Where Is Solar Energy Most Effective In The Us?

Solar energy has experienced tremendous growth in the United States over the past decade. As costs have fallen dramatically for solar panels and installation, more homes and businesses are adopting solar to meet their energy needs in a clean and renewable way. The growth of the solar industry has also created hundreds of thousands of jobs across the country.

However, the effectiveness of solar energy differs across the U.S. based on several key factors. Solar panels work by converting sunlight into electricity. Therefore, areas that receive more annual sunlight have higher solar electricity generation potential. State and local policies also play a major role, as incentives and favorable net metering laws can encourage solar adoption. Other factors like utility electricity rates, population density, and land availability also impact the growth of solar.

Understanding why solar thrives more in some areas over others is important for policymakers working to expand renewable energy nationwide. It also assists solar companies in marketing and strategic planning. For homeowners and businesses considering installing solar panels, these insights provide guidance on ROI feasibility based on location.

Solar energy is most effective in parts of the United States that receive high levels of solar radiation, or insolation. Insolation is a measure of solar radiation energy received on a given surface area over a period of time. It is commonly expressed as average daily kilowatt-hours per square meter per day (kWh/m2/day).

Solar Insolation Levels

The American Southwest region has some of the highest solar insolation levels in the United States. This area includes California, Nevada, Utah, Arizona, and New Mexico. According to the National Renewable Energy Laboratory’s PVWatts tool, cities in this region can receive 5-7 kWh/m2/day of solar radiation on average. For example, Daggett, California averages 6.59 kWh/m2/day and Phoenix, Arizona averages 6.08 kWh/m2/day.

The sunny, arid climate of the Southwest provides excellent conditions for solar power generation. With high amounts of cloud-free days and greater solar intensity, solar panels in this region can produce more electricity per installed capacity than anywhere else in the nation.

State Solar Policies

The policy environment in each state plays a major role in determining where solar energy will thrive. State governments set regulations, incentives, and programs that either accelerate or hinder solar adoption. As a result, some states have significantly friendlier policy landscapes than others.

California, New Jersey, and New York stand out as having the most solar-friendly policies in the country. These states have implemented strong net metering laws, robust solar incentives, and ambitious renewable portfolio standards that mandate utilities to source a set percentage of power from renewables. For example, California requires 60% renewable energy by 2030 and 100% by 2045. The state also offers generous cash rebates, property tax exemptions, and innovative programs to expand access to solar.

In contrast, policies in some Midwestern and Southern states discourage rooftop solar. Utilities in these regions have successfully lobbied for high fixed charges on solar customers, restrictions on net metering, and even solar panel taxes. Without policy reform, solar growth will remain limited in these states regardless of their solar resource potential.

Ultimately, state governments play a pivotal role in catalyzing solar energy adoption. Supportive policies that establish strong incentives, phase out barriers, and set ambitious renewable targets can rapidly accelerate solar deployment.

Utility Rates

Electricity rates play a major role in solar adoption, as higher utility rates make solar more cost competitive. Hawaii, Alaska, and California consistently have some of the highest electricity prices in the U.S., largely due to their remote locations and reliance on imported fossil fuels.

For example, Hawaii has the highest average residential electricity rate at 34.54 cents per kWh, more than triple the U.S. average. High electricity prices make rooftop solar financially viable, even with Hawaii’s below-average solar resources. The economics of solar improve further with state tax credits and net metering policies. As a result, Hawaii has the highest rooftop solar adoption rate in the nation, with over 14% of homes powered by solar panels.

Similarly, California has the 2nd highest electricity prices nationwide, averaging around 22 cents per kWh. Combined with ample sunshine and robust state solar incentives, high utility rates have made California the state with the most installed solar capacity. However, as California’s grid increasingly relies on solar generation, electricity rates have begun falling during peak solar production times, eroding some of the savings from rooftop systems.

Overall, places with high utility electricity costs stand to benefit the most from generating their own solar power. As solar costs continue to decline, even average electricity prices can start to justify rooftop solar purely on economics, opening the door to mass adoption.

Population Density

Population density plays an important role in determining where solar energy is most viable in the United States. More sparsely populated suburban and rural areas tend to be better suited for solar installations than densely populated urban cities.

High-rise buildings and limited roof space in crowded cities mean fewer opportunities for solar panels. Suburban neighborhoods with single-family homes, on the other hand, often have ample unused rooftop real estate to generate solar electricity. While rural areas have even more potential space for ground-mounted solar arrays, long transmission lines make distributed rooftop systems more practical near suburban population centers.

