hours at system costs competitive with legacy power plants. Its batteries were recently cleared for a demo at one of America’s largest solar plants.

10. Nickel-zinc batteries

One California start-up believes its technology can unlock the potential of a battery first invented by Thomas Edison, while also unleashing a “sleeping giant” of global energy storage capacity.

US warned over battery crunch threat to green energy storage plans

The breakthrough technology is a new electrode that Enzinc, the company commercialising it, claims can be dropped into factories producing the dependable but low-power lead acid batteries – converting them into production lines for far more energy dense nickel-zinc batteries.

Nickel-zinc batteries were developed by renowned US inventor Edison but never gained much traction as they would only last a few dozen cycles. Enzinc claims the new electrode solves this problem, resulting in a battery as powerful as lithium and as safe as lead.(Copyright)

Jan . 10, 2024 11:34 Back to list

Energy Storage-Energy storage technology

Energy Storage

Energy storage refers to technologies capable of storing electricity generated at one time for later use. These technologies can store energy in a variety of forms including as electrical, mechanical, electrochemical or thermal energy. Storage is an important resource that can provide system flexibility and better align the supply of variable renewable energy with demand by shifting the timing of energy supply and demand.

Introduction

Energy storage systems are technologies capable of charging energy from an external source and discharging this energy at a later time. The emergence of storage technologies, such as grid-scale battery energy storage systems (BESS), has created new opportunities for shifting energy supply and demand. This unique ability of energy storage can facilitate the integration of renewable energy resources through the provision of several types of services.

Location

Energy storage systems can be broadly categorized based on 1) where they are interconnected (e.g., in front-of-the-meter, behind-the-meter, or off-grid) and 2) the type of energy they store (e.g., thermal, mechanical, electrochemical, etc.). Where storage systems are interconnected has important implications for who owns them, what technology they use, their size and what services they are capable of providing:

Behind-the-meter (BTM) - these are small systems usually located directly at the customer premises, which directly interconnect to the distribution system. Often these systems are used to provide backup power or power-quality-related services to the system owner. However, as communication, telemetry and inverter equipment improve, these systems are increasingly being used to provide distribution level services. In some advanced markets, distribution systems are also being aggregated to provide transmission-level, wholesale market services.
Grid-scale, distribution systems – these systems are much larger than BTM systems and supply services to the distribution or transmission system, such as regulation reserves, load following or upgrade deferrals.
Grid-scale, transmission systems– these systems tend to be the largest and are connected at the transmission level to provide services such as regulation or load following.
Off-grid systems – these systems are isolated from and operate independently of the grid.

Technology Type

The technology used to store energy also has important implications for the types of services systems can supply. Each technology, whether mechanical systems like pumped hydroelectric storage or electrochemical systems like lithium-ion batteries, will have set characteristics and unique advantages and disadvantages that make them suitable for different grid system applications. A table of definitions for a few of these characteristics are shown below.

Table 1: Definitions of Key Battery Technical Characteristics

Technical Characteristic	Definition
Rated Power Capacity	Total possible instantaneous discharge capability (in kilowatts [kW] or megawatts [MW]) of the BESS, or the maximum rate of discharge that the BESS can achieve, starting from a fully charged state
Energy Capacity	Maximum amount of stored energy (in kilowatt-hours [kWh] or megawatt-hours [MWh]) a battery can hold
Energy/Power Density	Measure of the energy or power capacity of a battery relative to its volume (kW/L, kWh/L)
Specific Energy/Power	Measure of the energy or power capacity of a battery relative to its weight (kW/g, kWh/g)
Storage Duration	Amount of time storage can discharge at its power capacity before depleting its energy capacity
Cycle Life/Lifetime	Amount of time or cycles a battery storage system can provide regular charging and discharging before failure or significant degradation
Round-trip Efficiency	Ratio of the energy charged to the battery to the energy discharged from the battery
Self-discharge	Reduction of stored energy of the battery (% of charge/time) through internal chemical reactions, rather than through discharging to perform work.

A brief explanation of the various technologies is given below. Readers interested in a more detailed overview of these technology types can explore the DOE’s Electricity Storage Handbook or the Asian Development Bank’s Handbook on Battery Energy Storage System.

