Long duration energy storage is scaling fast. Here’s how to understand it.

Electricity generation produces about a quarter of U.S. greenhouse gas emissions, most of it from burning fossil fuels, according to the EPA. Energy storage is what lets solar and wind provide reliable electricity even when the sun isn’t shining or the wind isn’t blowing. The people who build and run these systems work at the center of the transition to renewable energy, where human wellbeing and the health of natural systems meet. This work offers opportunity and purpose.

What is long duration energy storage?

Long duration energy storage, or LDES, keeps electricity ready to release over many hours. The U.S. Department of Energy defines it as any system that can deliver power for 10 or more hours at a stretch.

Extended storage time is what makes this technology valuable. Solar produces most of its power in the afternoon but demand climbs after sunset. LDES acts like a reservoir for electricity. It fills while the afternoon sun is pouring out inexpensive power, then releases through the evening when everyone gets home and air conditioners are running. 

The underlying technologies vary with some storing energy in batteries, others relying on heat, compressed air, a spinning mass, or chemical fuels.

From minutes to hours

Grid storage is not new. For decades  pumped hydro dominated the field, pushing water uphill when power is plentiful and letting it fall back through turbines when it is needed. This type of system can run for many hours, even days, but it needs the right terrain and large reservoirs, so it only fits a handful of sites.

The past decade belonged to lithium-ion batteries. Costs dropped fast and installations multiplied, but most of  these systems are designed for short bursts. Grid batteries run for two to four hours, and many earn their keep in minutes, steadying frequency and covering the moment a cloud passes over a solar farm or a plant trips offline. That is enough to smooth a daily peak, but not enough to carry a city from a windless, cloudy afternoon through the next morning.

Now the challenge is changing. As solar and wind supply more of the grid, the gaps between supply and demand stretch past four hours, across long evenings, multi-day weather lulls and seasonal swings. Utilities are starting to buy storage measured in eight, ten, even eighteen hours, and a wave of technologies is being built or revived to provide it: iron-flow batteries, compressed air, thermal storage and CO2 based storage. The U.S. Department of Energy has set a goal of cutting the cost of 10-hour-plus storage by 90 percent within a decade. Lithium-ion batteries 

still lead the market today, but the grid’s needs are evolving. Storage is moving from being measured in minutes to hours.

The work is here, and it is growing

The workforce demand is already here. U.S. developers plan to add 24 gigawatts of utility-scale battery storage to the grid in 2026, up from a record 15 gigawatts in 2025, according to the EIA, with Texas, California and Arizona leading. Longer-duration projects are moving from pilots into construction, including Salt River Project’s 10-hour iron-flow battery in Arizona.

Every one of those sites needs people to build, operate, service, plan for and keep it compliant. That demand runs across the trades, engineering, manufacturing and public service. For people already working in energy, infrastructure or the skilled trades, understanding how these systems work is quickly becoming a career advantage.

What it solves on the job

Picture a lineworker fifteen years into the trade. She can replace a transformer and read a feeder in her sleep. But one morning, the work plan lists a new battery storage installation, and in the safety briefing an engineer talks about ten-hour discharge, round-trip efficiency and thermal versus electrochemical systems. None of it is in her vocabulary yet, but the technology is already arriving on the grid she maintains.

This is a common story. The most of the people who will install, operate, plan and regulate LDES already have jobs in the field, but haven’t  had a plain-language starting point for the technology. This leads to cross-team conversations stalling, and decisions waiting on the one specialist in the room.

That disconnect is what theIntroduction to Long Duration Energy Storage course was built to address. It is a self-paced introduction that runs about five hours, making it short enough to finish around a shift or across a workweek. The aim is a provide a lineworker, a manufacturing technician or a policy analyst with a working grasp of the technology they can immediately put to use.

The course moves through four modules:

1. Energy storage fundamentals
   • What you learn: how storage works and why LDES matters to a stable grid.
2. Comparing the technologies
   • What you learn: how electrochemical, thermal, mechanical and chemical systems differ, and where each one fits.
3. Storage in context
   • What you learn: how environmental, economic and policy factors shape where projects get built.
4. Careers and pathways
   • What you learn: the roles taking shape around the technology and how your own skills connect to them.

By the end, you can explain what LDES does, compare the main technologies and their uses, weigh the benefits and limits in clear language and name a career path or community application that fits your background.

The people behind the course

The course pulls from three people who work where utilities, community colleges and energy research meet.

Hank Courtright spent 24 years at the Electric Power Research Institute before joining Salt River Project in 2017, where he led the utility’s carbon reduction plan and its expansion into solar and storage. He knows grid planning from the inside, not from a textbook.

Andrew Clegg is dean of workforce development and skilled trades at Central Arizona College, with more than a decade spent aligning college programs to what regional employers are hiring for. Before higher education he worked in economic development, recruiting the businesses that create those jobs.

Ryan Klenner came to clean energy the way many of this course’s learners will. He spent more than 20 years in the building trades, moving from laborer to senior leadership, then earned a sustainability degree from ASU. He is now assistant director of business development at the LightWorks Innovation Accelerator, where he links companies to ASU’s energy researchers.

Where it can take you

The course ends with a shareable digital badge and a working vocabulary you can use the next day. It also asks each learner to name a pathway that fits their own skills, interests and region, so they finish with a badge and a plan of their own.

The roles are already posting: energy systems analyst, utility planner, energy program coordinator, energy policy analyst, sustainability officer, field service technician. The subject reaches across industries too, from battery manufacturing and grid modernization to environmental engineering and community energy programs. Each of these roles helps clean power replace fossil generation, which makes them planetary health work as much as energy jobs.

For someone already in a trade or a utility, the badge is something to point to when storage projects land in the work plan. For someone moving toward the field, it is a first concrete step and a way to speak the language before the interview. From here, a learner can stack it toward further study or carry it straight into the job they already hold.

Ready to start?

Introduction to Long Duration Energy Storage runs through ASU CareerCatalyst, takes about five hours at your own pace, and gives you a shareable badge at the end. It is built as an introduction, so an engineering background is not required to follow it.

Explore the course and enroll.