How Location and Design Affect Solar PV Performance

When you hear about solar in the news, it’s most likely about a large desert solar system that produces enough energy to power a specific number of homes, or a rooftop system in North Carolina or New York that offsets a certain fraction of a business’ energy consumption. By using complex equations, data, and simulation tools, we can determine how many homes that desert system will power, or offset “x” amount of energy for a business.

These calculations are part of the energy simulation process. Energy simulation tools are built to accurately predict how much energy a particular solar system will produce in a given year. There are several factors that can impact how much energy a solar array can produce, but they fall into two main categories.

Location, Location, Location

One key factor that will determine how much energy a system can produce is its location. Along with the distance to the equator, weather plays a significant role in determining how much solar energy can be captured in a particular area. The map below depicts how the rainy Pacific Northwest receives the least amount of solar exposure in the year, while arid Southern California and Arizona receive the most per year. Most of the US is typically in between these two extremes.


Other weather trends can also play a role. For example, the Northeast has abundant rainfall that naturally cleans panels. However, significant snowfall will reduce the amount of energy captured. California’s sunny skies allows panels to capture more energy, but the energy conversion process is slightly less efficient partly because dust is more likely to cover the panels.

The Importance of Design

Location plays a large role in determining how much energy output an array can receive, but there is plenty of room for system optimization in the design:

  • Tilt: The ideal tilt is closest to the latitude of the project. Reducing the tilt slightly will favor production in the summer months, when the panels produce the most energy in the year.
  • Orientation: The orientation, or azimuth, of a tilted module is simply the direction it is facing. Optimal azimuth is 180 degrees, or due south.
  • Shading: A shaded solar cell will not produce energy. Therefore, it is advantageous to design a system with as little shading as possible, including shade from other panels. Many solar companies use this principle to reduce the tilt of a solar system in favor of adding more modules (typically 10° for a flat roof), because the panels will leave less shade behind them at lower tilts.
  • Type of Mounting: Solar panels perform more efficiently with cooler temperatures. Although roof mounted panels can maximize property usage, ground-mounted modules and carports have more air circulation to release heat, so they will produce more energy than panels on a roof.
  • DC/AC ratio: Inverters are the device that turns the DC energy that panels produce into the AC energy that your business uses. Because inverters are often expensive, it is common practice in the industry to have higher DC power than AC power. How much energy you lose from this process depends on your location. As you go further south, the higher the DC/AC ratio can be without losing more than 2% of your overall solar energy. Typical values are between 1.1 and 1.35 Watts DC for every 1 Watt AC.
  • Electrical Wiring: The system loses a bit of energy as it passes through the wires (typically up to 2% before the inverter and up to 2% after the inverter) due to electrical resistance. Optimizing the electrical wiring for thickness, length, and material is crucial to maximize system performance and ensure safe operation of the system.

Where Do I Go From Here?

Energy simulation tools are very precise, but are often cost-prohibitive for the average consumer. Fortunately, the National Renewable Energy Laboratory (NREL) has a free software called PVWatts that allows anyone to estimate their own simulations. The standard values are based on decades of research from top-level scientists.

This brief overview outlines some of the ways that location and design can impact how much solar photovoltaic energy a system can produce, but there are many other factors. EnterSolar has years of experience designing optimal systems for commercial and industrial clients across the country, and we can help you design the best solution for your needs.

If you have any questions about the energy simulation process, please feel free to call us at 646-807-4600 or email us at

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    5 Reasons Why Garden State is the Next “Golden State”

    When it comes to the beach and sunshine, the first place that most people think of is California. It is a state filled with sunshine, and with its many supportive solar policies, California is the leader of the U.S. Solar Market.

    However, California is not the only Golden State when it comes to solar.  New Jersey also takes advantage of the sun, and here are the five reasons why New Jersey is the next Golden State.

    sunny231. Unparalleled Solar Leadership: 1,524 MW and 3rd Ranking

    According to the Solar Energy Industries Association (SEIA), New Jersey completed over 8,000 solar installations, equaling 240 MW of solar electric capacity, ranking the state 6th for solar capacity in 2014.  The cumulative 1,524 MW of solar energy currently installed makes New Jersey 3rd in the country in installed solar capacity, right after California and Arizona. In fact, there is enough solar energy installed in the state to power 241,000 homes.

    Top 10 States

    sunny23 2. Aggressive Renewable Portfolio Standards: 22 % and 4 %

    New Jersey has one of the most aggressive Renewable Portfolio Standards (RPS) in the United States, which requires local utilities to procure 22.5% of their energy from renewable energy sources by May 2021. The RPS is the fundamental driver for all the activities in the renewable energy industry because it creates a strong incentive for utilities to source renewable energy, thus creating a market for solar energy supply.

