Some significant climate change trends are evident in Ottawa
Ottawa is getting warmer. Between 1895 and 2010 there has been an overall annual mean temperature increase of 1.6 oC. The average mean temperature increase in winter has been 3.0 oC, which is higher than for any other season.
In addition, Ottawa’s total annual precipitation has increased by 63 mm. This has mostly come about because of upswings in precipitation amounts in the spring and fall. Summer rates have been relatively steady but precipitation in the winter months has fallen by 42 mm, a decrease in the order of 20%.
Climate is, of course, naturally variable. Throughout Earth’s history, sometimes dramatically so. But the release of heat-trapping gases from human activities is the main driver of current change.
Experts also predict that the annual number of extreme heat days in Ottawa will increase. This can result in fatalities, especially when combined with the “urban heat island effect” (higher temperatures in areas where non-reflective, impermeable surfaces have replaced natural vegetation). As an example, as measured on one 30°C day in June 2011, one area of the City with a concentration of commercial buildings, government buildings/warehouses, and parking had surface temperatures elevated by 13°C to 22°C. Areas with a well-developed tree canopy have cooler surface temperatures.
- Ontario Centre for Climate Impacts and Adaptation Resources. Adaptation Planning in Eastern Ontario. 2012
Ottawa made little direct progress in reducing greenhouse gas (GHG) emissions between 2004 and 2012
Greenhouse gas emissions in Ottawa come primarily from the energy demands of the building and transportation sectors, but also via energy use and methane production from solid waste, agriculture, and wastewater management.
The City targeted a 20% drop in emissions between 2004 and 2012. The actual reduction over this period was 12%, and was largely due to the provincial phase-out of coal-fired electricity generating plants. Most of the 25% decrease in building emissions is due to the phase-out.
Over the same period, agricultural emissions declined by 12%, apparently primarily due to fewer livestock. At the same time, emissions from transportation and waste grew. The further development of the light rail system will have a positive impact on transportation emissions in the future.
Emissions from City operations (“corporate” emissions) fell by 6% between 2004 and 2012, compared to a target of 30%. These are emissions associated with the hundreds of City-owned buildings, the transit fleet and other City vehicles, and other municipal services. Though these emissions account for less than 7% of Ottawa’s total, they are more directly under City control.
The phase-out of coal was again a significant factor in the 6% reduction, but the capture of methane gas at the Trail Road landfill also contributed, as did improved building energy performance. The performance of the City’s building portfolio continues to improve, with a 7% reduction in energy intensity between 2011 and 2015.
The City’s current target is a per capita GHG reduction of 20% of 2012 levels by 2024. With anticipated population growth this would mean an actual decline of 12%. Council has also recently approved a long-term target of 80% reduction by 2050.
- City of Ottawa. Air Quality and Climate Change Management Plan. 2014.
There is a large variation in the energy intensity of public-sector institutional buildings
As a basis for tracking against provincial energy conservation targets, and to help public agencies better understand and manage energy consumption, the Ontario government now requires municipalities, school boards, hospitals, and universities and colleges to report annually on building energy use. All reported energy uses are converted into kWh equivalents. As an important caveat, these numbers are self-reported and not further verified. Numbers obviously in error were eliminated prior to analysis.
Energy intensity (energy use per square foot) provides a basis for comparing between buildings in the same category. Ottawa’s public-sector buildings perform better than the provincial averages across all three types of buildings. Hospitals in general have the highest energy intensity of all publicly-funded facilities.
The range between the most and least efficient buildings in each category is quite striking. For schools, the difference is an order of magnitude (10 vs 27 ekWh per sq ft). It is important to note that many factors, including age of building, influence how much energy is used. Comparisons may be particularly challenging for recreation centres. For example, some but not all have a pool and/or arena, both of which have high energy demand.
Based strictly on self-reporting. Extreme outliers were removed.
- Government of Ontario. Energy use and greenhouse gas emissions for the Broader Public Sector. Accessed November, 2018.
- Ontario Ministry of Energy. A Guide for Public Agencies on Completing the Energy Consumption and Greenhouse Gas Emissions Template. 2013
Ottawa’s number of LEED-certified new constructions has been decreasing substantially in recent years.
The building sector is the largest source of greenhouse gas emissions in Ottawa. Many options exist to reduce building energy demand, especially in new constructions. One well-known program, Leadership in Energy and Environmental Design (LEED), provides an independent certification of building performance on a range of environmental issues including energy.
As of 2018, Ottawa had 21 Platinum, 76 Gold and 61 Silver LEED-certified new buildings. Most of these certifications have taken place since 2011. LEED certifications are also granted for existing building renovations and for office interiors.
In 2017 alone, there were 15 newly certified LEED Gold or Silver ranked buildings in Ottawa, however this number is down from 28 in 2016 and decreased to 7 newly certified buildings in 2018.
Canada Green Building Council. LEED Project Profiles. Accessed August 1, 2018.
Solar capacity has grown significantly, but still meets only a small proportion of demand
The rated capacity of the solar installations connected to the local grid through Hydro Ottawa and Hydro One stands at 77.8 MW. This is maximum rated capacity, not actual production. It comes from very small-scale generation by hundreds of residential providers, as well more significant contributions from a smaller number of commercial/institutional and agricultural installations.
The actual output from photovoltaic systems varies with conditions, the most important of which is the amount of energy from the sun. Solar potential is calculated based on this incoming solar radiation. Ottawa’s solar potential is around 1200 kWh per kW of capacity, which puts it in the top 15% among the hundreds of municipalities in Ontario. But taking this potential into account, the actual amount of electricity that can be generated annually from installed solar capacity in Ottawa is still a very small proportion of the 7.71 billion kWh that Hydro Ottawa billed for in 2015.
Hydro Ottawa is the third largest municipally-owned electric utility in Ontario. Energy Ottawa (EO) is a subsidiary that generates electricity from a number of “green” sources. The most significant is Chaudière Falls, whose current capacity is 16MW. By 2017 that is anticipated to grow to 45MW. The capacity of the landfill gas-to-energy plant at the Trail Road Landfill is close to 0.7 MW. Taking account of EO’s hydroelectric stations and another landfill gas-to-energy plant outside of Ottawa, Hydro Ottawa is Ontario’s largest municipally-owned producer of green energy.
It is also worth noting that Ottawa hosts a significant concentration of clean energy researchers and companies. Renewable energy is one of the key sub-sectors, along with energy management and green buildings.
- City of Ottawa. Environmental Business Services Branch, Environmental Services Department, email communication, June 20, 2016, based on information provided by Hydro Ottawa and Hydro One.
- Hydro Ottawa. Asset Planning, email communication, June 23, 2006.
- Hydro Ottawa Holding Company. 2014 Annual Report. 2014
- Natural Resources Canada. Photovoltaic and solar resource maps. Photovoltaic potential database. Accessed June 23, 2016.
- Ottawa Clean Technology Sector Profile Research Report, prepared by ICF Marbek for Invest Ottawa, 2012.