PragSust HQ going Passivhaus

At a recent institutional sustainability committee meeting I attended there was some discussion about the effectiveness of Passivhaus construction techniques. My  opinion is that broader adoption of building to Passivhaus certification would make a relatively simple but substantial contribution to cost-effective GHG emission reductions around the planet. On a personal note, I've recently done the offgrid energy system concept design for a green resort in regional Victoria that at this stage is aimed at Passivhaus certification. It was a lot easier and cheaper designing an offgrid solution for the minimal energy required. And in terms of walking the talk Mrs PragSust and I have just started the process of designing and building a Passivhaus extension to our house. This is something we have been working towards since I visited various certified Passivhaus buildings in Europe in 2012. I thought it would be worthwhile to list some points about how we will approach this project.

a/ We will require the extension to achieve Passivhaus certification; probably under EnerPHit. (https://passipedia.org/certification/enerphit.)

This is an objective standard that defines various energy metrics including:

1. blower air change results
2. post-occupation measurement and verification of the energy consumed at the site.

b/ We will treat this as a systems engineering project.

IMO any project with any more than minimal engineering component needs to be conducted in this fashion. Projects go astray when contractors are not familiar with working in a team, don't understand or won't commit to the level of quality required, there's poor project management and so on. Having a systems engineering approach with well defined requirements, design, a project plan and timeline and well-organised project management combined with the right architects/designers/builders/contractors drastically reduces the possibility that the project will fail.


c/ That's all very well but how does this relate to architects?

Architects/builders should have a reasonable degree of project management experience or they are unlikely to succeed in whatever construction technique used. One nice feature about aiming at Passivhaus certification is the extensive guidance on what's required to design and deliver the project and the objective metrics mentioned above representing very well-defined requirements. This helps architects/designers/builders/contractors faced with their first project requiring Passivhaus certification (and subsequent projects if they're successful)  to understand what's required. In particular, it gives the architect as the project manager a framework to work within.


d/ But what about the general population wanting to do a Passivhaus project?

Obviously there's a good whack of buyer beware in that regard as there is with any project. I've been asking candidate architects:

• will they commit to delivering a Passivhaus certified result with a payment schedule that depends on reaching this point and various stages on the way: https://passipedia.org/certification/enerphit
  
• will they use  the Passive House Planning package to do energy modeling for the extension: https://www.passivehouse-international.org/index.php?page_id=188
  
• will they use Passivhaus certified components or equivalent: https://database.passivehouse.com/en/components/
  
• are they Passivhaus certified. See http://www.passivhausplaner.eu/mitgliederdatenbank.php for a list of certified Passivhaus designers; Australians holding the certification can be found by selecting Australia as the country.
• do they have a crew of builders and contractors that can deliver the certified result. They can say whatever to this but if things get sticky later on it's good to have items like this covered.
  
• and ideally do they have a record of successful Passivhaus project delivery: http://passivehouse-database.org/index.php?lang=en
  

These are all questions that could be asked and checks that could be made by someone in the general population. We'll want more detail about certifiers and so on but the above is a good start. I've had affirmative answers to this list from architects.


e/ But isn't Passivhaus more expensive?

This was definitely an issue initially with Passivhaus as tends to be the case with initial deployments of any new technology. However, now that there's a lot more experience with what works and what doesn't, architects/designers/builders/contractors with experience in delivering certified projects, a good range of certified components and so on, much of the risk has been removed. And certified Passivhaus buildings need minimal HVAC kit which reduces their price. One architect with several successful certified projects told me that he will now only do Passivhaus buildings as they're comparable in price to good quality conventional construction but much cheaper to live in, excellent sustainability credentials etc Comparing Passivhaus costs to cheap construction is apples and oranges. Cheap construction is a poor outcome on many criteria not just energy efficiency.


f/ Does it work in hotter climates like Australia?

Again, this was relevant when Passivhaus was first deployed in cold climates in the northern hemisphere. The standards now have provision for warmer climates.


g/ The architect says that he can deliver an energy efficient building project without using Passivhaus certification?