Solar capacity does not increase linearly with available land area. Suburban locales hit the sweet spot, with robust distributed solar potential that avoids transmission inefficiencies. As population density increases, rooftop solar becomes less viable. And extremely low rural density creates solar hot spots far from demand centers. For these reasons, solar thrives best in the suburbs.

Land Availability

To effectively utilize solar power, homeowners and businesses need adequate roof space or land area for installing solar panels. For residential systems, the roof needs to face southward (in the northern hemisphere) and not be shaded by trees or other buildings. Larger commercial and utility-scale systems require substantial open land on which to build solar farms. Ideally, solar farms need at least five acres of flat, unshaded land in a sunny, remote location. While solar can work in urban areas, there are more siting challenges compared to rural locations with abundant open space. Solar farms are proliferating most in desert regions of the American southwest that offer ideal conditions.

State Solar Incentives

Many states offer incentives to make going solar more affordable. These include tax credits, rebates, solar renewable energy credits (SRECs), net metering, and financing options. Some of the top state solar incentive programs are in California, New York, New Jersey, Massachusetts and Colorado.

California has some of the most generous incentives, including an income tax credit for systems under 1MW and property tax exclusions. The state also has a Self-Generation Incentive Program (SGIP) which provides rebates for solar system installation. California’s net metering policy allows solar customers to get credit for excess energy sent back to the grid.

New York offers a 25% income tax credit up to $5000 for residential systems and varying incentives for commercial installs. New solar owners can also sell SRECs on the NY-Sun Solar Market, which provides additional savings. Municipalities and utilities often have local rebate programs as well.

New Jersey has an income tax credit called the Solar Renewable Energy Certificate Registration Program (SREC-RPI), which provides a rebate based on system size and energy production. This makes New Jersey one of the most lucrative markets for residential solar.

The top states for solar incentives make installing a PV system more affordable through tax credits, rebates, and other funding programs. Check your state and utility’s websites to find available solar incentives where you live.

Cities With Most Solar

When looking at cities with the most total solar capacity, many of the top cities are located in sun-rich states like California, Arizona, and New Jersey. The cities of Los Angeles, San Diego, Phoenix, Tucson, San Jose, and Fresno have emerged as leaders in total installed solar capacity thanks to their high solar insolation levels and abundant sunshine. These cities also tend to have high electricity rates, which makes installing rooftop solar financially beneficial for residents and businesses looking to reduce utility bills. In addition, cities in states with strong net metering policies and solar incentives like California and New Jersey have seen booming solar adoption. However, large populations and sprawling development patterns also contribute, as these cities simply have many more potential sites for solar panels across countless homes and commercial buildings. The combination of policy support, financial incentives, and untapped rooftop real estate has allowed cities in the sunny southwest and northeast to rise to the top for total solar PV capacity.

Rural Challenges

Rural areas can present unique difficulties for solar adoption compared to more populated cities and suburbs. Some key challenges include:

• Lower population density – There are fewer homes and businesses spread across large areas, making solar less cost-effective.
• Limited solar incentives – Rural areas often lack access to municipal and utility solar incentives available in more populated areas.
• No net metering – Utilities in rural areas sometimes don’t offer net metering, reducing financial incentives.
• Transmission constraints – Weak grid infrastructure in remote areas can make integrating solar generation difficult.
• High soft costs – Smaller markets mean less competition and higher non-hardware costs for rural solar.

However, there are some bright spots and innovative programs aimed at expanding rural solar access:

• Community solar – Rural electric co-ops are utilizing community solar to provide solar access without onsite installations.
• USDA grants – Federal grants specifically target solar development in agricultural and rural areas.
• Non-profit programs – Groups like GRID Alternatives are running programs to provide free or low-cost solar for low-income families, farms, and tribes.
• New financing models – Options like solar leasing allow rural residents to adopt solar with little or no upfront costs.

With smart policies and programs tailored to rural areas, solar can continue expanding its reach across all segments of the country.

Conclusion

There are several key factors that determine the optimal locations for solar energy in the United States. These include solar insolation levels, state solar incentives, utility rates, population density, and land availability.

Based on these criteria, the Southwest region of the U.S., including states like California, Arizona, New Mexico, Nevada, and Texas, have abundant sunshine and high solar potential. Other states with strong solar resources include Florida, Hawaii, Colorado, Utah, and parts of the Southeast.

Rural and desert areas often have the most favorable conditions for large-scale solar farms, while rooftop solar can thrive in populated cities with strong financial incentives. However, solar technology is improving and becoming more affordable every year. This means many regions that are currently less ideal could support growing solar capacity in the future.

With careful planning and supportive policies, communities across America can take advantage of their solar resources. Widespread adoption of solar energy will lead to a more sustainable energy system nationwide.