Solar farm: the complete guide to large-scale solar energy projects

Large ground-mounted arrays of photovoltaic (PV) panels

Designed for bulk electricity generation rather than on-site consumption

Either feed power into the grid or to a defined customer group

Lower carbon footprint and minimal operating expenditure than fossil plants

Highly scalable, from a few acres to thousands

Photovoltaic panel systems

Utility and distributed solar farms deploy highly efficient PV modules configured into strings that convert solar energy into DC current. Arrays can be mounted on fixed-tilt or tracking systems to maximize light exposure throughout the day.

Inverters and electrical components

DC current is routed through inverters and converted into alternating current (AC) that can be used by the grid or local systems. Medium-voltage transformers, switchgear, and protection relays maintain power quality integrity and ensure compliance with the infrastructure being supplied.

Monitoring and control systems

An array of monitoring and control systems, from SCADA (Supervisory Control and Data Acquisition) to advanced forecast systems and predictive maintenance tools, ensure maximum uptime and optimized power generation.

Concentrated solar power (CSP) systems

CSP plants use vast mirror arrays to concentrate sunlight onto a receiver, converting solar radiation into extreme heat. CSP systems leverage thermal conversion to generate power, unlike PV systems which generate electricity directly.

Heat collection and storage

One major advantage of CSP systems is their ability to collect and store heat, allowing them to generate energy even at night. Heat is transferred to a heat transfer fluid (HTF) like molten salt or synthetic oil, which is then contained in thermal storage tanks. This allows for energy storage of 6-12 or more hours at the utility scale, giving CSP the characteristic of being dispatchable – able to deliver power on demand when grid operators need it.

Steam generation process

When required, the HTF transfers heat to a steam generator, which then produces high-pressure steam to drive a conventional Rankine-cycle steam turbine. These operational characteristics bear considerable similarity with traditional gas, coal, or geothermal plants.

Agricultural zoning

Large-scale solar projects are most frequently sited on agricultural land (accounting for more than 70% of commercial U.S solar projects between 2012 and 2020). This is because agricultural land often offers ideal conditions, including large open spaces and flatter terrain. Many regional authorities classify solar as an acceptable use of agricultural land; however, there can be caveats. Wildlife surveys, visual buffers, and the requirement for dual-use planning, such as agrivoltaics, can play a role in shaping the development process.

Industrial zoning

Industrial-zoned land often faces fewer land-use objections but can also pose its own obstacles, such as higher land prices and smaller availability.

Local permitting processes

Zoning approval is typically followed by a combination of conditional-use permits, special-use permits, site-plan reviews, and utility approvals. These requirements vary widely by jurisdiction, and timelines can range from a few months to multiple years. Early engagement with planning commissions, county boards, and local stakeholders is critical to avoid delays, as opposition or procedural challenges can derail project timelines.

Environmental impact assessments

Most large-scale solar farm projects, particularly those to be built on agricultural land, are typically subject to environmental impact assessments. This could include, but is not limited to, assessments on wildlife habitats, wetlands, soil erosion, cultural heritage, and visual impact. For particularly large projects or those where federal land is involved, developers in the United States may be subject to a NEPA-level review.

Investment considerations

Large-scale solar farms are typically financed in the pre- and active-development stages with a combination of debt and equity. Solar is an attractive investment opportunity for both institutions and individual investors, as long-term profitability is usually secured by a Power Purchase Agreement (PPA) before development begins.

Power purchase agreements (PPAs)

For most large solar farms, a PPA establishes a long-term revenue stream (often 10-25 years) for the wholesale of electricity to a utility or corporate buyer. The PPA offers price stability and security in return for performance guarantees and delivery obligations – with the contracted price often serving as the primary factor in securing non-recourse project financing. This reduces risk for other investors and helps ensure project viability.

Regulatory compliance

Solar developers face a range of federal, state, and local regulations that they must comply with for project approval. These can include zoning approvals, land-use stipulations, environmental requirements, and grid compliance. Active stakeholder engagement and legal due diligence ensure that a project can continue on schedule.

Job creation in the renewable energy sector

The solar industry supports 280,000 jobs across all 50 states, at the latest estimates. Those roles cover a range of industries from engineering and construction to operation and maintenance.

Local tax revenue generation

The presence of solar farms has been proven to significantly increase tax generation, which in turn supports the wider economy. In one study, current renewable energy projects in Texas alone were estimated to eventually add more than $12 billion in additional tax revenue over their lifetime.

Energy cost reduction

The adoption of low-cost solar energy into the national energy ecosystem helps to reduce wholesale electricity prices and stabilize long-term energy costs. Community solar projects have also been found to reduce monthly energy bills by anywhere from 5-20% for those who adopt them.