Sunday, 12 April 2009

Designing your own electricity system - part 7 (fridges)

Here are some specifications regarding energy saving fridges.

Tafelberg sell some of the Ardo range of fridges.

The Ardo rating is: 130KWH rating per year. Even if it really uses 165KWH per year, that will be amazing as an A++ energy star fridge is rated at 380KWH per year and a normal fridge much higher than that.

My normal fridge (which I still need to replace) uses approximately 660 kwh per year which at 70 cents per kwh (my rate) is about R40 per month. Note that this is only based on one day's usage. After a few months, I will have a more accurate number.

The Ardo fridge uses about 40Watts when it is on and is so quiet that a friend on mind has it in his passage outside two of the bedrooms.

At 165kwh per year , the Ardo fridge costs R10 per month.

A normal fridge is about R2000 and an Ardo fridge is about R8000.

The difference is R6000, so R6000 / R30 (saving) = 200 months = 17 years. Not a very good payback period, but remember what I said in an earlier part of this blog series. The R6000 is locked in, ie there is no inflation. If electricity goes from 70 cents to 91 cents (30% increase), then the payback period is R6000 / R37.50 = 14 years. On so on.

The saving becomes clearer once we start looking at the costs of generating electricity compared with saving electricity.

Note that there are going to be paradoxes in this discussion. Whilst it is more expensive to buy an energy saving fridge, the more people buy them, the more the price will come down. If one adds in the environmental savings, then the total environmental costs are even lower.

If I have made any mistakes in my calculations please let me know so that I can fix them. In these cases, please let me know if I can publish your name as the person who found the mistake?

Designing your own electricity system - part 6 (energy efficiency)

See for my initial efficiency saving list.

Here are some more notes:

1) Turn off everything at the wall when the appliances are off so that nothing runs on standby.
2) Don't leave computers on when they aren't needed.
3) Try to use laptops where possible.
4) Playstations use a lot of electricity and should not be left on standby.
5) Is your house properly insulated. Are there gaps between windows and doors where hot or cold air can escape?
6) Use CFL lights instead of incandescent (normal) lights. Incandescent lights were designed 100 years ago by Edison and Tesla. CFL globes do contain mercury, but so do fluorescent globes. And the fillings in our teeth. All need to be disposed of properly.
7) If you have an airconditioner on and you need to put on a jersey, then you are wasting resources. Turn up the airconditioner. A minimum setting of 21 degrees should be cold enough.
8) If it is a very hot day, set the airconditioner temperature to less than 10 degrees below the outside temperature. You will feel the cool air and will save a lot of electricity; eg outside air temperature is 35 degrees celsius; minimum air conditioner temperature should be 25 degrees celsius. This excludes data centres and computer rooms and other rooms which need to be kept at a constant and lower temperature than this.

Designing your own electricity system - part 5 (where to find money for an RE system)

1) Once you have purchased an RE system, inflation is locked in. The more you use the system during daylight (sunny) hours or during windy house (if you have a wind turbine), the cheaper the cost is per kwh.

2) If you take your pension money and use if for an RE system, you are making a better investment than otherwise. This is my believe. It has not been proven.

3) Your house will be more valuable if you reduce its reliance on Eskom. If there is a power failure you might not even notice!

4) Many countries have 30% rebates on these kinds of systems. South Africa should have this kind of rebate program as well. It has been determined that a fossil fueled power station costs 30% of the cost of an RE power station and therefore the government would have spent this in any case to give you power and therefore should pay this back to you.

5) South Africa implemented feed in tariffs on 31st March 2009, but they don't include electricity made from Photovoltaic panels and someone has said that they are for Independent Power Producers only. ie not for private people who wish to supply the grid!

6) I know someone who has 3 water turbines on his farm. He produces 22kwh of power per day and powers 14 fridges on his farm as well as the rest of his equipment. He is on a river which flows all year. Small water turbines are the most efficient way of making electricity and they work in a similar way to a water dynamo.

Designing your own electricity system - part 4 (how much electricity are you using?)

1) Make a summary of how many kilowatt hours (kwh) you are using per month and how much it costs you. Calculate your cost per kwh. If you have a service charge remember to include this as part of your kwh charge.

2) To find out how much electricity you are using, buy a Voltage and Current metre from me. You can plug your equipment into them and they will tell you how much watts you are using. R500 cash before despatch price each plus postage and packing.

3) This metre tells you per plug what you are using. If you'd like a metre that shows what your house is using, then I have one for about R950. It has a special plug that goes into your electricity distribution board and a wireless screen that you can have with you anywhere in the house. This allows you to see your total consumption and to look for "ghost consumption" ie consumption you don't know about. This could be a geyser that you don't know about or devices that you think aren't using electricity, but which actually are using electricity.

4) Do you know how much electricity you are currently using? If not, buy a metre and find out.

Designing your own electricity system - part 3 (measuring success)

Here is my first thinking point.

What is more expensive?

1) Buying a new car for R150,000 or spending the same amount of money to take part of your house off the grid?

2) Spending R20,000 on the annual family holiday or the same amount taking your TV room off the grid? (note that this R20,000 makes some assumptions - we will look into this when we get to design).

How should we redefine "success" in the "green age"?

Should we continue to measure success as the Rolex watch or the fancy car or should we change our measurement to "successful people live off the grid"?

Designing your own electricity system - part 2

I am heartened by the amount of correspondence that is I have received since I started this process. I have received some private emails that will be difficult to respond to individually as I do not earning anything for answering them. If anyone wishes to pay for my time to design a system for them or help them with their installation, please let me know. I am prepared to do this at R450 per hour - ex VAT. Note that this may seem like a lot, but I have put over 1200 hours of time into my learning over the past year as well as over R500,000 of investment.

I am also thankful for the amount of support I am receiving, but am in the unenviable position of helping people free of charge for the past 6 months and now I need to convert that into income. I will be starting a training centre, so if anyone wants to come on a training course, please let me know?

So feel free to make your general points and ask your general queries here. If you wish to pay me to do research for you or to help you design and install a system or to help you design and install your own system, then please feel free to email me directly.

ok, now that that is off my chest, I think we need to start with the first ideas.

See separate reply about myths and costs and how our thinking needs to change before we can go green.

Designing your own electricity system - part 1

Dear all

I have started a new business called Orbital Renewable Energy. See

I would like to know if you would like me to run a thread on how you can size your own electrical systems using solar panels, wind turbines and water turbines?

This would give you an idea of what you need to run either your house or your critical loads, eg loads you want to run when there is a power failure.

There are lots of entry points into Renewable Energy and my company can provide you with a kit from as little as R3500 right up to full sized off grid houses in the millions. Note that we are working hard to reduce the price of our entry level kit. The kit comprises 3 LED lights, a solar panel, a battery box, and a cigarette lighter charger that has been designed to charge a cell phone, but which we are busy testing with running a laptop.

Please let me know if you are interested in this?