Maybe. Australia generally has very poor commercial and residential building energy performance. The 6 star residential rating is of some use but this is a design standard with no requirement for followup monitoring and verification that operational performance meets design estimates. A CSIRO study several years ago found that houses designed as 6 star frequently have operational performance below 6 star. 9+ star would be acceptable but only if this was a measured operational post-construction result - not a design estimate - and there were terms in the contract that final payments would not be made until the building met agreed requirements. What we want is results not nice drawings. One (uncertified) architect told me that he didn't think certification was required. He went into blather mode when I asked him what post-delivery energy requirements he would sign up to. Over the years I've had a number of conversations with architects along these lines. They'll talk a big game but are very reluctant to commit to an outcome. That's all neatly bypassed by requiring Passivhaus certification.


We might blog this project as per:

https://rochesterpassivehouse.blogspot.com.au/

Cute timber bench

We've done a number of posts on wood. Growing trees for wood, making things from wood, wood used in various ways, firewood and so on. I was at the University of Melbourne School of Design the other day to meet an Environmentally Sustainable Design (ESD) consultant who tutors at the Uni. While waiting by one of  the main entrances I noticed this cute bench made of small wood pieces:

We think this is great. It's playful, practical, attractive, made from a renewable, low carbon material, with small pieces of wood that could be offcuts from other timber processing and uses wood to make a sinuous curve as against a more common straight line. And it passed the PragSust comfort test ... at least for the short time I was sitting on it. The ESD consultant told me it was made as a student project. It's nice to see clever students making great stuff. Hope whoever it is has a great career making more delightful pieces.

Battery storage for PragSust HQ

Previous PragSust posts have discussed what we've done about reducing the GHG emissions from stationary energy use at PragSust HQ. And I wrote a high-level guide to how to tackle stationary energy GHG emissions at various scales.

We've finally started work on installing storage at PragSust HQ.

The battery in the photo was bought 2nd hand from a demonstration installation as part of a commercial project I worked on looking at a wide-scale rollout of residential PV-storage. I did the financial and system performance modeling for this project. This battery is going in an off-grid system at the block but we will also be getting more PV and storage installed as a grid-connected system at PragSust HQ.

I'll put up some modeling to give an idea of what we might expect from this battery and a larger PV installation based on our electricity consumption interval data. We're also going to use a leading inverter - made right here in Melbourne - supporting advanced charge/discharge capability. The company manufacturing the inverter has been quietly making increasingly capable kit for the offgrid market for decades. More about the inverter capabilities in a later post.

There's a lot of nonsense in the noosphere about batteries and PV. Storage is near enough essential for cost-effective grids with high-penetration of intermittent renewables like wind and solar. But granular control of charge/discharge is critical for optimal performance. Simple battery systems may have a crude control system that first allocates energy from PV to site use, followed by battery supply to onsite consumption with little or no control over when this occurs. In these simple systems when the battery charges is also uncontrolled. I've done a lot of modeling for various sites to optimise the benefits from PV/storage systems. But achieving these benefits needs more sophisticated control.

We will look at making available online operational data available from the battery. I'm tired of reading uninformed, doom and gloomer, apocalypterati cant and I'm also tired of reading unrealistic, over-enthusiastic rubbish about various potential technological pathways. What matters is the facts; not selective, poorly researched polemics channeling various authorial or sectoral bias.

Our new honey press

We have always used the 'crush & strain' method for harvesting our honey.  To do this we cut the comb from the frames, mash it using a potato masher and then place the mashed comb in a double strainer to let the honey drip through into a honey bucket. (The process is described in more detail here).  

This method works best when the temperature is warm, as the higher the temperature the more liquid the honey and the faster it drips out of the mashed comb. The strainer we have holds up to one full sized frame of mashed comb so a full box of honey can take us a while to process. Up until now we have done all our honey harvesting in summer so this process has worked fine.  Of course, in colder weather you could have your setup near a heater to speed up the straining process, but that's not so convenient for us as we have a wood heater and no suitable spot to set up near it.

To enable us to process our honey quickly, despite the weather, we recently became the proud owners of a stainless steel honey press.  It was actually sold as a fruit press but it works well for honeycomb too. 

