Solar irradiance, the measure of sunlight reaching the Earth's surface, plays a crucial role in determining optimal locations for solar energy production. Across the United States, solar irradiance levels vary significantly due to differences in geography, climate, and atmospheric conditions. Understanding where solar irradiance is the highest can help identify prime regions for harnessing solar power effectively.
Where is Solar Irradiance Highest in The U.S.?
Solar irradiance is highest in the southern and western regions of the United States, making it an ideal region for solar farms. However, across the country, photovoltaic (PV) systems perform effectively as they can capture both direct and diffused sunlight, ensuring a versatile energy solution. Ultimately, the energy output of any solar system depends on the amount of sunlight that reaches a specific location, highlighting the importance of site conditions in determining efficiency.
Which States Have the Highest Solar Irradiance?
Arizona, New Mexico, Nevada, California, Florida, and Texas are the states with the highest solar irradiance. These states receive the most sunlight on average due to their geographical location, climate, and terrain. This makes them ideal locations for solar energy production and has led to significant investments in solar infrastructure in these areas. Additionally, these states have implemented policies and incentives that have encouraged the growth of solar energy, making them leaders in renewable energy adoption.
Solar Irradiance in Arizona
Arizona is renowned for its vast deserts and abundant sunshine, making it one of the best locations in the United States for solar energy production. The state experiences clear skies for most of the year, with an average monthly solar irradiance of approximately 198 kWh/m². Thanks to its favorable climate, Arizona has become a hub for both residential and large-scale solar installations.
Phoenix, the state’s capital, enjoys an impressive average daily solar irradiance of 6.58 kWh/m², one of the highest in the nation. The summer months, especially June and July, see peak solar potential, offering optimal conditions for energy generation. Arizona is also home to some of the largest solar facilities in the country. With state-level policies promoting clean energy growth, Arizona continues to solidify its position as a key player in the solar industry.
Solar Irradiance in New Mexico
New Mexico’s high-altitude terrain and arid climate make it an exceptional location for solar energy generation. The state receives an average monthly solar irradiance of approximately 194 kWh/m², placing it among the top states for solar potential. Known for its expansive landscapes, New Mexico has leveraged its natural advantages to advance large-scale solar projects and support widespread renewable energy adoption.
Albuquerque, the largest city in New Mexico, enjoys an average daily solar irradiance of 6.48 kWh/m², providing ample sunlight for residential, commercial, and utility-scale solar applications.
The state is home to several large solar farms, including the New Mexico Wind and Solar Project, which contributes significantly to the region’s renewable energy grid. In fact, the State of New Mexico has even leased much of its state-owned land for solar farms. With state policies focused on achieving 100% renewable energy by 2045 under the Energy Transition Act, New Mexico is fostering a sustainable energy future while capitalizing on its exceptional solar resources.
Solar Irradiance in Nevada
Nevada is one of the top states in the U.S. for solar irradiance, benefiting from its arid climate and minimal cloud cover. The average monthly solar irradiance in Nevada is approximately 193 kWh/m². The state receives abundant sunshine throughout the year, making it an excellent location for solar energy generation. Nevada has leveraged this natural advantage by investing heavily in solar infrastructure, including numerous large-scale solar farms. Additionally, supportive renewable energy policies and incentives have spurred the growth of residential solar installations, further cementing the state's position as a leader in solar energy production.
Solar Irradiance in California
California stands as the nation’s leader in solar photovoltaic (PV) energy, boasting the highest installed capacity among all U.S. states. By June 2024, the Golden State had achieved an extraordinary milestone with 48 gigawatts of cumulative solar power, cementing its reputation as a pioneer in renewable energy innovation and as one of the best locations for solar energy development.
In California, the average monthly solar irradiance is approximately 189 kWh/m², highlighting the state’s abundant solar potential. Sacramento, the state capital, enjoys an average daily solar irradiance of 6.21 kWh/m², making it an ideal location for harnessing solar energy. August stands out as the peak month for solar irradiance across California, offering the highest levels of sunlight.
Solar Irradiance in Florida
Known as the "Sunshine State," Florida lives up to its nickname with abundant solar irradiance throughout the year. While its tropical climate brings occasional overcast days and rain, Florida remains one of the most solar-friendly states due to its high annual sunlight exposure and relatively flat terrain. The state experiences an average monthly solar irradiance of approximately 171 kWh/m², making it an attractive location for solar energy systems.
