Sunday, February 24, 2013

Perfect Passata

The next time its 26 degrees in February chuck a sickie and make passata. Lucky for Earth Carers, our miraculous 26 degree day fell on a Sunday.

We have been keen to try out our new, second hand, communal, 'Grow in Freo', electric passata machine. This wonderful contraption was purchased communally between a few community gardens in the Freo area. It is available for all the Grow in Freo garden members (and probably others if you ask Beck nicely!). It was a fantastic purchase!

I'm a super keen preserver but have always blanched and peeled my tomatoes before preserving. This is generally a whole of family, all day affair to preserve around 20 kgs. We were interested to see if we could make the process any quicker with some horsepower behind us. And it sure did! We aimed to do 30 kgs in a day and ended up doing 50!

So here's the quick vid of the machine in action:


And here are the step by step instructions. First, if you are a member of Hilton Harvest or any other 'Grow in Freo' community garden, ask Beck to borrow the passata machine her number is 0407 018 151 . Here it is all set up, ready to go.

On the left of the picture you see we have set up a milk crate with a bed sheet bulldog clipped in to it to catch the passata, then put the crate on some bricks. This is so the watery stuff can drip out and you are left with thicker passata without needing to reduce it on the heat before preserving. Ads said that you can actually capture the watery stuff and make good stock with it - we will try that next year.

If the tomatoes are bigguns you need to cut them in half first. We got roma's which fit down the shoot easily and are cheap during summer, this lot was $1 per kg, but we have purchased them at 50c per kg. You need to wash them first.

So, the easy bit is making the passata. Just switch it on and poke them down the shoot.

The passata pours out in to the milk crate with the sheet and the seeds and skin come out the side.

Its important to have the seeds and skin drop in to a clean container because if you put this through the machine again you will get more sauce. You can do it three or four times.

 It took us an hour or so to do the lot, including cups of tea and popping down to the shops to get another 20kgs of toms because it was all going so well! After this we just let the passata sit in the towels and drain for an hour or so more. It was amazing to see how clear the liquid was that dripped out. It's really tasty and like I said before, next time we will catch it and use it for stock.

In the meantime we washed our preserving jars and put the rings on. I've always used a Vacola set - others have told me they just reuse passata jars and lids but I've not tried that myself.

Then we pour in the passata into the jars with a little lemon juice (or citric acid). This is to keep the acidity level up and reduce risk of botulisms or something...I don't know, I just read about it in the instructions!

Then pop on the clips and lids and preserve. It takes around two hours in the stove top pot. You have to get it to 97 degrees, then hold it at that temp for an hour. This is our stove top 'big bertha'. She holds around 11 slim jars.

I also have an electric one, and for the day borrowed a second one. These systems take only an hour to preserve and hold around 8 slim jars. 

So, to do 50 kgs we did one load in Big Bertha and three loads in the electric sets. It was all over by 1.00pm with an 8.00am start. It honestly would take all day to just blanch 50 kgs of toms. I will never blanch again. The sauce and remaining clear liquid still separated in the jar after preserving, but it's still thick enough after a shake before opening. Generally though, you need to let it cook and reduce for your pasta sauce or whatever you are cooking. We ended up with 22 large jars and 15 small jars of passata, this works out to about 25 litres of sauce and should be plenty to keep us going for a year. No preservatives, minimal food miles, no waste at all! Awesome!

Sunday, February 17, 2013

Grey water installed

After years of thinking about installing grey water we finally did it. We had a bit of spare money and the thought of having a guilt free lawn and a more sustainable water source for our productive trees was irresistible.

