Bridge India

Rooftop Revolution: Uncovering Patna’s solar potential

In 2011, the per capita electricity consumption of Patna, the capital city of Bihar, was only 601 kWh[1] and even though it is a capital of one of India’s largest states, this is 23% lower than the national average of 780 kWh[2] and significantly lower than the global average of 3,044 kWh[3]. This shows that the city is still very far from providing enough power to its population.

  • BRIDGE TO INDIA’s modelling revealed that Patna has a geographical potential to install around 759 MW of rooftop solar
  • Analysts at BRIDGE TO INDIA have envisaged a road map for Patna to help meet its energy demands by adopting solar in a phased manner
  • The city could add 277 MW by 2025 without significant technical challenges, storage requirements or dedicated grid investments. Thus, solar could meet about 20% of the city’s power requirement

Rooftop Revolution: Uncovering the Solar Potential of Patna

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Bihar relies on power generated outside the state for about 70%[4] of its requirements. In addition, the state has a power deficit of 29%[5] and suffers from very high transmission and distribution (T&D) losses of around 38%[6]. This leads to frequent power outages. In the state capital, Patna, they range between two and nine hours a day. The power deficit is a key bottleneck for industrial and commercial growth as well as higher standards of living.

The key challenges faced by Bihar state power holding company ltd. (BSPHCL) include an ageing infrastructure, pilferage of power, a high cost of power generation, rapidly rising demand and ineffective energy accounting. All of these lead to a financial losses and curtail the SEB’s abilities to improve the situation.

Patna is the key driver of Bihar’s economy. An improved power situation in the city can help bring much needed investments into the state. For this to happen, Patna needs to de-couple itself from the overall power situation in the state and the region.

Patna should become a leader among cities and consider transformational changes in its power supply that will not only solve the city’s problems but also change the way it is perceived economically and politically.

Currently, the Bihar government plans to set up several coal-based power plants to meet the state’s power requirements internally. However, there is a nation-wide shortage of coal. Cost of imported coal is rising. The utilization factor of coal plants is falling. Even if the supply of coal is secured, pollution would increase substantially. Relying on coal alone is a risky proposition. Solar power, an energy source that is both easily and quickly installed and can be deployed in a distributed manner across Patna’s million rooftops, should be a key building block of Patna’s energy future.

If the power is generated at the point of consumption, the huge T&D losses can be avoided. Moreover, solar can help reduce the dependence on coal deliveries and on power producers from other states. In the beginning, solar power could help meet day time power requirements and conventional power could continue to meet peak demand for the evening and night time. Gradually, solar can start playing a more active role in eradicating the power deficit of the city.

This can be a financially sound investment. In Bihar, the Average Power Purchase Cost (APPC) for utilities has increased by 190% since 2005, but the tariffs have increased by only 30% in the same period. As a result, the erstwhile Bihar State Electricity Board (BSEB) incurs significant losses amounting to INR 16,180 m (USD 270 m) or INR 1.01/kWh (USD 0.017/kWh) for the power sold in 2011-12.[7] A higher adoption of distributed solar will lead to private sector investments and help reduce the burden on the state.

Based on the rooftop space availability for optimum solar power generation, we estimate that Patna has a geographical potential to install 759 MW of rooftop solar. This is significantly greater than the anticipated peak summer power demand of around 600 MW in 2014. It might not make sense to realize the entire solar potential and thereby generate excess power in the city. This excess power would need to be transmitted to other consumers in the state outside the city limits through investment in the grid. Also, such a high share of solar power would likely lead to issues related to balancing of loads and the local grids. Therefore, for the purpose of this study, we propose that 20% of the city’s power requirements comes from solar. This will not pose technical challenges or require costly investments into the grid infrastructure. It would still allow for a solar capacity addition of 277 MW by 2025.

The question then is: how can Patna go solar? Solar without storage is already very close to matching the cost of power from new coal plants. However, while storage can make solar a back-up power supply, it is still expensive and can distort the dynamics against adoption of solar. The challenge is to ensure a stable power supply before asking a customer to adopt commercially attractive solar (without storage). To solve this conundrum, we propose a phase-wise adoption of solar without storage. Adoption of solar can start in the areas with the fewest power cuts. The industrial areas in Patna and some of the residential areas in the city, for example, already receive a fairly reliable power supply. Mass adoption of solar power in these areas will allow for greater supply of power for other areas. This excess power can then create another area of reliable power. Subsequently, adoption of solar in this new area of reliable power can again have the similar impact and the process can be replicated through the city.

In the beginning, the government will need to invest into making the proposition viable for private investors. This can be done in the form of tax incentives, generation based incentives (GBI) and/or upfront capital subsidies. Distributed solar power is expected to reach parity with landed cost of conventional power for the government by 2019 and with the tariff for the consumer by 2021. Based on the roadmap provided in this report, if the government invests INR 1,496 m (USD 25 m) for a GBI, it will save INR 5,892 m (USD 98 m) in the next ten years.

Over time, as solar power becomes more competitive, policy makers can focus more on facilitating rather than incentivizing solar power for the end consumers. In the long term, solar power will make Patna more resilient and independent.


[1] CEED and BRIDGE TO INDIA analysis

[2] Combined Business Plan for North Bihar Power Distribution Company and South Bihar Power Distribution Company, by BSPHCL, in 2012

[3] World development indicators, by World Bank,

[4] “Combined Business Plan for North Bihar Power Distribution Company and South Bihar Power Distribution Company”, by BSPHCL, published in 2012,

[5] “Load generation balance report”, by Central Electricity Authority, published in 2013,

[6] Tariff order, Bihar Electricity Regulatory Commission, published in 2013,

[7] Combined Business Plan for North Bihar Power Distribution Company and South Bihar Power Distribution Company”, by BSPHCL, published in 2012,

Tobias Engelmeier is the Founder and Director of BRIDGE TO INDIA

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