via Zesa exports excess power at night | The Herald 7 July 2014 by Wenceslaus Murape
ZIMBABWE is exporting electricity generated during off-peak periods, particularly after 9pm to neighbouring countries at a time when it ironically imports power to offset deficit during the day.
Although Zimbabwe Electricity Transmission and Distribution Company (ZETDC) argues that there will be no demand at night, the firm still fails to supply enough power locally since some areas including high-density suburbs and the farming communities at times experience power outages.
Zimbabwe has a power deficit of about 800MW during peak periods, but the power company produces surplus electricity during the night, which is sometimes sold to the Democratic Republic of Congo and Namibia.
Demand often outstrips supply during the day, while excess power is generated during the night as industrial and domestic demand is depressed.
The majority of Zimbabwe’s industries are no longer operating 24 hours, resulting in excess power being sold at night.
Energy and Power Development permanent secretary Dr Partson Mbiriri recently said the country was generating some revenue from exporting the power at night.
He, however, refused to disclose the amount being realised.
He appealed to Government departments, industrial and domestic users of electricity to shut down machines, lights and other electrical gadgets, saying Government would push strongly the “Switch off Switches” campaign.
“If we were to switch off switches particularly at night, even as we speak, we export power at night to neighbouring countries and of course receive some revenue for it. We export power at night. If we switch off at night we will be able to export more,” he said.
The country is currently unable to generate enough power to meet demand, which peaks at around 2 200MW against generation capacity of around 1 400MW.
Mr Mbiriri said the country would be able to export more power at night if people switched off electrical gadgets and lights at night.
If that practice was applied during the day, he said load-shedding would be minimised.
He said circulars had been written to all ministries to enforce the SOS principle, saying most lights at Government and various other buildings were being left on during the night.
Dr Mbiriri said a raft of measures were being put in place to save power including distribution of compact fluorescent bulk lights commonly known as energy saving bulbs, which he said instead of being exchanged for free, Zesa should charge a fee.
ZETDC managing director Engineer Julian Chinembiri, justified the exports saying they were done during off peak when they would be left with excess power.
“During off peak hours when households would have switched off most of their electrical appliances, we remain with excess power. It is more prudent for us to export than to switch off generators during the time when we have excess electricity. There are other countries like DRC that experience critical power shortage even during off peak hours,” Eng Chinembiri said.
He said switching off generators was problematic in that it would take time for coal to heat up to optimum levels.
Zimbabwe is facing serious energy deficit and Government and Zesa Holdings are in the process of expanding Kariba South so that it produces 300 MW more and Hwange Thermal Power Station so that it produces 600 MW.
This will see Zimbabwe producing about 2500 MW against a peak demand of 2200 MW.
COMMENTS
The system makes sense ,however the ZESA authorities are not being truthful with the public.At what charge are we selling this excess electricity per kilowatt? I am sure that its not 11 US cents per kilowatt which is the cost we pay when other charges are factored in.Why not sell this excess energy to us at a cheaper off peak rate like TelOne and Mobile phone providers if they care about their local customers.
This country has no real excess energy, if we really take all the facts into account eg most street lights are not working maybe its done purposely in agreement with local governments to create false excess energy for the authorities to sell it to the outsiders when we really need it here.
Surely, our national demand does not drop by more than 60% of our peak period need to allow for the switching off of the generating equipment, if we do not export the so-called excess power.Sometimes its better to allow equipment to operate at 60% of its total output to allow things to cool down not to over drive it all the time,if it is to last for more years.Most generating equipment work well if they do not exceed their 85-90% of its total output.When you exceed that,most equipment start breaking down because the 10-15% tolerance is exceeded.
Addition-The secretary of energy should look at the safety of these energy savers lights.These should be used where there are lamp shades because they do explode due to some electronic components failures within them eg high voltage condensers used to trigger the small florescent tubes.This could cause fire if exposed,thus why its safer to have them installed where there are lamp shades like glass covers.This happened in my workshop,so I decided to break them done and analyse their circuitry.
Zimbabwe is selling to the highest bidder who pays – a lot of Zimbabweans do not pay their electricity accounts !
1. Zimbabwe’s electricity consumption is predominantly domestic hence the low demand at night.
2. Switching generators off and on increases wear and tear which increases the cost of generation. Its better to export to earn more revenue. There is also the risk of generators failing to start at the beginning of the peak period which results in increased load shedding. Its better to switch them on and off when its absolutely neccessary.
3.The operation of industries during the night to use the excess power is a decision for industrialists to make. This will depend on a cost benefit analysis.