With the Government of India promoting solar parks in a big way, the clearing of large areas of land for solar power facilities can adversely affect native vegetation and wildlife, causing a loss of habitat and interference with rainfall and drainage. Therefore, the feasibility study stage is extremely important. Additional third-party studies should be referred to during this stage, to further understand and identify the best practices and processes for sustainable solar park development.
Once a site has been identified, a detailed project report is undertaken that covers the potential environmental impacts of the proposed solar park facility, and identifies key mitigation measures to be taken up by the project developer before the park is set up. Some lending agencies have their own environmental safeguards and standards, which need to be followed. These requirements usually include assessing impacts, planning and managing impact mitigations, preparing environmental assessment reports, disclosing information and undertaking consultation, establishing a grievance mechanism and monitoring and reporting redressal. They also include particular environmental safeguard requirements pertaining to biodiversity conservation and sustainable management of natural resources, pollution prevention and abatement, occupational and community health and safety, and conservation of physical cultural resources.
A project is given the green signal if it is expected to have a limited number of potentially adverse environmental and social impacts, if the impacts are not unprecedented, and if they are limited to the project area and can be successfully managed using good management practices.
In India, as per the Environmental Impact Assessment (EIA) Notification of 2006 and amendments thereof, several infrastructure development sectors require an environmental clearance (EC) from the Ministry of Environment, Forests and Climate Change (MoEF&CC) before a project is initiated. Solar photovoltaic (PV) power projects are exempt from the EC requirement, as per the ministry’s notification dated May 2011. However, while this is true for individual solar PV projects, the MoEF&CC has not specified the requirements for multiple solar PV projects (that is, the category of solar park development).
A solar park could be defined as a large, centrally administered industrial park consisting of a cluster of individual solar PV power plants, under the category of industrial estate/parks. Under this category, if the total area of the park is within 500 hectare and does not house a Category A or B industry, then a prior EC is not necessary. Some of the large infrastructure development projects (including solar parks) may also be considered under the category of Townships and Area Development Projects, depending on the area. Here too, an EC will not be necessary.
It is, however, recommended that the exact site boundaries and locations of all proposed solar park sites be verified vis-à-vis reserves/demarcated forest areas as well as wildlife (avian fauna) areas, officially procured from the forest authorities. The proposed site can fall under the Coastal Regulatory Zone (CRZ) but as per the CRZ Rules, 2011, CRZ clearance is necessary.
Beyond the key environmental clearances mentioned above, the development and operation of the solar parks could warrant certain other environmental regulatory requirements, such as those for air/water/ noise pollution, wildlife/forest preservation, existing land use (farmland, fisheries, cattle grazing, for example), waste management and access roads.
Potential environmental impacts
Each solar park project envisages three distinct phases – construction, operations and decommissioning – for which environmental issues are relevant.
The major activities during the construction of roads, transmission corridors, pooling stations and water pipelines include earthwork excavation, material movement, the construction of buildings, the provision of infrastructural facilities like stormwater drains, sewerage lines, septic tanks, electrical and communication networks, etc. The support activities include the employment of labour, material transport, use of construction equipment, etc. These are expected to cause minor environmental problems during the construction and operational phases of the project.
Water sourcing and consumption
Large amounts of water are required during the construction (including for labour camps) as well as operational (panel washing/maintenance) phases of the project, which can be met using ground water abstraction. An impact assessment is required to understand the potential impact on local water tables and the possible replenishment of ground water using rainwater harvesting schemes (possibly as part of the local state agency’s corporate social responsibility). Water efficient mechanisms such as low volume, high pressure spray nozzles and recycling of water on site for panel washing can be used to further optimise water consumption.
Disruption of drainage channels and soil erosion
For sites that are located on hilly terrain and involve the removal of large trees/vegetation, some adverse environmental impact can be expected due to the disruption of existing natural drainage patterns (causing waterlogging in other areas) as well as associated soil erosion due to the exposure of soil. Water runoff from between the installed panels on slopes is expected to carry soil sediment, leading to their deposition on lower contours.
The proposed access roads could also cut across several non-perennial (monsoon-based) drainage channels and would require the construction of an adequate number of cross-drainage structures to mitigate the adverse impacts on the surface runoff.
A detailed hydrological study may be required to assess the impacts on surface drainage and to identify the precise location and number of cross-drainage structures. Natural streams may need to be diverted to suitable downstream channels, which could be used for ground water recharging or wells.
Removal of vegetation and trees for construction
The likely potential impacts related to the construction of new access roads to reach the proposed sites are the physical disturbance of soil and vegetation, and the creation of a physical barrier across a drainage channel that could potentially affect the hydrological and ecological functionality of the area. It must be ensured that no additional access roads are made other than those proposed as per the block layout, as this could disturb the ground cover leading to increased dust suspension and soil erosion. A detailed tree survey is recommended to ascertain the exact environmental impact and determine costs for cutting and for compensatory plantations.
