Well this is a bit of an odd post as it’s result of me getting carried away in a LinkedIn conversation and blowing the word limit considerably. I’ve ended up posting only the key points on the “linked in” conversation and the detailed response here.
To understand the background please have a look at this conversation (I think you’ll have to sign up to be part of the group) and this blog article. From there you will see where the rest of this following rant comes from.
I think this is pretty massive topic requiring a lot of discussion to get some good outcomes. I’ve ended up with a 50page response as a result.
It also has taken a few tangents which I’ll try to bring back into line with the original topic by breaking it down into four points:
- If you are taking aim at a particular legislation be very clear in your article that is your purpose.
- Don’t be prescriptive in your design approach and push only one strategy (such as passive house) or you’ll get perverse outcomes.
- Don’t write off onsite renewable energy it’s on the increase for some good reasons and is only set to grow even further – embrace it where it works.
- I’ve also gone to address several of your points in detail to provide some more structure to your original article
Those points in detail for those interested enough to read the 50 pages now….
1. If you are taking aim at a particular legislation be very clear in your article that is your purpose.
I was lead to believe it was all about reducing carbon and what targets to set to get there.
I’ll repeat – I’m not across the UK definition of “zero carbon house” and again if your aim was to identify flaws in it then please reword your opening paragraph as well as the bulk to ensure it’s more “explicitly” stated throughout the article. Otherwise it will continue to read as anti onsite renewables, pro passivehouse and not UK specific. This is really dangerous and we will continue to have people around the world blindly following a design strategy that can often result in bad outcomes for the planet.
You have also introduced “comfort targets” into the conversation which I agree is an important element to good design. However if we are targeting CO2e reductions “comfort targets” need to be defined as what is sustainable for 7b people on the planet and not just a lucky few who can live in large “eco” houses. I think this is another topic for another conversation….
If you’re aim in the article was to create some healthy debate then it was spot on 😉
2. Don’t be prescriptive in your design approach and push only one strategy (such as passive house) or you’ll get perverse outcomes.
If reducing CO2e is the goal then CO2e is the only priority when it comes to design strategy. More importantly CO2e should be the basis of your target not “energy efficiency”.
I am totally agnostic in regards to which strategies (be it passivehaus or solar pv) should be prioritised in a project until we have kicked of with Life Cycle Design. Then and only then can you start to see which strategies will provide a genuine reduction in CO2e over the buildings life cycle.
In my home city of Perth we have a Goldilocks climate and very carbon intensive grid which is no where near being destabilised by PV. Unfortunately we still have the vast majority of “eco” designers using all of their clients money to design something that doesn’t need an air-conditioner while having no budget left for solar hot water or solar pv. They’ll reduce their carbon footprint by 10% while the guy down the road in a standard design with solar hot water and solar pv will have a 90% reduction in carbon, lower operating costs and all with less than half the capital cost.
Worse still they’ll chuck large volumes of concrete into the design for thermal mass in the push to achieve the magic “energy efficient” design resulting in an overall increase in life cycle carbon (even with a carbon intensive grid).
If you took the same example up to Kununurra, with a hydro dominated grid, then the solar pv would be a waste of embodied carbon as would the majority of the “radical energy efficiency” strategies. In that circumstance it would all be about the embodied carbon in the materials, transport, construction and maintenance.
Shift it again to various locations in the UK and I bet you’ll find a whole set of new variables and changes in priorities for strategies. Again starting with blanket statements about what should be prioritised without checking each project variables first will result in perverse outcomes.
I know you guys have a much colder climate than we do but I’m still pretty confident that with a proper LCD approach onsite renewables (PV, solar hot water, pellet heater etc) will still come into the mix for a low carbon design.
