Multi-Mega-Scale PV Systems

Image from Gujarat Power Commission Ltd.

Multi-Mega-scale photovoltaic (PV) projects have been in news for a while but are they really the way to go? We analysed the pros and cons of such centralised solar electricity-generation systems to get some insight.

Pros

1. Technology forerunner: The largest solar project commissioned in the world so far is the Agua Caliente Solar Project in the USA, 26 MWp larger than the Charanka Park, Patan district PV power plant. Developing a project over 500 MW project would not only establish the nation as a technology leader but also prove its seriousness towards the fight for climate change. 
2. A step closer to energy sufficiency: India is a power-deficit nation, with a generation deficit of 10–12% of its peak demand. Large-scale solar projects would help in bridging that gap quickly and in reducing the nation’s CO₂ emissions per MWh.
3. Cost–benefit: Large-scale projects would benefit from economies of scale and hence potentially lead to lower bidding price. Other factors, such as lower overhead costs per MWh, would further lead to lower cost of generation.
4. Ease of implementation: Distributed solar and rooftop schemes have been effective in many parts of the developed world but at the same time have proved to be expensive and unsafe if not controlled or regulated properly. Also, in a country like India, where grid stability is still an issue, it would be difficult to reap full benefits of such schemes. Therefore, the centralised multi-Mega-scale projects would be more beneficial and easier to implement.

Cons

1. Lack of experience: With the current largest plant in the world being a 250 MWp plant, designing, installing and commissioning projects larger than 500 MW would pose new problems requiring innovative solutions.
2. Lack of local expertise: Projects of such scale would require several hundred technicians and engineers to be working onsite at any given time. Although this would create job opportunities for the local workforce, training the workforce onsite in the local dialect would be a major issue.
3. Grid stability issues: An important factor that directly affects the performance ratio of PV plants, the lack of a stable and robust grid capable of handling large fluctuations would be one of the biggest issues when implementing such projects.
4. Safety: Raising the capacity bars would require generation at higher voltages and transmission of higher current. Such high-current, high-voltage DC supply might render the plant unsafe.
5. Transmission losses: It makes sense to install these multi-Mega-scale projects in areas of high irradiance and, because of their size, the systems would require large open areas for installation; therefore, the projects would generally be located far from demand centres. This would mean higher transmission losses and lower overall energy efficiency.
6. Technology is critical: Selection of appropriate technology suited to the location and the local climate would be of utmost importance. Lack of prior experience in such projects would mean devising new techniques to categorise technology based on local requirements.
7. Boom–bust cycle trend: It is important to maintain certainty in the market for sustainable industry growth. Large-sized projects often lead to on–off cycles in the market, making the market unsustainable.
8. Village remoteness: In India, there are a large number of remote villages and towns without access to the electricity grid. Large-scale centralised generation systems bring no light to villages in darkness.

With a widening energy deficit, rising oil and gas import burdens and global pressure to act on climate change, the country needs innovative solutions and quick reforms in its electricity industry. Large-scale PV plants, if successful would not only support India’s burgeoning manufacturing industry but also establish the nation as a world leader. However, large-scale systems form just a part of a three-pronged solution, with small-scale distributed systems and standalone off-grid hybrid systems forming the other two. Equal emphasis has to be laid on all three to meet the energy demands of this fast-growing nation.

We would love to hear back your comments and opinions. Write to us at [email protected] with ‘GSES September newsletter’ as the subject.