Zero Emission Buildings

by Alex Cameron

We are still planning to follow up on our Achieving Net Zero Buildings by 2050 submission to the Net Zero Advisory Body (NZAB2060). Hopefully, by the time you read this newsletter, or in the worst case, shortly thereafter, we will have updated our website to better reflect our plan of action. 

An interesting topic that has come up a few times is some people feel that they can’t form an opinion on this – because it is technically complicated. In fact, I disagree with that. I think many people, in fact most people, with a little bit of thought can follow the issues involved with this. Please have a look at our Achieving Net Zero Buildings by 2050 report, and let us know if we raise more questions than we answer. Would a webinar to discuss this report be a good idea?

Per the previous newsletter, as well as the report, we believe our course of action is fairly clear:

Government Advocacy

• Identify federal politicians, both in the government and in the opposition, who we want to ask to consider this report, and start sending them letters to share the report.
• Ditto for the provincial government
• Ditto for the City of Toronto
• As well as the politicians, identify the key civil servants at each of those government levels and share the report with them.

Academia, Industry and Finance Advocacy

• We believe that we need to identify the key academic and industrial bodies and send them advocacy letters as well.

Communication & Outreach

• Create a discussion forum for “Net Zero Buildings by 2050” and share this widely. Google Groups? Discord? Some other technology?
• Per above, should we set up a webinar to discuss this report?

Liaison

• Start sharing this report with other organizations working to address the climate crisis, and see if we can get them to help us share these ideas further.

What do you think of our position? That is, do you think that district energy is going to be really important? Or, should we focus on increasing electrical system capacity (generation, storage, transmission), and focus on getting everyone on CC-ASHPs (Cold Climate Air Source Heat Pumps)?

Also, we are still getting organized as far as a letter writing campaign and petitions. What do you think of the following statements?

1. Instead of petitions, we want to focus on letters being sent to politicians from constituents in their riding. We think that this is likely to have a lot more impact with the politicians. We think that as well as the letters, we need to offer the politicians access to some data tools that make it easy for them to track how many letters on this topic they have received.
2. We believe that the letters should be offering to partner with them to find solutions. That is, they should remain positive, even if we have concerns that the particular politician or their party may not be sincere about taking action on the climate – we think that by communicating in a positive way, we can drive home the message that to keep getting elected, they need to have a real plan.
3. The same goes for the letters we want to send to academia, industry, and the financial industry.

Lots of topics here to discuss. Sure hope to see some discussion in the ECA Google Group. 

e spent a bunch of time these last two months working on a submission to the Net Zero Advisory Body (NZAB2050) to recommend what we should do to Achieve Net Zero Buildings by 2050. That link will take you to the report – please have a look and share your thoughts on the ECA Google Group.

The elevator speech goes something like this:

• This is an important area to focus on – buildings are the 3rd largest source of GHG emissions in Canada.  By getting going early, we lessen the GHG impact, and create a great economic opportunity for Canada and Canadians.
• We think the key technologies are shallow retrofit, Cold Climate Air Source Heat Pumps (CC-ASHPs), District Heating and Cooling (DHC), and Solar. The opinion is divided on CC-ASHPs or DHC being the most important.
• Finance is critical – we need some good thinking on how to make sure that property owners, developers, utilities (including new DHC utilities as well as existing electrical utilities), educational institutions, businesses, and governments have access to the required capital to quickly scale up to deal with this opportunity.
• Rules, regulations, guidelines, training – By making sure that we have consistency across the country, we make it much easier for skilled workers, and production of components to be easily used across the country, which makes scaling up as well as costs easier to manage.
• Scalability – Ensure that the solutions to each of the above components (technology, finance, regulation, training) can be scaled-up to meet the requirement. To retrofit all buildings in Canada by 2050, assuming we are in full motion by the beginning of 2023, we will need to do 2,000 buildings per day. This means that a good deal of thought must be put into ensuring the proposed solutions are massively scalable.

The version linked to above was sent to NZAB2050 on 2021-12-22 – the last day for submissions.

We plan to continue improving this document, and we will make sure that the website has an easy-to-find link to the most current document. We would love to hear your thoughts on where to go next with our effort to define and advocate for a path to net zero buildings by 2050. Our current thoughts are:

1. Identify federal politicians, both in the government and in the opposition, who we want to ask to consider this report, and start sending them letters to share the report.
2. Ditto for the provincial government
3. Ditto for the City of Toronto
4. As well as the politicians, identify the key civil servants at each of those government levels and share the report with them.
5. Create a discussion forum for “Net Zero Buildings by 2050” and share this widely. Google Groups? Some other technology?
6. Start sharing this report with other organizations working to address the climate crisis, and see if we can get them to help us share these ideas further.