We decided to get this rather than a dedicated honey extractor for several reasons:

• For reasons of disease control we prefer to add new frames with wax starter strips and let the bees build fresh comb, rather than reusing comb. 

• We don't have room in our freezer to freeze frames of comb to in order kill wax moth, nor do we have a suitable space to store and monitor frames after freezing. 

• Because we let the bees build their own comb and don't wire our frames, our honey-filled frames aren't always suitable for use in an extractor.  Frames in which the comb has been built out to completely fill the frame can go in an extractor but the extractor needs to be spun more gently than when processing wired frames (we've tested this).

• We can also use it to press fruit from our fruit trees.

Recently we packed down our country hive for winter into a single box. After ensuring the hive had sufficient stores for winter, we were left with some frames of honey to process.  Although it was the end of Autumn and rather cold, the honey press enabled us to process the honey quickly.

Here's what we did:

Because we didn't know how it would all work out for this first time with the press we used a large piece of clean vinyl flooring to catch any spills and make the cleaning up process easier. The comb was cut out of the frames and placed in a clean, food grade plastic bucket.

We filled the mesh basket with pieces of comb and put a bowl in place to catch the extracted honey. Screwing the handle down presses the plate into the comb which crushed the comb to release the honey. 

   

It worked really well, despite the ambient room temperature being around 15 degrees celsius. 

 

Adding more comb to the basket

The honey collected in the bowl was then put through the double strainer and bottled.  
Here's our little harvest:

 
After processing all the frames we were left with a cake of sticky wax, well two actually  - there was a solid layer of wax in the bottom of the mesh basket and a cake of wax stuck to the underside of the pressing plate. The wax in the basket came out easily. To remove the wax stuck to the pressing plate we used a knife to prise it loose around the edges of the plate and then a wooden spoon (to avoid scratching the plate) to lever/scrape it off.  

We divided this wax into 2 oven dishes and put it in the oven to melt the wax and separate out the remaining honey, as described here.  

Wax cake ready to be melted in the oven

We found that because the wax cake holds far less honey than hand mashed and strained comb, this step didn't yield any useful amount of honey.  Plus the wax cake also contained a lot of old brood comb and associated debris that didn't melt too well. 

Wax cake after being melted in the oven

So next time, if we have a lot of old comb to process, I think we'll skip using the oven and melt the wax cake using this method to clean it up.  We'll do that now with this lot.  The final step is purification using our solar setup which works like a charm....but we will have to wait for warmer weather to do that.

To clean the honey press I took it outside on the front lawn and blasted it with the jet setting on the hose. That removed obvious remnants from the press and did a great job on the mesh basket. I put the basket through the dishwasher for a final clean. The rest of the press can be wiped down with a suitable natural disinfectant.

The whole process was complete, including the clean up, in a few hours.  

We were very happy with how the honey press performed - the increased speed, efficiency and easy clean up IMO justifies the investment, particularly as we plan over time to build up our hive numbers. Plus being able to use it to make fresh fruit juice from our various fruit trees is also something we're also looking forward to doing 😊


Update 25/5/2017:
In this instance, our usual method for cleaning really dirty wax did not result in a nice disc of wax floating on the water in the bucket. Instead we were left with some wax stuck to the underside of the flywire funnel, and a sort of waxy sludge in the water in the bucket.  I'm not really sure why. Not to be deterred, we put this wax and water mixture back into the double boiler and when all the wax had melted, we poured the contents into 2 clean milk cartons and let it set.
The next day we cut a hole in the bottom of each milk carton and let the contents drain into a bucket.  This left behind a wax block in each carton which was easily removed. The water in the bucket contained very little wax sludge so this extra step seemed to work quite well.

