Energy & Efficiency

Energy underpins every action and is so fundamental to our modern way of life that we don't even pause to consider how reliant we are on affordable, reliable concentrated flows of energy. We take pride in doing as much as we can with renewable energy, usually in the form of human muscle power derived from sunlight via plants. 

What would you do when fuel becomes more expensive or temporarily unavailable? How will you manage a prolonged power outage during winter?

Having backups and redundancy is one way to mitigate the disruption and discomfort. What does this look like for you? Grow some firewood, store candles, insulate, consider solar powered solutions.

In Ground Storage - Root Cellar Construction

In Ground Storage - Root Cellar Construction

One thing that's been on my todo / wishlist is the creation of an underground cool storage room or chamber for fruits and vegetables.

Having grown up in a house that had a cellar I was familiar with the benefits of a low technology and energy efficient way to protect and store harvests for long periods.

After selecting a suitable location that shouldn't accumulate ground water, the project was initiated in November 2022
May 23, 2024
  construction  2024 
Olmec Sinclair
Learn More
Sustainable firewood

Sustainable firewood

A lot of activities get labelled as 'sustainable' these days, despite having a hidden subsidy of non-renewable resources or energy. The only truly sustainable energy source is the sun and the various manifestations of that energy such as biomass, wind etc. The rate and method (technology) used to harness or extract that energy determines it's long term sustainability. Wind turbines constructed from huge volumes of concrete, steel and carbon fibre are not sustainable while harvesting a tree with a stone axe is sustainable if practised at a rate that permits regrow under local ecological conditions.

Note: I used a pseudo sustainable electric chainsaw rather than a stone axe to dissect this manuka tree. It will be replaced by a five finger (Pseudopanax arboreus), already growing up out of the decaying stump.
August 19, 2018
  firewood  energy  sustainability 
Olmec Sinclair
Chimney Oven

Chimney Oven

I first came across this novel concept when I was a kid and friends of my parents had one. Seems like a pretty common sense idea so I've been on the look out for something like this for years.

Finally I got the chance to purchase this stainless steel beauty. On the initial test firing we easily got the temperature up to 350 centigrade and it hovers nicely round 200 with the vents closed and the fire idling.

We have used the oven to cook bread, muffins, roast nuts, muesli and veges. A very versatile and useful addition.
July 17, 2017
  fire  cooking  baking  oven  off grid  sustainable  efficiency 
Olmec Sinclair
Electric lawnmower upgrade

Electric lawnmower upgrade

After trying various different 'eco' lawn mowing solutions we were struggling to find something that could live up to our expectations. Our latest attempt is so far proving quite satisfactory, despite my misgivings about battery powered tools capability to deliver enough power. Introducing the STIHL RMA 410C A quiet, exhaust free way of keeping the paths under control.
December 01, 2016
  lawn  electric  technology 
olmec
The brazier

The brazier

Details   Both a focal point for outdoor gathering and warmth with perhaps the option for grilling, frying, toasting etc. Constructed from welded metal fencing standards held within a circular 'collar' made from the cut down wheel of an old sheep shearing machine. Located at the focal point of the outdoor spiral.
Date   September 04, 2016
Tags     fire 
Related info
Pumping with free energy

Pumping with free energy

Using water to pump water, now that is cool! I have been building a small ram pump for lifting water. The design uses off the shelf components assembled and then cast in concrete.

Overview: Water from a small creek enters a screened intake and is carried via 32mm polythene piping. This has a drop of perhaps a meter over about 70 - 80 meters. This connects to 18 meters of rigid steel 25mm pipe which drops a further 10 meters to the pumping unit. The outlet from the pump delivers water via 15mm poly tubing up to an elevation of around 30 - 40 meters.

While the device works technically it has a number of drawbacks:
  • The water delivery is very slow, perhaps 1 litre every 2 - 3 minutes. This is a result of the various measurements. More water in, dropped from higher or delivered lower would improve the situation.
  • The pump unit stops every day or so due to (I believe) air accumulating at key points in the delivery line. This can be improved by eliminating high points from the line.
  • Pump stops when river drops too low
August 15, 2015
  energy  water  technology 
olmec
View 3 photos
Solar - third time lucky

Solar - third time lucky

After several failed attempts to create a low cost, low tech solar water heater I gave in and purchased a complete kit off the shelf. It's only August but we've been having some nice fine days and the temperature has been getting up to high 50's. This unit has 20 evacuated glass tubes with some kind of antifreeze that exchanges heat with water that is pumped through the header. While I would have preferred a passive system I do like the modular nature and programmable smarts of the control centre.
August 21, 2013
  solar  energy  water  technology 
olmec

Energy efficiency with hot water

Currently most of out hot water heating is done by electricity although we are are working on a number of strategies to reduce this component. One part of the approach is to keep the thermostat set so that the water is just hot enough.

