The 26th South African Universities Power Engineering Conference (SAUPEC) was hosted by the School of Electrical and Information Engineering of the University of the Witwatersrand in Johannesburg recently. The event provided a forum for post-graduate students and faculty from the region to present their research work in power-related fields.
In addition to three international key note speakers, 106 papers in four streams, were presented over three days at the conference rooms at the university’s Science Stadium. A number of company presentations were also made during the event.
The conference made clear that many opportunities exist for engineers in the electrical power field as the world seeks for greater levels of electrification at low cost and with minimal environmental impact.
Key note addresses
Key note speakers including Dr. Rob Stephen, the international president of Cigre and master specialist at Eskom; Jiang Liping, the deputy president of the Chinese State Grid Energy Research Institute, and Prof. Malcolm McCulloch, the head of the electrical power group at the University of Oxford.
Addressing about 165 delegates made up of primarily final-year or postgraduate students, as well as faculty, these three experts discussed the power system of the future, the integration of renewable energy in China’s power system, and a low-cost simple mini-grid system to supply power to rural communities.
The power system of the future – Dr. Rob Stephen, Cigre
Dr. Rob Stephen said that ten factors will affect designs for future power systems:
Power development and the integration of renewable energy in China – Jiang Liping, State Grid Energy Research Institute, China
Jiang Liping, describing the Chinese power system, said that seven regional grids provide power to 1,1-billion users living in 88% of the land area.
Total installed capacity is 1777 GW, with an annual energy generation of 6419 TWh. Peak load in 2016 was 939 GW.
China’s generation technology mix consists of PV (1,8%), wind (4,8%), nuclear (3,9%), thermal (70,9%, 61,8% of which is coal-fired, down from 73% in 2010, hydroelectric (18,6%).
China uses both HVDC and HVAC systems: HVDC up to 800 kV, and HVAC up to 1000 kV.
Predictions for the future
The country predicts consumption to grow to between 12 300 and 14 400 TWh in 2050.
Table 1: Planned renewable energy generation over the next 13 years.
|Hydro||350 GW||480 GW|
|Wind||250 GW||500 GW|
|Solar PV||150 GW||500 GW|
Wind and solar
The Chinese government is working on a de-carbonising programme which will see 15% decrease in fossil fuels by 2020, rising to 20% decrease in 2030.
Installed capacity in wind-powered generation grew from 45 to 145 GW between 2011 and 2016, while solar PV grew from virtually nothing, to 75 GW in the same period. In 2017, the installed capacity of wind-powered generation was 164 GW, and solar PV was 130 GW.
Despite the massive growth in renewable energy sources in China, much of it has to be curtailed as a result of a number of challenges the country faces. Wind was curtailed by 17% (49,7 TWh) and PV by 10% (7,04 TWh) in 2016.
China intends to continue with its de-carbonisation programme and to strengthen its regional interconnections. New lines will be UHV to compensate for voltage drops over very long runs across the country. The country also plans to decouple heat from power generation by encouraging its citizens to use electric boilers for central heating and hot water supply.
Powering Africa from the ground up – Prof. Malcolm McCulloch, University of Oxford
Prof. Malcolm McCulloch, in addressing the challenges of new power grids for Africa, proposed a simple solar PV-plus-battery storage mini-grid solution for rural communities. Siting the statistic that 600-million Africans have no access to electricity, he said that people want services – not electricity. They want to be able to charge and use their mobile phones, to watch TV, have light at night, be able to pump water from a well, etc. These basic services can be provided using a mini-grid concept, Prof. McCulloch said.
He suggested that, in a rural village, a structure should be built upon which PV panels are mounted. This structure becomes a virtual power station feeding the homes in the village with electricity via a simple distribution network. The solution, which he described as being a “hub and home” system, comprises an autonomous hub feeding a few homes with electricity. Each home is equipped with a battery and a DC to DC controller which powers equipment and charges the battery.
Prof. McCulloch said that since more and more appliances operate on low voltage, a 60 V distribution system supplies power to feed low-cost 300 W DC to DC converters which charge batteries and operate appliances in people’s homes. This voltage was chosen because, Prof. McCulloch said, 60 V is “touch safe” yet high enough to allow for the volt-drop caused by the resistance associated with long runs of thin wire which would be used in such an installation.
The system has been tested in Kenya, Prof. McCulloch said, with great success. The cost of a typical installation, including the PC panels, batteries and DC to DC converter, is less than US$ 100 per hub, he said.
The post SAUPEC2018: The sky’s the limit for power engineers appeared first on EE Publishers.
Source: EE plublishers