Gas for heating and cooling

Gas for heating and cooling

We are not connected to the electricity grid and that makes the simple tasks like boiling the water for coffee different to most households.  We use LP Gas as the main source of energy to drive the equipment that is very energy hungry.

Although we have a solar panel and battery pack to supply us with electricity, these energy hungry activities are best managed with gas.  They simply use too much electricity to be supplied by our solar system.
 

Stove

The stove is used quite often in our house and the interesting fact is that it is mostly used to boil water for our hot drinks like tea and coffee.  On average we boil 750ml of water every 2 hours or so during normal activity in the house.  That leads to a total number of kettles to heat at between 6 and 8 per day.  If it takes 5 minutes to boil the water it means that one large burner is active for 40 minutes per day.

The other thing about heating the kettle is that you mostly want the water hot as quickly as possible.  Therefore we use the larger burner to heat the water.  The amount of energy that is lost by setting the flame too big is substantial, but I understand that the timing is an issue.

The dinner preparation takes about 1 hour every evening and then at least 1.5 burners will be active during that time.  So dinner uses a substantial amount of gas, but it equates to almost twice the amount of gas used to heat the water for drinks.

Oven

My wife bakes excellent homemade rusks.  These rusks are kept in the oven for an hour to bake and two hours to dry afterwards.  The oven's lowest temperature is 180 degrees C and that is achieved by burning two long burners at the bottom of the oven, for baking and the drying. 

The gas used by these burners is approximately the same as one of the large plate burners and uses quite a substantial amount of gas.  I am not happy with the heat distribution within the oven.  I will build another oven for my wife to do more baking, where the heat can be better regulated and distributed in the oven.

Fridge

Our fridge is a combination fridge and freezer on top.  It has the option to either use LP gas or electricity.    There is a small flame burning at the bottom of the exhaust pipe at the back.  That heat is used to make the heat transfer gasses flow through the pipes to cool the compartments down.

It was easy to determine the energy use when it was connected to the batteries. The electricity is used to heat an element that performs the same function as the flame.  That is not very energy efficient, but it allows for redundancy in the system in case we run out of gas.  As an emergency workaround it works well, but will not work on a more permanent basis.

A small thing to get used is that there are no electrical light in the fridge. 

Shower

We have a shower in the guest bathroom and the bath in the main bedroom's bathroom.  The shower is on a separate gas line to ensure the isolation of heated water and a separate gas supply.  

When the gas was finished in the three 19Kg cylinders feeding the stove and fridge, we simply moved the cylinder that feeds the shower, to the case that holds the rest of the gas bottles.  That allowed us time to refill all the other cylinders.

We have the shower's gas as a type of emergency reserve for the rest of the appliances.  

We use approximately one 19 Kg cylinder of gas per month for the shower and two 19 Kg cylinders for the stove and fridge.  That is for our family of 3 people.
 

The Future

Although we are happy with gas as the main energy source for the heating and cooling, the costs are still linked to the oil price.  It proves to be not an efficient solution for the long term.

We have investigated bio-gas and will start with the production of the bio-gas as soon as we have our animals in their sleeping quarters.  Their manure can then be used to feed the bio-digester that would produce the needed bio-gas.

More details can be found on  www.biogaspro.com

The ideal situation is to use the bio-gas in an additional burner plate in the kitchen.  Although the heat properties of the methane gas are lower than LP gas, you can use a larger quantity to get the same result.  

As most of the cooking is done during the day, the digester is mostly active in the day.  That means that the storage of gas can be smaller if the gas is used as it is generated.  In the case where the oven needs to be used, the LP gas option is still available.  

So eventually the bio-gas can be used as the primary source of heat, with the backup of the LP gas to cater for the situations where the bio-gas is not available or suitable.

We are using LP gas as the current source of heating and cooling and it is workable, but there is enough incentive to look further and develop a more sustainable and cheaper source of gas.

Till next time

We need water

We need water...

It was difficult to start the development of the property without access to water.  So that was the first goal to achieve.  Once we had water we could start the building process.

The only borehole on the plot was tested and only measured at 2000 l per hour.  Our water consumption is currently 1500 l per day.  That meant that the pump must run for 1 hour every day to replace the used water in the tank.

The fact that we did not have electricity on the plot made that situation unworkable.  I had to look for more water and the water needed to be closer to the house.  The existing borehole was almost 600m from the house and close to the low point of the plot.  The cost to lead the water from the hole to the tank would have been almost as expensive as drilling a new hole closer to the house.

So we drilled a new hole and we were lucky enough to have found 10000 l per hour water in the hole.  That meant that we would only have to pump once a week water to fill the tanks.

It's always a weekly task then to load the generator in the back of our Toyota and pump the week's water. It takes about an hour to fill the two 5000 l tanks on the container.

The container was very handy to keep the material and tools through-out the building project.  It also doubles as the stand to lift the tanks to generate water pressure.

It's one thing to buy all the parts wholesale and get the discount.  It's another exercise to connect a water pump for the first time.  The pump is hanging 50m down the borehole on the nylon line next to the black pipe.

The borehole is sunken to hide from plain sight.  The lines are buried 1m deep from the borehole to the container with the tanks.  The pump of the borehole pumps the water into the tanks where it uses a gravity feed to the rest of the plot.  The container is set at the highest point on the plot.

It took a full 3 days for the machine to dig the trenches of +- 500m

The pipes were laid from the borehole to the inlet of the tanks and back out again from the tank to the corner where the connection to the house would start.

The first Saturday, as we completed the drop of the pump into the hole, we realized that the hole collapsed and we could only insert up to 25m of the 50m hose.  So the contractor had to come and open the hole again and this time inserted the sleeve deeper into the hole as to prevent the walls of collapsing again.

The second time it worked perfectly.  It's nice to work with professional contractors.

The picture is of the pump installed and sunken into the ground.  The only part was to fill the hole and hide the whole pump in the ground.  If they cannot see it, it's very difficult to steal.

The maximum zoom from the borehole to the container with the tanks on and connected to the piping in the trench.

This is the same picture on normal zoom to show the +- 250m of piping.  After testing the whole system, the closing of the trenches can start.  This completes the installation of the water.

Fresh water at last!  Now the building can start.
The portion that took some time as the amount of work that was needed to dig the trenches and level the ground.  The machine was working for 10 days to do all the digging and closing of the trenches.

Once you had to work without water, you realize how difficult it is if none of the infrastructure is there.

So every few days we load the generator in the car and drive to the borehole to pump the water.  It's a habit by now and we use the water pressure to recognize when we need to pump water again.

The generator runs on Petrol and uses approximately 500ml of fuel for 10 000l of water. So our expense for water is around R30 per month.  I reckon that it is at an acceptable level and could be sustained.

As long as the well has water in it, we would be self sufficient.  I would like to see the account of a normal household in the city.  I am sure it is not only R30 for their water per month.

All of the equipment was sourced locally and can be maintained locally in the case that something breaks.  

At least we are not dependent on a municipality to supply us with water.  During the first part of 2010 we lived in Hartbeespoort, next to the dam, but had only running water 4 out of the seven days, in the complex.  I believe that water is going to become scarcer and less available because of the deterioration of the water infrastructure in the municipalities.

We are not connected to any municipality for any service and that in my book is living off-grid. 

Our water security is now a reality. 

Till next time