Stacked Household Energy Storage System FlexPIus-EN-512

Thermal energy storage systems – these operate by creating a temperature gradient or by inducing a material phase change anywhere from hours to seasons. They are primarily used in large, front-of-the-meter installations. When used for storing and generating electricity, as opposed to meeting heating and cooling demands, are typically paired with concentrated solar power (CSP) plants and use molten salt as a medium.
Mechanical energy storage systems – these systems transform potential and/or kinetic energy into electricity. Examples include pumped hydroelectric energy storage (PHES), compressed air energy storage (CAES) and flywheels. PHES and CAES are typically used in very large, front-of-the-meter transmission-level installations and are mainly used for load-following applications. Flywheels, however, may also be used in behind-the-meter applications such as uninterrupted power supply.
Electrical energy storage systems – these are short-duration systems that store electricity in the electric field of supercapacitors or in the magnetic field of superconductors. In the power sector, these are primarily used to maintain a high level of power quality.
Electrochemical storage systems – these generate electricity through reversible chemical reactions. Battery energy storage systems (BESS) are the most common and commercial form of this technology and are widely deployed at the behind-the-meter, distribution and transmission levels. Battery technologies are classified based on different chemistries and technical properties and include lithium-ion (currently the market leader for a wide variety of applications); lead-acid; nickel-based; sodium-based; and flow batteries. Each of these chemistries varies strongly with respect to technical characteristics and costs and are accordingly used in a wide variety of applications.

Storage Services

Energy storage systems are capable of providing a wide range of system services depending on where they are interconnected and their technical characteristics (which are, in part, determined by their technology type). These services can be broadly categorized as:

Providing capacity services and energy shifting: System operators must ensure they have adequate supply of generation capacity to reliably meet demand during the highest-demand periods in a given year. This peak demand is typically met with higher-cost generators, such as gas plants; however, depending on the shape of the load curve, energy storage systems can also be used to ensure adequate peaking generation capacity. System operators can also improve the ability of variable renewable energy (VRE) plants to contribute to peaking capacity by pairing VRE with energy storage. Pairing VRE resources with energy storage can enable these resources to shift their generation to times when it is needed most.
Providing fast-response ancillary services: Many forms of energy storage, notably batteries, are capable of rapidly and accurately changing their charging and discharging rates in response to external signals. By quickly changing their output, these storage resources can provide valuable ancillary services that system operators use to help balance differences between demand and supply. These ancillary services are particularly important in systems with large amounts of variable renewable energy generation, as system operators must be able to respond to unexpected changes in energy supply. Currently, ancillary services are predominantly provided by partially loaded conventional generators. Using energy storage to align supply and demand as well as to provide ancillary services can increase the flexibility of the grid and help reduce the curtailment of renewable energy resources and spinning reserve requirements from conventional resources.
Transmission and Distribution Upgrade Deferral: The electricity grid’s transmission and distribution infrastructure must be sized to meet peak demand, which may only occur over a few hours of the year. When anticipated growth in peak electricity demand exceeds the grid’s existing capacity, costly investments are needed to upgrade equipment and develop new infrastructure. Deploying energy storage can help defer or avoid the need for new grid investments by meeting peak demand with energy stored from lower-demand periods, thereby reducing grid congestion and improving overall transmission and distribution asset utilization.
Black Start: When starting up, large generators need an external source of electricity to perform key functions before they can begin generating electricity for the grid. During normal system conditions, this external electricity can be provided by the grid. After a system failure, however, the grid can no longer provide this power, and generators must be started through an on-site source of electricity. On-site energy storage such as a lithium-ion battery storage system can provide this service, avoiding fuel costs and emissions from conventional black-start generators. As system-wide outages are rare, on-site energy storage can provide additional services when not performing black starts.

Some energy storage systems, in particular Battery Energy Storage Systems (BESS), can maximize their value to the grid and project developers by providing multiple system services. As some services are rarely called for or used infrequently in a given hour, designing BESS to provide multiple services enables a higher overall battery utilization. This multi-use approach to energy is known as value-stacking. For example, a BESS project can help defer the need for new transmission by meeting a portion of the peak demand with stored energy during a select few hours in the year. When not meeting peak demand, the BESS can earn revenue by providing operating reserve services for the transmission system operator.

