Sanchi solar city and the looming storage problem

Read in Hindi | Vishwas Saxena, a resident of Sehore City in Madhya Pradesh, has successfully installed a 5-kilowatt (KW) rooftop solar system at his house. The comparison of his monthly electricity bills suggests a remarkable reduction in expenses. The bill used to be between Rs 8,000 and Rs 10,000, especially in summer when the air conditioners were on. Now it is negative. Vishwas says this renewable energy source has transformed his financial situation.

The on-grid system on the Saxena rooftop buys and sells electricity to the grid, all measured by a ‘net meter’ that moves both ways. A negative amount in the bill means the distribution company would pay the Saxenas next March.

On-grid/utility-scale 

During the 2021 UN climate summit in Glasgow (COP-26), Indian Prime Minister Narendra Modi made a significant commitment towards achieving a target of 500 GW of non-fossil fuel-based electricity in India by 2030. This was later changed to 450 GW. Even that is an ambitious goal, and to meet it India must increase its renewable energy production capacity by an additional 50 GW on an annual basis.

Furthermore, the government recognizes that it is not solely about production, but also about transmitting this non-fossil energy. Due to heatwaves, and other industrial needs, India’s power demand is expected to nearly double in the next five years. For power transmission and state-based trade, certain infrastructure needs to be developed in the long term. India has made significant strides in the renewable energy sector. However, the true challenge lies in India's endeavour to achieve net zero emissions by 2070.

Currently, India's primary focus is on the on-grid system of renewable energy, whereby electricity generated from solar panels, wind turbines, and other renewable sources is seamlessly integrated into the existing transmission grid. This ensures that even in the absence of sun or wind, energy demands are met through conventional energy sources, like coal.

In an ideal scenario for solar cities, solar rooftops and solar farms would be established to generate more energy than the city’s consumption– both day and night combined. Thus, producing surplus energy throughout the day.

This surplus energy can be sold to other states or industries by the respective state governments. In the process, coal-based energy is not utilised to fulfil the city’s energy needs during the day. Hence, not emitting carbon that otherwise would have been in the atmosphere.

The government is actively promoting the use of rooftop solar panels to generate primary energy. Additionally, they are adopting the 'resco' model, (Renewable Energy Service Company)  which involves encouraging private entities to establish solar farms. In turn, the government purchases electricity from these farms. The tariff for this electricity is determined through a competitive bidding process.

Solar rooftop system

Sakshi Bhardwaj, a resident of Kolar in Bhopal, has recently installed an 8 KW capacity rooftop solar panel system at her house. Inspired by her love for nature and a desire to create a sustainable home, Sakshi says,

“Generating one's own energy is a viable option, particularly considering the increasing demand for electricity in the country.”

By doing so, she believes that those who are financially capable can contribute to meeting their own energy needs and help provide electricity to those who are in need.

Another example is Goldie, the owner of Eaters Hunt, a restaurant located in Sehore City. Goldie shares the advantages of having rooftop solar panels installed at his establishment. He states that his electricity bill has been reduced by more than half since the installation. Previously, his monthly bill used to amount to 6-7 thousand rupees, but now it has decreased to only 2 thousand. 

Sanchi’s Solar City

Sanchi, a city situated in Madhya Pradesh in India, has undergone a remarkable transformation into a solar-powered city. With a current population of 10,000 residents, Sanchi effectively utilizes solar energy for its power consumption, amounting to nearly 2 megawatts (MW), through surplus day-time production as mentioned above.

In order to cater to this energy need, the Narmada Hydroelectric Development Corporation Ltd. (NHDC) has established a 3 MW on-grid Solar Park in the area; another solar park of 5MW capacity is to come up soon. According to Amit Satam, an expert associated with Sanchi Solar, the 3 MW solar park was completed in one and a half months. Spanning 6 acres of land, this park comprises approximately 1,500 high-quality solar panels. 

Storage viability

Engineer Udresh of Goldie Solar, the company responsible for establishing the solar park in Sanchi, emphasizes the necessity of installing batteries on a large scale to ensure power backup during the night for a city like Sanchi. However, he acknowledges that this will double the overall cost of the project. Shrikant Deshmukh, the senior engineer of Madhya Pradesh Urja Vikas Nigam, confirms that Udresh's point is valid. He adds,

"The cost of energy acquired from the solar park will increase from the current rate of Rs. 3.22 paise to approximately Rs. 6 due to the integration of a battery-based storage system."