Firstly, what is grey water? Usable grey water is water from bathrooms (shower, bath and sink) and laundries (washing machine and trough). It does not include water from toilets and kitchen water (known as black water). I asked Josh Byrne to recommend a system which was a low power user and fairly low maintenance. He said we should get a Grey Flow system so I looked into it and it sounded good. The systems are made by a local company called AWWS. Grey Flow systems are diversion systems with no holding tank. This means they are fairly simple and low maintenance. Our system was installed by Mark Harland of Water Capture and I thoroughly recommend him. Here's how it works:

We cut into our bathroom and laundry discharge pipes and diverted them to a chamber. Inside the chamber is a float valve and pump, when water gets to a certain level the pump sends the water through a filter and out to a rotor valve. This operates hydraulically (no power use) to direct water to up to six zones of our garden. It pumps 100 litres per station before switching to the next.  Then the water goes to dripline piping, either subsurface (for lawn) or sub mulch (for trees and shrubs). If power goes out the system automatically sends water to the main sewer. The main proviso is that the water is not used on herbs or vegetables due to the health risk. Also washing products such as shampoo, soap and laundry detergent need to be 'grey water suitable'.

So what about forever cleaning the filters to keep dripline from blocking up? Every ninth pump out activates an air cleaner which blows air up through the filters and diverts the resulting gunky water to the sewer (self cleaning option). This means that the filters only need to be cleaned once a year. The drippers are one way so shouldn't suck fine particles in and air release valves reduce the risk of this happening as well. Flush points need to be opened once a month to release gunk from the ends of drip lines. Apart from that it's a once a year clean of filters and the pump, which is about as low maintenance as you can get.

Enough of the boring technical stuff, here are a few pics of us installing it.

This is bits and bobs that do the work. When it was filled in and the pipe on the left was cut down to level it looks lots neater. The pipes are (from left to right) reflux valve, secondary filter, primary filter and at the back the main chamber which houses the float valve, pump and air cleaner.

Here is the sub-surface dripline going in.

Then the geotextile goes down. This is to stop lawn roots wrapping around the dripline and to spread the water out evenly.

Here's some dripline in a grid pattern in a fruit tree/globe artichoke bed.

And here's some dripline looped around a fruit tree. This will be covered in mulch soon.

Here's the rotor which directs the water to the different stations. At the moment we have 4 stations on the lawn and 2 on the fruit trees, but we may re-jig this if the lawn does well and we feel that the fruit trees could do with more.

This is one of the filters, I can see tomato seeds from preserving tomatoes today!

It will be interesting to see how much water this saves us. By my reckoning we should harvest around 200-300 litres a day. The great thing about grey water as opposed to rain water is that it's available 365 days a year (as long as you're at home). This means we'll get it when we most need it, through Perth's hot, dry summer, unlike rain water which mainly falls in the cooler 3-4 months of the year. So we should be able to capture at least 70,000 litres of water a year this way, which is the same as our rain water tank harvests. Our lawn should thrive without the need to use drinking quality water on it. The fruit trees should also prosper and become more productive. At the moment we have two stations, the lawn and the trees in the back garden. We'll monitor the results for a while and see if we have enough water to add another station out the front. I'm now considering planting more thirsty trees such as avocado and mango out the front. In a year or so I'll let you know how it has affected our water use.

The other benefits of grey water are more on a community/society level. Perth's water resources are rapidly dwindling and in our rush to increase supply we are putting our security above the well being of future generations. Desalination consumes huge amounts of power which fuels climate change. Current levels of groundwater use is both unsustainable and has unknown effects on ecosystems.Even the delivery of scheme water is very costly, both economically and ecologically. Watercorp, who manage WA's water resources are the number one user of power in the state. This power is needed to clean and pump water to our houses and then pump sewerage away, clean and return it to the ocean. It's crazy that we clean water to drinking quality, only to use most of it to water the garden and flush the dunny! So with grey water we're closing the loop on most of the water in our home and hopefully this will become standard practice in the future.

Think carefully before you install grey water. Ideally you should use a fair bit of water and have enough suitable garden area to put the water on. There's no point paying all that money if you don't use much water and don't have lawn, garden beds and trees to use up the water.