Sustainable shopping - buying in bulk

Grocery shopping - like it or not, it's something most of us have to do.  But rather than thinking of it as being a bit of a drag, there is a positive way to look at it. Grocery shopping is one way that we as customers (we hate the word consumer) can use our purchasing power to help bring about changes that we want to see in the world.  We can exert our influence by shopping mindfully. No company or store is going to stock products that don't sell.  By buying a particular product we are sending a message to the manufacturer to produce more of it. The rise and rise of cage-free eggs in Australian supermarkets is one such example. That means what we spend our money on counts!   Over-packaged products full of hard to decipher ingredients and way too much fat or sugar - is that really what we want to see more of?  Um....no, I don't think so.   Organic, environmentally friendly goods that support our health and that of local businesses - well, yeah.  So let's get voting with our dollars 😊

There are lots of ways we can use our purchasing power for the good of our health and the environment and buying in bulk is one of them.

Buying in bulk can take different forms. One way is for a group of people to put money in to purchase a large quantity of an item and then portion it out amongst the group. Many people will have heard of Community Supported Agriculture schemes that supply boxes of fruit and veggies straight from the farmer to customers. Our permaculture group has done this with biodynamic spelt, as well as other things. This can be a great way to access quality products direct from producers who don't deal in small quantities. And the producer doesn't have to pay a cut to any middleman. Win win.

Another way is to shop at a bulk store. Bulk food stores, relatively common overseas are now catching on in Australia. These stores stock food in large unpackaged quantities, allowing customers to purchase as little or as much as they like of any item.  

One such store opened up a few years ago not far from where we live. It's called The Source Bulk Foods and it's where we buy our dry goods such as grains, beans, lentils, pasta, spices, seeds etc. 

Our local bulk foods store

Bulk food stores can benefit the environment in multiple ways.

Firstly the food and other goods are completely unpackaged - this is waste free grocery shopping.  The Source encourages zero waste shopping and I bring my own recycled glass jars, mesh bags and homemade cotton bags when I shop. Zero waste living, a concept popularised by Bea Johnson in her terrific book  Zero Waste Home, aims to eliminate trash from all aspects of life by following a simple guideline she calls the 5Rs: Refuse, Reduce, Reuse, Recycle and Rot (and only in that order). Any steps we can take toward zero waste living is a way of helping us to live more sustainably.

The second benefit of shopping at a bulk store is that you have access to a carefully considered range of products. Previously we had sourced organic products from a variety of places, making shopping more time consuming. Now I can find local/organic/biodynamic options all in the one store, which also focuses on supporting Australian producers and growers.

Then there's the range of options available. The list at The Source is extensive, carrying many hard to find items. 

Finally, while you are buying quality products, because they are free from packaging, the price you pay can work out cheaper than what you'd be paying for a similar item in the supermarket. I have certainly found this to be the case with some of the things I buy. We make our own muesli from a combination of rolled oats, quinoa flakes, sunflower seeds, linseeds, sesame seeds and cinnamon. I buy all of these organic items at the bulk store and save money. 

Below are a few more photos taken at my local store. As you can see, the store is well laid out, with all items clearly labelled and easily accessible.

Rice, beans, spelt and other goodies in barrels

seeds and spices along the top shelves

the brown rice I purchased

freshly ground coffee bean (left) and fresh nut butter (right)

Top row: black tahini, hulled tahini, unhulled tahini, tamari. Middle row: 2 kinds of extra virgin olive oil, macadamia oil, sunflower oil, sesame oil

Top row: blackstrap molasses, coconut syrup, maple syrup, rice malt syrup, dark agave syrup. Middle row: 2 types of honey, balsamic vinegar, apple cider vinegar

So how does bulk store shopping work? It's pretty easy really. I take my empty jars to the counter to be weighed and the sales staff mark the weight on the jar. Then it's off to fill the jars with whatever I need. Back at the counter the jars are re-weighed and the weight of the jar is deducted from the total - so I'm only paying for the contents. Same deal with my homemade cotton bags - I write the weight of each bag in pen on the bag and this weight is deducted at the checkout.

Some of my purchases at the counter

Customers using the paper bags supplied by the store use a pen to write the item number on the bag before filling it, for easy identification at the checkout. There are scales available to check your quantities.

the friendly staff

This seems like such a sensible way to shop - it would be great to see bulk stores become as common as supermarkets.  

Have you ever shopped at a bulk store?

