If we could pick one thing that our government could do to have a profound impact on pollution, our electricity crisis, greenhouse gas emissions, and the safety and sustainability of our cities, it would be to convert massively to ground-source heating and cooling of homes and businesses.
This could be achieved by the following very simple regulation: require special permission to install anything other than ground-source (geothermal) heating and cooling systems in new homes, shopping centers, schools and businesses.
There are several significant benefits to converting to ground-source heating and cooling of homes. First, if every new home in Ontario were built to modern standards of energy efficiency and were heated and cooled using a geothermal system, the amount of electricity saved annually after seven years would be equal to the production capacity of Toronto’s proposed Portlands generation plant.
Second, ground-source units remove a significant amount of pollution from our already polluted cities. The greenhouse gas emissions saved annually from installing geothermal units in new homes alone would amount to 3 million metric tons⎯1,500,000 from the new homes and approximately 1,700,000 from elimination of the Portlands plant. Massive conversion to geothermal across the country would contribute significantly to Canada’s efforts to reduce greenhouse gas emissions.
Third, not only would converting to ground-source heating and cooling of homes and businesses generate a significant amount of economic activity, the infrastructure savings would be such that the net cost to the taxpayer could be zero. This is because capital markets can be used to fund the conversion to geothermal. There is sufficient value in the future benefits, relative to the capital costs, to permit good returns for investors willing to fund such a conversion.
Fourth, energy generation using geothermal is more decentralized, and hence less risky, than the existing system. If a system’s geothermal pump is powered by solar or wind power, homes will be able to operate their heating, cooling, and hot water systems even if the grid is down. A distributed energy system is inherently less risky than an environment that relies on massive centralized generators .
Finally, while these ground-source units would result in slightly higher electricity consumption in the winter (when we have a large excess generating capacity), demand would be significantly reduced in the summer, when we have peak-load problems. These ground-source units would even the load.
How does ground-source heating and cooling save electricity in summer? The source of energy for cooling is the ground and is “free.” The cost of operating the cooling system is simply the cost of pumping a liquid through underground pipes using electricity. The net result is a reduction of fifty percent of the amount of electricity used compared to the most efficient modern electric air-conditioners available. And the reduction occurs precisely when we need it: during peak loading times on summer days.
A key to sustainability of our cities is renewable-based, distributed generation. Canadian cities have, for the most part, a perfect climate for ground-source heating and cooling. A massive, country-wide retrofitting of our homes and offices, where possible, and a regulatory-driven set of incentives to make sure all new buildings are so equipped, would be relatively cheap, generate many jobs and new industries, and would result in a far safer, more sustainable energy infrastructure for Canada. It is a sensible adaptation strategy in the face of climate change. It would significantly lower pollution levels, result in far healthier environments for our cities, and could be implemented in a public/private economic model that would result in minimal cost to taxpayers, or none at all. We cannot put off looking at an energy solution with benefits on this scale.
Imagine a Canada in ten years time that has implemented a massive move to ground-source energy. In addition, imagine this supplemented by renewable energy from distributed solar, wind, and micro hydro. Not only will we be a country that can face enormous volatility and other effects of climate change, we will have developed in a way that will foster future sustainable growth. Our cities will be more robust, less polluted, less vulnerable to rising fuel costs, terrorist attacks, and violent weather. We will also have created new industries, industries of the future.
Appendix (Calculations)
Geothermal’s environmental benefits
If every new home we built had a geothermal system, we could reduce summer peak demand by the capacity of the 550 mW Portlands Power Plant in 7 years.
Most new homes built have central electric air conditioning and natural gas heating and hot water.
According to the OPA, Ontario’s electricity supply mix is now classified as summer-peaking, rather than winter peaking. Two of the OPA supply mix advice reports key findings are below:
1. Peak demand is now greater in summer than in winter because of air conditioning load
2. Peak demands in the summer are stressing the supply/demand balance to the point of load interruption, despite the addition of some generation to the supply
As more and more homes are installing air conditioning systems, this trend is expected to continue. Natural Resources Canada documents an increase of 4,000 room air conditioners between 2000 and 2004, and an increase of 382,000 central air conditioning systems between 2000 and 2004 .
Tony Cooper, technical expert at Waterfurnace, the largest supplier of ground source system, through an energy model, estimates that the peak electrical draw of a typical house on geothermal is 2.2 kW less than a typical conventional A/C.
The lowest estimates we have heard calculate the peak load reduction at 1.0 – 1.5 kW.
I have averaged this to 1.75 kW. If we assume that Ontario builds homes (both semi-detached and detached) at a rate of 45,000 per year , we could displace the Portlands plant in 7 years.
The calculations are: 45,000 homes x 1.75 kW = 78.75 mW per year, 7 years to displace 550 mW plant.
A total of 314,286 homes would be retrofitted.
Average residential customers use about 2500 cubic meters of natural gas . Displacing the average natural gas usage for every home retrofitted would save a total of 785,714,285.7 cubic meters.
The Canadian Standard Association uses a total co2e emission factor of 1.902007 /m3 natural gas, so these retrofits would save 1.5 million metric tonnes of co2e.
If we retrofitted every home currently on electric baseboard heating, we’d displace 1055 MW of nuclear generating capacity, or about 2 of the 540 MW Pickering station power plants.
Natural Resources Canada (2004) reports that there are 187,000 single detached homes , 60,000 semi-detached homes , and 384,000 apartments on electric baseboard heating. This is a total of 631,000 homes.
NRCan reports (2004) that 35.9 PJ of energy were uses by homes on electric heating . This is 9,972,222.2 mWhs of electricity, or 15.8 mWhs per house. A geothermal system is 3-5 times as efficient as an electric baseboard heating system on a direct COP comparison. Electric baseboard systems have a COP of 1.0 (or a stock efficiency of 100%) , while Natural Resources Canada lists geothermal systems as having a COP of 3.1 and 5.2 .
If we average this to 4 times as efficient, the homes heated with electric baseboard heating will reduce their consumption by a factor of 4, to 3.95 mWhs.
This means that every house retrofitted will save an average of 11.85 mWhs per year. If all 631,000 homes were done, this would reduce consumption by 7,477,350 mWhs.
How much electricity does a nuclear plant produce? The lifetime generating factor of nuclear plants in Ontario is 80.9% , meaning the plants are on 80.9% of the time. As there are 8765.81 hours in a year, the generating capacity required to generate 7,477,350 mWhs by a nuclear plant is: 7,477,350 / (8765.81 * 80.9%) = 1054.4 MW
The nuclear plants at Pickering nuclear station are 540 MW each; approximately 2 of these plants are required to generate the energy we save from geothermal retrofits.
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