May 21, 2019


Is it possible to get rid of PPC’s expenses if he has a middle-sized country house he visits for a few days a year? The answer to the question below.

As we have said many times, the big “bet” of our time is smart spending cuts without the slightest “discount” on our level of life. One way to achieve this is also the implementation of renewable energy sources in our everyday lives. For example, if we have a holiday home, which we use for minimum days a year, we can make it “autonomous” using photovoltaic systems. Thus, we are exempted from the accounts of PPC and the assets that accompany them. But what should we know about these systems?

 How does such a house work?

Independent homes are powered by renewable energy sources (photovoltaic systems, wind generators, etc.). Such systems are ideal for residences located in remote areas, because their connection to the grid is in many cases a time-consuming and expensive process, and why in such areas it is easier to install renewable energy sources. In particular, in America, Australia and in Europe, it is very common to have residential units with renewable energy systems in isolated or remote areas (the vast majority of autonomous dwellings use photovoltaic systems to produce energy, while a smaller percent is fueled by hybrid systems including wind generators). In addition, in many countries there is legislation that provides for favorable arrangements for homeowners who produce the electricity required for the full functionality of the home. Also, we should emphasize that the autonomy of housing is a global trend. That is, a house consumes as much energy as it produces through RES. In this direction, the European Union has also launched the corresponding legislation on the conversion of buildings into zero-consumption buildings by Directive 2010/31 / EU of the European Parliament and of the Council of 19 May 2010 on the energy performance of buildings. In many countries, some of which include Great Britain and the United States of America, additional incentives are given to citizens, such as part-financing or tax breaks, to promote energy autonomy technologies. In addition, several certifications related to the energy status of the home are used in several countries, with LEED certification being typical. LEED (Leadership in Energy and Environmental Design) is a certification scheme developed by the United States Green Building Council. and consists of a series of ranking systems for the design, construction and operation of high performance green buildings. LEED standards indicate minimum building criteria to make them sustainable and energy-independent.

How to install an autonomous system

To install an autonomous home-based system, follow the following procedure, which is done exclusively through the company we have chosen:

1) Analysis of the area (irradiation, shading, etc.). Initially, solar radiation in the area should be calculated for the whole year. Unlike interconnected systems where the maximum annual energy gain is the goal, autonomous systems have applications where energy needs are greater at some specific months of the year or even at certain specific times of the day (as is the case with holiday homes, which are mainly used in the summer).

2) Recording of energy requirements. Each country house (or even main residence) has different energy needs (electrical appliances, machinery, etc.). So, for a plant to be efficient, a proper design must be carried out, based on the energy loads and the desired time of autonomy (the factor “time” determines the number of accumulators – batteries). An important parameter is also the type of device. If our requirements are high enough, we can integrate into our stand-alone system, apart from photovoltaic panels, solutions such as wind turbines or even conventional fuel generators for support.

3) Economic and technical study. After the analysis of the above elements has been completed, in order for the system to be able to meet the requirements, the economic and technical study of the installation follows. At this stage, the installer presents the final proposals to the homeowner based on their financial capabilities and technical features that the system should have.

   Parts of an autonomous system

An ordinary stand-alone system consists of solar panels, which convert solar energy into direct current and:

  1. a) Batteries that store electricity to be available on a 24-hour basis irrespective of instantaneous sunshine,
  2. b) From a charging regulator that manages the charging of the batteries to maximize the available energy,
  3. c) An inverter converting direct current into alternating current for use by conventional household appliances and,
  4. d) From a wind turbine that exploits the winds of the area (if it is a hybrid system).

Perfect place for installation in Greece

Greece presents remarkable prerequisites for the development of autonomous systems, since:

  • There are high levels of sunshine and large wind potential in many areas.
  • There are many island or remote areas characterized by a lack of electricity.
  • It is possible to increase electricity production through renewable sources in the summer, where demand is higher.

Systems that can be combined to produce the required energy are multiple and their use depends both on the geographic characteristics of the area and on the required total energy. All kinds of renewable energy sources can participate in a stand-alone system (wind, solar, biomass, geothermal, etc.), without however excluding the simultaneous use of non-renewable sources. The most common application is photovoltaic panels. In some cases, hybrid systems are preferred as they complement each other.

Their strengths

Their main and main feature is that they relieve you of the expenses of PPC and especially for the cases where it is an average country home. Beyond that, autonomous photovoltaic systems have many advantages:

– They operate silently

– They do not produce exhaust fumes or other pollutants

– They do not need to be supervised or operated during operation

– They are in harmony with the environment

– They require minimal maintenance

– They offer high and predictable performance

– No purchase, transport and storage of fuel is required

– They have extremely low operating costs

– Energy costs are not affected by fluctuations in fuel prices

Why does an autonomous system benefit a countryside?

The solution to the stand-alone system is quite advantageous, especially in the case of holiday homes. As mentioned above, by moving to such a facility in our countryside (where use is limited mainly to minimum days a year), we can get rid of the bill and the fixed costs that accompany it. How does this translate into practice? The following case study responds to all queries.

 The study data

The following autonomous system only includes a photovoltaic system rated power of 2.35 kWp, which can withstand an average daily consumption of 6.7 kWh per day. That is, it produces 2,450 kWh per year, when a primary home, full of electrical appliances, needs 3,000-4,000 kWh each year. Therefore, the needs of a countryman are overcome with the above. It is designed in such a way that it is in operation throughout the year and its days of autonomy are 3, with full daily consumption. This means that the energy it stores is sufficient for 3 consecutive days if weather conditions do not allow solar energy to be collected (practically this is impossible, especially when it comes to a summer season). Also, we should emphasize that the system can be combined with a wind turbine, while it is fully expandable. That is, at any moment we can increase its power and support it with a generator. With regard to the cost of such a system (with features such as those presented in the table below), it ranges from EUR 9,000 to EUR 11,000 (of course, costs may be reduced according to our energy requirements).

What does this system cover us for?

In the table below we present the “covers” offered by the particular autonomous system. That is, the devices that are supported, their daily hours, and the total energy required. Also, we must emphasize that in order to attribute such a system, we must make some necessary assumptions and retreats. For example, we need to install economy light bulbs, use energy class A devices (if possible) and replace the cooker with another less energy-consuming device, such as LPG (the cooker and air conditioners are considered as the most energy-intensive devices).

Can it suddenly become a “blackout”?

One of the most common questions of stakeholders is about system support and what happens when batteries are discharged. However, this can not happen unexpectedly, as the charging regulator will alert you to reduce the stored energy, and the batteries have similar indications. Also, an owner can also power the system with a conventional generator if needed.

Did you know that…

  • An autonomous system can even be applied to a caravan, making holidays … even more accessible
  • The autonomy of such a system depends, among other things, on the energy class of our appliances, as well as on the type of lamps we use.