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Sunday, 30 December 2012

Barriers to 'Green' - Ignorance?

Marc Stoiber recently sat down with Jim Nelson - Senior Marketing Manager at BC Hydro, and extracted Jim's list of seven psychological barriers to the general public accepting and embracing 'green' (Full interview).

But I believe there may be another even bigger barrier, that Jim has missed, and that is ignorance.  I do not mean this in a negative way, but a true definition of the word way.  You see, I consider myself fairly well informed on many energy efficiency issues and I definitely want to do the 'right' thing, even if it costs me a little extra in the short term.

But what is the 'right' thing?

I presently do not have enough knowledge to make that decision and I believe that many people would be in a similar or even worse situation. I have spent a LOT of time researching my upcoming build.  I have literally spent hundreds if not thousands of hours over several years researching the best practices of building envelopes, HVAC, electrical efficiency, etc.  But in many ways, I am no closer now to being able to make the 'right' decisions than when I started.  There is so much information available these days thanks to the internet and search engines like Google.  Answers are literally a few clicks away, but unfortunately much of these answers are conflicting depending on the bias or knowledge of the presenter.  You are often unable to determine the best course of action.


This has often left me felling frustrated and can paralyze you from moving forward.  An example is needed:

Over the last few days there has been a discussion on Linked-In asking about the sanity of using electric resistance baseboard heaters (Full Discussion - Building Science Group: Have we lost our minds when we use resistance heating in low load buildings?)  I have been actively participating in this conversation because I though I could provide knowledgeable responses. But in the end, my assumptions were challenged leaving me wondering where I stood and feeling quite ignorant on the subject.

The basic premise I first had was based on the fact that I live in a region blessed with abundant clean energy, that being Hydro Electric.  Currently, 90% of our Province's power comes from Hydro Electric generation with the balance being made up with Natural Gas fired Thermal (7.5%) and the rest is purchased energy (much of it from Alberta's coal generation with a smattering of renewable like wind).  My logic was that I should utilize this 'green' energy in my upcoming build in order to reduce my carbon contribution to the planet.  I would look at an air source heat pump ASHP (utilizes electricity to harvest free 'heat' from the air outside your home much in the same way as your refrigerator works to evacuate heat from its interior - just in reverse).  I would use the heated refrigerant created by the ASHP to heat water (through the use of a heat exchanger) that would then be circulated through radiant panels I would place in my walls and ceilings (I will discuss why I will not do radiant floors in a future blog).  In the summer time, I would reverse the heat pump and created chilled water that I could then use to help cool the home.

Many models of ASHP are available, but efficiencies as high as 4+ are available (meaning for every unit of electricity used, there will be 4 units of heat available).  This sounds pretty good, doesn't it.  But we are not done yet, we also have to take into account the source losses for the energy used and reduce our efficiency accordingly.

In a conversation I had with Dr. John Straube of Building Science Canada last winter, he suggested that an appropriate way to look at electricity generation may be to look at all of the generation sources feeding your particular electrical interconnection.  I am part of the Western Electric Coordinating Council (WECC) interconnect  which does have a lot of hydro electric generation, but is also supplemented by dirtier generation sources like coal. He suggested a source energy factor of 1.5 to 1.7 may be appropriate (for every kWh consumed at site, 1.5 to 1.7 kWh must be generated.  The .5 to .7 lost kWh's represents transmission losses and generation inefficiencies).  So a ASHP efficiency of 4 now drops to 2.35 - 2.67 when taking into account the source energy factor. Not as good but still at least 235% efficient.

What are the alternatives?  For me, the logical alternative would be a high-efficiency-modulating-condensing-natural gas fired boiler.  These type of units can have a site energy efficiency of 95%+ which translates into a source efficiency around 90% when adding in a 1.05% source energy factor (yes there are also 'transmission' losses - venting and pumping - in gas pipelines that account for most of the 5% loss).  This is starting to look a lot less attractive.  We have 90% efficient gas compared to 235%+ efficient electricity, and this formed the basis of my preliminary decision to not even re-connect the gas line up to my upcoming build.

Now the original Linked-in conversation was considering the use of electric resistance baseboard heaters.  These are considered to have a 100% site efficiency which would translate into a 66% down to 59% source efficiency when taking into account the source energy factor of my region.  This is poor in comparison with even the Natural Gas fired boiler efficiency.  I would never consider such a heating source UNLESS the heating load was so low, due to the envelope efficiency, that electric resistance baseboards or radiant panels were the only heat source that could ramp down low enough to not overheat the dwelling.  This can often be the case in dwellings that have extreme levels of insulation like those certified in the PassiveHaus program.  These homes, by virtue of their certification, must have heating loads not exceeding 10W per square meter of living space.  Unless the dwelling is quite large, this low of a load is often exceeded even by the smallest equipment currently available on the marketplace. Unfortunately, electric resistance baseboards are common in my region for some single family houses and abundant in multi-family housing.

On the surface, the decision looks easy - choose the 235% minimum efficient ASHP and that was were I stood a day ago.  But I was then challenged by individuals in the discussion to visualize a larger picture.  As mentioned I live in BC which has an abundance of hydro.  My interconnect also has a high ratio of Hydro arguably giving it a source energy factor around 1.5 to 1.7.  The rest of the USA in comparison is dirty, to just plain filthy, due to its heavy dependence on coal fired power plants.  The average source energy factor for the USA is around 3.3 meaning for every unit of electric energy used in the home, 3.3 units of energy have to be created and added to the grid.  This would bring our ASHP example down to a efficiency of 1.2 or 120%. Still better than gas but a lot worse than the average for my region.  An electric baseboard on average in the USA would only have a efficiency of 30% when the source factor is taken into account - clearly a poor choice!

On the surface, no regions should use electric baseboards (unless the loads are VERY low) and in all regions, an efficient ASHP would be a better choice than even the most efficient gas boiler or forced air furnace.  Again, the decision seems clear - right?? 

But what happens when a person in a region with 'green' hydro energy decides to use a gas fired heating system to reduce their electrical usage to allow more of that 'green' electricity to feed into the grid, and by doing so, hope to reduce the ratio of filthy coal power?

Does anyone benefit?  Will the extra kWh's made available offset coal production or will the power just be consumed by increased demand of a non-energy conserving nation?  How does one predict the actions of a consumer?  How does one measure the result of such a decision?  Should one use a 'green' electricity themselves, or use a dirtier energy so that they can pass on their clean power to users that only have filthy electricity available?

What is the right answer???  This is just one example of how difficult the right answer may be to obtain.  An ignorance of the needed facts to make the right decision can paralyze a person from making any decision, which in turn could often lead to the adoption of the status quo (one of the barriers mentioned by Jim Nelson).

Now of course, I do not have this as an option.  I must put some form of heating system into my planed build.  To this end, I would appreciate input from those with relevant knowledge, that could help provide the information I need to make this decision.




 


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