Found 13 results tagged with 'energy'

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 
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 
The reversal of the economic engine

The reversal of the economic engine

A brief article summarising my understanding of the current and possible future economic modal based on energy and resource extraction, consumption and growth.

The picture seems far from bright and there are a number of factors that could influence the outcome but the overall direction seems clear.

Picture: Neville Sinclair
June 08, 2011  future  post peak  energy 
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 
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 
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 
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 
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