Posted on Dec 19, 2007 under Uncategorized |
I’m going a little off-topic here, but part of running a blog, or any kind of website for that matter, is promoting it. Someone pointed out rssHugger to me, a new website that helps bloggers promote their website. The site is a directory of blogs, categorized by subject and currently contains over 400 listings in over 90 categories. So, if you are looking for blogs on any subject be sure to have a look at rssHugger.
I have also added my blogs rss feed to FeedBurner, which lets you track how many people have subscribed to your rss feed. Since adding my feed about 2 weeks ago I have gained 35 feed subscribers. If you are one of them: thanks for subscribing to my feed, I’d love to read your comments on my posts! If you haven’t subscribed yet, you can do so here and be updated on any new posts on my blog.
Posted on Dec 11, 2007 under Aquaponics, Fish, Gardening, Self Sufficiency |
The nice thing about aquaponics is that it is very scalable and can be set up almost anywhere. If you want to try out aquaponics you can set up a small system to grow herbs in your home. All you need is a small fish tank and a container that can be used as a grow bed. The fish in the tank will fertilize the water with their excrements and the growing plants use these nutrients to grow while cleaning the water.
In a small setup you can locate the grow bed above the fish tank. The grow bed can be filled with lightweight expanded clay aggregate or gravel. A water pump on a timer will fill the grow bed with water and small holes in the bottom of the grow bed let the water flow back into the aquarium. The holes have to be sized to let less water pass through them than the pump delivers to the grow bed. This way the grow bed will fill up while the pump is running. Once the pump shuts off, the grow bed will empty out into the aquarium.
A system like this is called flood and drain and makes the plants grow nicely. In the flood stage the plant can take up water and nutrients and in the drain stage the plants roots have access to oxygen. You can place your setup by a window or, if you don’t have a suitable spot that receives enough light, you can add some lights.
(sketchup model by: Dave)
Posted on Dec 07, 2007 under Heating, Solar power |
There is a lot of free energy coming our way each and every day, all we have to do is convert it to some usable type of energy. I’m talking about solar energy of course. There are a few ways we can use the energy packed rays that the sun sends down to us.
We all know about solar panels that convert light into electricity, the major problem with them however is that they are quite pricey and not very efficient. We can also use solar power to heat water in a simple to build solar water heater. The hot water can be fed into your central heating system to help heat your house or tap water. This energy will not be completely free, as we need some electricity to run a water pump so the heat will be transported from the collector to where we need it.
But there is another way we can use solar heat to heat up our house and it is completely free after setting up this simple device! All we need is some timber, a corrugated black sheet of roofing sheet and a transparent sheet of plastic or glass.
Start by making a wooden frame and attach it to your outside wall. You will have to use a south facing wall (or north facing if you live in the southern hemisphere) for this to work. Within the wooden frame you have to cut some holes in the wall, so air can circulate between the house and the solar heater. The holes will be placed at the top and bottom of the frame. You can make the whole thing as big or small as you want. Ideally you want to cover your whole south facing wall, the part that doesn’t have any windows that is.
Next the black corrugated sheet of roofing will be screwed against the wall. The black color will help in converting the incoming sunlight into heat. Black works best because it absorbs the complete spectrum of light rather then reflecting some wavelengths like colored objects do. Once the sheet has been heated up by the sun, it will heat up the air around it. It will stay warm for a while when the sun is not directly shining onto it. This makes the solar heater have a somewhat constant heat output even on days with some clouds.
All that is left to do is adding the clear plastic or glass cover. Make sure that there are no gaps between the wood and the cover (or the wood and the wall) or heat can escape and cold wind can enter the solar heater (and your house) That’s all there is to it, you will now get some free heating when the sun shines! How come we don’t need any fans to move the air? This is simple physics: as the air is heated it will expand and move up and through the gaps in the top of the heater. While doing so, it will pull in cold air through the bottom gaps which will be heated up by the black sheet and continue the cycle.
Posted on Dec 04, 2007 under Electricity, Heating, Off-Grid, Self Sufficiency, Solar power |
In Europe, Canada and the US, the power companies are required to buy back any excess energy you create. The rates, at which they buy back the energy, depends on a few things and the rules are different in each country and state. You can get detailed information on this subject from your utility company.
Solar energy, for instance, will be paid at a higher rate than power generated with a diesel generator because it is obviously much cleaner energy. In Europe you will also get a better rate if you burn vegetable oil instead of diesel, but you will have to show proof of the origin of your oil, so waste vegetable oil collected from restaurants will not get you the higher rate, although the collected oil will be cheaper than buying new vegetable oil, possibly still making it an interesting alternative on the bottom line.
The amount of energy you can sell back also differs from each power company to the next. While some will buy back as much as you can generate, others will only buy back as much power as you buy from them, effectively leaving your power meter at the zero mark.
Since we are currently looking for a new house, I don’t know which power company we will be dealing with. Assuming, for now, that I can only sell back the amount of electricity that I use, generating our own power will not bring in any money. After working out the fuel usage for the generator and assuming that I have to buy vegetable oil to run the generator, plus the generators initial purchase price and ongoing maintenance, the bottom line is that the power from the utility company will cost about the same or maybe even a little less.
However, the electricity is not the only thing I will be generating. A big part of the energy will be lost as heat. Lost if you don’t catch it, that is! Running the engines cooling water through a heat exchanger in the central heating system will have a positive effect on the total fuel consumption of the central heating.
The whole thing can also be turned around: so, instead of running an engine to cover your power needs and use the excess heat to complement your central heating system, you could also have the engine running to generate the heat to warm your water and house, while running a generator head along side to create electricity while you are heating. Sure, ultimately we are talking about the same system, that generates heat and power, but the sizing of each system would be different.
How our system will be sizes isn’t decided yet. We will first have to find a suitable house. Depending on the age and condition of the central heating system, we will then go one way or the other.
Posted on Dec 02, 2007 under Aquaponics, construction, ferro cement, Fish farming, Water |
If I want to set up a big aquaponics system I need some big water tanks and grow beds. Looking at various suitable tanks, they all had one thing in common: a very high price tag! Living self-sufficient means doing a lot of DIY, so I went on searching for a low cost alternative to use as tanks. I quickly stumbled upon ferro cement, which is basically a 3:1 sand and cement mixture with chicken wire used as rebar.
The strength of the chicken wire concrete is amazing and the uses are endless! Entire houses are being build with ferro cement and due to how these structures are build, you can go nuts and make your house a piece of art. Once finished, your structure will be truly low maintenance and it can withstand earthquakes and hurricanes.
I’m not building a house but fish tanks and grow beds both need to be sufficiently strong to be able to hold their contents and be water tight. The ferro cement is water tight and is used to build water containers around the globe. Because of its low cost it is used a lot in developing countries. The biggest saving comes from the incredible strength of the material, with the need of much thinner walls, compared to rebar concrete, you will only have a fraction of the material costs.
