Welcome back: Ontario repowering a return to renewables

Posted by Duncan Halstead /

In 2018, the newly-elected Ontario government cancelled hundreds of wind and solar energy contracts, including a partially built wind farm. Over 750 contracts for renewable power projects were stopped as part of a pledge to revamp the province’s energy policies.

Now, six years later, the same government is opening the door for a renewables return as the province faces an ever-increasing need for electricity procurement. With the growing adoption of electric vehicles (EVs), electrification of rail transit, and expected growth in other industrial sectors, electricity demand in Ontario could double in the next 30 years, and the Independent Electricity System Operator (IESO) has estimated it will cost $400 billion to decarbonize the power grid by 2050.

The government’s initial procurement efforts concentrated on energy storage, with more than 2,900 MW contracted to-date. The next phases of the program will focus on net producers and non-emitting renewable power sources. This stage of a long-term energy procurement program will bring its own set of challenges, as renewables bidders determine their best projects to put forward in the competitive energy procurement process.

This presents a special opportunity for operators with existing renewable energy assets such as wind and solar farms, as they can modernize their generators and provide additional new capacity into the grid, a concept known as “repowering.” Repowering projects are usually cheaper compared to building new facilities and therefore represent a cost-effective option for adding needed power to the grid. 

Welcoming wind power

While the repowering of renewables is great news, there are still very specific rules and guidelines for permitting. Ontario’s noise control guidelines for wind turbines have undergone multiple revisions since the first wind farms were built over 15 years ago, with each revision making the noise measurement and modelling regulation more stringent and conservative.

Most existing wind farms were designed to maximise their wind turbine noise allowance at the time to generate more power which, combined with the more stringent noise and acoustic regulations of today, means existing wind farms are limited in the changes they can make to equipment or operations without breaking the wind farm noise rules. Allowances for old wind farms to make changes are written in the noise regulations but their requirements are nuanced and significant risks can exist that may not materialize until commissioning. 

Companies with wind energy development experience will benefit from the refocus on renewables, but the same headaches and challenges from 10 years ago have not gone away – it is not an easy path to repowering wind today. However, with the right technical experience and sound engineering capabilities to work through the wind farm permitting process and with the demand for electricity and renewable energy set to soar, the potential opportunity to be a larger part of the power solution is enticing.

Here are some critical considerations for companies looking to take advantage of Ontario welcoming back renewables.

  • Path to repowering and re-permitting is possible: The rules for permitting a wind farm are different now than they were in the 2000s and early 2010s. If you took the same equipment from a wind farm facility of that vintage and modelled it according to today’s acoustic engineering rules, your sound levels may be too great to secure a permit under the current noise regulations
  • Transition rules exist, and they must be evaluated carefully: The Ministry has written transition rules for older wind farms in the current guidelines. That means companies wishing to upgrade their turbines in an existing wind farm facility may do so if they can prove that the changes will not increase the environmental noise levels. These changes need to be carefully evaluated to make sure the requirements for using these transition clauses are maintained throughout the acoustic design process. 
  • Modelling and measurement requirements are different: Transition rules for wind farm modelling do not exist in the corresponding noise measurement protocol. Your modelling could be within the noise guidelines but your measurement levels still run the risk of being offside. In the worst-case scenario, wind farms securing permits under these transition rules could end up producing less than in previous years based on all the adjustments needed to meet the wind turbine noise measurement protocols.
  • Managing risks: It is still early days in the repowering path but it is possible to manage the risks involved with expanding energy renewables. It is all about understanding the acoustic implications of the particular technology packages being evaluated as part of the repowering efforts. Risks can be predicted, anticipated and managed. 

Developers need to understand that permitting work is required as wind energy regains traction in the mix of Ontario power generation. Trying to thread a needle to meet the noise and measurement requirements after a wind farm is repowered is possible but more time-consuming and expensive. Trying to resolve issues following post-construction noise measurement is not ideal.

We have extensive experience working with Ontario wind farms to help mitigate risks and bring projects online. The repowering of renewables in Ontario is an exciting opportunity but make sure you complete the preparatory work before, to make the permitting process easier and less expensive.

Duncan Halstead


Duncan is a formidable leader within Aercoustics’ team, working alongside his expert colleagues to not just meet the industry standards, but to help develop and challenge them.

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