Small scale solar PV: Current status and future prospects



Privately owned small-scale photovoltaic (PV) plants meant primarily for own generation, are becoming more and more popular and being installed at an increasing rate in this country. The industry suffers both from a lack of quality control and a lack of applicable standards and legislation. The problems are being addressed by both the industry and the administration.

The statistics, projections and accompanying graphs used in this article were produced by PQRS, and are a best estimation of the current situation based on information obtained from the industry. The number of small-scale PV systems installed in South Africa at July 2017 is estimated at 138 400. The capacity installed at the end of 2016 is estimated at 144 MW. Fig. 1 shows the distribution of installed systems per sector and based on system size. Table 1 shows the distribution of systems based on size [1].

Table 1: Estimated number of small PV installation at July 2017 [1].
Range No Size of installation No. of installations
0 > 5 MWp 27
1 1 MWp – 5 MWp 27
2 100 kWp – 999 kWp 289
3 50 kWp – 99 kWp 316
a 11 kWp – 49 kWP 330
4 1 kWp – 10 kWp 8741
5 < 1 kWp 128 622

The range of solar systems covers residential and commercial/industrial usage, which is increasing faster than residential usage. C&I users include airports, distribution centres, factories, filling stations, business parks, hospitals, shopping centres, mines and offices. Shopping centres account for 34 MWp, but the ultimate capacity is estimated at 700 MWp nationwide [1].

An often overlooked sector of the PV market is the agricultural sector, comprising both rooftop and small ground-based installations as well as freestanding solar water pumping and irrigation systems. This range of applications also now extends to processing plants, bottling plants, cold storage and dairies. The size of systems used for agriculture extends into range 1, and includes cold storage for fruit farms as well as wineries.

Fig. 1: Small PV system distribution [1].

Growth of small PV systems

The commerce and industry sector is enjoying great growth. The reasons for installing PV on business premises range from energy and cost savings and energy security to the need to be seen-to-be-green and carbon footprint reduction. The agriculture sector is obviously driven by the non-availability of reliable grid power in remote areas, or the cost of bringing power to a site, even on a farm which is not remote. Fig. 2 shows the growth of PV in the different sectors in Gauteng up until 2016. The total growth for the whole country is shown in Fig. 3. The estimated capacity for residential solar PV, based on household income is shown in Fig. 5.

Fig. 2: Growth of small PV systems in Gauteng [1].

Fig. 3: Historical growth of installed capacity [1].

Fig. 4: Total market growth based on current trends [1].

Fig. 5: Estimated capacity for residential solar PV [1].

Regulations and standards

Electricity generation is covered by the electricity generation regulations. The regulations clearly never anticipated grid-connected own generation systems which could feed surplus generated electricity to the grid. The regulations define generation for own use and not considered as a generator and therefore do not require licensing, provided that energy is not delivered to the grid. If the regulation is followed to the letter then any grid-connected system that delivers energy to the grid at any time is considered as a generator, even if it consumes more energy from the grid than it delivers.

The minister of energy has the duty of making a determination of new electricity generating capacity. No such determination has been made for grid-connected rooftop solar that is capable of delivering energy to the grid.

One interpretation is that provided consumption exceeds generation over a period of time then the consumer is not a generator and does not need a license. The current arrangement is that a small-scale grid-connected generation system that consumes more electricity than it delivers does not require a license but needs to be registered. The National Energy Regulator of South Africa (Nersa) is the licensing authority but has allocated the registration function to the distributor due to the volume of installations involved.

Nersa discussion document

In 2015 Nersa issued a discussion document (DD) on ssmall-scale embedded generation regulatory rules [4]. The DD contained several proposals which are outlined in the following section.

The Electricity Regulation Act (Act No. 4 of 2006) states that no person may, without a licence issued by Nersa in accordance with the act:

  • Operate any generation, transmission or distribution facility
  • Import or export any electricity
  • Be involved in trading of electricity

Activities listed in schedule 2 of the act are excluded, namely:

  • Any generation plant constructed and operated for demonstration purposes only and not connected to an interconnected power supply
  • Any generation plant constructed and operated for own use
  • Non-grid connected supply of electricity except for commercial use

The prime purpose of small-scale renewable energy generators (SSREGs) is to generate electricity for own use, but if connected to the grid, supply of electricity can occur unless prevented by the system, a situation not contemplated in the act or the regulations. The opinion stated in the DD is that SSREGs will be connected to the grid and will be operated for commercial purposes since they will “sell” to the municipalities or Eskom, and they would, therefore, need to be licensed or registered as per the act. This is considered to be a fairly liberal interpretation to circumvent the fact that neither the act nor the associated regulations anticipated or made provision for this segment of the market.

In addition, the regulations state that only the minister of energy can issue a determination of new generation capacity, and no such determination regarding privately owned SSREGs has been forthcoming. We have then the situation that SSREGs are considered to be generators which need to be licensed but are not considered to be “new generation capacity”.

The DD, therefore, sought to regulate this situation, which is not covered by the act but i, in fact, happening by agreement between customers and distributers. According to the DD, Nersa has agreed to license grid connected SSREGs which supply electricity to the grid subject to certain conditions. The DD acknowledges that the process of applying for a licence and processing is complex, time consuming and costly, and would place a burden on small installations. In addition, the high volumes of solar rooftop installations will put constraints on the regulator, and therefore registration of these plants by distributors, in accordance with the requirements of Nersa’s “Standard conditions for embedded generation within municipal boundaries” document, is considered to be a viable alternative to licensing.

