Using a sun chart to place solar module panels

The placement of solar module panels is arguably one of the most crucial factors in designing a good solar power system. Sun exposure will help determine if the solar module panels will have enough sunlight exposure to provide power for your needs. How do we determine if your site has optimal sunlight exposure? One tool we use is a sun chart.

We can create a sun chart to plot how much direct sunlight your site will be exposed to each day. The sun chart helps us first to determine if solar power is a good option for a client, and then helps us evaluate where to place solar module panels. The sun chart shows the movement of the sun across the sky, and shows us the approximate amount of sunlight the site will receive over the year.

We use two angles to plot the position of the sun. The azimuth is the angular distance of the sun from a fixed line. Here in New Jersey or Pennsylvania, we use a line that runs directly south, because solar module panels are placed south-facing in the northern hemisphere. For example, at noon, the sun is directly overhead in the sky, so the azimuth angle is zero.

The second angle used to chart the sun’s position is the elevation angle. It is created using a line which is parallel to the ground and a line running from the ground up to the sun. For instance, at noon, the angle is 90 degrees. At sunset when the sun is on the horizon, the angle is zero. These two angles are used to graph the sun’s movement through the sky over a period of a day.

The sun chart can be used to plot the sun’s movement in the sky throughout all four seasons. The changing seasons affect the length of sun exposure each day. Charting the exact sunlight exposure for each season will help us determine the correct amount of solar module panels you’ll need to power your home or business through even shorter days, like the summer and winter solstices.

A sun chart also accounts for impediments in the skyline. Things like trees, buildings, and towers can block the amount of sunlight your site receives. The sun chart allows us to determine if these impediments will prevent your site from receiving adequate sunlight exposure. We may find that your roof is not an optimal location for placement of solar module panels, but there is an area of your yard that receives perfect exposure where solar module panels can be mounted.

Why hire a contractor to install solar panels

Doing it yourself is very tempting for many household projects. Doing it yourself can save you hassle and money. Many can be tackled just fine by a homeowner, but there are some that are better left to the pros. Installing solar panels is one task that you are better off hiring a contractor for.

Designing a solar power system and installing solar panels is a complex process, and many elements factor in to the final plan. Choosing an experienced contractor to handle your installation will help you avoid errors and unnecessary costs. Before the system is even installed, there are several considerations a contractor will help with. Permits and inspections may be necessary, depending on where you live. Your contractor will deal with the often time-consuming, confusing task of obtaining permits for your job.

Doing it yourself can have some pretty big disadvantages. If you are looking to tie into the utility grid, the power company may not permit connection if an approved contractor doesn’t install your solar panels. Plus, your homeowner’s insurance may not cover a self-installed system. Plus, if you install solar panels yourself, you won’t get the same warranty you would if using a contractor.

Choosing a contractor to install solar panels offers many distinct advantages. They have experience doing this work, whereas you most likely don’t. A good contractor knows how to design and install solar panels so they will work as expected- do you? If you don’t install solar panels properly yourself, individual warranties may not be honored and you’ll have a harder time working out the kinks in your system. Plus, using a contractor can help you get a better price on equipment because they have greater buying power. Some manufacturers won’t even sell to self-installers, so using a contractor is your best bet for getting great equipment at a great price.

There are many more advantages to using a contractor for installing solar panels. Installing solar panels is a big investment- protect it by making the right choice from the get-go. Looking for a trusted contractor to install solar panels in New Jersey or Pennsylvania? Contact Smith Sustainable Design today.

Going off the grid: solar installation needs

Going off the grid is different than a solar installation which will be tied to the grid. Off the grid, your solar installation must provide for all your power needs, you won’t have utility backup power to depend on. Off-grid solar installations require a few additional elements that aren’t needed for a grid-tied solar installation. Below is a list of the components you may find in an off-grid solar installation.

Battery Bank

The battery bank is an essential component of an off-grid solar installation. It stores extra electricity which isn’t immediately used, and will power a home or business through periods where sunlight is not optimal. The bank is usually composed of multiple individual batteries arranged as a series or in parallel, which are connected via cables.

Charge Controller

The solar installation’s charge controller is the component which feeds collected current into the batteries in the bank. The charge controller has a big impact on the economics of the solar installation. To make the most of your solar power, you’ll need a charge controller that can maximize the performance of the batteries in the bank.

Inverter

The inverter component switches DC voltage to the AC voltages which are needed to power most household devices and appliances. If only DC voltages are used in the facility, an inverter may not be necessary.

DC Loads Controller

A DC loads controller is needed in installations where DC and AC voltages are needed, and maintains the necessary voltages and currents for DC loads.

AC Generator

The AC generator isn’t a necessary component for your solar installation, but is useful for providing backup power during periods where solar collection isn’t optimal.

AC Loads Controller

Like the DC loads controller, the AC loads controller maintains appropriate voltages and currents for the AC appliances which are being operated.

Transfer Switch

The transfer switch is used to switch between power coming from the inverter and power created by the AC generator.

How large should my photovoltaic solar system be?

Photovoltaic solar systems are not “one size fits all.” Each household and business has different requirements, which will help determine the size of the system needed. To get an idea about the size of the photovoltaic solar system you’ll need, the following are factors we figure and consider when designing a new photovoltaic solar system installation:

1.  Determine the total number of watt hours of energy will be needed each day. Put together a list of all the appliances and devices which are in use every day. Next, list how many hours that each device runs throughout a typical day.

2. Find your peak power output. Using your list of appliances and devices, determine the power draw of each device in watts- approximate power usage for household appliances and devices can be found online. To find your peak power output, determine which devices will be operating at the same time throughout the day. Add up the watts of all devices which will be used together to find the highest wattage that will be needed at any one time during the day.

3. Determine the duty cycle. If you’ll be installing a photovoltaic solar system for your primary residence, it’ll likely be in use 7 days a week. On the other hand, photovoltaic solar systems in use for offices and businesses may get a break in use over the weekend period when operations are shut down.

4. Estimate the number of good sunlight hours a location should receive. Sunlight hours can vary from day to day due to seasonal changes and weather conditions. If an installation location for a photovoltaic solar system will only be in use seasonally, such as a vacation residence or a business with seasonal operation, this factor will also be considered.

To learn more about sizing your photovoltaic solar system, contact Smith Sustainable Design. Our team installs photovoltaic solar systems for home and business owners in New Jersey and Pennsylvania.