Sparks Electrical News August 2018

ENERGY EFFICIENCY

16

CONCERN OVER DRAFT REGULATIONS ON EMBEDDED GENERATORS

ENGIE TO CONTINUE EXPANDING DECENTRALISED ENERGY OFFERING G lobal utility ENGIE is confirming its focus on off-grid energy provision in Africa, with plans to continue expanding its solar home system (SHS) and mini-grid activities. The company is launching new mini- grid projects in Zambia and starting commercial sales of SHS in Ivory Coast with its subsidiary Fenix. This forms part of ENGIE’s goal to provide 20 million people around the world with access to decarbonised, decentralised energy provision by 2020, using the lat- est digital technologies. The company is already a leader in off-grid electrification in Africa, offering clean, safe and reliable decentralised electricity from its mini-grids and SHS to more than a million people living in multiple African countries. Almost 87 percent of the world’s rural population does not have access to elec- tricity. If the current trend continues, an estimated 674 million people will remain without access by 2030. TheWorld Bank reports that themajority of these individu- als live in sub-Saharan Africa. ENGIE took a leading role at the Africa Energy Forum in June, an annual summit which brings together senior decision-makers from across Africa’s energy sector to form partnerships, identify opportunities and innovate within the industry. PowerCorner launched in 2015. The initiative is effectively providing electricity to rural areas via sustainable mini-grids. ENGIE will soon launch the construction of its first mini-grid in Zambia after the success of the model in Tanzania where it has eight mini-grids currently in operation or in final construction stage. ENGIE has demonstrated that mini-grids are an efficient solution to power products such as water pumps, grain mills or welding machines, enabling economic growth. HOW DO SOLAR DISTRIBUTION BOARDS DIFFER FROM REGULAR DBs? S olar distribution boards, sometimes called combiner boards, form an integral part of a solar supply system. The workings of solar distribu- tion boards, and the differences between them and regular distribution boards are discussed below. The basic construction of a distribution board A basic distribution board (DB) consists of a steel enclosure which contains circuit breakers connected to DIN rails or busbars. This allows for the distribu- tion of power within an electrical power system. In a normal distribution board the system is fed from a main circuit breaker which in turn feeds other smaller circuit breakers that control their respective load circuits. The basic mechanisms of photovoltaic panels Photovoltaic (PV) panels or solar panels, as they are commonly known, gener- ate electrical power when exposed to sunlight. A group of solar panels, used to produce power, is arranged in a PV array. The PV array outputs a dc voltage and current corresponding to the amount of solar radiation that reaches the PV panels. This voltage depends on the arrangement of the panels, but it is usually 12 V. This dc power is then converted to ac power with the use of a dc to ac inverter to produce 220 V ac. The inverter then feeds the power to the solar DB. It is sometimes necessary to implement more than one PV array. Fortunately, the solar DB can accept more than one inverter output. The power produced by the PV array is highly sensitive to changing weather conditions, which is why electric power systems using PV power usually rely on grid based supplies as well. The power system thus relies on a dual power supply. The two power supplies need to be synchronised in order to protect the electric circuitry from damage due to mismatched voltages. This is done by synchronising the inverter output voltage to the grid voltage. The PV array can thus not completely supply an entire business without the support of grid based power, but it greatly reduces the amount of grid based power the business uses and the kWh meter will have a much lower reading at the end of the month. For an entirely off-grid solution it is wise to invest in generators and backup battery supplies to ensure that a continuous and steady supply of power is available. Why is a solar DB upside-down? In a solar DB, the flow of power is sometimes referred to as being ‘upside- down’. This is because the feed of power is in the reverse direction to regu- lar DBs. Multiple smaller lines of power feed into a bigger line of power. The smaller lines come from the PV array inverters. Thus, in the solar DBs a col- lection of smaller circuit breakers feeds into a large main circuit breaker, which feeds a load. The direction of power flow is important as this determines the direction in which measurement devices such as current transformers (CT) and energy meters should be placed. In the solar DB, the direction should thus be reversed. Certain circuit breakers are also direction specific and should also be installed in the correct direction of current flow. Enquiries: www.engie-africa.com