Zero Emission Buildings Working Group Report

Joseph and Alex continue to act as the “core” of this group – but hugely valuable input from Martin, John, and Bob has been really helpful. Joseph created a Terms of Reference document which was accepted as laying out what this group wants to do:

• To facilitate as many districts, private homes, and businesses to retrofit so as to achieve as close to zero carbon emissions as possible. This must include understanding districts, since District Heating and Cooling may be a critical part of the strategy.
• To advocate for city, provincial, and federal legislative bodies and applicable commissions, municipal corporations, and committees to legislate, implement, and enforce the highest degree of near-zero emissions development for new structures and buildings.

More specifically, we want to work to help define:

1. Residential Building Retrofit Strategy
2. Commercial Building Retrofit Strategy
3. District Heating Strategy
4. Heat Pump Strategy
5. New Building Strategy

Specific objectives include:

1. Alignment with Government Strategies – all three levels
2. Zero Carbon for Major New Building Projects – Identify a few major building projects in Etobicoke and advocate that those new buildings should be built to Zero Carbon standards now. Consider the Christie Lands and Six Points projects.
3. Gas Cooktop, Oven, and Dryer Elimination – This is something that we need to do – compile the research and help people understand how easy and cost effective this is. 
4. Identify Key Heating and Cooling Strategies to get to Zero CO2. This is the big one – what combination of retrofit, heat pumps, and district heating makes the most sense.

District Heating and Cooling (DHC)

Opinion by Alex Cameron

Following discussions with Martin, John, and Bob,  plus discussion at GNN, as well as a fair bit of reading, I am very excited about the possibility that District Heating and Cooling (DHC) might be an important part of the green energy strategy for Etobicoke. 

Both Martin and John are advocates of DHC, and Bob is advocate of Solar Photovoltaic (PV) combined with a  Cold Climate Air Source Heat Pump (CC-ASHP). I think it is fair to say that I am on the fence, but leaning towards DHC.

My hope is that with this article, I can supply the interested reader with a brief introduction to the technology, including links to articles which will supply more information, and then  lay out the cases presented by Martin, John, and Bob for their preferred solutions

A Brief Intro to the Technologies

see footnote (1)

Let’s start by making sure that everyone knows what a heat pump is. Basically, it is a refrigerator. That is, it uses a  compressor, a condenser, an expansion valve, and an evaporator to pump heat. 

• When you want to use it for cooling, you dump the hot air “outside”, and the cool air “inside”;
• When you want to use it for heating, you dump the cool air “outside”, and the hot air “inside”

Unlike  when you burn natural gas (NG), or use electrical  resistance heating (baseboard heaters or similar), you can get more energy out of the system than you put in. This is called the Coefficient of performance (COP), and the reason it can be greater than 1 is that you are using energy to pump additional heat from one place to another.

  see footnote (2)Next, a brief description of Solar PV. Solar Photovoltaic systems is a system where sunlight is used to produce electricity. You do see “off grid” solutions where the homeowner supplies batteries to store electricity for when the sun does not shine, but in Etobicoke, we believe you will see mostly grid-connected solutions. Note that Solar Thermal and Solar PVT can also be used to harness the energy of the sun.

The reason Solar PV is likely an important part of a CC-ASHP solution is that when you compare the cost of NG to electricity you find out that electricity is much more expensive. If we look at the NRCan Data, and the NRCan Conversion rates, we find that 1 Gigajoule (GJ) of NG cost $8.781 and 1GJ of electricity costs $32.778(see footnote 3,4), – which means electricity is nearly 4 times (3.732) the cost of NG. So – even though a high efficiency gas furnace will still have a COP < 1 (meaning you will need more energy than for an electric radiant heat solution which has a COP of 1), the cost of switching to electric will be very noticeable – unless the COP is very high (say, >3).

Electric energy cost is one problem with CC-ASHP and using Solar-PV to minimize that extra cost is a good solution. The other big issue which needs to be discussed is the ability of a CC-ASHP to meet the heating requirements on a really cold day. Remember we talked about COP > 1 for a CC-ASHP to be used efficiently? Well, to be cost efficient, and to not put an unsupportable load onto the electric grid (if every home on the grid suddenly needs a lot of electricity) – it needs to operate at a COP up around 2 or even better 3 or higher. Once it drops near to 1 – it is the same as electric radiant heat – which is very expensive and a big load on the grid. There are a lot of reports (see footnote 5) that quote different abilities of heat pumps to work at different low temperatures – so in my opinion, a definitive study for Toronto / Etobicoke needs to be done to establish this number. Because – if you can make it work down to about -25°C – it might be viable.

 see footnote (6)

Well then what about DHC? The above diagram shows how various sources of heat can be used to supply heat for an entire neighbourhood and illustrates how these systems have migrated from very hot (steam in the 1st generation) to much cooler in the 4th generation.

see footnote (7)

The above diagram shows how a 5th generation DHC solution works. The idea is to use water not much above or below ambient as the storage of thermal energy – and then use a heat pump at each building to extract the energy. So instead of an air source heat pump – it is a water to water heat pump. Much more efficient.

