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Investors show huge interest in SA’s wind and solar programme

PRIVATE sector investment in renewable energy generation will reach R193bn following the announcement on Sunday of another 13 preferred bidders for wind and solar photovoltaic (PV) projects by Energy Minister Tina Joemat-Pettersson.

Renewable energy is regarded as the quickest way to add capacity to the grid, but, as it is weather-dependent, it cannot provide base-load capacity. SA’s renewable energy programme is the fastest growing in the world and has seen large investment flow into the country, while prices of energy production have fallen.

In order to accelerate the programme, Ms Joemat-Pettersson said in April that in addition to the 13 bids she selected in the fourth window, a further 13 projects that were good to go would be added at a later date. The addition means SA has commissioned 92 renewable projects with the potential to add 6,327MW of capacity to the grid.

As part of their bids, independent power producers are obliged to contribute to socioeconomic development in the relevant area, with R19.1bn committed in projects in the next 20 years.

Several large multinational and foreign national power utilities in partnership with local entities have shown a keen appetite for the programme, which has four rounds, with a fifth anticipated in the second quarter of this year. As technology improves and risk diminishes, prices of renewable energy in SA’s projects have been plummeting.

The Department of Energy’s deputy director-general Ompi Aphane said “there had been an overwhelming interest from local and foreign investors who offered excellent prices, which demonstrates confidence in public-private partnerships (PPPs) in the South African energy sector”.

The process works through a competitive bid system in which bidders strike a power purchase deal with the department on behalf of Eskom, which undertakes to buy the power they produce.

Since the first window bid in 2011, the solar photovoltaic energy price has dropped 76% and has fallen 55% for wind. Wind tariffs are now competitive with the predicted cost of producing coal-fired energy at Medupi and Kusile.

Mr Aphane said the country had the potential to become “a global player for alternative solutions that will ultimately unlock Africa’s potential”.

In her budget vote speech last month Ms Joemat-Pettersson also presented plans to expand the production of energy by other fuels. Most significant was the release of a request for data for gas-fired generation. She said the request would “guide the design of a gas-to-power procurement programme” with a combined 3,126MW allocation.

The Gas Utilisation Master Plan, which is a critical building block of establishing a natural gas sector, was “in the final stage of internal approval” and would be released for public comment within the next three months, she said.

The first request for coal-fired generation by independent power producers, which was announced last December and was due to close this month, would be extended for another two months “in order to ensure a successful procurement process with firm results”.

The minister said the procurement of 9,600MW of nuclear energy would begin next month. The process to choose “a strategic partner” would be complete by the end of the financial year.

Article Source: Business Day Live


New solar PV backup solution launched

Powermode, a Johannesburg-based power-provisioning specialist has launched a new addition to the Soltra range of solar photovoltaic (PV) energy generating solutions.

The high capacity Soltra GTB 10 000, which complements the successful Soltra GTB 3000 in the Powermode lineup, is a 10kVA capacity, utility grid-connected, hybrid solar PV power system targeted at small-to-medium-size enterprise and domestic markets.

“The Soltra GTB 10 000 is designed to help businesses and households cope with load-shedding and power outages, functioning as a back-up rather than a complementary power source in these eventualities. This sets it apart from conventional solar PV power systems,” says Jack Ward, Powermode MD.

He says the GTB 10 000 is aimed at larger-sized installations, where it is capable of dealing with bigger loads with a greater degree of backup battery autonomy. “It is also able to obviate the need for costly diesel generators in noise-conscious environments,” notes Ward, who adds that it’s ideal for rooftop installations.

The new unit features an integrated charge controller and inverter and can be operated in three modes: linked to the electricity grid (grid-tied); as grid-tied unit with battery backup (in a hybrid configuration); or as a stand-alone hybrid unit.

The GTB 10 000’s built-in electronic monitoring system facilitates the back-up, by automatically drawing current from storage batteries when the mains power fail. “Switchover time is a rapid 15 milliseconds,” says Ward, adding that this is designed to protect sensitive computer and other delicate equipment from power ‘brownouts’ and ‘spikes’ common to South Africa’s unpredictable electricity supply.

The computerised system is also able to automatically prioritise its power delivery channels; to back-up batteries to facilitate recharging during daytime, for example, or to appliances during user-definable peak periods. At other times the system will automatically juggle power sources between, solar, batteries and the grid to meet changing demands based on individual consumption dynamics.

“In addition, the unit is also able to feed power back into the utility grid – legislation permitting – slowing or even reversing consumption meters to significantly minimise costs to the consumer.”

Ward says the Soltra GTB 10 000 and its companion, the popular GTB 3000, represent a new-generation of cost-effective modular solar solutions requiring a comparatively low initial investment.

“The units can be expanded in terms of capacity to meet future demands. They can also be configured as three-phase solutions to meet commercial and industrial users’ requirements,” he explains.

With the escalating cost of utility power and the imminent arrival of ‘smart metering’ systems that will allow municipal authorities to bill for electricity consumption at much higher rates during peak periods in a process known as time-of-day-billing, Ward maintains that solar solutions will soon be on par with conventional power from the perspective of amortised installation and maintenance costs.

“This is particularly relevant as prices are expected to rise exponentially for power consumed during peak periods in the near future,” he adds.

Article source: Cape Business News 

Sizing your load shedding system correctly

The sudden uproar of solar and battery “experts” driven by the need to mitigate the risk and inconvenience of load shedding represents a risk to the unwitting consumer, with all the technical jargon flying over the heads of most, including the seller or installer. It’s not as simple as plugging everything together and incumbents will know there is a lot of consideration that needs to go into sizing a load shedding and solar solution for its application.

