Here
at the entrance of the ETC is a climate sensible (or solar passive)
seminar building. There is a pond on the north side to reflect light
into the classroom. It is filled with native aquatic plants and fish.
This shipping container on the left actually houses the core of our
wind energy conversion system - the battery bank, control system and
back-up diesel generator. Later we will see the large wind turbine is
located on top of the hill (for maximum wind speed).
This
is the back of the classroom - you can see a rainwater tank collecting
from the roof. The additional pipe on the side allows suspended solids
coming in with the first flush of each rainfall event to be removed.
You should also clean the gutters regularly. The screen filter on the
top of the tank also prevents entry of any solids that pass over the
first pipe. Many people will prefer rainwater to scheme water for drinking.
This will also provide savings of up to 10% of the total domestic water
consumption. The geodesic dome demonstrates the apparent solar paths
of the sun at the winter and summer solstices.
On
the right is the ablution block is the focus of another research project
here at the Centre. They were earlier designed for construction in Aboriginal
fringedweller camps by the RADG. It also promotes water conservation
principles with water efficient appliances in use throughout, e.g. the
dual flush 6/3-litre toilet and the front-loading washing machine. You
know the average Perth home consumes about 370 kL of water per annum.
Some 60% of this is used outdoors on the garden. About 40% of water
used ends up as greywater and is disposed of to the sewer and ultimately
the sea. There is a solar hot water system on the roof which is also
providing hot water to the anaerobic digester unit (silver barrel) which
turns brewery waste into biogas which can run a BBQ. The water from
the bore is filtered through the sand filter (white box).
The
toilet, laundry and shower all discharge their effluent into the Dowmus
wet composting tank here. You can also throw all of your food scraps
into this green cone on top as well as some waste paper and garden wastes.
The pile of compost inside sits on top of a pile of plastic extrusions
and acts as a biofilter for the effluent passing through it. The solids
are removed in the compost before the effluent settles on the bottom
of the tank. When the level rises to near the underside of the compost
a pressure switch activates the submersible pump and the effluent is
pumped up the hill to a series of constructed wetlands where it receives
further treatment before being irrigated into the nut orchard (that
is in Zone 3 using the Permaculture parlance).
The
nursery area has several structures which demonstrate alternative building
materials. The actual plant propagation nursery consists of two shadehouses,
one incomplete, each demonstrating different use of simple methods and
low-cost readily-available materials. In here will be grown the Centres
annual requirement for some 1,000 native seedlings for its ongoing revegetation
efforts here and elsewhere. Many other plants will be grown also. The
nursery will also serve as an excellent training resource for the many
courses offered through the Centre.
Walking
up the hill a little further is the largest of our ponds at some 200
square metres which is being managed for aquaculture. Aquatic systems
can be up to 20 times more productive than terrestial ones! The target
species here are marron and black bream and being a polyculture system
there are a wide range of aquatic and edge plants. Some of these are
also target species such as the water lillies and water chestnuts for
their tubers. Others such as the floating aquatic azolla are harvested
for their nitrogen content as a compost improver and the local native
edge plant Common Lake Sedge acts as a hide for breeding insects and
marron. The challenges we have encountered so far are the enormously
fast growth rate of some of the latter which depletes oxygen from the
water thus requiring a high aeration rate and regular but difficult
harvesting; the high acidity of the groundwater which is used as top-up;
and shags and ducks predating on the marron. We hope these will be overcome
with time as management improves. The edging trees include polownia
whose leaves will provide food for the marron. The red roofed shelter
is made of strawbales, its a lovely spot to sit and watch the water.
Flow forms oxygenate the water and make a very attractive feature.
On
the far side behind the bana grass is the "Zone 2" mixed temperate fruits
orchard. This positioned here in relation to the house because of its
lower frequency of visits necessary. There are apples, peaches, nectarines,
mulberry and apricot. The ground floor can be used for green manure
cover crops such as alfalfa and perennial vegetables such as artichoke.