Martin Green’s GNN Presentation

(see footnote (8)

Martin Green created a presentation titled “Why Toronto  needs district  energy systems to  reach  GHG  reduction  targets” which he presented to GNN on 2021-10-15. He digs into the issues I mention above in much more detail. He also published a Q&A Document from that GNN session. I think he makes a compelling case that DHC needs to be considered. If you don’t have time to review both of those documents, do note Martin’s statement near the beginning of the Q&A document that:

• JudyB, a Discord contributor who lives in the Yukon, has been testing the more current Mitsubishi Zuba CC-ASHP, and reports performance similar to the Alaska report, with a COP of 1.2 at -22 C. From those studies, it is clear that ASHPs offer little benefit over electric resistance heating at very low temperatures. Converting most Toronto homes to CC-ASHPs would result in untenable peak load on the electric power system on those rare very cold days.

John Stephenson’s Heating and Cooling Report

John Stephenson has created a document titled “Heating and Cooling the Greater Toronto and Hamilton Area with Zero Emissions”. John also makes a strong case for DHC. In this paper – John argues that  “nine non-emitting heat sources that could be used to extend DH throughout the GTHA.   They amply meet the need for 40 TWh of zero emissions heat energy per year and 18,000 MW capacity identified in Section 1.” (see footnote 9) John goes on to identify these sources as:

1. Solar Thermal
2. Cooling Waste Heat
3. Industrial Waste Heat
4. Lake Water
5. Air
6. Wind 
7. Bioenergy
8. Nuclear
9. Deep Geothermal

DHC Summary

Both John and Martin, as well as the reading, make it clear that a key advantage of the DHC strategy is that it allows us to use “wasted energy” in the form of heat and store it in a repository, then use it through a “thermal grid”. It allows us to exploit Solar Thermal, and store that heat for when we need it. It avoids creating a sudden load on the electric grid – especially on very cold days. Not discussed, but likely of fairly large importance – DHC would also allow summer peak load to transfer from the electric grid to the thermal grid – that would be a good thing. BUT – it does that by creating a new “thermal grid”. So – we would need to make sure this grid does not fail at critical times – and we would need to make sure we consider the economics.

Bob Bach’s Experiences with CC-ASHP and Solar-PV

Bob Bach has published a number of short articles about his experience with converting his house to get its primary heat from a CC-ASHP using Solar-PV as a source of electricity. After reviewing Bob’s  articles, a couple of discussions in public forums, as well as one-on-one, I remain very interested in this approach. Bob makes a very strong case that CC-ASHPs can deal with cold Etobicoke days, but I think he agrees that more research is required to understand exactly how much supplemental heat is required on the really cold days (as well as where the supplemental heat comes from). One of the articles (see footnote 10)  Bob forwarded to me states:

• Overall,  heat  pumps  show  excellent  potential  as  an  emerging  renewable  technology  however,  further research  is  required  in  the  areas  of  standardization  of  installation  in  addition  to  long  term  monitoring  of North  American MURB  retrofit  case  studies.  It  should  not  be  assumed  that  all  heat  pump  technologies  will work  in  urban  settings,  each  installation  needs  to  be  assessed  on  a  case  by  case  basis  taking  into consideration  factors  such  as  the  climate,  land  availability,  budget,  thermodynamic  conditions,  energy prices,  energy  requirements,  original  heating  and  cooling  system  and  building  size.  Only  through continuous  monitoring  will  researchers  be  able  to  conclude  the  true  performance  and  feasibility  of  urban heat  pump  installations. 

Final Thoughts

Two of the reports Martin mentions on his Discord server make slightly different statements about CC-ASHPs:

• The British Columbia Cold Climate Heat Pump Field Study states that “Results show that the overall average COP for all heat pumps is greater than 1, even down to -14°C”
• The Zero Energy Project report Achieve Comfort and Reliable Performance with Cold-Climate Heat Pumps states that “With hyper-heating technology, heat pumps offer significant heating capacity down to -13°F outside” Note that -13°F = -25°C.

That is a big difference. As per the TAF report other factors come into play – and there is bound to be a big difference between different installations. If it is mostly -25°C,  then CC-ASHPs by themselves can solve most if not all of the problems for Etobicoke. BUT – even if that is true – with COP down near 1 – that would mean a large draw on the electric grid if the cold day happens on a day when Solar-PV is not providing most of the required electricity.

