PHOTOVOLTAIC SYSTEMS

What is a PV panel?

A PV solar panel, referred to in the industry as a solar module, is constructed by connecting photovoltaic cells (or PV cells) to produce electricity. The cells are a semiconductor-based technology that converts solar radiation into direct current (DC) electricity. Solar panels for grid-connected home or business use typically use 60 or 72 PV cells.

What are the benefits of using PV solar systems?

By utilizing PV solar cells, home or business owners are able to generate electricity from sunlight saving money and avoiding the harmful pollution generated by traditional methods of generating electricity. This solar generated energy is used to offset or replace power that would normally be purchased from the utility.

What is Net-Metering?

Net Metering is a useful tool in the field of alternative energy. For owners of PV systems, net metering provides an opportunity to sell excess electricity produced to your local utility company. In North America, forty states currently have net metering policies in place. Net metering means that the amount of solar electricity produced (measured in KWh) is subtracted from your overall usage, meaning you only pay the utility for the difference (the “net” amount).

What is a grid-tied solar system?

90% of PV solar panels installed in the EU are grid-tied systems, meaning that the system is tied to the power grid (local electric power utility company). The solar power is added to the grid power, reducing the amount of power that must be purchased from the utility.

What is an off-grid solar system?

An off-grid solar energy system is where there is no connection to the utility company power grid. This type of installation requires a charge-controller, a bank of batteries and in most cases an inverter, so that electric power requirements can be met at night or during cloudy conditions.

What is “turn-key” solutions principle?

Here, at ARESE Solutions, “turn-key” principle means:

Analysis of requests, consultations whether a location chosen is suitable, proposal of possible solutions, guidance through the process and providing needed documentation (project documentation, construction approval, preparation of documentation for obtaining license for production of Electrical energy from renewable resources, preparation of requests for obtaining consent for connection to the power distribution network); equipment specification, purchase, installation, connection and configuration; trial operation, testing, ‘go live’ operation, end user training.

Besides the standard package of services based upon the “turn-key” principle, we can also offer you: maintenance of your PV plant (preventive and regular), servicing (on call/per agreement), monitoring services and preparation of daily/periodic reports, corrections of existing PV plants for performance improvement / irregularities elimination.

What are the different types of PV panels?

1. Monocyrstalline – these are made from cells created by cutting thin slices from single crystal silicon block and are higher in efficiency, but also higher in cost per watt. They are easy to spot because they have a smooth even color, usually black.
2. Polycrystalline – these are made from cells created by cutting thin slices from polycrystal silicon block and are slightly lower in efficiency, but also lower in cost per watt. Polycyrstal silicon is the “chicken nugget” of silicon, made by combining many individual crystals. They are easy to spot because they have an uneven color, usually blue.
3. Thin film – these are made by depositing a thin layer of very finely powdered silicon (amorphous silicon) or other photovoltaic material, on a substrate. These are much lower in efficiency that crystalline cells, and somewhat cheaper per watt. They are a good choice for large ground mounted utility scale solar arrays where real estate is plentiful. Their low efficiency makes them undesirable for commercial and residential applications because they consume a large amount of roof space compared to mono or poly panels.

How do I decide how large my PV solar system should be?

Call us, we will help you and offer you the optimal size and type of PV system.

What is insolation?

Insolation refers to a daily total of direct sunlight. In the solar industry it usually refers to the average daily hours of sunlight equaling 1000 watts per square meter. On average, locations within the EU will get between 4 and 6 hours of insolation per day depending on season and location.

How does shade affect the performance of a PV solar system?

One of the leading causes of power loss in a solar PV system is when part of the panel or array becomes shaded. In a panel there will usually be either 60 or 72 cells connected together. Each cell produces a certain voltage and amperage, the cells are configured and connected in a combination of series and parallel connections to produce the correct amount of power. If any individual cells performance is degraded by shade, the performance of the entire panel will fall to a point relative to the worst performing cell. Likewise, in a string of panels, the entire string suffers performance reduction to that of the lowest performing panel. A solar installation should be designed in a way such that none of the panels are even partly shaded at any point of the day.

What about cloudy days?

PV solar panels will generally produce electricity at a reduced rate under cloudy conditions. Severe clouds will interrupt the production of power.

How long will a solar panel system last?

Solar panels are known to last 40 years or longer. Solar panels are designed to withstand hail, severe wind and weather conditions assuming proper installation.

What are the maintenance requirements or other costs for a PV system?

For a grid-tied system where no batteries need to be replaced, there is typically little or no maintenance required. You might consider a periodic inspection to ensure that the panels remain clear of leaves, dirt, bird droppings etc. Other than that, unless there is an equipment failure there should be no maintenance required.

What is the warranty on a PV solar system?

Typical guarantees of a solar panel include 10 ~15 years workmanship and materials warranty and a 20-30 year performance warranty.

Can I power my entire building with solarpanels and disconnect from the utility company?

Yes you can. In an off-grid installation, you must have batteries, a MPPT charge controller and an inverter – in some cases the batteries will cost nearly as much as the solar panels and only last 6-8 years before replacement becomes necessary.