I was having a conversation with someone about energy efficiency and hot water heating and what was the best temperature setting for the hot water cylinder.

The friend was operating under the incorrect assumption that it was better to have the cylinder as hot as possible so that when water was taken out, for a shower say, there was less cold water entering that required heating. There is a certain surface logic to this but it seemed to me that it doesn't matter what temperature the water is, when you have a shower or do the dishes you are extracting the same amount of energy (in the form of hot water) from the tank and so the energy needing to be replaced is the same.

The issue with keeping water extra hot then, is more to do with the extra energy that is required to maintain a greater temperature  differential between the temperature inside and outside the hot water tank.

According to one website:
"The ideal setting is 60°C. It is important that the water in the cylinder is this hot to kill bacteria such as legionella but higher temperature settings only increase your power bill."
June 17, 2011
  energy  hot water  electric  temperature  efficiency 
olmec
Energy efficient bulbs

Energy efficient bulbs

I recently purchased a couple of compound LED light bulbs. These use an extremely low level of power (11 Watts each) while providing a useful illumination.

Available in either Edison thread or bayonet they fit into a standard light socket. Being LED they do not contain any mercury.

Unfortunately I have already had one cut out for some reason.
http://www.eoutlet.co.nz/catalog/viribr...
June 10, 2011
  LED  Light  Energy 
olmec
Measuring the sun

Measuring the sun

As part of my ambition to get a solar electric system up and running I have been conducting some tests.

My interest is in the effect of the suns angle to the panel array and the relationship to voltage. While there are probably some models put there, I have not seen any and find that actual experience is much more convincing and reliable.

My observations will influence my decision to include tracking capabilities to my solar installation.

Notice the clever little rod below the panels whose shadow (or lack of) can be used to determine if it is pointed directly at the sun.
May 18, 2011
  solar  electric  measure  photovoltaics 
olmec
Spinning with the wind

Spinning with the wind

Experimenting with vertical axis wind energy harvesting mechanisms.
Using old bicycle wheels and pieces of fat pipe I managed to put together a trial device for collection energy from the wind. Determining the angle of the 'blades' is the important factor. The next version will be bigger and better and allow for fine tuning.
January 13, 2011
  wind  energy  VAWT 
olmec
Ride on mower - fossil fuel extravagance

Ride on mower - fossil fuel extravagance

Having no grazing animals leaves us with an abundance of tall grass that is beginning to get out of control in the places where I have not attacked it with the scythe.
Bring on the old mower I 'inherited' from my father. Time will tell if it's a useful tool or a lemon...
December 04, 2010
  grass  mowing  fuel  energy 
olmec
Portable Electric Chainsaw

Portable Electric Chainsaw

Configuring an electric chainsaw for mobile firewood collection.

Electric chainsaws are light, with no fumes, less noise and fewer complex parts to cause issues.

The problem is they require a fair amount of power, thus limiting their portability.

Check out how to set up a useful system for mobile sawing...
April 27, 2010
  Chainsaw  Electric  Inverter  Firewood 
olmec
Read More
Scything like it's 1809

Scything like it's 1809

Trying out some rustic scythe techniques in the orchard. No noise, no smell, just good old fashion manual labour.
The scythe is best known as the weapon of choice of the grim reaper, basically a long, curved metal blade on a wooden pole with handles. Traditionally used for mowing grass and harvesting cereal crops, the scythe has a long history in agrarian (and revolutionary) societies.
December 25, 2009
  scythe  grass  tools 
olmec
The full story
Bio fuel (turning food into energy)

Bio fuel (turning food into energy)

Ok, so this isn't what most people mean when they say bio fuels but turning lunch into energy certainly can reduce dependence on fossil fuel.

Our push mower is cheap to run, quiet, doesn't smell bad, easy to service and takes up hardly any room in the shed. Oh, and it keeps you fit! What's not to love.
October 22, 2009
The bio fuel mirage