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IRRIG
ATION
BESPROEI
ING
MAGAZINE TYDSKRIFTHE MAGAZINE FOR THE SOUTH AFRICAN IRRIGATION INDUSTRY • DIE TYDSKRIF VIR DIE SUID-AFRIKAANSE BESPROEIINGSBEDRYF
Volume 12 • Issue 2 • SABI | December 2019/January 2020
ISSN 2071-1883
LVG PlantsLarge-scale sustainability and excellence
SABI School Awards winners
Irrigation as a career
Bekmar Irrigation’s new store
Hydro and Solar energy
Rooibos benefits for San and Khoi
Ornamental floral feature
LVG Plants – big, beautiful and sustainable 5
Energy
Hydro Case Study, on a farm in Cookhouse 9
Motor efficiencies 11
Bigtime solar in Gordon’s Bay 13
Circular economy, anaerobic digestors 32
Biogas digestors 34
Hoedspruit air force base’s solar 42
Business
Drymac innovation 15
Energy Partners merges with Venus Water Treatment 16
Irish AgriTech showcased in South Africa 26
Advertorial – Netafim 18
Events
Bekmar Irrigation opens new branch 20
SABI Agricultural High Schools
Introductory Irrigation Course Top Learners 29
Big 7 Africa big trade show next year 40
Solar pump event in Western Cape fascinates 46
SABI 21st Western Cape Golf Day celebrated 47
Training
Explore a Career In Irrigation 43
Travel
Mozambique travel tips from Kingsley Holgate 14
Regulars
From the editor 2
President’s message 3
SABI Approved Designers 22
Company members 23-25
Climate 34
Dam levels 35
Subscribe now 47
Advertisers’ contents 48
Contacts and Diary 48
contents
Pg5
Pg9
Pg16
Pg26
Pg26
Pg32
CONTENTS
Carol Posthumus
Editor
Riana Lombard
Advertising Sales
René van der Merwe
Subscriptions and circulation
Annemarie van der Westhuizen
Training Officer
Liam Hamer-Nel
[email protected] | alliancephoto.com
Graphic Design
Contributors:
Ian de Jager, Chris Braybrooke,
Raymond Campling.
Printing
Colourtone Aries, Cape Town, RSA
Tel: +27 21 981 8873
Distribution & Media Support www.mediasupport.co.za
Cover Photograph
LVG Plants Greenhouse
Photo by Charlaine van Geest
Published by SABI
(South African Irrigation Institute /
Suid Afrikaanse Besproeiingsinstituut)
T: +27 21 850 8220 | E: [email protected]
Web: www.sabi.co.za
Address: PO Box 834, Strand, 7139,
Western Cape, South Africa
SABI magazine / tydskrif
is a bi-monthly publication.
© Copyright: South African Irrigation Institute/Suid-Afrikaanse Besproeiingsinstituut (SABI). Requests to reproduce material herein should be addressed to [email protected].
All rights reserved. Disclaimer: The views expressed herein by authors or advertisers are not necessarily subscribed to or endorsed by SABI or the editor.
SABI | DECEMBER 2019/JANUARY 2020 1
SABI | DECEMBER 2019/JANUARY 2020 5
Floral focus
T he largest growers of ornamental plants in South Africa LVG Plants, based in Krugersdorp, west of Johannesburg, have a proud 34-year tradition of
growing excellence and innovation.
Notably, a strong commitment to sustainability is a much-admired hallmark of LVG Plants. LVG Plants, a family business, have put much energy and time into reducing their carbon footprint, investing R25 million in solar energy for the high-tech and precision-controlled greenhouses. Most of the farm’s 70 million litres of water for irrigation derives from rainwater and recycled water.
LVG Plants is attracting acclaim internationally in the very best of company. Indeed, LVG Plants is one of ten nominees for the prestigious accolade of 2020 International Grower of the Year. This is a world first for South Africa, as LVG Plants is the first South African horticultural company to be nominated for this award.
Says MD of LVG Plants Geert van Geest: “It is an honour to be selected as a finalist, along-side strong contenders from around the world.”
He says that for them their selection also shows that even in the face of nega-tivity regarding South Africa’s economy, entrepreneurs and companies here are able shine in our endeavours with the best in the world.
Rainwater harvesting
On the LVG Plants’ farm, dams are highly visible, and show just how a large-scale operation can capture and utilise rainwater harvesting to excellent effect. Indeed, LVG Plants’ rainwater catchment dams – storing 70 million litres of water
– supply the irrigation
requirements of the plants. Drip irrigation is mainly utilised here. Irrigation, heating and cooling is automated with sophisticated computerisation and scheduling ensuring optimum use of resources.
A family business, established by Lourens van Geest more than three decades ago, LVG Plants’ greenhouses and operations are described variously as breath-taking, vast, incredible, extremely modern and sustainable by people in the irrigation and horti-culture sectors who have visited the 11ha farm.
There is something beautiful on all farms when bountiful crops are growing. But the sheer beauty of rows of the beautiful blooms en-masse in LVG Plants’ green-houses is simply spectacular. A visual feast. To cut down on carbon emissions, battery operated golf carts and bicycles, rather than cars and motor bikes, are used to get around the expansive 11ha of farming enterprise, employing some 400 people from the local community, mostly women.
Big, beautiful and sustainable LVG PlantsLine up for top international growers’ contest
By Carol Posthumus
“It is our generation’s responsibility of building a
truly sustainable business, and to take constant action to ensure that we pass on a sustainable,
thriving business to our children and future generations.”
Geert van Geest
Photos by Charlaine van Geest
Renewable energy
SABI | DECEMBER 2019/JANUARY 2020 9SABI | DECEMBER 2019/JANUARY 2020 9
In the Cookhouse area (Eastern Cape) the electrical distribution is managed by the local municipality – Blue Crane Municipality. This means that the energy price is
about double the Eskom prices. The average price is nearly R 1.90 / kWh. This makes projects aimed at generating own energy very viable.