    Moreover, the Garden State shows its firm commitment to solar by having a specific 4.1% RPS requirement for solar by May 2028. That means, for every 100 kW of electricity generated in Garden State, 4.1 kW must come from the sun by 2028. 4% may not sound impressive, but it is a lot considering the 2,300 Trillion Btu energy consumed by the state per year!

    sunny233. Stronger Net Metering Policy: 2.9% and 700 MW

    On August 10th 2015, New Jersey Governor Chris Christie signed S-2420, increasing the electric power net metering capacity threshold from 2.5% to 2.9 % of total annual kilowatt-hours sold in State.  Net Metering means that a company’s meter is bidirectional, so that when the solar system generates more than the building needs, it can be fed back to the utility, and the customer can be given full retail credit for that energy production.

    According to advocates, the increase on the net meter cap will allow New Jersey to install an additional 700 MW over the next three years. In addition, unlike many other states, there is no net meter cap on the size of solar system, which allows any sized solar system to be built.


    4. Lucrative SREC Market: $331 vs $240

    The aggressive RPS creates a high demand of Solar Renewable Energy Certificates (SRECs), because in order to meet the RPS requirements, local utilities need to buy SRECs.  If utilities fail to meet the RPS, they have to face the Alternative Compliance Payment (ACP), as well as Solar Alternative Compliance Payment (SACP), which means, utilities must pay a severe penalty for that failure. The ACP is currently $50/MWh and the SACP is $331/MWh in 2015, which is a great amount of money.

    New Jersey SREC prices rallied over $240 early this week to reach the highest levels since 2012! Prices are up over 30% from this time last year. Obviously, it makes more senses for utilities to purchase cheaper SRECs than to pay the higher SACP. Thus, there should be a lasting demand for SRECs in New Jersey, driving the price high and making going solar in New Jersey lucrative.


    sunny235. Attractive PSE&G Funding Program: 40%-60%

    Again, thanks to the aggressive RPS in New Jersey, local utilities have strong motivation to roll out solar initiatives. As the largest utility in the State, Public Service Electric and Gas (PSE&G) of New Jersey launched the PSE&G Solar Loan Program in 2008. This attractive program provides participating solar system owners with a significant upfront cash payment equal to about 40-60% of the system cost, which can be repaid with SRECs over a 10 year period.

    Over the past several years, New Jersey has relentlessly promoted solar power, and deservedly earns the title of “the 3rd best state in the nation for solar”. The market will continue to be strongly driven by the solar RPS, progressive Net Metering policies, the lucrative SREC market, attractive utility incentive programs, and, of course, solar providers’ continued hard work.

    Right now there are 36,000 installed solar systems, 519 solar companies, and 7,200 people working in solar in New Jersey!

    As a leading provider of solar photovoltaic systems to the commercial marketplace, EnterSolar has helped many New Jersey businesses, including Chelten House, and Perfect Printing, leverage the power of the sun. As experts in the dynamic legislative environment, EnterSolar provides clients with real-time guidance in order to best utilize the Federal, state, and local financial incentives, and partners with clients throughout the entire solar installation process.

    Contact our New Jersey director Danny Ptak at to learn more about how solar makes financial sense for your business.

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      Renewable Energy Pledge Aims to Streamline Corporate Access to Clean Energy Projects

      Most companies want access to renewable energy on a large scale because it allows them to diversify energy supply and reduce greenhouse gas emissions (GHG) to demonstrate leadership in corporate sustainability.  And, because the cost of clean energy is declining, more companies can afford clean energy than ever before.

      To promote corporate access to affordable renewables, World Resource Institute and the World Wildlife Fund created the “Corporate Renewable Energy Principles” pledge. The pledge consists of six principles that help corporations navigate the process of becoming more energy efficient.

      The following principles aim to improve the marketplace for renewable energy:

      1. Greater choice in energy procurement options
      2. Cost competitiveness between traditional and renewable energy rates
      3. Access to long-term, fixed-price renewable energy
      4. Have access to, or drive forward, new projects that reduce energy emissions
      5. Increased access to third-party financing vehicles, as well as a streamlined process to finance projects
      6. Opportunities to work with utilities and regulators to expand choices for buying renewable energy.

      At its core, the principles’ goals are to make clean energy projects affordable, accessible, and navigable.

      Currently, 60% of US companies have public climate and energy goals to increase their use of renewable energy.  The companies that signed the “Corporate Renewable Energy Principles” – including Bloomberg, Target, Facebook, Johnson & Johnson, Unilever, and Starbucks – hope that these principles will further streamline the process to take advantage of renewable energy sources to support their business and sustainability plans.

      EnterSolar is already developing projects with a few of the aforementioned companies, including Bloomberg L.P. and Target.  Both projects enabled these companies to further develop sustainable practices, while ensuring a high return on investment.  In fact, the Bloomberg L.P. project is a landmark solar project for New York, as it is the first Remote Net Metering project for a Manhattan skyscraper.  These projects illustrate how EnterSolar can tailor solutions to maximize savings by going solar.

      EnterSolar’s values enable corporations to access renewable energy.  Find out how EnterSolar’s rigorous analysis and expertise in managing and understanding the pertinent financial policies can help you leverage the “Corporate Renewable Energy Principles” pledge.  For more information, contact 1-888-225-0270.

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