Frequently Asked Questions

  •  When is GRECO founded and where is its factory?

    GRECO is founded in Hong Kong in 2010 as a green energy group of companies. The company designs and develops highly reliable and the most efficient photovoltaic solar panels, Solar powered lighting systems, and produce these products through its dedicated manufacturing factories. Our main manufacturing factory is based in Jiangsu, China.

  •  What is your current manufacturing capacity? How many quantity you have shipped?

    We have total 600MW manufacturing capacity of mono and polycrystalline solar panels in 2021, as well as 200,000 sets Solar lighting systems. By end of 2020, we have shipped an accumulative quantity of over 2.60GW to our customers in Germany, Italy, France, Spain, USA, Australia and other countries.

  •  What about your product certification and warranty?

    GRECO produces its solar panels and solar powered lighting systems through its dedicated manufacturing factories. All our GRECO products are sold with the factory original certificates and 25-year factory warranties.

  •  How can we purchase your products?

    GRECO sells its products through authorized official distribution partners. If you prefer to deal with us directly, please send an inquiry by email to

  •  How long is your lead time and how will you ship our order?

    Our standard lead time is 15 days after receiving your order and down payment. While the exact time differs from order to order, we promise to ship as earlier as we can. We benefit from the global network of our logistic partners that are able to ship your order to virtually any places in the globe.

  •  How can we track our order and your shipment?

    We will finish and ship your order from our site normally within 15 days. Our sales representative will keep you informed along all the steps until shipment. We will send you relevant custom documents (bill of lading, packing list and invoice) once we have completed exportation procedures.

  •  What is a solar LED street light?

    Solar LED street light is the street light consisted of crystalline silicon photovoltaic solar panel (supply power), smart controller, lithium or lead-acid battery (stock power), LED light source and other components. An extra PIR sensor can provide smart control capabilities or multi-function extensions.

  •  What are the advantages of GRECO integrated solar lights?

    The GRECO all-in-one integrated solar light features an efficient solar panel, long lifespan lithium batteries, bright LEDs, intelligent controller and PIR sensor, all of which have been integrated into one cabinet. The integrated solar light is easy to install—it takes two workers only about five minutes to finish installation and no heavy equipment is required.

  •  What are LEDs?

    LEDs are light-emitting diodes, or electronic components that produce light by converting electrical energy directly to light by the movement of electrons within the material of the diode. Because LEDs are highly efficient, they are beginning to replace most conventional light sources.

  •  How do traditional light sources and LED light sources compare?

    LED light sources are normally 30-50% more efficient than most traditional light sources.

  •  Why is LED technology called solid-state lighting?

    The term solid-state lighting is used because the electronics produce light directly from solid materials in which the electrons are embedded. This is unlike other technologies; for example, fluorescent technology requires a gaseous discharge medium to initiate production of light.

  •  What are the advantages of switching to LED?

    LEDs have no gases, filaments or other moving parts. They provide light through a one-step process that takes place within the diode. You don’t have to worry about broken glass or other parts breaking or coming loose.

  •  How do solar panels work?

    Solar panels are made of semiconductor materials like silicon, along with phosphorous and boron which create conductivity within the cell and activate the movement of electrons. When activated by the sunlight’s energy, the electrons move across the cell and into the electrical circuit attached to the solar panel.

  •  How much maintenance do solar panels require?

    Solar photovoltaic panels require very little maintenance. It is, however, important to place panels where they will remain relatively clean, and clear of shade and large debris.

  •  How much shading is too much for photovoltaic solar panels?

    Shading a photovoltaic solar panel will decrease its power output. Just shading the bottom row of cells alone amounts to nearly 80% reduction in efficiency.

  •  Do I need to have southern exposure to install solar system?

    Although southern exposure helps increase the energy yield of a residential roof-top solar system installation, your home may still work for solar power without having south-facing exposure. Seek advice from a professional solar photovoltaic designer or installer to ensure the suitability.

  •  What is a controller?

    Controllers are very important for solar street lights because they can remotely turn lights on or off. Some modern controllers are programmable so that the user can decide the appropriate amounts of charging, lighting and dimming.

  •  What type of controller should I use with high voltage solar panels?

    One of the ways to get full power out of high voltage on-grid solar panels is to use an MPPT controller. Since most MPPT controllers can take up to 150 volts DC (some can go up to 600 VDC) on the solar panel input side, you can often series two or more of the high voltage panels to reduce wiring losses or use smaller wires. With the 175 watt solar panel for example, putting two of them in series would give you 66 volts at 7.6 amps into the MPPT controller, but the controller would convert that to about 29 amps at 12 volts.

  •  What is a lithium-ion battery?

    A lithium-ion battery is a rechargeable battery in which lithium ions move from the negative electrode to the positive electrode during discharging and back during charging.

  •  How long does the lithium-ion battery last?

    Normally more than five years. If you are using double batteries interactively, they would have an even longer life.

  •  What are the installation requirements of integrated solar lights?

    1. Protect the solar panel from sharp/hard objects
    2. Clean the solar panel to maintain its conversion efficiency
    3. Avoid sheltering or shading the solar panel
    4. Make sure the solar panel faces the sun in order to absorb maximum sunlight

  •  Is it easy to maintain the integrated solar lights?

    The all-in-one design with modular structure is easy to check, maintain, and replace as necessary.

  •  What is the evaluation index of roadway illumination?

    1. Car lane: average illumination, illumination uniformity and lengthways uniformity, glare limit, surround ratio and inductivity
    2. Sidewalk: average illumination, mix illumination and vertical illumination