We hope to help you clarify all your doubts and for this we present this list of questions and answers of each topic. In any case, we invite you to contact us to provide personalized advice.

Photovoltaic System

What is an Interconnected Photovoltaic System?

It is a set of components that by means of photovoltaic technology harnesses the sun's energy to produce electrical energy for use either domestic, commercial or industrial and is linked or connected to the local electrical network (CFE).

How does an interconnected photovoltaic system work?

Does it use batteries?

There is the option of installing batteries, however, they are regularly used for non-interconnected equipment that are usually to supply moderate energy demands, in most cases in remote communities with zero access to the CFE network. The main reason that an Interconnected System is more advisable is due to the high costs of the batteries that must be replaced periodically as well as to the lower efficiency in the systems since they have limited storage and require more components, all this making it an investment less profitable.

It is expensive?

It is very cheap if you consider that, depending on your current rate, it is like paying 2 to 4 years of energy in advance so you do not have to pay it again in the next 40 years. Of course, it can be considered an important investment that will depend directly on the amount of electricity you require. In any case, you start receiving the benefits from the first month.

How long does it last?

The useful life of a panel of good quality is between 35 and 45 years depending on atmospheric conditions such as the intensity of solar radiation and salinity in the environment.

How much does a panel cost?

It is a very common question, however, we do not sell panels separately but turnkey systems that include calculation of needs, design, installation, procedures with CFE and all necessary components such as power inverter, structures, wiring, etc.

We invite you to contact us to request a personalized and specific quote to your needs.

How much can I save?

You can get a monthly savings of up to 99% of your current electricity cost depending on several factors such as:

  • Current consumptions
  • Current and residual rate with CFE (residential, commercial, industrial, agricultural irrigation, etc.)
  • Available spaces for installation.
  • The capital you want to invest.
We invite you to contact us to give you an accurate analysis of your savings expectation.

How do I know if I should buy a system?

If your interest is environmental, convenience is absolute in all cases. If your interest is economic savings, the first thing you should consider is the current cost of your energy since currently some CFE rates have significant subsidies making them very competitive such as subsidized residential or 01, agricultural for water extraction or industrial among other. This can make the return on your investment be extended to many years reducing economic convenience.

It is very convenient for you if you are in a residential high consumption, commercial rate or if you pay more than $ 2,000 bimonthly pesos.

Also if your rate is residential with subsidy but you are about to install air conditioning or plan to increase your consumption considerably with some electronic equipment.

We recommend you send us your energy bill to receive advice, if you do not have it, do not worry, contact us to advise you and find the best option for you.

What guarantee does it have?

The equipment has different specific guarantees for each component, and the controlled panels have a 10-year factory defect guarantee as well as the 25-year power production where at the end of that time they require at least 80% of their capacity initial. Inverters have 5 year warranties and can extend them to 10 years and the installation has a 2 year warranty.

How many panels do I need?

This should be determined through an in-depth analysis where we must consider the geographical location of your property as well as your energy requirements which we can do by reviewing the history on your current energy bill with CFE. Contact us to perform a calculation and define the best option to meet your needs.

What happens if my property is new or I have no history of consumption?

Do not worry, although we will require a slightly more complex method where we must contemplate all the charges (electrical equipment) and calculate their use time as well as the amount of energy each consumes. With our advice we can identify your needs as well as the system that suits you. Contact us to provide personalized advice.

Can I increase or decrease the size of my equipment at some time?

Yes, because the equipment is modular you can increase the size and production capacity of your system at any time if the space and conditions of the system are adequate. You can also reduce the size of your equipment if you decide, but for this you must consider the technical conditions of your power inverter to ensure its proper functioning. If feasible you can get to use your removed panels to integrate another system and use it in another building where you may have to complement it with the missing components for its installation and proper operation.

What is a power inverter?

It is a key and basic component for your system being this the central computer or brain of the system. This fulfills the functions of converting the energy coming from the panels into direct current (DC) and transforming it into alternating current (AC) where at the same time, for interconnected systems, it synchronizes it with the current coming from the CFE network into parameters such as voltage and frequency.

Can I combine types and brands of panels?

It is not recommended for new installations but in the extensions it is possible and it can become 100% functional with the proper advice, calculation and components.

Can they be installed in my company or is it just for my house? (or vice versa)

We can install it anywhere, we are specialists in integral systems for any type of electricity consumption and based on your needs we offer you the best option for you to live and / or functions with solar energy.

How does it work with CFE and SOLAR ENERGY combined?