Some system services may be mutually exclusive depending on the BESS design (e.g., a short duration storage device used to supply regulating reserves would have limited value for deferring transmission or distribution upgrades). Even if a BESS is technically capable of providing multiple services, the additional cycling of the battery (charging and discharging) may degrade the battery and shorten its lifetime and economic viability. Finally, a BESS can only provide a limited duration of any set of services before it runs out of charge, which means batteries must prioritize the services they provide.

Policy examples to increase storage deployment

Incorporate consideration of storage into grid integration studies to determine the cost-effectiveness of storage relative to other flexibility options at a variety of variable RE penetrations
Conduct integrated resource planning to identify locations for feasible and effective implementation of storage measures
Develop modeling tools that can fully characterize the costs and benefits of storage technologies
Support early-stage research and development into emerging energy storage technologies
Streamline implementation of new energy storage regulations to reduce administrative delays that limit storage deployment
Address revenue compensation mechanisms and market shortcomings for the services offered by energy storage resources. These can include:

Explicitly allowing storage systems to provide system services;

Ensuring that the unique technical characteristics of storage (fast response time, ability to act as both a load and supply source) are properly compensated;

Removing barriers to value-stacking.

Reading List

Lawrence Berkeley National Laboratory, Electric Power Research Institute, and Clean Kilowatts, 2020

This article explores the advantages, disadvantages, development trends, near-term value proposition, and market participation options for utility-scale hybrid battery projects in the United States, with a focus on PV-battery and wind-battery hybrids. The article is meant to inform electric-sector stakeholders—including industry participants, regulators, market organizers, analysts, and policymakers—who are seeking to understand these types of projects and integrate them into wholesale markets.

Energy Storage in South Asia: Understanding the Role of Grid Connected Energy Storage in South Asia’s Power Sector Transformation

National Renewable Energy Laboratory, 2021

During the last decade, the cost of energy storage technologies has declined rapidly. At the same time, grid flexibility is becoming more important as renewable energy integration increases across the world. Storage technologies have the potential to provide some of this flexibility. However, uncertainties around costs and regulations remain when considering energy storage in India and other South Asia countries, including Bangladesh, Bhutan, and Nepal. This study provides a first-of-its-kind assessment of cost-effective opportunities for grid-scale energy storage deployment in South Asia. The report covers both a near and long term analysis, and discussion of energy storage drivers, potential barriers, and the role of storage in system operations. The state-of-the art modeling approach compares the value of battery storage and pumped hydro storage for 2030 and 2050, considering system operations in India, Bangladesh, Bhutan, and Nepal as a single South Asia interconnection with no institutional barriers to cross-border electricity trade (CBET).

Utility-Scale Battery Storage: Frequently Asked Questions

National Renewable Energy Laboratory, September 2019

This fact sheet provides concise answers to frequently asked questions about utility-scale battery energy storage systems.

The potential for Battery Energy Storage to Provide Peaking Capacity in the United States

National Renewable Energy Laboratory, June 2019

This study examines the potential role of limited-duration battery energy storage in meeting peak demand. As battery storage costs decline, they have become important sources of peak capacity because they reduce net demand. Yet, the economic value of peak capacity storage decreases because peak demand flattens as more storage is added to the system. The paper evaluates the potential market size of peak capacity storage and its sensitivity to various mixes of solar PV and wind. The authors find that this potential strongly depends on the shape of electricity load and grid conditions. Under high penetration of renewable generation, the potential of storage increases substantially. The value of storage doubles when solar PV penetration is greater than 10% whereas the impact of wind is unclear and requires more study.

Battery storage in New Zealand

Transpower New Zealand Limited, September 2017

This study by New Zealand’s grid owner and system operator explores the value of battery energy storage across the electricity supply chain to electricity consumers and the New Zealand electricity system. Findings specific to New Zealand’s electricity market suggest that:

The greatest value is in behind-the-meter applications
Existing market tools limit consumer participation in the various energy markets
The potential value of each service provided by storage varies widely based on physical location and location in the value chain
Dynamic tariff design such as time-of-use pricing could improve the economic value of batteries
Behind-the-meter batteries and grid-scale batteries expected to be economic by 2020 and 2022 respectively

The value of energy storage in decarbonizing the electricity sector

Argonne National Laboratory & Massachusetts Institute of Technology, May 2016

This paper examines the value of electric storage in grid decarbonization efforts by using forecasts of hourly electricity demand in Texas in 2035. Electric storage provides a carbon-free source of operational flexibility to the grid by shifting power supplied by variable renewable energy sources, which increases their value to the grid. The authors determine the optimal mix of thermal and renewable resources given various operational limits and assuming different scenarios of installed energy storage capacity and CO₂ emission limits. Results suggest that the value of energy storage is only economical under strict emission limits and depends on the availability of flexible nuclear, pumped hydro storage and the share of renewables in the mix.