One of these farmers is Michael Vermaak from Klipfontein. His farm is situated just below the Elands Drift dam / weir, along the Fish River. Firstly, notably, the river runs through his farm and, secondly, the canal which provides water to the lower-stream farmers also runs through his farm.
In 2008 Michael decided to explore the idea to install an Ossberger Hydro Electrical plant using the flow of the river. He was able to install 280 kW off-grid using the reserve flow of the river with a head of 12 metres. Michael built his own private electrical network to supply power to all his pump stations and workshop.
Off-grid means he does not connect to the national grid but only supplies energy to his private
grid. In this case, the turbine must always ensure that the alternating current stays within close range of 50 Hz and follows the energy demand of the farm. Michael does not always need the full capacity. However, there is ample water to continuously generate at full capacity. In this case, Michael wanted to store the excess energy in a dam at high elevation, in order to be able to use the energy when needed.
Centre pivot irrigation
Therefore, Michael also built a dam at the highest elevation avail-able on his farm from which he could irrigate by using the static pressure by gravity feed to irrigate his crops, which are under centre pivot irrigation. By constructing a pump station with a bank of vari-
able speed driven (VSD) pumps he could utilise all excess energy (in the evening) to fill the dam with his permitted water from the river. This means that his Hydro Plant could always run at peak performance generating energy to the farm as well as to the pump station pumping water to the dam. This pump station is controlled to keep the frequency at 50 Hz. If the frequency rise above 50 Hz the pumps start and if the frequency drops below 50 Hz the pumps reduce speed one after another until all stopped.
Last year Michael decided to expand his farming activities by adding milk production as well as a cattle feed plant. These activities required more energy. By negoti-ating with the irrigation board, he could utilise the canal to deliver water to lower stream located farmers on the river.
With the available head of 28m and a flow of 3m³/s we installed another Ossberger Hydro Electrical plant, feeding
a maximum of 520 kW into his private grid to add electrical energy to the farm activities. This plant was designed to either produce energy off grid as a stand-alone plant or it could follow the original plant as a connected to grid plant to add energy to the existing production. By doing this he created his own mini grid. During 2019, Michael bought the neighbouring farm and is expanding again with a third Ossberger hydro plant. This plant is now in design phase and will also follow the original plant.
With an off-grid Hydro you need to provide for peak energy demand i.e. starting of pumps. This means that the Hydro must be able to generate starting current which makes it larger than normal operation needed. By connecting to the Eskom grid, you can use the grid as starting current and thus reduce installed generation capacity. Read on to learn a bit more about options that make use of net metering and banking – especially in Eskom fed areas.
Hydro power project on the farm Klipfontein Near Cookhouse, Eastern Cape
by Ian de Jager
SABI | DECEMBER 2019/JANUARY 2020
With electric motors consuming almost 70% of industry’s energy, companies are always looking for better motor
efficiencies. For many years, motor efficiency has been well defined; however, when driven by a variable speed drive (VSD), the VSD efficiency and the total efficiency of the VSD and the motor has not been well understood. For many years, motor efficiency has been well defined. Choosing the right product combination can also be more difficult as manufacturers’ data is not always easily comparable. This is where the international IEC61800-9 standard comes to the rescue, according to global motor and VSD manufacturer WEG.
The IEC61800-9 standard – based heavily on the previous EN 50598 standard – gives manufacturers a clear framework for grading a complete motor system. End-users can compare the overall efficiency of a manu-facturer’s products, irrespective of design and component selection.
The IEC61800-9 standard uses the Extended Product (EP) approach. This considers the efficiency of the Motor System, which is comprised of the Motor, the Basic Drive Module (BDM), the Complete Drive Module (CDM). Together, these make up the Power Drives System (PDS), which also includes any switch-gear and controls.
Terminology
This terminology sounds confusing but is just a technical way to say: Switchgear + VSD + Motor.
The efficiency levels are defined by considering eight different operating points, covering low to high speed and torque. The user can easily compare his application load and speed requirements to the motor system defined speed and torque points.
The EP approach employs a semi-analytical model to calculate the efficiency of each of the compo-nents at the operating points of the driven equipment. The calcu-lations are also based on tested and verified values. This results in the most efficient component selection for the application.
Using this standard, the user may be assured that:
� A motor complies with the defined motor efficiency levels of IE1, IE2, IE3, IE4 or IE5;
� A VSD complies with VSD efficiency IE0, IE1 or IE2; and
� The manufacturer’s motor and VSD used in combination will meet or exceed a system energy standard of IES0, IES1 or IES2.
Using this EP approach, the European Commission expects the increasing use of more effi-cient systems to help achieve its targets for carbon dioxide (CO2) reduction. In line with these efforts, WEG VSDs and IE2 motors in combination achieve IES2. And significantly, WEG’s VSDs and IE3 efficient motors exceed the highest system levels of efficiency. Additionally, WEG has product lines that exceed even IE4 and IE5 classifications.
Reducing CO2 emissions
Recognizing that global popu-lation growth and economic development is driving up energy demand around the world, the European Union has set stringent targets to reduce CO2 emis-sions. These aim to cut emissions by 40% by the year 2030. This means creating more renew-able energy sources, and also increasing the energy efficiency of industrial systems. Studies suggest that almost half of global energy consumption comes from industry – followed by commercial and residential use.
Energy
Motor system efficiency high on global agenda
SABI | DECEMBER 2019/JANUARY 2020 11
A WEG motor and drive combination.
Extended product illustration showing the motor system, power drives system and complete drive module.
