Renewable energy generation in North America continues to rise. The Energy Information Administration (EIA), part of the American federal government, projects that renewables will generate 42 gigawatts of power in 2024, accounting for nearly a quarter of America’s electricity generation. Canada’s renewable capacity grew by 2.3 gigawatts in 2023 to a total installed capacity of 21.9 gigawatts.

Growth like that means mitigating the volatility of renewable power generation is crucial. Renewables come with peaks and valleys. Nowhere in the world is it always windy or always sunny (not even in Philadelphia). A battery energy storage system, or BESS, is one of the best ways of smoothing out that variance.

“You can’t control the sun, but you can control your batteries,” says Walter Schachtschneider, director of engineering for the solar arm of PCL’s team in Ontario.

Schachtschneider has worked with BESS systems for decades.

“I spent 28 years working for the phone company. We had rooms of lead-acid batteries. Each was the size of a mini-fridge and would generate two volts,” he says. “Now the batteries are little lithium-ion cells and you can have millions of them.

“The chemistry has changed and the applications have changed too.”

These days a typical BESS installation consists of one or more containers filled with lithium-ion battery cells, plus some safety, HVAC and electrical connectivity equipment. The containers are wired together, if applicable, and connected to a broader power system. That broader system often includes renewables and commercial power users.

For example, PCL installed more than 1,500 solar modules at the largest community center in Summerside, Prince Edward Island. The solar array saves the facility more than $100,000 per year, but its generating capacity of 336 kilowatt-hours (kWh) produces more power than the building needs when the sun is shining.

That’s why the project also included a BESS. With 890 kWh of storage capacity, the BESS charges up when the sun shines in Summerside and discharges on cloudy days. It also provides backup power for the host facility connected to the grid in Summerside, which isn’t connected to a major grid and relies on diesel generation for most of its power.

A BESS and a renewable power generation project offer complementary benefits for clients. But the benefits of a BESS go beyond this. Efficient local power storage and discharge is a potent concept with powerful applications for a wide variety of businesses and utilities.

“There’s a whole compendium of uses as the world evolves and the grid gets smarter,” says Schachtschneider. “A typical BESS container installation can store 4,000 kWh, which can run hundreds of houses or a typical shopping center for hours and reduce peak generation requirements. It can also, for example, allow you to finish painting cars during a power interruption on your painting system at a car factory. There are all these valuable or critical applications.”

Many of those uses will grow more attractive and urgent as demand for electricity continues to climb. EIA forecasts project that power consumption in the U.S. will reach almost 4,096 billion kWh in 2024 and 4,125 billion kWh in 2025. This growth is driven both by population expansion and the shift from fossil fuels to electricity for heat and transportation.

That growing demand will place greater demand on the grid. The strain of this has already been seen. In early 2024, for instance, the Alberta Electric System Operator issued grid alerts for three consecutive days to residents in the province. In the spring, rotating brownouts hit Alberta.

California, meanwhile, has long grappled with a problem known as the “duck curve.”

“It’s basically a mismatch between peak generation and peak demand,” says Schachtschneider. “Typical peak generation is solar noon. Peak consumption is when everybody goes home and turns their stove on, when the sun is on its way down.

“There’s great opportunity in California to store surplus energy in the 10-to-2 window and inject it into the grid during peak demand, which is around 5 to 7 p.m.”

Depending on specific market regulations and client needs, BESS installations could be used to boost grid reliability, defer or avoid infrastructure expansion, boost the bottom line by selling power at times of peak demand or avoiding power purchases at that time, or reduce expenditure on power.

The money-saving angle is salient in markets like Ontario.

“The electrical system here bills based on your peak hour of electrical demand,” says Schachtschneider. “So big users might have battery systems for when they anticipate that peak hour to occur. They disconnect from the grid for that time and turn on a BESS. It can save huge money.

“It’s similar to flying home for the holidays. Airlines and airports don’t have infinite capacity. A ticket home on December 23 might cost $3,000, but three weeks before it’s $400.”

The benefits and many possible uses of BESS projects have driven demand across the country. PCL has built BESS projects from the Maritimes to Alberta for renewable energy firms, water treatment plants, community centers, and grid operators.

But peak demand for BESS probably lies somewhere in the future. And it might be here sooner than you suppose.

“The first BESS project I did was in 2016 in downtown Toronto,” says Andrew Fleetwood, chief estimator and manager of preconstruction services for PCL Solar. “It was 12 megawatt-hours.

“Now people are looking for 300, 800, 1,200 megawatt-hours in a single project. The grid operator in Ontario recently put out an RFP for six gigawatts of battery storage. Our grid is not going to be able to support our needs in 10, 20, 30 years without systems like this to push and pull power.”

Fleetwood has worked on solar projects since 2010. In that time, he’s seen the cost to purchase and install photovoltaic panels plummet and the efficiency of the panels rise. This changing math has nudged countless solar projects from concept to reality.

He sees a similar trend right now with BESS projects.

“We might see other cell technologies beyond lithium-ion,” he says. “Battery efficiency is going to get better just like panels did. Just like electric cars did. Batteries won’t lose as much performance over time. Projects are only going to get bigger.”

Fleetwood’s colleague Andi Kasapi shares this view.

“When I started working on solar, the solar facilities would be fixed — the panels would all face in one direction,” says Kasapi, a senior project manager with PCL. “The cost for moving them east to west to follow the sun over the day was too high.

“But as the market developed and more suppliers entered it, the math changed. The extra power you get from following the sun and the lower cost of the panels made it viable. I see batteries making the same journey. More people are interested and asking. The market will get more efficient.”

Of course, tipping points are only obvious in retrospect. A BESS-curious organization today looking at the math needs a construction partner that can help them accurately assess the potential return on investment.

“Thanks to the expertise of Walter and his team, we can evaluate return on investment on a battery project at a really early phase,” says Kasapi.

Fleetwood adds that PCL’s partnerships and breadth of experience can also help clients lower costs and manage risk.

“About 80% of the cost of a BESS project is the batteries themselves,” he says. “We have relationships with the battery technology providers that can help clients keep capital expenditure down.

“And these systems are also really powerful and fast. They don’t need to turn on or warm up to discharge, which is great, but it means that when something goes wrong, it goes wrong really fast.”

PCL’s extensive experience working on critical infrastructure like hospitals and power plants can help clients identify and manage risks in using BESS.

And with demand for BESS projects rising, picking the right partner can make a huge difference to many different organizations.

“In a world of renewable energy,” says Schachtschneider, “BESS lets you control supply.”