We take advantage of the network as a storage system to inject the excess energy produced during the day by the solar photovoltaic system and be used at some other time or season, such as nights or winter with heaters or summer with air conditioners. By this way we eliminate the batteries as a component of the system since they are very expensive, saving you a considerable sum and the need to have them replaced every 4 to 6 years. When installing your system we will carry out a series of procedures with CFE where your current meter will be replaced by a bidirectional one that measures the current that enters as well as the one that leaves your property. In this way, CFE will continue to send you your receipt periodically in which you can check your balance and identify how much energy you have accumulated.

What happens if I require more energy than calculated to be produced by my system?

Since your property is interconnected to the CFE network, if you require more energy from that produced by your system or stored as yours on the network, you will automatically be provided with CFE energy. You should consider that this additional energy will be charged to your receipt and you will have to pay it according to the corresponding rate of CFE or local supplier.

Does the CFE buy me the energy I produce?

As of January 2017, it is possible due to the new regulations, although there have been delays in the application of this scheme caused by disagreements between the sale and purchase prices of energy. What we recommend is to stay in the old scheme that allows the net balance in kWh (Energy Units) since it is accounted for in an equal exchange of ONE TO ONE, this means that what you deliver is returned to you with the same value. In the CFE charging scheme, the balance is made in pesos and different values are considered for the energy injected as well as for the energy extracted from the network. This must be well understood so that you find benefits since you must produce more energy than you actually use so that the surplus produced by your system and injected into the network generates enough credits to cover the cost of your consumption and thus generate additional income.

What happens on cloudy days?

The system is reduced in its electricity generation although this continues to generate energy since the system works with direct sunlight and although the clouds reduce it, they do not block it completely. In the same way you should not worry about this since we calculate the size of your system considering the annual weather conditions based on historical installation area with studies conducted by specialized agencies such as NASA among others.

What happens when there is a power outage or a considerable increase in voltage in CFE?

Due to regulation and protection, your system detects rises or falls outside the parameters considered normal, cuts off the power supply and disconnects ensuring the integrity of your equipment as well as that of the network. Since the reason for the sudden change could be due to a failure or accident with the possibility of having the wiring or some component compromised, generating a risk for civilians or the CFE technical team.

How long does the installation take?

This will depend on the size and complexity of the area but regularly a residential or commercial installation does not take more than 3 days to complete although for the powering up of the system it takes approximately 6 to 8 weeks due to administrative processes in CFE and the procedures that must be perform for registration, interconnection and finally the change of meter.

Can I install my system?

It is not recommended since specialized technical knowledge is required as well as the legal registration of the system. We deliver you a 100% installed and tested installed system. We also include the legal procedures before the CFE and interconnection contract. The CFE will be in charge of changing the meter to be able to turn on the equipment and immediately start receiving the benefits.

What maintenance do I have to give and how much does it cost?

The maintenance of the equipment is basically to clean the dust or dirt of the panels with a rag and water without solvents or abrasives. Inspection of connections and wiring sporadically is also recommended.

Is the equipment dangerous?

No, although it produces high voltage, we take care of leaving everything well protected with special terminals that perfectly isolate the connections, however, its installation is recommended where children do not have access so that they do not introduce conductive materials into the various components or connections.

Is there any government incentive for the purchase of these equipment?

Yes, according to article 34 section XIII of the ISR Law that says:

Deduction to "100% for machinery and equipment for the generation of energy from renewable sources or efficient electricity cogeneration systems".

This means that for Moral and Physical Persons with a tax obligation of ISR, within the first fiscal year (first year) they obtain an additional recovery that can be up to 38% of the total cost of the system, this will be according to your declared amount of profits and the tax tab.

If the payment is made with bank financing, the deduction will be applied according to the payments made each year within the contracted term.

Do you have financing plans?

In order to offer the best options to our customers, we have payment by credit card where you can request the deferred payment of 6 and 12 months and that could grant you additional benefits if you manage a points program. We can also advise you for the acquisition of a bank loan.

Solar Heaters

What is a solar heater?

A Solar Heater is a PHOTOTHERMAL device which means that it converts solar radiation into heat that is used to heat fluids such as water.

What uses can I give to a Solar Heater?

Its application can be residential, commercial or industrial, its most common use is to heat water for general sanitary services such as showers, washing machines, lava dishes, etc. but they can be used wherever hot water is required. They can also be used to heat fluids in commercial or industrial processes.

How much money can I save with a solar heater?