Engineer Amit Satam, who is involved in the Sanchi project, explains that a substantial number of batteries will be necessary to create a storage system for a 3 MW plant. Until now, our reliance on fossil fuels has provided us with the ability to have complete control over the generation and consumption of electricity, allowing us to produce it continuously day and night. However, renewable energy sources are entirely reliant on natural elements, and their electricity generation is not consistent. In order to ensure a more stable electricity supply, we require storage solutions.

Unfortunately, the technology needed for energy storage is considerably more expensive compared to the technology for generation. Currently, solar and wind power can be more affordable alternatives to coal and gas, but only without the inclusion of storage costs. Once that is incorporated, the production cost of renewable energy surpasses that of fossil fuels.

Search for alternatives

Currently, lithium-ion batteries are recognised as the most efficient available storage choice. Further, battery maintenance is expensive, and its optimal lifespan is 3-7 years, necessitating replacement afterwards. Not just this, lithium-ion has significant environmental costs, from mining to disposal. Regardless, on-grid solar power is currently the most advantageous choice. While storage options must be considered, relying solely on lithium-ion batteries may not be viable, making it crucial to explore alternative solutions.

Chetan Solanki, Professor at IIT Bombay's Department of Energy Science and Engineering, emphasizes that solar power presents the most advantageous solution currently to effectively reduce carbon emissions. He says,

“For individuals who may express scepticism regarding the expense or sustainability of solar energy, it becomes vital to compare it to the ongoing use of coal. Given the era of climate emergency, we find ourselves in a situation akin to warfare, where costs should not take precedence.”

Here, it is essential to point out the other side of renewable energy expansion apart from the lack of storage capacity. Photovoltaic deployment is rapidly accelerating in India, driven by the growth of solar parks and rooftop solar.

India currently ranks fourth globally in this regard. While this progress fuels enthusiasm, it also raises concerns. A 2016 report by the International Renewable Energy Agency estimates that India will accumulate 50,000-3,25,000 tonnes of photovoltaic waste by 2030. This is predicted to escalate to 4 million tonnes by 2050, positioning India among the top five generators of photovoltaic waste worldwide.

According to Udresh Mishra, deputy manager of Goldie Solar Pvt Ltd, involved in the operations at Sanchi Solar Park, solar panels have an estimated lifespan of 20-25 years, beyond which they lose their functionality. He said,

“The project costs are gradually recuperated over time, unfortunately, only 50% of the waste generated from the panels can currently be recycled… 25 years is a long time. We are yet to see how these photovoltaic cells function during heatwaves, and how they can be disposed of.”

India is now the third country/group, following the UK and the European Union, to have legislation for the disposal of renewable energy waste. However, unlike the UK or the EU, India has categorised such waste under e-waste.

Sadly, only 20% of e-waste in India is directed to recycling units, while the remaining waste is irresponsibly disposed of in landfills. This leads to the leaching of harmful substances like lead and cadmium into the soil.

This ongoing cycle of pollution poses a severe threat to local water bodies. Solar panels might face the same fate. Furthermore, the incineration of solar panels emits gases such as sulphur dioxide, hydrogen fluoride, and hydrogen cyanide, consequently polluting the atmosphere.

India urgently needs to establish an integrated system that covers the collection, storage, recycling, and repurposing of photovoltaic waste, and must also recognize solar waste as hazardous waste in order to effectively address this issue.

Besides the e-waste, there is with installation waste like wires, cardboard, wooden spools or coils. The installation of solar farms can impact the local ecosystem by taking up land, and the waste can turn into a pollutant. In the second article of the series, we will explore pumped storage power projects, sodium-ion batteries, and molten salt storage systems, among others.

This is the first of three articles part of India's renewable energy expansion, and storage system. This story is produced with the support of the Earth Journalism Network story grants.

Keep Reading

• Part Two: Renewable Energy Expansion Needs An Integrated Sustainable Storage Solution, Here’s How
• Part Three: India’s Renewable Energy Expansion Posing Threats To Its Grid Stability 
• Solar Power in Mountain Nation Nepal and Missing Science-Based Information to Locals

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