Frequently Asked Questions

FAQ Solar Thermal System“Digenis”

Digenis Solar Thermal is any solar system that uses the Digenis Device for a solar station

The solar thermal system produces hot water only during the sunshine, just as photovoltaics do, since they produce electricity only from the sun.

No, it does not use batteries, its components use the power of the photovoltaic panels directly.

The Digenis solar thermal system consists of solar water collectors, one or more boiler containers for storing thermal energy and the Digenis solar station. The device has the necessary photovoltaic panels that are necessary for its operation.

When the sun falls on the solar water collectors, the water that passes through them heats up. The Digenis device has a circulator with which the hot water circulates from the solar water collectors to the boilers where it stores it. The stored hot water can be used for home heating, hot water for use in hotels and industry and of course for domestic use.

The appliance has a fan cooler and a triode that are activated as soon as the boiler tank (s) are filled with heat, as instructed by the electronic programmer.

No, the photovoltaics it has serve to power the electronic programmer, the circulator, the fan and the triode.

We prefer the installation with local craftsmen who will then maintain the system. Of course, if you wish, it is supervised by our Engineer.

Yes it is a plug & play device.

The warranty is 2 years for professional use and 5 for home.

According to ANNEX II the energy footprint of construction and use at a depth of 10 years is 36 (the smallest for a solar station)

The Digenis solar thermal system does not evaporate and thus emits at least 23% more energy than any system that vaporizes.

The components we use have evolved in collaboration with large factories in Greece. They have been certified and sold normally for the last decade.

Only 34.8 sq.m. are required surface of solar panels. We know from previous projects that for 4-5 summer months with a fullness of over 80%, the consumption does not exceed 60 liters of oil.

We have to calculate this using the system in 5 years: annual maintenance, annual oil costs. We will also calculate the smaller size due to the higher yield of 23%. So in installation costs we have a lower cost by at least 35% and in using the same design of solar thermal systems by 85% lower cost.

Like all solar systems it needs annual inspection. The cost does not exceed 80-100 € plus VAT.

After first contacting us, we advise you how to proceed with the interventions.

It is done in a day and is easily done by a plumber and an electrician.

Using the installation brochure, its installation is simple and is done by a plumber and an electrician.


It is a Nearly Zero Energy Building, ie a building with almost zero energy consumption. It is a global code name for the buildings that produce from RES (Renewable Energy Sources) as much energy as they consume.
Energy that will not be used by anyone is not counted in the building that produces it, so it cannot be considered to be NZEB.
So we will call NZEB the well-insulated building that produces the type of energy it will use, without calculating that part of the energy it will produce can be used by an adjacent building. Example: it needs thermal energy to heat it, it will produce hot water from a solar thermal system to heat it. It needs electricity to work, it will produce the electricity it will consume.

Thermal insulation study is important to ensure that we will shield our building properly.

Good thermal insulation is important but not enough. We need to ensure that we do not have losses from thermal bridges and that the materials inside our building store enough energy to save money.

With proper study of thermal insulation, study of elimination of thermal bridges and study of indoor materials.

FAQ Net Metering

We will need a copy of the last bill of your electricity provider to be offset.

We need a copy of the property contract of the property with the certificate of its transfer to the Mortgage Office. If you have a rental or warranty from the landlord, then you will bring it to us as well.
We need a topography of the plot, a copy of the identity of the owner(s) and an authorization that we give you ready for the processing of the file in the services.

Comes once at the end of the year with the same date as the system activation.

FAQ Energy Inspection Building/Businesses

Energy Inspection is the recording of a company's consumption through measurements on individual machines and their comparison with purchase invoices. The "baseline" is created.

The purpose of the Energy Inspection is to identify the points where energy is wasted for any reason. Once the points are identified, the Energy Inspector makes suggestions for improving the company's energy efficiency.

The process is repeated every two years.

It is mandatory by law 4342/2015.

FAQ ISO 50001/2018

The word ISO comes from the initials of the Greek word "Equal" and refers to the equality of the grades of ISO Inspectors worldwide in case of dispute of an inspection result.
ISO is a system for monitoring business indicators and related to energy consumption. These are records kept by various people in the company at all levels.

The installation is done by a certified person called "Inspector-Chief Inspector" and lasts from one to 4 days depending on the size of the business.

The inspection is done once a year unless the company requests it earlier.

FAQ Saving-Autonomy

The program includes those who have TIN, property in Greece and their property has been constructed before the entry of KENAK, ie before 2011.

Our experience has shown that each new program has different terms and conditions. For this reason, we do not risk a forecast for the future. Our position is that as soon as we have the PGG(Paper Of Greek Government or FEK) of the program to update the FAQ page with the final questions and answers.

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