Orlando, a central hub in Florida, enjoys an average daily solar irradiance of 5.67 kWh/m², demonstrating the state’s considerable solar potential. Florida’s peak solar generation typically occurs in the spring months, when clear skies and milder temperatures create optimal conditions for energy production. Solar installations in Florida range from residential rooftop systems to large-scale solar farms, which helps meet the growing energy demands of the region. With continued investment in renewable energy infrastructure and support from state policies, Florida is emerging as a powerful player in the U.S. solar energy market.
Solar Irradiance in Texas
The sprawling plains of Texas provide the perfect setting for solar farm development. With abundant sunlight and vast open land, the state is uniquely positioned to lead in solar energy production. Texas’s strong commitment to renewable energy, paired with a favorable regulatory environment, has made it a magnet for solar industry investment.
Texas ranks second in the nation for installed solar capacity, which is expected to double by 2025. With an average of approximately 162 kWh/m² per month, Texas boasts ample sunlight throughout the year, making it an ideal location for both residential and utility-scale solar projects. In Q3 2024 alone, the state added an impressive 2.4 GW of solar capacity. Home to some of the largest solar farms in the U.S., Texas now accounts for 26% of all new solar capacity introduced in 2024, cementing its status as a leader in renewable energy innovation.
Where is Solar Irradiance Lowest in the U.S.?
The states bordering the Great Lakes, like Minnesota, Wisconsin, Michigan, New York, and New England have the lowest solar irradiance. These regions experience more cloud cover and have cooler climates, resulting in lower levels of solar radiation compared to states like Arizona, Nevada, and New Mexico. Despite these challenges, advancements in solar technology and improving economics have made it possible for these states to also harness the power of the sun. For example, Minnesota has made significant strides in recent years towards achieving its renewable energy goals by making investments into solar research and development.
Factors Affecting Solar Irradiance
Solar irradiance is largely influenced by latitude, with regions closer to the equator receiving more direct sunlight than those farther away. The sun's angle is another crucial factor—higher angles result in greater solar energy reaching the Earth's surface. Additional elements, such as cloud cover, air pollution, and terrain, also significantly affect solar irradiance. States with clear skies and minimal pollution typically experience higher levels of solar exposure. Furthermore, solar irradiance varies throughout the day and across seasons, reflecting changes in sunlight intensity and duration.
Additional Land Requirements for Solar Farms
Although important, solar irradiance is not the only thing that impacts an area's suitability for solar energy production. Other factors that impact whether or not land is suitable for a solar farm are acreage, government incentives, and proximity to energy grid infrastructure.
Acreage Required for Solar Farms: Utility-scale solar farms typically require around 30 buildable acres of land, while smaller sites ranging from 5 to 10 acres are better suited for community solar projects. On average, each megawatt (MW) of solar capacity demands approximately 2 acres of space.
Proximity to Energy Grid Infrastructure: Properties near electrical grid infrastructure, such as substations and transmission lines, are highly suitable for solar energy due to reduced costs for connecting the solar farm to the power grid. Ideally, sites within four miles of a substation and half a mile of a transmission line offer the greatest advantages for solar farm development.
Government Incentives for Solar Energy Production: Government incentives for clean energy production vary widely across the country, with a growing emphasis on promoting solar energy development. If you live in an area with strong solar incentives, leasing your land for solar panel installation could significantly increase its value. Programs like Renewable Energy Certificates (RECs) and various tax incentives, such as sales and use tax exemptions, state median property tax reductions, and state sales tax exemptions, all contribute to determining the value of solar energy projects.
Leasing Land for Solar Farms
Solar irradiance plays a crucial role in determining the viability of solar energy projects across the United States. With abundant sunlight resources available in various regions of the country, states like Arizona, Nevada, New Mexico, Texas, California, and Florida have emerged as leaders in solar energy production. The continued investment in renewable energy infrastructure, coupled with favorable state policies and natural advantages, have made these states key players in the solar industry, paving the way for a sustainable and cleaner future.
To determine your land's solar irradiance, landowners can access a free property report using LandGate. LandGate's free property reports provide detailed information about your property's solar potential, helping you understand its viability for solar energy projects. If you're interested in leasing your land for a solar farm, LandGate also allows you to list your property for lease for solar farms at no cost. By doing so, you can connect with potential developers and take the first step toward maximizing the value of your land through renewable energy initiatives.