So, what about cost? Our system cost us $4,500 all up.  The council didn't charge us for the permits, but check with yours, some do and some don't. I drew up the plans and filled in the application myself. This, along with ripping up and re-laying the lawn, saved us around $1,000. This is a pretty good price in my view for something with great benefits for our garden and society as a whole. In comparison our rain water system cost us around twice the price. Of course we will never make our money back in lower water bills, water is just too cheap for that now, but that's not the point. Our garden will thrive and we'll be doing our bit for a more sustainable future.

Sunday, February 3, 2013

Sneaky chooks

Over the Christmas New Year break we had a heat wave in Perth. The girls went well off the lay, fair enough. But we have also had some lovely weather... But still not heaps of eggs. We'd been wondering if our little faithful brown girls were at the end of their productive lives. But then today we discovered their little secret nest in under the wormwood. There were heaps of eggs! And now we feel bad for ever doubting our wonderful girls. Ads will have to make some serious spreadsheet adjustments.

Friday, February 1, 2013

PV payback time: Is it still worth it?

PV (photovoltaics) have become very popular in Australia recently due to generous government incentives. These incentives (such as feed in tariffs) have now all but gone. So the question is, is it still worth installing PV? Well the answer is a definite yes and I'll tell you why.

In Australia most electricity providers are ripping people off when they feed power back to the grid. They charge customers around 25 cents a kW and pay them about a third of that for power fed to the grid. This means there's no great incentive to feed power into the grid but it doesn't make PV uneconomic. I've updated my payback calculator spreadsheet and come up with the following numbers:

Price $2,000 $2,500 $3,000 $3,500
System size 1 kW 1.5 kW 2 kW 2.5 kW
% generated fed into grid 50 67 75 80
Payback (years) 6.1 6.1 6.1 6.1
10 year average annual bill $981 $899 $816 $733
25 year average annual bill $1,441 $1,315 $1,190 $1,064
BAU average annual bill (10 years) $1,307
BAU average annual bill (25 years) $1,935
25 year savings $12,353 $15,503 $18,628 $21,778
25 year savings minus outlay $10,353 $13,003 $15,628 $18,278

Assumptions: 775 kW from PV used in home per year, 1550 kW generated from a 1kW system per year, 10 kW is overall consumption per day. Price rises of 5% per year, feeding power in at 8.5c per kWh, paying 25c per kW and a daily service charge of 45c. NB: Payback time is independent of annual bills, but annual bills are a big factor in your choice of system. Payback calculated by subtracting 10 year average bill from BAU 10 year average (10 year average annual saving), then dividing the cost of system by this average. The savings made relate to the value of the power your panels generate, costed at either 25c per kW if you use it in the home or 8.5c per kW if you feed to the grid.

Sorry, the formatting of the table didn't come out too well, but you should be able to get the drift of it. BAU stands for business as usual, or the price you'd pay if you didn't have PV. The prices for PV systems are based on ones I've seen advertised at Energy Matters. Power prices are based on current WA tariffs, assuming a 5% rise per year. Please note that these calculations are just a rough guide and will vary depending on your electricity provider, the power you use and the time of day you use it, the amount of power your panels generate and the price of the installed system.

What's interesting is that larger systems are still better in the long run, despite the fact that power fed to the grid is poorly priced. The payback time is the same, but savings over 25 years are higher. The essence of this table is in the savings you make, which range between $414 and $731 a year over 25 years.  A relatively small investment now (eg $2,000) will give you a high return (eg $10,353). If you put it in the bank it would earn $4,450 at 5% compound interest (if the banks don't go bankrupt in the meantime!). And I haven't even mentioned the other benefits to society, such as greenhouse gases abated and water saved.

But I'm going to move house some day I hear you say. Don't worry, PV adds value to your house and makes it easier to sell so you'll make your money back anyway.

So if you're thinking you've missed the boat on PV then think again. Sure, the payback time has risen since the scrapping of feed in tariffs, but power prices are going to keep rising and I certainly wouldn't want to go into retirement without panels on my roof. By the way, most solar panels can last for 40 years.