Alternatively the chooks can be grazed through here as an added fruit
fly control measure or the area can be used to raise quails for meat
production.
The
site office is just an ATCO site hut which offers more examples of climate
sensible building. Its length is positioned along the east-west axis,
most of the glazing is on the north face for winter solar gain with
none on the east or west walls, a solar pergola has been placed on the
north side which keeps out summer sun. This shady area is expanded by
a brushwood structure covered with grape vines which covers the Zone
1 plucking garden. The garden has a mix of annual vegetables, perenials,
herbs and flowers. This needs to be near the home as opposed to its
normal location, the bottom end of the yard, because if its productive
you will be picking from it all the time, an example of the energy efficient
zone planning system in permaculture. Various types of irrigation demonstrated
are microjets, in-tube drippers, and "Aquapore" porous tubing made from
recycled tyres, each of these being judiciously applied to a specific
microclimate or application within Zone 1. Throughout the garden are
tyre ponds which attract predatory insects and provide small sources
of aquatic foods. Along with companion planting and benign traps biodiversity
is maximised and natural pest management occurs. On the far side of
the pergola is a dry composting toilet.
On
the righthand side of the hut is a new planting including a passionfruit
vine which is watered by greywater. Greywater reuse is now permitted
by the State Government agencies in the shires of Bassendean, Kalamunda
and Kalgoorlie/Boulder on a trial basis for 1998 only. From the sink
we have demonstrated one permissible greywater recycling method at home
simply and cheaply by the use of a diverter valve from the sink, through
a clear plastic tube and under the ground into a length of sewer pipe.
Here
at the top of the hill are the two bores which fill the 90 kL tank and
can gravity irrigate the rest of the site. The first bore has a 100
Volt DC submersible pump powered by a 3 kW.hr/day wind turbine located
on the 12-metre tower at the other end of the ponds. Nearby is the second
bore using solar pumping powered by 2 x 50 Watt photovoltaic (PV) panels
on a solar tracker. The groundwater is of good quality and is used to
irrigate the gardens, orchards, nusery as well as for drinking and domestic
use at the ablutions facility after sand filtration and chlorination.
In the shed is housed a research project on a solar-powered desalinator.
Have
you read your electricity bill lately? If you are energy conscious and
live in a climate sensible designed home you may be using as little
as 5 units (kW.hr/day). But as with many people if your not careful
with your heating, cooling, lighting, ventilation and window protection
and you live in a typically poorly designed house you may be using as
much as 20 units/day. The electricity supply for the ETC comes from
the large 20 kW.hr/day wind turbine up on the 24-metre tower on the
hill. So this could power 4 efficient homes or one of poor efficiency.
The DC electricity generated is sent down to the shipping container
through a cable where it is converted into 240 volt, 50 hertz electrical
power via the 10 kW inverter for use around the ETC with normal appliances.
The turbine itself, named Survivor by its inventor and now marketed
by Synergy Power Corporation, is an innovative downwind bladed combination
of vertical and horizontal axes. It has a large tail connected to this
pivoting axis. In low wind speeds the tail hangs down and the blades
face directly into the oncoming wind. As wind speed increases the tail
still faces the blades into the wind but the tail lifts and pulls the
blades up until, in high speed gales, the blades are almost horizontal
and almost cease rotating. This prevents the turbine from exploding.
In other systems the blades are individually furled out of storm gales
but involves more complicated engineering.
Over
the back here on the eastern side of the ETC coming down the hill we
have "Zone 4". Zone 4 is a long narrow strip between a steep bank and
the back fence which is only starting to be developed. In this area
we have apiculture (bee hives for honey) and a range of tree crops.
The latter have benefitted from a new type of soil improvement we have
developed and which was also used in Zone 3. Trenches or "swales" have
been dug parallel to the contours and tree plantings. In these are deposited
lawn clippings from contractors, brewers spent grain, fish offal from
the on-campus fish research group, and other such wastes. These break
down into a wonderful rich humus into which the adjacent trees roots
find their way.
