Steady as we go

Robert Hornung | May 11, 2021

A reliable electricity grid can be built on a foundation of wind and solar energy

Wind energy, solar energy and energy storage, working together, will provide reliable solutions to meet Canada’s energy needs in a net-zero greenhouse-gas emission economy.

Everyone knows that the energy of the wind and the sun is a variable force—the sun does not always shine and the wind does not always blow.

Thanks, however, to emerging technologies in the electricity sector, and to new approaches to using existing technologies and infrastructure, it is now clear that a reliable electricity grid can be built on a foundation of wind and solar energy.

Relying on wind and solar

This is not science fiction. Wind and solar have already demonstrated they can make a very significant contribution to energy needs.

Today, approximately 6.8% of Canada’s electricity demand is met by wind and solar, and the contribution is much larger in PEI (25%) and Nova Scotia (13%).

But wind and solar can also go much further.

Wind energy already meets 16% of electricity demand in the European Union as a whole, with the numbers exceeding 20% in Ireland, Portugal, Germany, Spain and the UK, and reaching nearly 50% in the case of Denmark.

At the same time, solar energy now meets close to 10% of electricity demand in some countries.

In fact, Bloomberg New Energy Finance projects that wind and solar will account for 56% of global electricity production in 2050, with penetration levels reaching 70 to 80% in some countries.

How can this be, given the variability of wind and solar energy production?

Wind energy production tends to be higher at night and in the winter, while solar energy production is highest in the summer and during the day. This natural complementarity can help reduce variability but, for the electricity-system operator tasked with balancing supply and demand, more is required to ensure reliability.

While wind and solar represent low-cost and emissions-free renewable energy, their rapid growth does introduce more variability into the grid.

Fortunately, system operators are being presented with an expanding number of tools to manage this variability while optimizing the benefits of solar and wind energy.

One rapidly emerging tool is energy storage.

Energy-storage technologies are quite diverse (batteries, flywheels, pumped hydro, compressed air, hydrogen), but they all share a common characteristic: they store electrical energy produced at one time for use at another time.

Battery technologies have attracted significant attention recently. They are being rapidly deployed, having declined in cost by 90% over the last decade.

Batteries can be used in conjunction with renewable energy projects (also known as hybrid projects), or on a stand-alone basis. They can respond quickly and accurately to system operator directions, making them attractive providers of reliability services to the grid, such as renewable-energy shaping, transmission-congestion management and voltage support.

While batteries can store energy for several hours, other developing technologies, such as compressed-air energy storage, have a longer-term storage capacity.

Canada’s massive hydroelectric resources can also store energy for much longer periods of time. Reservoirs behind dams store energy when wind and solar energy are operating, and release that energy when required. In fact, Minnesota uses Manitoba Hydro’s hydroelectric resources to help manage the variability of the state’s wind-energy production.

Interconnection between grids

Interconnection between electricity grids is another important tool for managing variability, and increasing these interconnections expands the range of options available to do so.

There is a significant body of research demonstrating the excellent investment value of improving interconnections and its critical importance in supporting increased deployment of renewables.

But it’s not all about building new transmission.

The rapid emergence of distributed-energy resources, and the prevalence of smart-grid technologies, are also providing system operators with new options to manage variability from the demand side.

For example, wind-energy production generally peaks at night when electricity demand is lower, so by increasing demand at that time—such as by encouraging electric vehicle charging in the overnight hours—this low-cost electricity could be easily utilized. In essence, the batteries in electric vehicles permit electricity to be stored on-site for later use.

It is also worth noting that new wind- and solar-energy technologies can themselves provide a variety of reliability services to the grid, such as Fast Frequency Response and Reactive Power Control. Another example is when electricity demand drops rapidly, these technologies can ramp down production much more quickly, and at a lesser cost, than any conventional generating technology can.

Foundation of the future grid

So, can we take advantage of the incredibly low cost of wind and solar energy and place them at the core of a reliable electricity grid? The answer is yes.

In fact, wind, solar and energy storage will serve as its solid foundation. The future grid will be more diverse, decentralized and interconnected. It will place wind and solar energy at its core, while providing the tools required to ensure reliability. And as a result, Canadians will receive better services, at a lower cost, while also fighting climate change.

This is the fourth article in a series of CanREA Vison blogs, in which I’ve argued why wind energy, solar energy and energy storage will be at the core of Canada’s energy transition. 1. Because these technologies represent the most affordable path forward for Canada’s electricity system. 2. Because  they offer many important economic benefits, such as good stable jobs and investment in rural communities. 3. Because they enable Canada to combat climate change, the most significant environmental challenge of our time. 4. Because they will help provide reliable solutions for Canada’s energy future. And 5. Because they empower Canadians.