17 MW Mithapur solar power plant for Tata Power: Delivering beyond expectations
For Tata Power Solar, decades of experience in the capable hands of its exemplary team is reflected in the whopping 17MW solar power plant at Mithapur, Gujarat in January 2012. A project of this proportion is an achievement in itself and is most noteworthy for its impeccable record completion in a short span of 9 months. The 17MW Mithapur power plant stands testimony to Tata Power Solar as a leading solar solution provider that continues to bank on smart design, timely execution and above all, creating superior value for all of their customers.
Tata Power in an effort to fulfill its Renewable Purchase Obligation (RPO) was looking to build a 17 MW solar power plant in Mithapur, Gujarat. Amidst tough competition, Tata Power Solar won the project owing to its rich experience in delivering integrated solar solutions across India. The project was completed in an aggressive time period of 9 months and commissioned in January 2012. In its two years of operation, the project is performing at 83.80% performance ratio and generating more than 30 Million kWh of electricity per year.
Challenges and Solutions
Tata Power Solar faced several local, technical and regulatory challenges in this project. Tata Power Solar had to do several design interventions to address many custom requirements and also to liaise effectively with the external stakeholders (government bodies, local community, vendors etc.) to ensure effective implementation within timelines.
Proximity to airstrip: The safety guidelines followed by the airport authorities requires that in the near proximity to the airstrip, there is no sunlight reflecting objects, as it distracts and hampers the visibility for the pilots. The project site’s proximity to the Mithapur airstrip required special clearance from Directorate General of Civil Aviation (DGCA) since reflection of sunlight by conventional solar panels posed a significant risk to flight operations in the region. To overcome this, Tata Power Solar designed and implemented the use of solar panels with Anti Reflective Coating to avoid reflection of light from the solar panel glass and worked with external vendors to ensure timely delivery of the same.
Irregular site layout: For a project site with a size of 71 acres, the irregularity in the terrain makes it challenging for the engineering team to come up with a module array design. To come up with a design that works on such a site extensive skill, experience and capability is required from the engineering team which is the pillar Tata Power Solar strives on. The design involved several non standard rows that accommodated 73,920 modules while minimizing DC losses. With this, Tata Power Solar achieved an effective landscape utilization of less than 4.2 acres per megawatt as against the standard 4.5 acres per megawatt.
High salt content: Situated near the sea, Mithapur’s air and soil has high salt content which is corrosive in nature. Early testing at the site showed high level of saline in ground water at even 1 meter depth. To tackle corrosive soil and rough terrain, engineers dewatered each of the 13,440 plant foundation pits, provided mechanized concrete foundations and customized pillar heights. The structures were coated with a special epoxy and hotdip galvanized coating to ensure longer life and protection from corrosion.
Compensating grid connection issues: Voltage fluctuations occur where the plant gets interconnected with the grid substation. Tata Power Solar to avoid these issues filtered the voltage fluctuations with the help of an inverter. It also implemented a block power evacuation concept to independently test and transmit generated power from the plant in blocks of 4 MW and above to the plant switchyard.
Increase in revenue: The plant generates electricity at a performance ratio of 83.80% which was 4.7% above target and resulted in a revenue increase of Rs. 2 crores in the first year of operation.
Access to power: The Mithapur plant generates more than 30 million kWh of electricity per year that powers the neighboring villages (~15 million homes) through the grid.
Promote employment within community: Tata Power Solar trained and employed the local community in the areas of construction, operations and maintenance thus generating employment for the local community.