In terms of this registration procedure the distributors must register and maintain a database of all SSREGs within their area. The conditions for registration are detailed in the DD. According to a recent press announcement The Department of Energy (DoE) is to publish a notice under the Electricity Regulation Act that will exempt small electricity generators from having to apply to Nersa for a generating licence. The notice, which will relate to small electricity generation of less than 1 MW, is expected to be published before the end of September 2017.

In a report to Parliament’s energy portfolio committee, the DoE stated that there was an increasing number of applications to generate electricity. With the changing electricity landscape, the DoE, Nersa, Eskom and municipalities are faced with the challenge of managing and regulating the increasing number of small-scale embedded generators. The challenges are the result of the lack of a regulatory framework, and technical and installation specifications.

Five categories of generation facilities as well a certain category of electricity resellers will be exempt from the requirement to hold a generation licence although they will have to be registered.

Municipal requirements

An interim arrangement has allowed municipalities to register SSEG systems under 1 MW, under their own requirements and standards. According to the SALGA 2016 report in Table 1 some 26 municipalities are actively involved in the registration process. Many municipalities have produced their own set of technical requirements. For instance the Ethekwini municipal standards [2].

Nett metering

Municipalities only accept reverse flow when done through a properly approved bi-directional meter. The older mechanical type meters could be spun in reverse, however, they are not calibrated for reverse flow which results in inaccurate readings and is in any event, not an approved method. The accounting balance differs amongst municipalities. Some examples are:

  • Feed-in not allowed. The rooftop PV system must be sized to ensure that generation never exceeds demand. To achieve this the customer needs to do a load profile analysis.
  • Feed-in allowed, with billing based on net consumption there is no difference between the amount paid for electricity exported and that paid for electricity consumed. Connection charges may differ from a standard consumer.
  • Feed-in allowed, with separate billing for electricity exported and electricity consumed. In most cases the rate paid for electricity is significantly lower than that charged for electricity consumed, and in future TOU rates may also apply, meaning that electricity supplied during periods of low demand will be priced considerably lower than electricity consumed during periods of high demand. This makes a strong case for behind the meter storage.

Grid code

NRS 097 covers the performance requirements of SSEGs connected to the distribution grid, and all SSEG plant must comply with these regulations.

SABS national standards

In addition to the NRS 097 requirements, the rooftop PV system has to comply with electrical installation standards which cover the compliance of all components used with safety standards, and compliance of the installation as a whole. Rooftop solar and any other behind the meter solar or renewable energy system is considered as an electrical installation and must comply with the relevant South African national standard. In addition, in terms of the electrical installations regulations of the DoL, the installation must be performed by, or under control of a “registered person” (RP), and a certificate of compliance (CoC) for the installation must be issued by an RP.

The relevant national standard is SANS10142-1: Low voltage electrical installations, which at present does not cover renewable energy installations, specifically rooftop PV, which is the most common renewable energy source associated with premises covered by SANS10142-1.

According to an SABS contact, an addition to SANS10142-1, covering rooftop PV and other systems is under preparation and is expected to be published later this year. The addition, which started life as SANS0142-3, has been under preparation for some time by a working group associated with the 10142-1 working group, has now been given out to consultants, on a contract facilitated by the Council for Scientific and Industrial Research (CSIR). The number and name has also changed to SANS10142-1-2: Small embedded renewable energy systems. The numbering has been changed to comply with the scope of 10142-1 i.e. low voltage installations. Systems where the DC voltage exceeds 1500 VDC are not covered by this standard.

Industry and utility initiatives

A certificate of compliance is required before an installation can be connected to the distribution network. In the absence of a standard, most municipal distributors now require certification by a registered engineer (PrEng) or registered technologist (PrTech) before they will allow connection of the system to the grid or to the existing installation. There is no requirement that either of these professionals have the required knowledge of PV systems.

Once SANS10142-1-2 has been published the usual regulations will apply, ie a CoC will have to be issued by an RP. This poses question on the qualifications and knowledge of the RP. Will an RP be required to be trained on parts 1 – 2 to issue a CoC, and will the CoC be modified to cater for the specific requirements of PV and other systems? At the moment any RP could issue such a certificate.

In the absence of SANS 10142-1-2 a number of interim guidelines have been compiled by various institutions and are recommended for use:

  • Solar PV Installation Guidelines, issued by SAPVIA/Greencard and available at www.pvgreencard.co.za
  • Proposed Interim Guideline for the wiring of LV grid-embedded PV installations not exceeding 1000 kVA in South Africa, issued by PQRS and available at www.pqrs.co.za

There is concern that a large number of rooftop PV installations are being installed without the necessary certification, thus placing the customer and the owner of the property at risk. In the absence of a reference standard, several industry initiatives have emerged in an attempt to regulate the quality and safety of installations, and to provide assurance to customers.

The PV Green Card initiative

Driven by SAPVIA, The South African PV Green Card is a safety certification, a quality assurance standard, and training programme for solar PV installers. Quality and safety are assured via the specialised education and training provided to solar PV installers prior to them being certified and registered on the PV Green Card database. This certification means that these installers are proficient and compliant with all of the relevant national and municipal electrical regulations.

The Greencard initiative only covers behind the meter PV installations and does not cover other types of renewable energy installation.

The PQ platform initiative (P4 platform)

PQRS developed a quality assurance platform with guidance from organisations and stakeholders involved in the sector. The platform is called the PQRS PV Performer Platform or P4 platform in short and measures 5 disparate performance metrics promoting good practice in the solar PV sector. The PQRS PV P4 scores contractors involved in the PV sector on performance, knowledge and best practice. The score rates the contractor in terms of risk. The lower the score, the higher the risk.

References

[1] C Ballack: “ The future of solar PV business in SA” PQRS Workshop, September 2017.
[2] Ethekwini Energy office: “Technical specifications for solar PV installations”.

Send your comments to energize@ee.co.za

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