Energy Storage Requirements for Achieving 50% Solar Photovoltaic Energy Penetration in California

National Renewable Energy Laboratory, 2016

This report estimates the storage required for high PV penetration on the grid (up to 50% in California with renewable penetration over 66%), and quantifies the complex relationships among storage, PV penetration, grid flexibility, and PV costs due to increased curtailment. The authors find that storage needs depend strongly on the amount of other flexibility resources deployed. With very low-cost PV (three cents per kilowatt-hour) and a highly flexible electric power system, about 19 gigawatts of energy storage could enable 50% PV penetration with a marginal net PV levelized cost of energy (LCOE) comparable to the variable costs of future combined-cycle gas generators under carbon constraints.

Market and Policy Barriers to Energy Storage Deployment

Sandia National Laboratory, September 2013

This report details the barriers that restrict the deployment of energy storage technologies in the United States. The findings are based on interviews with stakeholders and review of regulatory filings in four regions roughly representative of the country. The report suggests that while high capital costs remain a barrier to energy storage, deployment is also impacted by regulatory, market (economic), utility and developer business model, cross-cutting, and technology barriers. The report also presents a discussion of possible solutions to address these barriers and a review of initiatives around the country at the federal, regional and state levels. [Also, read an earlier discussion of barriers to storage deployment].

Regulatory and Policy Examples

FERC Order 841: Electric Storage Participation in Markets Operated by Regional Transmission Organizations and Independent System Operators

Federal Energy Regulatory Commission, February 2018

FERC Order 841 is a final rule from the United States Department of Energy’s Federal Energy Regulatory Commission that directs RTOs and ISOs to develop tariffs to integrate electric storage into all electric (capacity, energy, and ancillary service) markets. This rule is expected to usher in the wider use of electric storage and in turn result in higher integration of intermittent and variable onto the grid. The rule applies to all storage capable of both charging from and discharging to the grid, regardless of whether it was a behind-the-meter, distribution, or transmission level system. In May 2019, citing their jurisdictional authority, FERC commissioners declined to allow states to opt out of this rule.

Rulemaking 15-03-011: Decision on Multiple-Use Application Issues

Public Utilities Commission of the State of California, January 2018

Battery storage systems can maximize their value to the grid and to project developers by providing multiple services. This multi-use approach to BESS is known as value stacking. To ensure battery projects can select the most cost-effective combinations of services to provide without negatively impacting the reliability of the grid, California regulators developed 12 rules dictating battery behavior around value-stacking. Among other considerations, these rules ensure batteries:

Cannot contract for additional services that might interfere with obligations to provide reliability services;
Meet all performance and availability requirements for the services they provide; and
Inform the utility of services it currently provides or intends to provide.

Xcel Energy: Guidance No. 1 for the Interconnection of Electric Storage as Stand-Alone Sources, Parallel Operation for Customers without Generation, and in Parallel with Self-Generation

Xcel Energy, January 2017

This document outlines electric storage interconnection guidelines for three different configurations:

Case 1a: Stand-by energy storage – Provision for facilities that require stand-by (backup) systems to provide power through onsite or grid-charged batteries.
Case 1b: Parallel Operation without onsite generation – Provision for batteries without onsite generation to operate in parallel with utility
Case 1c: Parallel Operation with non-net metered, non-renewable onsite generation – Provision for batteries with onsite generation to operate in parallel with utility

To ensure compliance with interconnection rules and prevent unintended export of power to the grid in cases 1b and 1c, meters and the appropriate control systems must be installed and registered.