LCD ensures you apply a rigorous and unbiased approach to each project and provide something that planet and the occupant can be happy with. I would suggest that become familiar with standards such as EN15978 as it will allow you to integrate passivehouse within a much more holistic design philosophy. EN15978 is scientific approach to assessing the environmental performance of a building and is not biased by any existing rating system, design concepts or technology. It’s fast becoming the new benchmark for good design
3. Don’t write off onsite renewable energy it’s on the increase for some good reasons and is only set to grow even further – embrace it where it works.
“It is less costly and more effective to consume radically less energy and emit less CO2 by design, rather than to meet higher energy demand with building mounted ‘Zero-Carbon’ renewable generation.”
Sorry, but this statement is just not true. In some cases the opposite is more accurate. Again horses for courses! I think I addressed this point somewhat above.
Solar PV has dropped in price dramatically and continues to do so. Distributed storage is now doing the same. So if you continue to ignore it or try to push it to the side you will be left behind. Yes it does have it’s challenges as does any developing technology but they are disappearing fast.
I did read that article from Japan and it’s interesting we had a very similar situation in Australia a few years back. In small isolated network there was a really fast uptake in PV and the local utility got scared of stability issues and put a halt on further installations. As a result the industry responded by integrating cost effective distributed storage and away it went again. I’d almost guarantee we’ll see similar responses around the globe not to mention increase in electric vehicles.
Installing PV on roof in Perth can be as cheap as a solar farm ($1-2/Wp). There is already frames (the roof), electrical infrastructure (existing switchboard and meters) and no land costs. More importantly they are off the shelf items without need for expensive engineering, approvals and regulations. As far as this scary maintenance cost the systems I’m familiar with in Perth over 8years old have never skipped a beat. It just comes down to a life cycle cost analysis and trust me it looks pretty good with people taking it up purely on a cost basis with no rebates.
4. Specific points in your original article
“4. ‘Zero-Carbon Buildings’ may increase national CO2 emissions”
Why can’t these buildings also run gas and have the best of both? This is a pretty massive long bow to draw and very misleading to say that it will increase demand on the network.
“In the dark freezing depths of winter, with a gale howling outside, everyone has their heating turned up high and all the lights switched on … and since the sun isn’t shining the photovoltaic systems on the ‘Zero-Carbon Buildings’ aren’t generating electricity. And since the wind is gale force and highly changeable the wind turbines have switched to safety-mode and aren’t generating electricity!”
Wow, this is sounding like some of the anti renewable energy climate change skeptics. Again can’t the house have both renewables and gas? Furthermore distributed storage is on the way and on the way fast. If you don’t think so then have a think about the people who said mobile phones would never get past one per 200 people.
Houses with onsite renewable energy somehow increase the demand on the network even in hot climates?? Well I can tell you from personal experience in Perth we saw the government build another $300m power station to deal with this peak only to find that solar pv cut the peak dramatically and they never turned it on. Again you need to ensure you’re treating each project on it’s merits and not casting blanket statements or you’ll get tripped up.
8.‘Zero-Carbon Buildings’ is an abstract and unreliable idea
Sorry this is totally incorrect and also damaging to the progress we are making in getting people to think about CO2e. EN15978 lays it out pretty simply. Run a Life Cycle Assessment and you’ll have a much more reliable picture of reducing CO2e in a building.
Energy is not CO2e much like food cost is not measured in volume of food. Saying the only way to reduce CO2e in a house is to focus on radical energy efficiency is like saying we are going to cut our weekly food bill by eating less volume. So off you go to the shops and buy cheese wine and caviar and cut out the bread, rice and fruit (too much volume), furthermore you stop eating the produce from your own veggie garden. Somehow your food cost went up?
Many forms of energy have really low carbon intensities, some you can grow at home with very small carbon intensities and sometimes investing large amounts in energy efficiency can increase your carbon emissions.
Please explain how tackling CO2e by looking at energy and not CO2e be can less abstract than just targeting the CO2e in first place?
To wrap it up in conclusion this whole article first up appeared to be about reducing CO2e associated with houses. If this is the goal (which it should be) then setting a “zero carbon” target is exactly what we need to do. Simple….