Renewable energy’s role in a reliable power system
By Carson Fong, Senior Analyst, BRC-Canada
On a planet getting pummeled by climate change, the rapid rise of renewable energy is hopeful progress that we must embrace. It’s not the first time humanity has changed its primary source of energy production – and maybe it won’t be the last. We’ve switched from thinking of wood and whale oil as primary sources of heat and light, and now we’re moving away from fossil fuels. Every time we do this, we adjust how we get the energy, how we handle it and how we coax the most out of it.
Renewables are no different.
Wind and solar power are built for our age. They are quick to build, the energy source they run on is free and unlimited, and they produce no carbon emissions. All this in a time when we witness daily the dire need to move rapidly away from carbon-emitting energy sources. On top of that, it’s cheap to build: between 2009 to 2023, the technology prices of wind and solar fell by 63 per cent and 83 per cent, respectively.
Now, we are learning how to wring the most out of renewables. As we noted in a previous blog on capacity factors, all sources of electricity produce varying amounts of power over time. Coal and natural gas plants need to be shut down (or have to reduce their production) when the weather is too hot or when they need maintenance. (In Alberta in 2022, 85 per cent of combined cycle natural gas capacity was available for electricity generation.1) The wind does not always blow for wind turbines. Every day, the sun sets on solar panels. So, each energy source has different situations where it cannot provide energy. Really, this is not a problem for humans. We adjust.
Witness the fact that whenever we turn on our lights, run our dishwashers, or watch an old episode of The Office on TV, our electrical appliances always turn on.
How does that happen? How have system operators always managed to use all these different types of energy sources to consistently provide reliable power? Obviously, some careful study is needed: at what times are energy demands highest and where? How do we get the energy from the source to the need? What is each source capable of? And good planning also considers backup power.
In the case of renewables, it helps that wind and solar hourly generation patterns are complementary. Broadly speaking, it is windier at night when there is no sun, and less windy during the day when there is lots of sun.2 This means the blend of wind and solar power produces a smoother output of electricity.
Humans have been studying weather for centuries, and in increasingly sophisticated ways. Wind and solar production have become predictable creatures. The Alberta Electric System Operator (AESO) forecasts wind and solar power production in the long term (seven days ahead) as well as the short term (12 hours ahead) to manage variability and adjust other energy sources. It is quite accurate, too: in 2022, the short-term forecasts had an error of just 3.1 per cent of the installed capacity for wind, and 3.9 per cent of the installed capacity for solar.3
As the composition of energy sources on the grid changes, so do the tactics to ensure reliability. A metal alloy has a mix of different metals to make it stronger than any of its individuals parts, and we can see that this is how we can build the strongest net-zero grid. It will be a mix of renewable energy, energy storage, natural gas and gas peaking plants that would be idle except when demand spikes (and both with carbon capture and storage), and thoughtful grid connections to neighbouring electricity systems that will forge the reliable and resilient energy system that we all want. Interties between Alberta, B.C., Saskatchewan and Montana would readily balance variable production or changes in demand.
We can also focus on demand-side management, a term that describes the tools used to change how much energy is needed and when it is required. This includes energy reduction measures, like high efficiency washing machines, as well as interventions to adjust energy demand patterns, like smart electric vehicle chargers or variable electricity pricing to encourage usage during off-peak hours.
Energy storage technology also has a big part to play. Grid-scale storage can store energy when production is high and supply it back to the grid when it’s most needed. This smooths out any peaks or valleys in energy production.
There are two main types of storage. Globally, pumped-storage hydropower stands at over 160 gigawatts (GW) and accounts for about 90 per cent of energy storage. This is basically water stored in a reservoir which is released to produce hydroelectricity when needed. It can be stored until it’s needed.
Grid-scale batteries are expected to make up the majority of storage growth worldwide, according to the International Energy Agency4. As of the end of 2022, grid-scale battery storage capacity stood at close to 28 GW and most of that was added in the last six years. They are mostly used for sub-hourly, hourly and daily balancing of energy needs.
Canada has some of the largest battery storage projects in the world. The Oneida project in Ontario is a 250-megawatt (MW) project under construction, soon to be eclipsed by an even larger one (300 MW) in the same province at Hagersville.
Corporations are showing interest in storage projects as add-ons to their power purchase agreements. TC Energy, a BRC-Canada Gold participant, recently announced a new pumped hydro storage project to help provide Loblaw’s with 24/7 carbon-free electricity. We expect to see more corporate involvement in storage projects, as they offer a path towards achieving goals beyond 100 per cent renewable energy.
What happens when you put that all together? Your fridge and microwave consistently work, all without you needing to think about it and with the confidence that it’s running on emissions-free energy. A diverse electrical grid with increasing amounts of wind and solar energy provides reliable, affordable energy through robust planning and a wide range of balancing tools.