Regularly a residential Solar Heater will generate from 60 to 85% savings in gas consumption. This will depend on several factors such as the size of the equipment, the amount of solar energy available in your area and very important, the amount and shape that you use hot water.

The cost is amortized on average between one to two years.

How does a solar heater work?

Taking advantage of the technology of high vacuum borosilicate glass tubes that have an inner layer of aluminum or copper nitrate, they absorb heat from solar radiation and transfer it very effectively to water. The water that is heated rises to the tank while more cold water enters the tubes repeating the process. Water circulates through the system through the so-called "thermosiphon" effect that causes temperature differences. That is, the system operates by natural convection, since hot water is lighter than cold water and therefore tends to rise. This is what happens between the pipes and the storage tank generating a natural circulation. The water is kept warm inside the tank due to its thermal insulation based on polyurethane avoiding the loss of heat generated. You can visit the “Section of Solar Heaters” to see a graph of its operation.

How long lasts a solar heater?

This depends on the quality of the components, we can offer high quality heaters so they can last up to 25 years, several years longer than a conventional boiler.

What temperature does water reach in a solar heater?

The water obtained can reach 100 ° C (under conditions of higher than atmospheric pressure) so it is also used for industrial or commercial processes, as well as for boilers and steam generators. However, under conditions of regular use in which almost all of the water contained in the tank is extracted every day and the heating process with cold water is started every day, the temperature is usually around 55-70 ° C. which is very convenient considering that the temperature for a shower is between 38 to 42 ° C.

How long does it take to heat the water?

There is no exact figure given that the weather depends on many variables, for example the predominant climate, initial and final water temperature, amount of sun, etc. but an average of 4 to 6 hours of direct and indirect light can be considered.

Will I have hot water early in the morning?

Yes, Solar Heaters have a hot water tank with an insulating coating much better than that of a common boiler, so if the hot water was not consumed at night, it will be available for use early in the morning.

Will the water heat on a cloudy day?

Yes, the technology of these equipment allows them to continue producing hot water even on cloudy days, however this will depend on the intensity of the cloudy. If the cloudy is very closed and constant, with black clouds or even raining, the heating will be reduced a lot although the water in the tank will not cool down so you can continue using hot water until it is finished. You can regularly notice the reduction if you use too much hot water or after about 3 days with these constant weather conditions.

What happens if I run out of hot water from the Solar Heater?

In the event that hot water from the Solar Heater is terminated due to a higher demand than usual, it is recommended to have an electric or gas heater (boiler) as a backup.

Can a solar heater be installed anywhere?

Yes, solar heaters require a shadow-free surface and where glass tubes are not hit by any foreign object. For Solar Gravity Heaters, they are required to be at a lower height than the water tank but not far below it.

Why is a higher height of the water tank required in relation to the Solar Heater?

Solar heaters with hot water tank will always have their hot water outlet from the top of it, this is because hotter water is always kept at the top while incoming water that is cold is kept at the bottom. So since the outlet is at the top, we require that the feeder tank has its water level above this height so that there is sufficient pressure to bring the water up and out of the Solar Heater. High Pressure Solar Heaters do not require a water tank because the pressure of the hydraulic network makes the water flow through the equipment and then out through the upper part.

How tall should the base of my water tank be?

That will depend on the height of the solar heater, many brands and models by design may require that the base of the water tank be up to 1.50 meters. For our heaters it can be that height and we also have special designs to feed on tinacos with low height that only require that the base of the tinaco be 50 cm. We invite you to contact us to review the conditions of your tinaco and recommend the best option.

Can I install a Solar Heater if I don't have roof water tank (Tinaco)?

Yes, regularly a property without a water tank is due to the fact that they have a hydraulic pressure system and for these cases we have High Pressure Solar Heaters.

What is the difference between a Gravity Solar Heater and a High Pressure Solar Heater?

Unlike Solar Gravity Heaters, High Pressure heaters are designed to withstand the changing pressure of hydraulic water distribution networks.

You can see the operation diagram in the “Solar Heater Section

Can I install a Solar Heater with a hydropneumatic or pressurizing pump?

Yes, we have special models for High Pressure. Our High Pressure Solar Heaters withstand up to 6 Kg / cm2 (85 psi) of working pressure.

Where should I install my Solar Heater?

The most common is that it is installed on the roof, although they can actually be installed anywhere as long as it receives sun. We recommend that it be installed as close as possible to the place where the hot water will be used. Ideally it would be placed on the bathroom to make the direct connection to the hot water line (whenever possible).