My personal opinion (I think that John, Martin, and Bob agree) is that every single homeowner (and building owner) is going to need to do an energy evaluation and a shallow energy retrofit.  By “Shallow energy retrofit”, I mean – fix the easy things:

• Insulation – in the attic and other places that are easily reachable
• Air leakage – doors, windows, air barrier between the attic and the body of the house
• Better thermal doors and windows

However, with an old, uninsulated,  double brick house like some of us in Etobicoke live in (cough, cough) – this needs to be thought of as a shallow retrofit. A deep retrofit would involve much more – and might include things like “Entire Buildings Can Be Wrapped in Jackets to Save Energy”.

As Martin points out:

• On the question of economics, the elephant in the room is the enormous cost of deep energy retrofits. The City estimated $73 billion, just for houses. To get a crude estimate of the cost of district energy, see https://www.osti.gov/biblio/1402044-lcoh-estimated-from-existing-geothermal-district-heating-systems, which puts it at USD 36/MWh. A typical Toronto house needs 12 MWh/yr. Adding solar thermal input and geoexchange and water thermal storage systems might double the cost, but it is still far less than deep energy retrofit (and maybe even less than continuing with NG).

As I think we all agree – the current climate crisis is a problem in economics.  And guess what? The solutions will also be a problem in economics. This is where we need to do the study:

• Cost and time required to pursue deep retrofit
• Cost and time to pursue district energy
• Cost and time to pursue CC-ASHP with or without deep retrofit
• Cost to do grid upgrade and integrate new generation capabilities into the grid? 
• What are the roles of Solar? Is Solar Thermal in a DHC configuration even a better bet than Solar PV?

So, in conclusion, I need to see a little bit more in the way of hard facts, and well-financed research to convince me that the investment of resources required to build a DHC network in Etobicoke is worth it. It sure sounds like it might be. But the time, effort, and cost would need to be justified before starting. It might make more sense to upgrade the electric network to allow for more distributed generation and storage. More research should make this clearer.

Footnotes

1. Public Domain, https://commons.wikimedia.org/w/index.php?curid=3216789
2. By Rfassbind – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=34961018 
3. NG – 1 GJ  = 26.853 m3 @ $0.327/m3; , Electricity – 1 GJ = 277.778 kWh @ $0.1118/kWh
4. Note that comparing these NRCAN rates to my rates – I see that my NG charge for the last 12 months averaged $0.417/m3 (higher) and that my electric charge for the last 3 bills averaged $0.1875/kWh (also higher). Of note – the difference in rate is still NG = $11.198/GJ and Electricity = $52.083/GJ – so electricity is more than 4 times as expensive
5. Two excellent examples discussed on Martin’s Discord server are “Achieve Comfort and Reliable Performance with Cold-Climate Heat Pumps” and “British Columbia Cold Climate Heat Pump Field Study”
6. By MrmwAndol – Based on [1] and Henrik Lund et al: 4th Generation District Heating (4GDH): Integrating smart thermal grids into future sustainable energy systems. Energy 68, 2014, 1-11, doi:10.1016/j.energy.2014.02.089de:Wikipedia:Grafikwerkstatt#Fernwärmegenerationen, CC0, https://commons.wikimedia.org/w/index.php?curid=70759354 
7. By Stef Boesten, Wilfried Ivens, Stefan C. Dekker, Herman Eijdems – Stef Boesten, Wilfried Ivens, Stefan C. Dekker, Herman Eijdems: 5th generation district heating and cooling systems as a solution for renewable urban thermal energy supply. Adv. Geosci., 49, 129–136, 2019. https://doi.org/10.5194/adgeo-49-129-2019, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=92036189 
8. Slide 19 of the quoted presentation deck
9. Page 5 of the quoted paper
10. TAF Global Heat Pump Performance Review

Lots of info available!

• Martin Green has created a Discord server for discussion of Home Energy Retrofit
• Have a look at the great videos at BetterHomesTO
• Report: Canada needs a mission-based approach to decarbonize our buildings
• The Pocket Change Project put together a very interesting presentation for GNN on the topic of “Scaling Up Single Family Home Retrofits: A Community-based Approach to  Setting up a Retrofit Coordination Service“
• Natural Resources Canada has a very interesting Energy efficiency for homes site

Lastly, Bob Bach, one of our members, recently wrote a very interesting article “Imagine Our Community Powered Entirely by Solar  Energy” where he discusses his experience with adding Solar PV to his home, as well as the recent discussion in Ontario on allowing “community net metering projects.” Bob concludes that “Community Solar PV would seem to  have a future in Ontario, and  in Canada, and you can be ahead of the market by simply installing a  system now.”

There is an overwhelming amount of information. One of our objectives is to create a summary of the information available, and hopefully some recommendations. Stay tuned. Or – even better – if you have thoughts on what that summary should look like please let us know.