Homemade Yoghurt

As part of becoming more self-reliant, we've been enjoying making some of the food and other products we use at home. Foods like honey, preserves such as olives, jam, sauces and fruit, and products such as soap, dishcloths, laundry detergent and home cleaners.

With an interest in fermented foods from a health perspective, I had been wanting to make our own yoghurt for some time. Well I finally got around to it, and now that I've made several batches, I don't know why I put it off for so long!  

Breakfast - homemade yoghurt and homemade muesli

The basic process involves adding yoghurt culture to milk at 37C, whereby the culture consumes the lactose (or any other sugar) in the milk.  After a minimum of 8 hours at this temperature the milk becomes yoghurt.  

There are all sorts of nifty ways to keep yoghurt warm while it ferments.  Some of these include:

• put it on top of hot water heaters (unfortunately our HWS is located outside in the open air so the option is not really suitable for us) 
• on top of coffee machines (we don't have one) 
• in a warm oven (we didn't want to wait for the oven to have been used in order to make our yoghurt) 
• wrapped in blankets 
• in an esky (cooler) with hot water.  

After considering our options I took the easy way out and bought an EasiYo yoghurt thermos ($23.50 from BigW) to incubate the yogurt in.  I'd heard that this system worked well so I thought I'd give it a try.  It consists of a thermos and a jar that sits inside the thermos to hold the yoghurt. Yeah, it's plastic, but it works well and makes the process simple ........... which means I'm far more likely to make yoghurt than if I had to fuss around with blankets. But that's just me.

EasiYo thermos

Boiling water is poured into the hole to fill the space below the red shelf

For my first batch I used some live yoghurt culture bought from Green Living Australia.  I bought the Tangy Yoghurt Culture ($16.95) and the Non-Dairy Yoghurt culture ($17.95). Each sachet contains enough culture for 100 litres of yoghurt (you only use a very, very tiny amount to make 1 litre) and you can make this stretch even further by using some of the previous batch of yoghurt as the starter for the next. The culture will keep for 2-5 years in the freezer. I liked the idea of purchasing the culture as it means I don't always have to have a previous batch on hand if I decide I want to make yoghurt.

We have a thermomix so that is perfect for mixing and heating.  However you could easily do it on the stove using a thermometer.  

The method I followed was from the Thermomix Everyday Cookbook but I have played around with quantities and use slightly less than the recipe in the book:

Ingredients: (makes 1kg yoghurt)

• 800g full cream organic milk
• 50g milk powder (the addition of milk powder makes a thicker yoghurt - I used 20g or none)
• 3 tablespoons yoghurt containing live culture (I used the Tangy culture for my first batch and 2 dessert spoons of homemade yoghurt for subsequent batches)

Method:

1. Combine milk & powdered milk in Thermomix bowl for 10 seconds, speed 7.
2. Cook for 30 minutes at 90 degrees, speed 1. (This kills any bacteria in the milk, preparing it for the addition of the live yoghurt culture)
3. Cool mix to 37 degrees. The mix must cool to this temperature before adding your starter or you will kill the live culture. It may take up to 60 minutes but you can speed this up by putting the bowl in the fridge.
4. Once at 37 degrees add your starter (the yoghurt or the purchased live culture), mix to combine for 4 seconds, speed 4.
5. Then heat for 10 minutes, 37 degrees, speed 1.

It's very important that the utensils you use to make your yoghurt are clean and sterilised. While the yoghurt is cooling to 37C I wash the yoghurt jar and lid in hot soapy water and then rinse them. Then while the yoghurt mix is heating in the final step I fill the clean yoghurt jar with boiling water and let it sit until the yoghurt is ready to add. I also pour boiling water over the underside of the clean lid, let it sit for a little while then put the lid, underside down on a clean tea towel. 

Once step 5 is complete, pour boiling water into the EasiYo thermos up to the correct level. As shown in the photo above, the yogurt jar sits on a shelf above the level of the boiling water in the EasiYo thermos. (You don't want the container holding the yoghurt to come in contact with the boiling water).  Empty out the boiling water sitting in the yoghurt jar and pour in the yoghurt mixture.  Screw the lid on and put the jar inside the thermos. Leave the thermos somewhere where it won't be disturbed for at least 8 hours, and longer for a thicker yoghurt. Once done, you can  transfer the yoghurt into another jar to free up the yoghurt jar for making another batch.