Do I have to modify the pipe in my house to install a Solar Heater?

The entire installation of the Solar Heater can be done externally and the connection with the hot water network can be carried out in the Boiler, in this way it is not necessary to modify the existing installation in the house and it can be adapted to practically any place.

Do I need to have a gas or electric boiler as a backup?

Having a gas or electric backup boiler is totally optional. In general, the Solar Heater alone delivers quite a lot of hot water all year round, especially if you live in a warm area and the Solar Heater that was purchased has the right capacity for the number of users. If where you live the weather tends to be cold or with frequent clouds or the Solar Heater you purchased is very small, a gas or electric boiler may be a good option as a backup system.

Check here the options we have for you

If the Solar Heater that I have does not fit me, can I increase its capacity?

Yes, another Solar Heater can be installed in parallel to complement the capacity of the existing system.

Do I need a specialist to install my solar heater? or Can I install it myself?

Installing and connecting a Solar Heater is a laborious but relatively simple task, so if you have knowledge of plumbing, you can install it by following the instructions properly.

Can I use a Solar Heater to heat other liquids?

Yes, although it should be confirmed that the liquid to be heated is not corrosive with stainless steel or incompatible with the silicone seals between the tank and the tubes. A viable option that eliminates these risks is to use an external heat exchanger that is heated with water from the solar heater.

Can I heat a pool with this type of Solar Heater?

It is not recommended since the chemicals used to maintain a pool in optimal conditions such as chlorine and water acidity, sooner or later will damage the equipment. Special panels are used to heat water in Pools or Jacuzzis.

Do solar heaters represent a risk?

No, unlike boilers, properly installed solar heaters are completely safe and have no risk of explosion.

What maintenance does a solar heater need?

Since they do not have any mechanical or electrical part to operate, they require a minimum of maintenance that is recommended primarily as a preventive measure for its proper functioning and thereby avoid any damage. It is based on very simple actions which are:

  • Cleaning the collector or tubes. Even when its shape, rain and wind keep the tubes clean, it is advisable to clean them at least four times a year to avoid the accumulation of dust, which prevents the proper incidence of sun rays.
  • Draining the hot water tank. This should be drained at least once a year to reduce the formation of tartar deposits in its inner lower. It is important to be careful when draining since the water that comes out may be at high temperatures.
  • Deep cleaning. It consists of doing a general cleaning to avoid the embedding of solids in the inner walls of the tubes or hot water tank. This type of maintenance is important mainly in places where the water is hard, since in the absence of it, it could gradually lose its proper functioning and reduce its efficiency.
  • Pipe insulation It is important to annually check (in cold seasons) the insulation of pipes, to check their good condition and thus avoid heat losses.
  • Prevention out of order. When the solar collector is out of service for extended periods, it is necessary to cover it so that it does not get the sun and ensure that it never lacks water, as this can cause irreversible deformations.

Is it true that vacuum tubes explode if heated without water?

Borosilicate tubes under high vacuum are elements that absorb heat very efficiently, if we expose them to the sun for a long time they can become quite hot but will not explode. However, if cold water is added at that time, the thermal shock could cause them to break. To avoid damage to the tubes, the solar heaters must be connected in such a way that they are always filled with water, for this purpose a check valve is placed that allows the water to only enter the tank but not leave it from the bottom. Thus, if the water supply to the heater is interrupted we will not be able to use hot water but the heater will not remain empty either.

What happens if a tube breaks?

The tubes are very resistant since they are made of borosilicate and their shape is cylindrical, they resist the impact of a hail up to 25 mm in diameter. However, if for some reason a tube becomes damaged, it can easily be replaced very economically.

Will my solar heater withstand low temperatures?

Unlike flat-collector Solar Heaters that break when the water inside the tubes freezes, solar vacuum tube heaters can operate without risk of damage at extremely low temperatures (up to -17 ° C).

It is suggested to insulate the hot water pipe so as not to have significant temperature loss in the service line.

Are tube solar heaters more efficient than those of glass plates and copper coil?

Yes, due to the high efficiency of solar radiation absorption of vacuum tube systems even during unfavorable weather conditions, combined with the excellent insulating properties of collectors and storage hot water tanks. Traditional systems with glass plates and copper coil are much less efficient, less aesthetic, take up more space and are not reliable in winter.

If I have to change my address, can I disassemble it to change it to my new house?

Yes. It can be disassembled to move it into parts such as before it was installed and reinstalled in its new location.

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GROEN Mexico 2018