Why Solar PV Power Plants?
With an installed capacity greater than 137 GWs worldwide and annual additions of about 40 GWs in recent years, solar photovoltaic (PV) technology has become an increasingly important energy supply option.
A substantial decline in the cost of solar PV power plant (80% reduction since 2008) has improved solar PV’s competitiveness, reducing the needs for subsidies and enabling solar to compete with other power generation options in some markets.
While the majority of operating solar projects is in developed economies, the drop in prices coupled with unreliable grid power and the high cost of diesel generators has driven fast-growing interest in solar PV technology in emerging economies as well.
Many emerging economies have an excellent solar resource, and have adopted policies to encourage the development of the solar industry to realize the benefits that expanded use of PV technology can have on their economies and on improving energy security, as well as on the local and global environmental.
Also, solar installations can be built relatively quickly, often in 6–12 months, compared to hydro and fossil fuel projects that require more than 4–5 years to complete. This presents a major incentive in rapidly-growing, emerging markets with a high unmet demand and urgent need for power.
Assuming that PV technology prices continue to fall relative to competing sources of electricity, the market penetration rate of utility-scale solar power projects can be expected to continue growing rapidly, including in emerging markets.
PV Plant Design
Designing a megawatt-scale solar PV power plant is an involved process that requires considerable technical knowledge and experience. There are many compromises that need to be made in order to achieve the optimum balance between performance and cost.
For most large solar PV plants, reducing the levelized cost of electricity (LCOE) is the most important design criteria. Every aspect of the electrical system (and of the project as a whole) should be scrutinized and optimized. The potential economic gains from such an analysis are much larger than the cost of carrying it out.
It is important to strike a balance between cost savings and quality. Engineering decisions should be “careful” and “informed” decisions. Otherwise, design made with a view to reduce costs in the present could lead to increased future costs and lost revenue due to high maintenance requirements and low performance.
The performance of a solar PV power plant can be optimized by reducing the system losses. Reducing the total loss increases the annual energy yield and hence the revenue, though in some cases it may increase the cost of the plant. In addition, efforts to reduce one type of loss may conflict with efforts to reduce losses of a different type.
It is the skill of the plant designer to make compromises that result in a plant with a high performance at a reasonable cost.
Design Considerations
For solar PV power plant design, there are some general rules of thumb. But specifics of project locations—such as irradiation conditions, temperature, sun angles and shading—should be taken into account in order to achieve the optimum balance between annual energy yield and cost.
It may be beneficial to use simulation software to compare the impact of different module or inverter technologies and different plant layouts on the predicted energy yield and plant revenue.
The solar PV modules are typically the most valuable and portable components of a PV power plant. Safety precautions may include anti-theft bolts, anti-theft synthetic resins, CCTV cameras with alarms, and security fencing.
The risk of technical performance issues may be mitigated by carrying out a thorough technical due diligence exercise in which the final design documentation from the EPC contractor is scrutinized by an independent technical .advisor