Two batches of yoghurt in the fridge - some from the batch on the left was used to make the batch on the right

As you can see, yoghurt made in this way is super easy. The organic full cream milk we used was purchased on special (50% reduction) so that made the yoghurt even cheaper to make.  I've yet to try making the non-dairy yoghurt but as I only drink soy milk I'll have the ingredients on hand. 

The Green Living Australia website has recipes for dairy, soy, almond and coconut yoghurts so there are plenty of yoghurt making options available.  Making your own yoghurt is not only easy, it will save you money while at the same time, give you control over what goes into the yoghurt you eat. I won't have to make many batches before I've covered the cost of buying the cultures and the thermos.  What's not to like about that?

An unexpected harvest

Last month we set up a hive on our country block. At the time we weren't sure of the forage supply so we gave the bees some sugar syrup, just in case. Five days after installing the hive I had a quick peek under the lid. It didn't look like the bees had been feeding on the sugar. Two and a half weeks after installing the hive I did a more thorough inspection. And I was pleasantly surprised.

Once I'd opened the hive I could see that the bees were not feeding on the syrup.  So we took that away. Looking into the hive it seemed clear that they were finding some sort of nectar flow - the hive was full of honey.  In fact there was very little room left for the queen to lay. Yikes!

Ideal size box containing the sugar syrup

Nobody was interested!

 
I had spare boxes on hand but no frames (another beekeeping lesson learnt - when tending more remote hives be prepared for abundance!).  The hive was in danger of becoming honey bound and I didn't want the hive to swarm if they ran out of room.  Fortunately we did have a supply of clean 2 litre icecream containers in the shed. 

Here's what we did to make some room in the hive:

• Removed a full frame of honey and took this back to the shed.
• Found 4 clean 2 litre icecream containers with lids
• Cut the comb out of the frame and put this into the icecream containers. I cut a quarter of the comb out of the frame at a time, which fitted nicely into a 2 litre icecream container.  
• Left an inch of comb along the top of the frame to act as a guide for the bees to build on.
• Put the frame back in the hive.

We hoped the bees would get to work building comb on this empty frame and give the queen some more room to lay.  We planned to come back in a few days with frames to add a 2nd box to the hive.

So what happened?

Well, we came back 4 days later to find that the bees had almost completely filled the frame with fresh comb.  Go girls!  

To give the bees plenty of room we added a second box with fresh frames. We don't wire our frames - instead we use a thin strip of wax in the top of the frame as a guide and let the bees build their own comb. Yes, they consume honey in order to make the comb but we figure it's better to let them build the comb that they want rather than use frames with full foundation.

To make room in the brood box we moved 2 frames of honey up into the second box and put 2 fresh frames with wax starter strips into the brood box.  Based on how quickly the bees had filled out the frame we'd put in a few days prior, it seems likely that they should be able to build out the 2 empty frames.  The presence of the honey in the 2nd box will hopefully draw the bees up there too.  Just how much comb they build in the top box doesn't really matter - we just wanted to make sure there was room in the brood box for the queen to lay. 

Here's how we processed the comb once we got it home:

One of our 4 containers of comb

Using a potato masher to mash the comb

Fully mashed comb on right

Mashed comb is spooned into the double strainer sitting over the honey bucket

Honey is left to drain from mashed comb into honey bucket. Because the lid of the honey bucket doesn't clip on when the strainer is in place we use a plastic bag secured by a rubber band to cover the lot.

 

Here's the harvest from our single frame of honey. Well over 2 kg of honey:

Honey harvest from single frame - large jars on left each hold 500 gms of honey

We hadn't planned to harvest from this hive this season, thinking that it might struggle to amass stores. Our suburban hive is certainly not making much honey. Just goes to show that as a beekeeper you need to be prepared for multiple outcomes, especially when you are tending hives in more remote areas.   Now that the country hive has plenty of room we can leave it to do its thing and check back on it in a few weeks.

If you keep bees, how are your hives going?