Disturbance to avian fauna
Avian fauna (birds) in the region can be impacted either by a glare effect (although the glare from PV panels is much less severe than that from mirrors used in concentrating solar power projects), or by the destruction of their nesting/perching/feeding habitats due to the removal of vegetation and large trees on and around proposed sites for the solar park. A quick review of the reference guide published by the Bombay Natural History Society (BNHS), Important Bird Areas (IBA), would indicate the presence of any threatened or endangered species in the vicinity of the proposed sites. However, even local bird species may be adversely affected, considering the required removal of vegetation at certain sites.
It is recommended that an assessment of bird habitat utilisation be carried out for relevant sites while conducting the tree survey for the removal of vegetation. Mitigation measures could then be planned on the basis of this study.
Impacts due to new transmission lines
While most of the power generated in solar parks is evacuated using existing transmission infrastructure, some new lines are expected to connect the sites with existing power distribution infrastructure. Depending on the routes of these alignments, land use along the right of way (RoW) may be affected in case there is a presence of any sensitive environmental components such as waterbodies, forests or vegetated areas, or hilly topography.
An impact assessment would need to be carried out to ascertain the specific environmental impacts possible due to these lines, and to determine the requirement of alternative routes as well as mitigation measures.
Waste generation and disposal
Waste management could be a challenge considering the hilly and complex terrain at certain sites.
During the construction as well as operational phases of the project, various hazardous waste streams such as waste oil, oil filters, grease and oil-laden cotton rags, discarded spares and parts from equipment (during maintenance, etc.), along with packaging material (such as plastic, paper, cardboard and wooden pallets) of panels are likely to be generated. If not segregated, stored and recycled/treated/disposed of in a sound manner (as per regulatory requirements), these could lead to the contamination of land around the site.
Construction of sewage treatment plants/ septic tank systems may also be required. Further, for the health and safety of the staff and labour working on-site, an occupational healthcare centre (medical facility with relevant infrastructure) would need to be established at the location.
Lower GHG emissions
Greenhouse gas (GHG) emissions are largely responsible for global climate change and the rise in temperatures. While there are six major GHGs, carbon dioxide (CO2) is considered the most important indicator of climate change, due to its large contribution. The recent emission factor for CO2 (based on a mix of conventional power generation technologies) released by the Central Electricity Authority (CEA) is reported as 0.82 tonnes CO2 per MWh generated. As compared to conventional power generation (based on fossil fuels), solar PV-based power generation has a much smaller footprint in terms of GHG emissions.
However, solar PV projects are not completely emission-free. Some activities that contribute to GHG emissions are the removal of vegetation/trees, emissions at the time of manufacturing of PV panels and other equipment, transportation-related vehicular emissions, leakage emissions of sulphur hexafluoride (SF6) from electrical substations, and other indirect emissions associated with construction and operation of power plants. The savings expected from the proposed solar park sites (for an estimated generation) could accordingly be worked out based on the utilisation factor (percentage), annual generation at each site, auxiliary consumption and degradation over their operating life.
Roles and responsibilities
It is important to identify specific roles and responsibilities for various stakeholders involved in the project. This will allow an environmental management plan and mitigation measures to be suitably put in place based on relevance and feasibility. Decisions also need to be taken as to which party will pay for which cost component.
To ensure that the mitigation measures and management plans implemented are adequate and effective, a periodic auditing and monitoring mechanism should be established. This would include measurement of atmospheric and environmental parameters such as noise, air quality, soil quality, as well as health and safety indicators. Third-party auditors/monitoring agencies could be engaged to submit reports every six months. Corrective actions could be taken on the basis of these reports.
Periodic disclosure will need to be made to all stakeholders to communicate the project performance with regard to environmental, health and safety issues and actions.
Going forward, solar parks will play an increasingly important role in power generation. As part of its efforts to reduce the production cost of solar power and promote the use of clean energy, the Ministry of New and Renewable Energy rolled out the Development of Solar Parks and Ultra Mega Solar Power Projects scheme on December 12, 2014. The scheme was conceived along the lines of the Charanka solar park in Gujarat, which was the first-of-its-kind, large-scale solar park in India, with contiguous developed land and transmission connectivity.
Land in rural areas is being increasingly used to build these solar parks. This will increase the requirement for land as well as the associated ecological impact on biodiversity. On the other hand, solar parks will make an important contribution to future energy supply and may provide a refuge for plants and animals.
In order to balance the pros and cons of setting up such parks, land use needs to be carried out responsibly. Local communities should be empowered to identify suitable land that minimally impacts the climate and biodiversity, is in line with legal requirements and has been acquired in cooperation with local stakeholders. Guidelines set by the government or the Solar Energy Corporation of India, the nodal agency responsible for the solar park scheme in India, could help foster case-by-case decisions. The PV industry, environmental organisations and decision-makers should engage in a dialogue on ecologically responsible solar power plants. It is important to anticipate potential conflicts, propose solutions, and help increase acceptance of solar PV as a key source of energy.
By Anita Khuller