Solar PV, Methane, and The Living Building Challenge
Thursday, February 25, 2010 at 9:30am
Our Energy Journey Continues:
Despite our Eco-Sense home using a fraction of the energy of a regular BC home, and our lifestyle choices for conservation, we are still challenged as to how to cook our food sustainably.
We produce the majority of our food onsite, cook from scratch, and process much of our winter food. In this past year we have consumed propane for a total energy of 1890 kWhrs. (two kitchens and 6 family members).
The Living Building Challenge 2.0 does not allow any form of combustion, however Eco-Sense registered for version 1.3 which did allow biogas. But, as we just discovered, this biogas is only allowed for heating/energy production and NOT for cooking. We had planned on designing and building an onsite biogas digester fed from the organic wastes locally available to produce methane for cooking. The fact that thais was not allowed was our misunderstanding.
The standards for the Living Building Challenge (LBC) are indeed hard to reach. This vision is admirable indeed…and hard to achieve, which is the whole point.
Eco-Sense is net zero electricity, but currently is not net zero energy. In order for us to provide the additional 1890 kWhrs from solar PV for electric cooking we would need to install 6.9 new panels. (round up to the nearest two is 8) If we didn’t cook from scratch, and purchased processed foods from elsewhere we would probably need two or three less panels, and if we were only one family we would already be producing enough energy to be totally net zero energy.
Here’s the calculation:
total produced/12 existing solar panels = 195 kWhrs/panel
new energy required – excess already produced = 1351 kWhrs
1351/195 = 6.9 solar panels
So lets explore this to identify the barriers for eco-sense to become truly net zero energy for the purposes of the LBC.
If BC Hydro had a better net metering program, many of the cost barriers would be overcome. BC Hydro is WAY behind as they only pay 8.2 cents per kWhr. Shameful for a province that claims to be leading the way towards sustainability.
Embodied energy (tGHGe produced) to mine, manufacture, and transport the solar PV panels, aluminum frames, and all the other bits and pieces is still VERY high. We compare the solar panels of today to the first computers that came out…they are big, heavy and require lots of stuff to connect up. The future of solar PV is more like a leaf…very small and lightweight.
Currently, we think that producing our own biogas onsite (for cooking) from chicken manure and broom would have a lower carbon footprint – any thoughts on this????
Removal of all the current tax disincentives to solar PV. (Here are a few of them)
- HST on solar technologies
- building permit fees on entire solar installations
- increase in municipal taxation because of property value increases due to BC Assessment of all future energy energy production
Eco-Sense pays an extra $400 per year in municipal taxes because we generate sustainable energy (works out to $10,000 over the 25 year life cycle of the system)
We recently discussed this issue with the BC Assessment appeal board and MLA John Horgan, and everyone agrees that this is wrong. Solution involves changing the Legislation with the BC Minister of Finance.
Education: Require more public pressure to push governments to create meaningful incentives for solar technologies AND support for research to fast track technology.
So, to sum up, It doesn’t look like Eco-Sense will be able to fully meet the Living Building Challenge, but we are are still applying. Our community of the Highlands has chipped in the $1000 registration fee for our home to be assessed for all six categories.
There is much to be learned and contributed from our application to the Living Building Challenge. Let the assessment begin.
Ann and Gord Baird
Friday March 12, 2010
Gord and I had a conversation about COMBUSTION with Jason McLennon who is the CEO of the Cascadia chapter of the US and Canadian Green Building Council. He is also the lead author of the Living Building Challenge (LBC)…A building system well beyond LEED platinum. Combustion is not seen as a sustainable option under the Living Building Challenge. This conversation arose when Gord and I were considering using a biogas digester from waste (broom and goat manure) to produce methane for cooking. Since our Eco-Sense home is a registered Living Building Project this issue of combustion is very important to us. Below is an email conversation I had with Brian (a local mechanical engineer). We are still thinking about which route to go.
Brian: While nature does not burn fuel to get energy, it does set itself on fire all the time. Forest fires are natural and essential for healthy forest growth. Not to mention volcanoes will decimate hundreds of square kilometres but deposit phosphorous rich ash that improves soil fertility. Both of these processes burn and destroy, but they also revive and renew.
I agree with the desire to mimic the natural world but we don’t yet have the ability do perform perfect Biomimicry; and I fear that this no-combustion rule is letting perfect be the enemy of good.
Ann Baird: Great points Brian. The conversation with Jason went well and we discussed many things including combustion. Here is the summary as I understood it of the LBC reasoning for NO COMBUSTION:
- Combustion uses fuel which can change or run out at any time. Since the equipment (infrastructure) has quite an upfront cost it is not likely to be changed if the “green” fuel supply changes. This could lead to perhaps raw wood being used or crops grown to produce the fuel to justify the infrastructure.
- Particulates. Using combustion for cooking or energy production releases other waste gasses and particulates into the home or the community. If everyone was doing this it would lead to reduced air quality in the environment or the home. Ever notice how having a propane stove in the kitchen makes everything in your kitchen slightly sticky over time…some of this comes from the burning of propane. There is also an increased risk of uncontrolled combustion (explosion) occurring from human error…no matter how good the system is engineered. (but in all reality the risk of damages from climate change from doing nothing is much greater and I totally hear your point about perfect being the enemy of good…very wise comment)
- What would nature do? This input comes from Biomimicry expert Janine Benyus. Humans are the only species to directly use fire for cooking, heating etc…all other creatures use chemical forms of energy from their environment…ie photosynthesis, etc.
For the LBC, the only exceptions are for laboratory bunsen burners, and possibly in the future the family hearth for cultural purposes…we evolved with fire…but using it to heat our homes is somewhat primitive.
We also chatted about resiliency and how we felt strongly about utilizing simpler technologies.
Although resistive cooking may not be the most efficient (in fact it’s pretty poor), it may ultimately be a better choice…so I think the LBC folks get your point about perfect being the enemy of good.
All in all we had to agree with Jason. We are now thinking about putting a few more solar panels on the roof and setting ourselves up for more solar cooking, but lots to consider. We had an initial visit with a engineering PHD student from UBC who is interested in working with us to design and build an onsite digester if we go that route.
As far as our wood gassification boiler goes, we are thinking of getting an electric chipper, and pellet maker for converting boom into pellets for the stove. This still wont qualify under the LBC, but all agreed that is a good local solution.
We will be including these comments on the BCSEA at some point and our blog. thanks again Brian for your input.