I n an attempt to regulate the use of power generators, the Energy Depart- ment has proposed restrictions that could stifle the uptake of renewable en- ergy systems and inhibit job creation. This is according to Dominic Wills, the CEO of SOLA Future Energy, who is calling on the department to carefully rethink the draft regulations. Energy Minister Jeff Radebe published the proposed rules on the licensing of electricity generators in June for public comment. It comes after the National Energy Regulator of South Africa (NERSA) caused a stir with its ‘consultation paper’ on Small-Scale Embedded Generation (SSEG). “According to the draft regulations, a T raining for certification as a Renew- able Energy Professional (REP) at the Nelson Mandela University (NMU) always comes with a welcome bo- nus for candidates as they enjoy the vast variety of site visits to experience renew- able and alternative energy solutions first hand, as well as research facilities available in the friendly city. REP is an Association of Energy Engineers (AEE) program to distinguish professionals in the renewable energy industry through an internationally recognised certification program that re- quires continuous learning. NMU and the Energy Training Foundation (EnTF) have over the last three years teamed up to present the REP program under the AEE license in Port Elizabeth with Dr Sean Poole from NMU being the accredited AEE trainer for REP. Port Elizabeth is a favourite training site for REP due to the added excursions for trainees at no additional costs. This year the group travelled in the electric Joule vehicles from NMU to Van Stadens to visit the wind farms, whereafter they stopped over for a tour of the Rhino House in Crossways which

these numbers would work out to 7600 people permanently employed for 10 years on construction alone, never mind manufacturing and design. This is versus 2 600 people employed over the same period at power-stations and coal mines, which require approximately 130 people per 100 MW for coal generation. “Restricting embedded capacity to 1 MW restricts the potential to create and sustain these jobs,” says Wills. In addition, adding another layer to the registration process could slow down the rollout of solar systems. Wills says these restrictions could affect growth and job creation in the renewable energy sector and beyond.

generation facility with more than 1 MW of installed capacity would have to apply for a licence in addition to registering with NERSA,” Wills explains. “Imposing an arbitrary restriction of 1 MW is a problem for businesses that might want to utilise their ample roof space to install a larger solar power system and maximise their self-consumption. Solar energy has cost-saving benefits for small to medium businesses and these rules are encumbering growth.” Wills explains that for each Megawatt, solar employs 20 people on site for 10 weeks, of which six need to be skilled. The embedded market in South Africa has the potential to reach 20 000 MW, and on 20 people per MW over 10 years, is the epitome of a house operating completely off the grid. A visit to the algae plant, eYuilo mobility facility, solar research centre and the wind research, as well as the battery research facility added great value to experience renewable and alternative energy solutions in action. Refreshments and lunch for the excursion were sponsored by Rhino Energy. The REP theory modules were presented at NMU and the syllabus and exam covers a variety of alternatives to generate energy including hydropower, geothermal, large scale alternative utility systems, solar thermal systems, PV systems, biomass with integrated gasifier-genset, biofuels, waste-to- energy, hydrogen fuel cells, hydrogen gas vehicles, energy storage combinations with renewable generations, among a myriad of others. The REP training covers a packed program during three days delving into the causes and effects of sustainability problems, energy categories, energy intensity of economics, solutions to carbon reduction, renewable energy

Enquiries: www.solafuture.co.za

RENEWABLE ENERGY PROFESSIONAL TRAINING IN PE ENJOYS PRACTICAL SITE VISITS

projections, urban sustainability, some history on the various protocols, carbon credits and offsets, carbon calculators, carbon economics and management, energy storage applications, alternative energy strategies for buildings, renewable fuels like vegetable oils, synthetic gas, compressed gas, methanol, fuel cells, with a host of other topics and financial and business case considerations. The next REP course with all the practical visits to the wind farm, Rhino House, algae plant etc will take place in Port Elizabeth at Nelson Mandela University from 19-23 November 2018. principles of

Enquiries: go2energy@entf.co.za

Enquiries: www.switchmanproducts.co.za

Article by Jannes Smit, 3 rd year Electrical Engineering student at the University of the Witwatersrand.

SPARKS ELECTRICAL NEWS

AUGUST 2018