The global market for photovoltaic (PV) solar energy systems is growing rapidly, and as all solar projects require extensive wiring, it presents a significant opportunity for cable manufacturers. But to successfully take advantage of this ongoing development, it's important to understand where growth is focusing, why it's focusing on these areas, and the challenges it poses, both environmentally and legally.

This article gives cable manufacturers a clear grasp of what it takes to meet the expectations of the solar industry, highlighting these issues and opportunities. It also demonstrates how, with its cable testing and certification services, BASEC (British Cables Approval Service) can help manufacturers meet all the necessary compliance requirements for the industry. This is based on a background of how solar energy opportunities are distributed worldwide.

Why is the solar industry growing?

The solar industry today owes the speed of its growth to multiple factors rather than a single cause. Fossil fuel pricing is expected to continue to rise over time, so proof-of-the-future proof – by reducing dependence on such fuels – makes solid economic sense. Equally important is the pressure on business entities to meet their environmental obligations and create a sustainable, green energy policy. This pressure comes not only from shareholders, employees and trading partners, but also from the government and related institutions in the form of mandatory legislation.

Accordingly, major energy market players are pioneers in large-scale renewable energy projects; Brands such as Amazon, Apple, BBC, Ikea and Unilever have all invested in the big plans.

However, governments and individual consumers, as well as many other international businesses, have also contributed to the increase in solar energy demand. This need for solar energy output has been reported to be steadily increasing in installed solar energy systems.

Plans based on renewable energy sources, including solar power, also offer valuable solutions for remote and developing locations. Providing self-sufficient, renewable energy to rural communities in developing countries helps the population power their homes, schools, hospitals, stores and industries using ways out of poverty.

Overall, the latest figures show that the global installed capacity for solar photovoltaic (PV) systems exceeded 400 GW in 2017 (as shown in Figure 1).

Figure 1: Cumulative global growth of solar PV installations

These factors contribute to many business growth opportunities around the world. In January 2018, GTM Research reported that 53 countries have established tender and auction programs that allow their supply chains to offer opportunities to support upcoming solar projects. The research also found that 29 countries plan to set up these programs to hire the best suppliers to meet project specifications and requirements.

This statement is also reflected in the figures published by the International Renewable Energy Agency (IRENA) on employment in the renewable energy sector. In 2017, this reached 10.3 million worldwide. The solar PV industry accounted for about 3.4 million of these jobs and was highlighted as the largest employer of all renewable energy technologies.

What is the role of cables and what are their critical requirements?

it illustrates a simple domestic PV system, but the same principles apply equally to larger installations. Pay particular attention to the inverter that converts the DC cables and DC outputs into a usable AC source for connecting the modules. While AC cables downstream of the inverter are usually inside the closed, protected environment of a building, DC cables are usually outside, where they are subject to environmental pressures and potentially human intervention.

While the technical and legal challenges associated with overcoming these issues are significant, the opportunities they represent to these cable manufacturers to overcome them are also impressive.

After discussions with several firms involved in solar technology, BASEC recommends the following list of features that DC cables should be tested to maximize potential opportunities:

• Abrasion resistance

• Flame retardant

• Halogen free

• Moisture and water resistance

• Low smoke emission

• Ozone resistance

• Protected against environmental salinity – especially for floating photovoltaics

• Resistant to chemical stresses - acids and alkalis

• UV resistance

• Withstands wide temperature ranges (-40°C to 90°C).

• Resistance to mechanical stress: compression, tensile, bending and cutting loads

The specifications of some projects may also include external armoring for protection against rodent and insect damage, if appropriate.

A declaration that cable manufacturers subject their cables to rigorous testing is not enough – they must prove that solar products meet the transition requirements associated with each of the specific tests involved in the verification of the above product specifications. Using a testing and certification partner such as BASEC will provide the assurance that operators and stakeholders need.

Using improper wiring shortens the life of a project, and many solar projects are supported by local governments and can therefore be accountable to public stakeholders for the return on financial investments.

The industry-standard warranty period provided by solar panel manufacturers is 25 years. As a result, this is sometimes also recommended as the lifespan of solar cables. However, the life of a cable cannot be accurately given without resorting to a temperature. The results from a thermal resistance test as specified in IEC standards can be used to estimate the service life of cable products.

The location of solar projects requires long life and low maintenance, especially in remote applications as mentioned above.

All cables must comply with relevant international legislation and project-specific requirements. The two standards that apply to solar cables for use in DC devices are IEC 62930:ed 1.0:2017 and (BS) EN 50618:2014.

Although the EN standard specifies the use of only low-smoke, halogen-free types, the standards are very similar in terms of requirements, while the IEC standard allows materials with or without these properties. There are also other differences, such as the placement of Class 2 cables and a slightly wider range of conductor sizes in the IEC standard.

How can you manufacture cables that meet the requirements of the solar PV system?

On a technical level, innovations in compounds and extrusion technology are now available to help cable manufacturers meet the unique characteristics of the solar industry. Many cable manufacturers work closely with project markers to produce cables that meet the requirements of design and local manufacturing standards.

For reliable and efficient fulfillment of international legislation, BASEC can help certify cables that comply with IEC 62930:ed 1.0:2017 and (BS) EN 50618:2014 standards. The class 5 conductive, low smoke, zero halogen types are similar enough and can therefore be evaluated for certification in a combined test program with an intensified test set for both product ranges.

BASEC's teams of engineers, technicians and auditors have extensive commercial, industrial and technical experience. As a result, BASEC has earned a reputation for its professional and rigorous evaluation processes, which ultimately leads to the issuance of our respected product certifications and test reports.

In addition, BASEC provides supporting services for cable manufacturers, traders and users, including management system certification, bespoke type testing, impartial investigation of compliance issues, and testing and reporting in the event of disputes. In addition, if bespoke cable designs require independent testing, Assessed Design Certificates are available for innovative cable products.

BASEC is committed to National, International and European cable product standards (e.g. BS IS ACCREDITED TO PROVIDE CERTIFICATION TO EN, IEC, ISO and country-specific), national and industry cable standards and quality management system (ISO 9001), environmental management (ISO 14001) and health and safety (OHSAS 18001/ISO 45001). BASEC also offers other certifications for cable stockists, markers and industry-specific standards.

How is demand distributed globally?

Germany, an early adopter of solar PV systems, was recognized as the leader of solar installations for a decade until 2015, after which China took over this leadership (see Pioneering Solar PV systems). Figure 3). China's solar installations began to start sharply in 2012, and with newly installed foundations in 2017, it has significantly more solar power capacity than the top nine leading countries combined. Then Japan and the U.S. are also outpacing Germany and following a higher installation rate. The data shows that the race to produce renewable energy-focused initiatives is truly global. Therefore, it is important for specifications, buyers, cable distributors and manufacturers to take into account that they use the product that complies with international and local standards to ensure that the product supplied is commercially fit for purpose.