We know all about load shedding and we’ve been warned about water shedding. So what do we do about it?
According to rainwater harvesting specialist Patrick Rosslee, a good idea is to have your own tank – the biggest your space can afford.
Your roof must have gutters. A sloping metal or concrete tile roof is best and a thatch roof – which rarely has gutters, anyway – is the worst. An asbestos roof is a no-no unless the water is used only to irrigate the garden. Be aware of the danger of toxins posed by a painted roof and those spayed with herbicides and insecticides.
“Get a rough idea of how much rain water you can capture. On every square metre of roof, a millimetre of rain will give you one litre,” he said
“Try to choose the right size tank. This can be tricky to work out. There are a variety of shapes and sizes. You need to shop around for that.
Water quality is an issue. “Leaves, dirt, insects and bird droppings are all likely to be washed in the direction of the tank,” said Rosslee.
This is where types of filters come in useful. One is a mesh, which can stop bigger debris getting in but a lot can be dissolved in the water, he warned.
“You’ve got to watch the quality of the water entering the tank to stop it from going off, smelling or gathering sediment. You want to make sure the water is the best it can be.”
Then there’s the problem of mosquitoes. “Often, people complain they have mosquitoes and they wonder where they are coming from. They’re breeding in their tanks!”
To avert that, all exits and entrances to the tank must be sealed. Rosslee said people usually initially use harvested water to irrigate gardens, to fill swimming pools and to wash cars. “One may consider using harvested water to flush a toilet. However, it may not work in some houses where the plumbing works are in the walls and difficult to access.
“People also use it in their washing machines and dishwashers. Untreated and unfiltered water is not safe to drink. If you have to, in an emergency, water should be boiled for an hour first.”
A Durban-based water tank installer who did not wish to be named, said it was a waste of time to install a small tank as it would take years to pay off.
“The more you harvest, the quicker it will pay you back. The bigger the installation, the better. Schools, hospitals and factories are more cost effective than houses.”
Gauteng-based Erika Theron believes otherwise. “I don’t think there’s a choice any more. It’s a worldwide problem and it’s not going to get any better. The only thing to consider is what size tank. Houses using small tanks should simply use more of them.”
According to Allan Webb, who installs JoJo Tanks in KwaZulu-Natal, demand for water tank installations has been high in beleaguered areas north of Durban, fed by the drought-affected Hazelmere Dam.
He said houses needed a concrete base to be in place after which a 700 to 800 kilolitre tank, connections, labour and other essentials would cost around R8 000 to R10 000.
When it comes to electricity, Glenwood off-the-grid guru Graham Robjant recommends that people should not jump into the deep end and go completely off-grid. Rather, start out being equipped for load shedding. “You can start by storing power from Eskom using a battery.”
He stressed that outages were particularly hazardous to elderly people. “Out come the matches. If a candle is not stuck in properly it can fall over and start a fire.
“Just to get light, they can have a small system to run some light-emitting diodes (LEDs). No inverter is necessary, just a small 12-volt battery with a day-light sensor and a little charger so it can be plugged into Eskom.”
The charger should be an intelligent charger, as opposed to a regular one.
For under R1 000 they can buy a battery, LED lights, a day-night sensor and a charger.
One can take it to a higher level by installing solar panels.
“The first thing to consider is where to put them and how to attach them. They need full sunshine on the panel every day. They must cover east and west to avoid being limited by shadows.”
Robjant said it was not ideal for panels to lie flat but rather at an angle of at least 30º.
Between the solar panels and the batteries, a regulator will have to be applied to control the flow of voltage and this needs to be a solar regulator, said Robjant.
The connections between these three should be as short as possible.
The battery connects to the inverter, which is the entity that will step up the voltage to 220 volts from 12 or 24 volts – depending on the make – to run household appliances.
“You’ll find that most household equipment will run on a modified sine wave inverter.”
The modified is cheaper, but is not suitable for certain items, including kettles, hairdryers, microwaves and geysers, certain types of motors and clock radios. An inverter should only be wired up to a distribution board by a qualified electrician.
A basic kit to light up a room using a 12 volt battery would cost around R468, according to Tony Parasuram at ManTech Electronics in Greyville. One that would power a burglar alarm, a television set and light three rooms and included a battery, a charger and an inverter would cost R4 800.
A completely off-the-grid set up in which solar panels powered everything, including the demanding microwave, would cost more than R80 000 to set up, he said.
According to Umbilo-based environmental philosopher Tom Dennen, we have food shortages to look forward to if the water and electricity crises are not addressed.
An electricity crisis can lead to petrol pumps not working, he warned. “Then food will not reach the supermarkets.”
Buy our book - OFF THE GRID - a tour of American off-grid places and people written by Nick Rosen, editor of the off-grid.net web site
Leave a Reply