In lieu of what I have seen happening in the market with grossly undersized systems being proposed to the markets that will not deliver on what is promised purely based on the general lack of knowledge on the subject, I will give you some advice from my own experience in system sizing and important considerations. I will cover, battery sizing and operation, solar considerations and sizing, inverter selection and ideal operation.

A few basic principles that you need to know:

·         (Power = Voltage x Amperage) This equation is absolutely critical to understanding your need and what your system can provide you with. Power expressed in Watts, Voltage in Volts and Amperage in Amps.

·         (AC vs DC) Incidentally not the world famous band, but rather the type of current flow that we use in everyday applications. Alternative Current (AC) is what we receive from Eskom, meaning the current changes direction 50 times each second at 50Hz. When you plug an appliance into the wall you will be using 230 Volts of AC power. Direct Current (DC) as the name suggests, only flows in one direction and is what you get when using a battery or the type of current that your solar power will generate.

·         The inverter is the device that you use to convert DC current from your batteries and solar to the AC current that you require for your appliances. Bi-directional inverters conventionally have chargers or rectifiers built-in which allows you to charge your batteries and in turn converts AC from your Eskom supply to DC for charging those batteries.

·         Grid-tie inverters and MPPT’s are used in conjunction with solar PV panels, where the grid-tie inverter converts the DC current generated by the PV panels directly into AC current in line with the standard required by the Eskom power network, allowing you to provide excess power to the utility grid. The Grid-tie system however does not provide you with load shedding backup as it is required by law to shut down when there is a power failure for line operator safety reasons. It is also heavily regulated and consumers need to become acquainted with their local regulations. The MPPT or Maximum Power Point Tracker is a charge controller that will optimise the solar yield and charge your battery bank. It will not convert DC to AC and is functional only to use solar with battery backup. This system will provide you with both solar power and load shedding backup.


The proverbial Achillies heel of any system, the sizing of your battery backup is literally the make or break for a good return on investment. It all starts at the manufacturer that will test a battery and give the battery specification at 25°C operating temperature and at a given hourly rate or C-Rate. This is absolutely critical to sizing your battery. The most well know battery size in the South African market is the 105 Amp hour 12 volt deep cycle battery and this battery is mostly given at a 20-hour rate or C-20. This means this battery will deliver a TOTAL of 105 Amp hours over 20 hours or only 5.25 Amps per hour for 20 hours when you divide the 105 by the 20 hours it is given at. So in essence when you use the equation above you will get Power = 12 Volt x 5.25 Amps = 63 Watts or 0.063 Kilowatt per hour for 20 hours.

The problem is that we do not have 20-hour load shedding periods, but only 2 – 4 hours per load shedding, which means we will not be using the battery at its 20 hour rate, but rather its 2 – 4 hour rate. This rate is hardly given by the manufacturer, seller or installer, but is critical to correct sizing. The same 105Ah 12V battery will have a reduced capacity at higher discharge rates and depending on manufacturer, may be in the vicinity of only 75Ah at its 3-hour rate. This in turn means the total of 75Ah divided by its hourly rate of 3 hours gives us a discharge current of 25 Amps and this multiplied by the voltage of 12 Volts will give us 300 Watts per hour for the duration of 3 hours.

You can see that four of these batteries will then give you 1200 Watts or 1.2 Kilowatts per hour for 3 hours and eight of them will give you 2.4 Kilowatts per hour for 4 hours and so forth. I have seen plenty of sellers and installers offering consumers 4x105Ah batteries using the 20-hour rate and selling these solutions as a 3 Kilowatt load shedding backup which is far from the truth. If you draw 3 Kilowatts from 4 of these batteries you will simply kill them in a matter of a couple of months and they will not last your entire load shedding period.

This is not even all the considerations as you need to look at your operating temperature, charge and discharge rates and especially the Depth of Discharge (DOD) which in turn will all influence your battery life.

In the next part I will cover the solar aspect, but be aware of what you buy, there are plenty “fly-by-nights” that will not size your system correctly, give you a cheap solution and never be able to carry the warranty.

Article source: Fin24


Solar Powered Classrooms In Focus

Cape Town – The South African technology company Ambit’s solar powered classroom is poised to provide “off-grid” electricity and connectivity to rural classrooms and help teachers overcome the pitfalls of load shedding.

It not only harnesses the continent’s most abundant resource, the sun, but can also provide power for the rest of the school.

The so-called education delivered intelligently (EDI) classroom is a standard, modular container-sized, fully operational classroom and ICT hub in one. It is already used with great success at the TlamaTlama Primary School in Tembisa on the East Rand.

Visitors to the upcoming SABC Education African EduWeek in Johannesburg from July 1 to 2 will be able to see an example of the EDI solar powered classroom on the Ambit Technology stand on the expo floor.

Conquering the digital divide

“The EDI solar powered classrooms are designed to be used in rural, remote or even urban areas,” said Louise van Loggerenberg, director of Ambit.

“Standard systems seamlessly integrate with solar PV, wind turbines and a range of other renewable sources. The classroom is fully insulated and can be supplied with electric lighting, heating or cooling and internet connectivity.”

The project was launched in July 2013 and 32 solar classroom solutions will be delivered and implemented by the third quarter of 2015.

Article source: Fin24


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