AB-2514 Energy storage systems

Public Utilities Commission of the State of California, September 2010

California established a target of 1.325 GW of energy storage by 2020 for its various investor-owned utilities. Key details included:

Specific biennial procurements requirements for each utility. As at June 2018, California’s three main investor-owned utilities - Pacific Gas & Electric, Southern California Edison and San Diego Gas & Electric were 40%, 70% and 95% towards their respective goals of a combined 1.325 GW of battery energy storage.
Value-stacking of energy storage allowed. That is, energy storage could be used in multiple applications in capacity, ancillary and peak shaving services.
Utilities’ ownership of storage could not exceed 50%.
Large scale pumped hydro storage could not be used to meet requirement.

Jan . 10, 2024 09:57 Back to list

Energy storage technology

Distributed Energy Resources: A Beginner’s Guide

by Tara Energy | Educational, Energy

Distributed Energy Resources Image of Power Energy Plant

Power plants are one of the most prominent features of the electric grid. They’re large, intricate structures where electricity generation takes place, and they’re a key part of the power systems that provide us with electricity service. But small-scale options are beginning to change the way the energy industry handles power generation.

Distributed energy resources (DERs) are an emerging category of energy technologies in which power is either generated onsite at a residence or commercial building, or else very close by. Because power is generated from multiple local sources rather than one distant, centralized power station, DERs have the added advantage of addressing the inconvenience — and sometimes catastrophic consequences — of power outages not to mention the aging power grid in the U.S.

Let’s explore distributed energy resources, how they work, and what they might mean for our energy future.

Electrochemical energy storage Mobile-PW-512

What Is Distributed Energy?

Distributed energy is an electricity generation system that uses a variety of small-scale devices rather than one centralized system operator and distribution network. Distributed energy resources often have a capacity of one megawatt (MW) or less, but they can also include utility-scale generators with greater capacity.

More broadly, “distributed” and “centralized” energy refer to two different approaches to creating an energy distribution system. It’s worth trying to understand how the distributed and centralized approaches are distinct. An easy way to do this is to consider a couple of examples from the extreme ends of the spectrum.

In a maximally centralized energy system, a single electric utility (probably the government or a government-backed monopoly) would be responsible for all electricity generation on the power grid within a specific country. On the other hand, in a maximally distributed energy system, all power generation would occur at individual buildings, and everyone would effectively be their own grid operator.

Of course, today most power generation systems are nowhere near these two extremes. In the United States, for example, electricity is sold to consumers by a variety of different entities, including investor-owned utilities, public-sector firms, cooperatives, and other providers. Since power companies tend to be fairly large, we are closer to a centralized system than a distributed one, but we’re still far from being fully-centralized.

What Are Examples of Distributed Energy?

Distributed Energy Solar Panels on Rooftop source

Distributed energy resources can be used to supplement electricity needs in a number of different locations. While many DERs use clean energy sources, it’s worth noting that some can run on fossil fuels. Here are some ways in which distributed energy resources are used as upgrades to residences and industrial sites.

Solar photovoltaic (PV) and rooftop solar panels: Clean energy has become more popular over the past few decades, and today as much as a third of solar energy produced in the United States comes from small solar installations such as the solar panels seen on the rooftops of homes. These are examples “photovoltaics” in which energy from the sun is absorbed and converted to electricity.
Small wind turbines: Though we usually picture wind turbines as very big structures, there are also much smaller models that can contribute electric power generation to a home. As long as you live in a place with enough wind energy, these microturbines could be a viable option.
Fuel cells fired by natural gas: Among the many ways of generating power from a fuel source, fuel cells are the most efficient. Fuel cells can take a variety of fuel sources, including biogas, natural gas, and plain hydrogen.

Backup generators: There are many different kinds of backup generators that can provide power in case of an emergency (such as an extreme weather event) when you experience electricity disruptions.

What Is Distributed Energy Storage?

Power isn’t just generated and used immediately. A variety of energy storage technologies exist to store energy and make it available when it’s needed.

Distributed energy storage refers to technologies that complement distributed energy resources, making it possible to create power onsite or nearby and keep it handy for later use.

This isn’t simply a matter of convenience. Without good energy storage technologies, it would be impossible to ensure the reliability that modern, advanced industries require. Unreliable energy would make many aspects of life — from medical procedures to cross-country flights — much more precarious, reducing the functionality of the systems we rely on.

Perhaps the most common form of energy storage is battery storage. Batteries are found in remote controls, baby monitors, and many other everyday devices.

