Harnessing the Sun Year- Round: A Vision for Solar Storage in the Yukon

Why Solar and Pumped Storage Could Be Yukon’s Best Path to Renewable Energy Independence

When people think of solar power, they often imagine it working overtime in summer and falling short in winter, particularly in the Yukon. But the true value of solar here isn’t to generate energy year-round. Rather, it’s to provide the lowest-cost renewable energy annually—energy that can be efficiently stored seasonally for when it’s needed most. A perfect example of this concept was in the Moon Lake pumped storage project proposed by Yukon Energy Corporation (YEC). With a storage capacity of 40GWh at an output of 40MW, it’s worth examining how solar energy could sustainably fill this storage capacity for winter months.

Let’s break it down. A 50MW ground-mounted solar plant in the Yukon would generate 55GWh of power annually. From November through mid-February, it would only produce about 6GWh due to reduced sunlight, but the other 49GWh could be stored in a pumped hydro reservoir. Given an 80% round-trip efficiency, this translates into 39.2GWh of usable energy—enough to cover much of Yukon’s winter power needs from renewable sources.

Calculating the Costs and Comparing Alternatives

The Moon Lake storage project was initially estimated to cost $300 million in 2018, but large infrastructure projects often go over budget, so let's air on the side of caution for this exercise and double that amount to $600 million. Building the 50MW solar array would cost approximately $1.05 per watt to install, this would add another $52.5 million. Together, this would bring the total project cost to around $652.5 million. An investment like this would offset roughly 11.25 million liters of diesel annually—a significant step toward reducing Yukon’s reliance on fossil fuels.

Now, let’s put this cost in perspective with other large-scale renewable projects in the Yukon:

1. The Atlin Hydro Project: Initially this project was estimated at $230 million, in 2022 that cost ballooned to $310 million, so again lets double that to $600 million to be realistic. This project would yield 31GWh but only offer 8MW of capacity, meaning it falls drastically short of offsetting our Territory's rental diesel generation, which this winter (2024/2025) will be 26MW of thermal power, even with substantial investment.

2. BC Interconnect: Currently, the estimated costs to interconnect to BC is $2.2 billion, again with cost overruns and additional expenses this could easily rise to $4 billion—this project would connect the Yukon grid to BC. However, the interconnect costs don’t include the cost of energy once connected, which makes it far more costly in the long term. For the same capital ($4 billion), the Yukon could build six solar-pumped storage facilities, storing 240GWh with 300MW of solar capacity, without the added burden of purchasing energy from BC Hydro.

Local solar plus pumped storage would generate local jobs, support investment here into the Yukon’s economy, and keep our infrastructure in our Territory. Unlike the interconnect, which would primarily involve BC-based contractors for a single high-voltage infrastructure project.

Why Solar & Pumped Storage Makes Sense for the Yukon’s Growing Energy Demands

At present, LNG remains the cheapest option for winter energy in the Yukon when factoring in capacity, but all renewable options come with a high price tag. Despite this, solar and pumped storage remains the most affordable renewable option. And with emerging technologies like further advancements in Battery Energy Storage Systems (BESS), or hydrogen storage, seasonal storage costs will plummet further in the coming decade.

The Yukon’s energy needs will only increase due to population growth, electrification of transport, electrification of heating, and new mining activities. Solar plus pumped storage offers a reliable solution with a lower levelized cost than other renewable sources like wind or hydro. Solar also has the flexibility to be built near population centers, minimizing environmental impact. This approach could allow the Yukon’s energy demand to double while achieving 90% or more of its annual energy from renewables.

Of course, fossil fuels will still be part of the mix during the darkest winter months, but as storage technology advances, their role will steadily decrease. By investing in solar and pumped storage, Yukon could lead the way in developing a renewable, sustainable, and economically feasible energy future.