How much will I save, how quickly will a system pay for itself?

This will vary depending on the local cost of electricity, state and local rebates or incentives, and the installed cost of the solar panel system. The range can be from 3-4 years up to 10 years and even more depending on these factors.

What does a solar PV system cost?

Because of the wide range of variables in system size and installation requirements it is impossible to state the cost of a system. It is important to realize that the cost of the panels themselves usually represent about 1/3 of the total turn-key cost.

Please contact us in order to determine precisely the costs of the PV system.

How long does it take to install a PV system?

A typical residential roof installation can be completed in 2-3 days. The number of panels and type of installation will affect the installation process.

LED LIGHTING

What are LEDs?

LEDs are light emitting diodes. These are electronic components that convert electrical energy directly to light through the movement of electrons within the material of the diode. LEDs are important because due to their efficiency and low energy, they are beginning to replace most conventional light sources.

How do LEDs work?

LEDs are comprised of 3 main components: the LED’s (the chip set that produces light), the driver (converts AC to DC) and the heat sink (to keep everything cool). LEDs take DC power from the driver and create light. The heat sink captures heat from the LEDs and the drivers. Although LEDs produce significantly less heat than the light bulbs we have been used to over the past century, the heat they produce must be managed. The better this is done, the longer the life of the product.

LED’s also performs the job of converting electricity to light more efficiently than other light sources, that is why we can replace a 400W metal halide bulb with a 100W LED retrofit.

What are the benefits of replacing ordinary bulbs with the LED?

There are many benefits. Here is a list of a few:

  • An immediate reduction in your electricity bill
  • Less heat. LED fixtures are extremely efficient converting electricity into light
  • LED Bulbs last a very long time, typically 50,000 to 100,000 hours
  • They are virtually indestructible
  • They do not contain mercury or other hazardous materials
  • Highly recyclable – with no hazardous parts, you can easily reclaim most of the parts in an environmentally safe way.

How much money can you save when converting to LED?

It all depends what you are converting. Incandescent to LED, fluorescent to LED, Metal Halide to LED. But it is not uncommon to see at least a 70%+ savings on your energy consumption.

Can LED bulbs be used with dimmer controls?

YES and NO.

First, not all LEDs are dimmable. The driver must be designed to allow dimming. Secondly, you must purchase the right type of dimmer. Most retail stores now carry dimmers specifically designed for LED bulbs. Please note, if you purchase a non-dimmable LED bulb and try to dim it, it will cause the bulb to fail and also void the warranty.

Some of our industrial and commercial LED fixtures (high bays, floods, area lighting, retrofits) work with a 0-10V dimming system. 0-10V dimming requires special wiring and a special type of dimmer.

The two most common types of dimming is: 0-10V low voltage and Triac dimming.

What color temperatures are available with LED bulbs?

Color temperature for light bulbs is measured on the Kelvin scale. LED Bulbs come in a variety of colors, but the most common are in a range from 2700K to 7500K. The unfortunate thing is that the only consistent measurement is the Kelvin scale, Many manufacturers like to use terms like Day White, Natural White, Warm White and Cool White, but there is not a standard that defines a Kelvin temperature to associate with those terms. The general rule is WARM (2700K) to COOL(6500K+). The warmer the light, the more yellow tones, the cooler the light, there are more blue tones.

Here are the typical range of color temperatures:

* 2700-3200 – WW – Warm White
* 4000-4500 – NW – Natural White
* 5000-5500 – DW – Day White
* 6500-7500 – CW – Cool White

What type of bases are available?

LED Bulbs are the perfect retrofit for your existing light fixtures. There are standard bases, candelabra, standard or Edison (E26) , mogul (E39), MR16 and other typical bases that are common with incandescent and halogen installations. For fluorescent tubes, there are  bi-pin, single pin and HO Ends. Also there are PL based bulbs in G23, GX23, G24 and GX24 bases. The most commonly used types of bases are: Е14, Е27, Е40, MR16, GU10, G9, G4, R7S, AR111, PL  etc.

When I buy LED, should I buy based on watts or lumens?

Always buy based on lumens, watts is a number that is used to determine how much energy it takes to produce those lumens. It is important to pay attention to lumens per watt, or lm/w. The higher the number, the less energy you will need to produce the light. You will notice that some lights take less energy to produce the same amount of light, and this is something you should watch for. Typically, the higher the ratio, the better

What component of the LED system is typically the first to fail?

Almost always, it is the driver. That is why it is important to know who makes the driver in the LED fixture or retrofit you purchase. Brand names like Meanwell and Philips are good. A LED product with a 1 or 2 year warranty is an indication of how good the driver is in that product. Typically a good driver should last more than 50,000 hours.

What is the most common reason LEDs fail?

Heat. Heat is the enemy of electronics, the hotter it is, the shorter the light. However, with good design, you can create a light or fixture that can withstand some high heat environments. Typically a fixture or bulb with an external driver will last longer than an integrated fixture that has the LEDs and driver as one unit.