The
various tree crops include so far Carob, Italian Stone Pine (Pinus
pinea), and specialist timbers. In the future we envisage groves
of Bamboo and fast-growing pole timber trees with the possibility of
grazing livestock under. Also occurring in this Zone 4 is the long term
monitoring of biowastes used to make commercial potting mixes, past
the yellow sign. The presence and/or regrowth of pathogenic micro-organisms
such as Salmonellae is under investigation.
A recent
development are the poultry pens next to zone 1 and the site hut (since
it needs daily attention). We have developed a four bay rotation system
where we can crop vegetables in each pen successively. Each pen is effectively
a stationary "chicken tractor". The chickens are fed vegetable scraps
from the university food halls and outside supermarkets. In return we
get an abundant supply of tasty nutritious eggs.
The
bush regeneration is spread over several areas wherever some remenant
bush survived. All of this area used to be pristine Jarrah-Banksia woodland
(Eucalyptus marginata, Banksia attenuata/menziesii) up to some
150 years ago. The Jarrah was felled of course for railway sleepers
in India and road paving in England. Later the land was used for pine
plantations and we now have 10 or so of these pines (Pinus pinaster)
remaining. The debate is always ongoing amongst us whether or not to
fell these in the interests of a more vigorous bush regeneration or
for their stately grandeur and roosts for many birds including the spectacular
Black Cockatoo. The inhibiting factor for their removal to date as with
so many things has been the cost.
Because
the area is fairly small we use planting as well as the more large scale
bush regenerative techniques pioneered by the Bradley sisters in NSW.
These techniques rely on assisting nature by minimal disturbance (disturbance
encourages weeds) and working outwards from a core good area. It takes
several years but it can be used over large areas with the only inputs
being labour. We have seen the return of many endemic species as a result
of careful nurturing over the years. As well the has been strategic
plantings of pioneers (such as Acacia cyclops), windbreaks (e.g.
Acacia saligna) and beautiful small plants (e.g. Conostylis).
Here
in Zone 3 of our Permaculture system you can see the swales (ditches)
which follow the contours to slow down runoff and trap it for the trees
which grow alongside the swales. The swales are filled with weeds, prunings
and compost one year and the next year a crop is grown in them like
cucurbits and sweet potatoes. In this area of Zone 3 we have to the
south a cooler microclimate where our nut trees are planted.
To
the north - a warmer micro-climate - we have planted our Mediterranean
tree crops - olives, figs, citrus and Chinese dates. Just below the
dam wall is a humid micro-climate where sub tropical species planted
along the base of the swale - white sapote, avocado, mango, capuli cherry.
There are still some pioneer trees (fast-growing and hardy) such as
Albizias which were planted to provide wind protection and start enriching
the soil, they will gradually all be removed as the fruit trees mature.
In
the foreground is the dryland garden, a new planting to demonstrate
a range of native species which need little water and make beautiful
plants for a water-wise garden. The green building houses is a small
scale means of producing beautiful art paper from waste paper. Firstly
the paper is shredded in the "hydropulper" with water and a sizing agent
(which later provides a smooth surface for working on and photocopying).
In a bath tub these screens are trawled through the mix and after draining
turning upside down on the canvas sheet on the invert curve bench. The
canvas sheets with wet paper sheet are then hung up along the "stackman".
After drying the sheets are then pressed to 2.2 tonnes in a screw press.
Bingo - lovely art paper. You can even add bark and flowers.
The
biobox (white shipping container), cement mixer and Fabcon aerobic composter
(black tube) are industrial scale compost producers. A variety of waste
including sewerage sludge, prunings and fish waste is mixed with sawdust
(to a 25:1 carbon/nitrogen balance) with with about 20% red mud (the
bauxite refining residue). A range of domestic compost tumblers have
also been trialled.