A related but less common example is electric vehicles, which can store power in their lithium-ion batteries. In addition to their function as energy loads, electric vehicles can also act as power generators, putting stored energy back into the grid when demand is high.

What Is Distributed Renewable Energy?

Distributed energy refers to creating and storing energy somewhere near the point at which it will be used rather than generating and transporting it from a far-off location.

In principle, distributed energy can come from almost any fuel source, including fossil fuels, solar panels, and backup generators. Nevertheless, in the ongoing battle for sustainability, many are exploring the possibility of building DERs that rely solely on renewable energy.

Rooftop solar panels are one obvious example of distributed energy resources powered by clean energies. There are also efforts aimed at using reliable renewable options such as hydroelectric power, biomass, and wind turbines small enough to power residences or offices.

How Does Distributed Energy Reduce Carbon Emissions?

Distributed Energy Image of Smoke Coming From Factories source

Human activity, especially large-scale industrial activity, produces carbon dioxide. This greenhouse gas significantly contributes to the overall warming of the planet and climate change. For this reason alone, it’s important to explore a variety of different ways to reduce carbon emissions —and this is one place that distributed energy resources can help.

One way in which DERs can reduce carbon emissions is by making it easier to switch to alternative fuel sources. As solar panels become more prevalent and affordable, it will be possible for more of a home’s energy budget to come from solar power instead of fossil fuels such as natural gas, for example.

Likewise, electric vehicles are a type of distributed energy resource that can decrease reliance on oil substantially, acting as a key component in the transition to cleaner energy.

What Are the Benefits of Distributed Energy?

Benefits of Distributed Energy source

Over the past 10 years, the use of DERs has increased, and this is in no small measure because they provide a variety of benefits to end users — including the ability to reduce carbon emissions when using renewable sources for power generation. We can broadly group these benefits into two categories: energy efficiency and energy reliability.

Distributed Energy Resources Can Increase Energy Efficiency

Choosing a cost-effective DER can save on energy costs, meaning lower energy bills and less financial strain. Because electricity is generated locally rather than from a distant power plant, less energy is lost in transmission, resulting in better energy efficiency.

In fact, the U.S. Energy Information Administration estimates that “about 5% of the electricity transmitted and distributed in the United States in 2017 through 2021” was lost during transmission. Furthermore, DERs can scale up and down based on demand, or if they feature energy storage systems that let them draw on reserves later, it also becomes easier to “balance” the generation of power on the main grid.

Distributed Energy Resources Can Increase Energy Reliability

According to the U.S. Department of Energy, “More than 70% of the nation’s grid transmission lines and power transformers are over 25 years old, creating vulnerability.” DERs can directly contribute to increased energy reliability because it means power service is less vulnerable to a single point of failure.

In other words, if 100% of your energy comes from the local supplier and that supplier has a disruption, you’ve lost 100% of your energy. If you have solar panels, a backup generator, and/or a small wind turbine, however, you’ll be able to meet at least some of your energy needs while the local supplier fixes the issue.

In addition, distributed energy resources can also be networked into a microgrid that can act independently of the main electricity grid. Whereas the U.S. power grid refers to the sum total of power stations and transmission lines, which carry power across the country from California to New York and everywhere in between, a microgrid is a much smaller, local grid version comprised of an interconnection of homes and buildings.

Whether they’re used to power individual homes or to form microgrids, DERs make the power grid more flexible and resilient. For both individual users and businesses, distributed energy resources offer a panoply of different benefits that make them attractive options.

DERs Could Make for a Cleaner, More Resilient Energy Grid

We’re still in the early stages of understanding distributed energy resources and how they’ll impact the power grid, but the evidence so far is very promising. Whether it’s lowering a monthly energy bill by installing rooftop solar panels, protecting yourself from inclement weather with a backup generator, or contributing to the fight to reduce carbon emissions and improve the sustainability of energy production, there are myriad occasions in which it makes sense to generate and use power locally.

As the demand and need for distributed generation of power continue to grow, new approaches to DERs will be developed, making the grid less susceptible to single points of failure while cutting carbon emissions and costs. In the meantime, you can learn more about how you can boost your energy efficiency at home to save money and even help save the planet.

outdoor emergency power

Jan . 10, 2024 14:25 Back to list

Energy storage technology

Ten energy storage technologies that want to change the world

Energy Storage Cabinet Self-Cooling-EN-215