Hot ideas for saving electricity

Eskom’s planned electricity hikes of 25% a year are getting customers getting hot under the collar and frantically searching for ways to reduce their electricity bills.
More than 40% of the electricity bills of most households can be attributed to the use of geysers. A number of products on the market offer alternatives for heating water and reducing electricity bills - although the debates around them can be as hot as the water itself. These systems should not be seen as an alternative to the national electricity grid, but rather as a supplement.

Solar Water heaters

The use of solar energy not only reduces your electricity bill substantially, but this clean, renewable energy also significantly reduces the volume of greenhouse gas emissions in the atmosphere. Photo: Gabi Falanga



Anthony Schwedhelm, CEO of Totally Solar, explains at Kingswood College on Monday night how an evacuated tube solar water heater works. Photo: Gabi Falanga



Solar water heaters Increasingly popular are two types of solar heater: One is made of flat, glassy looking photovoltaic panels. The other is a series of tubes, known as evacuated tubes, with a water storage tank at the top. The best place to install a solar water heater is on your roof. However, it can be placed on the ground, provided it is at the correct angle, and still gets lots of sunlight. The evacuated tube system is hardy and requires little maintenance.

The outer layer of the tubes consists of a thick layer of borosilicate glass, ensuring minimum reflection. The vacuum created within the tubes is an excellent insulator and although the outside of the tubes will feel cold, the inside will be boiling. The heat generated inside the tubes will heat the copper inside the manifold (the section above the tubes) and this in turn will heat the water in the tank. If one of the tubes breaks, it will discolour, but this will not stop the system from functioning. The tubes are easily replaceable and cost about R80 each.

The system is designed to be low maintenance and the tubes self-clean when it rains or is windy. They are also relatively resistant to the elements. In extended periods of cold or overcast weather, your original geyser will kick in as a back-up, ensuring you always have hot water.
Michael Davies, from MD Plumbing in Grahamstown, prefers the flat photovoltaic panels to the evacuated tubes. He says although the two systems are very similar, the evacuated tube system makes the water too hot and he believes this is a safety risk, especially for families with children.
In order to control the water temperature, you would have to add a temperature valve at an additional cost. The initial cost of installing a solar water heater is relatively expensive (see table). However, Eskom offers rebates and, once the system has been paid off, you will always have hot water, for free. Doug Fincham, from Totally Solar in Port Alfred, believes that “the savings speak for themselves”.
Billy Morgan, chief technical officer for the Information Systems Department at Rhodes University, who installed an evacuated tube system in December 2009, says: “I believe that solar geysers are installed for environmental reasons and not financial reasons. I also believe that when one decides to go this route, one also has to consider modifying one's behaviour to suit the system."
"The geyser has an electrical element and the controller is set to operate the element between 4am-6am and 4pm-6pm (times given by Eskom as being low-demand times). If you have a morning bath or shower, the geyser will only get back to temperature by about 10am on a hot day and later on a cool day. Therefore, if you try and wash dishes at, say, 8am, there will not be enough hot water.
“Taking note of temperatures at various times, understanding the heating patterns of your installation and adjusting your habits to suit these times will ultimately result in your making the most effective use of it,” says Morgan.

Heat pumps

Heat pumps should be placed outdoors for maximum efficiency. They can be strategically placed to blend into their surroundings. Photo: Gabi Falanga

This is the control panel that is used to control your heat pump. It is small and can be placed anywhere in your house. Photo: Gabi Falanga

Heat pumps are an alternative to solar water heaters. The main difference between the two systems is that heat pumps do not make use of the sun. Rather, they draw energy from outside air and, along with one unit of electricity, produce three units of heat.
Our everyday geysers use three units of electricity to produce the same amount of heat. Therefore, heat pumps will always need electricity to function, which will be a problem during extended power failures. Heat pumps compress ambient air, causing a heat exchange which heats water.
The cold air that the system releases can be harnessed and used to run an air-conditioner unit in your house. The system is controlled by a small control panel inside your house and the water temperature can be set (normally at 55°C).
An attractive aspect of heat pumps is that the initial cost of installing them is significantly less than that of solar water heaters. However, in the long run, once the initial cost of either have been paid off, solar becomes more viable, as the running costs for a heat pump are higher. Although Eskom states that heat pumps will qualify for rebates, it appears that the process has not yet been put in place properly.
The use of heat pumps or solar water heaters will result in immediate savings on your electricity bill. These savings will increase once you’ve paid off the system.

How to qualify for an Eskom rebate:
Eskom offers rebates on accredited solar water heaters and heat pumps.

Heat pumps:
• Rebates apply only when you are retrofitting or replacing existing electrical element geysers. Customers who already have an electrical element geyser with a capacity of between 100 litres and 500 litres are eligible to purchase rebated heat pumps.
• Customers can buy a heat pump at rebated cost from the accredited, published registered suppliers and the supplier must perform a full installation.
• Rebates fall into two categories depending on the size of heat pump purchased: Systems with a tank size of 100 to 300 litres qualify for a R3668 rebate. Tanks of 301 to 500 litres qualify you for a rebate worth R4320.
• Must be SABS approved.
• The integrated system warranty should be at least one year, the compressor should be five years and the circulation pump should have a three-year warranty.
• No rebate will be given to customers who have already installed the heat pump prior to its formal announcement.
• The customer will have to fill the rebate forms at the point of sale and provide the following details: ID number, house address, tank size, details of the unit bought, date of installation, and the installer name.

Solar geysers:• The solar heater system and installation must be Eskom-accredited.
• The system must have a 5 year guarantee.
• The system must be SABS passed.
• You must submit a copy of your identity book, your invoice, proof of residence and a copy of your utility bill.
• Before you buy from a supplier, check whether the supplier will claim the rebate and offer you the discounted price, or whether you will pay the full price and then need to claim the rebate from Eskom yourself.
• Applying for a rebate is easy: There is one form to fill in, which is supplied to you by your installer on the day of installation. Include the above-mentioned documents. You will be provided with a self-addressed envelope which you can mail within six months. Within eight weeks the rebate is paid into your bank account directly – if the requirements are met.
The facilitating auditors will email or SMS you to inform you of receipt of your claim, or if the claim form is not completed in full. Claims are only processed once they are complete.
Sourced from: http://www.eskomidm.co.za/ and http://www.solargeysers.co.za/

Why convert to solar power?
• Conserving the environment: A solar geyser has the potential to save 3.7 tons of carbon gases per installed unit per year. This is a great way to practise environmental responsibility, considering that carbon gases are a huge contributor towards climate change.
• Reduction in electricity bill: Your geyser contributes to more than half of your electricity bill. The use of a solar geyser will reduce monthly electricity bills by between 40–50%.
• Price hikes: Families using alternative energy will be less affected by ongoing electricity price increases. • Future legislation: Soon it will be compulsory for citizens to make use of alternative energy sources. Added to this, the proposed introduction of energy usage restrictions and efficiency guidelines will mean that you save on fines or are less susceptible to fines.
•Sunny South Africa: South Africa has very high degrees of solar radiation and harnessing this energy is free.
 •Rebates: Install an Eskom-accredited solar water geyser and you will receive a rebate.
Sourced from: www.solargeysers.co.za

Published in Grocott's Mail on 11 March 2011. All photos by Gabi Falanga.