Stäubli, PV and the future of sustainable energy
According to Stäubli, the focus on the production and use of clean renewable energy has never been greater. A combination of world events, which has seen the costs of traditional fossil fuels soar in recent times, combined with an increased awareness of the need to speed up the transition towards clean energy, has reinforced both the environmental and economic arguments for alternative methods of power generation.
There are a number of ways clean energy is generated, ranging from on-shore and off-shore wind, hydro-electric, tidal based systems, and of course Photovoltaics (PV). Many of the government subsidies and incentives, which were once available for these green technologies, have either been scaled back or are no longer available. This in turn has placed a greater focus on ensuring high levels of efficiency and reliability to strengthen the case for a satisfactory return on investment, especially in large scale projects. Photovoltaic power generation must not only compete against other methods of power generation, but also with other similar installations using the same technology.
It is clear that PV technology will play an increasingly important role in the production of clean and renewable energy and as such the scale of the projects and installations is increasing year on year. There are many sites around the globe, some covering expansive areas, with capacities up to several thousand Megawatts (MW).
As for any large-scale project, to secure the funding, it is essential to be able to accurately predict not only the initial capital costs, but the total cost of ownership, and in the case of PV installations, this could be over an extended operational period of some 25 years.
Minimising Risk – Maximising Return – The Concept Of Bankability
The term bankability is used within the PV sector to assess and describe the degree of financial risk for any given project. The degree of bankability of any project, solution, technology, or supplier will ultimately impact the availability and cost of capital for the project.
Developers and investors must assess the investment risk: performing a qualitative evaluation on both the technical and legal aspects. This also involves a quantitative economic evaluation focussing on the balance between Total Initial Costs, Total Operating Costs and Levelized Cost of Energy (LCOE), which is a measure of the average net cost of electricity generation over the lifetime of the project. The result and output of the review processes must be rated as bankable in order to improve the chances of a positive financial decision as well as managing and mitigating risk.
The principles of minimising risk whilst maximising return can only be achieved through the use of high-quality components. Poor choices at the planning and design stages, as a result of lack of knowledge, or the selection of inferior-quality components, will eventually result in an unexpected loss of production or potential safety issues during the lifecycle of a PV system. An EU-funded Solar Bankability Project set out to establish a common practice for professional risk assessment on the basis of existing studies and by collecting statistical data of failures in PV installations. The resultant risk analysis assesses the economic impact of technical risks and how this can influence various business models and the LCOE.
The project presented cost-based Failure Modes and Effects Analysis (FMEA) to be implemented within the PV sector. It set out to define a methodology for estimating economic losses due to planning failures, system downtime and replacement or repair of components, with respect to their impact on electrical and financial performance. Failures on cabling and connectors were identified amongst the highest risk potentials according to the list of the Top 20 technical failures seen during operation and which have the greatest financial impact.
During the project design and planning phase of a PV system, the main focus is likely to be on the two highest-cost items: the solar modules and the power inverters. Smaller components, such as connectors, although a crucial part of the installed system, are often overlooked at the initial stages. Given the statistics generated from the FMEA study, it is clear that a greater consideration needs to be given to these items.
With the demand for PV technology continuing to grow rapidly, there are numerous businesses intent on securing a share of this potentially lucrative market. This applies to all areas of the technology from the high value solar modules and inverters, right through to cabling and connector products. The importance of the connector in these installations cannot be underestimated as it is clear that long-term reliability, together with consistent low contact resistance, are the key attributes required of the connectors if the highest levels of performance are to be achieved.
With several decades of expertise within the PV sector, Stäubli claims its MC4 connector has become recognised as the industry standard.
The company claims that this accolade has been hard won based upon the unique design, selection of materials and precision manufacturing methods which together deliver the predictable performance and reliability demanded by the sector. Stäubli’s says that its patented MULTILAM contact technology, is at the heart of Stäubli PV connectors, uses multiple contact points to improve both connection quality and energy transfer.
Thanks to MC4’s unique design and constant spring pressure, the company claims that connectors offer low contact resistance, ensuring safe, long-termoperation. In addition, Staubli also believes that connectors are very stable in terms of temperature and demonstrate no heat accumulation, significantly reducing downtime and ongoing service costs. Today, Stäubli claims its connectors demonstrate an impressive track record, currently connecting over 615 GW globally, which is more than half the world’s cumulative PV capacity.