to the planet
Lease Agreement Plan
Equivalent trees planted
Liters of water saved
Annual amount payable
Total amount payable
The production of energy from renewable sources, particularly photovoltaic, leads to a number of environmental benefits for the planet. Power Clouds decided to show and quantify (in a clear and direct manner) these positive impacts connecting electric energy production in the following 3 parameters:
- CO2 emissions avoided
- Equivalent trees planted
- Water saved
To determine this, it was necessary to estimate the conversion factors between the Power Unit’s annual production and these environmental parameters listed in the calculator.
Annual Power Unit Production
To derive a series of specific parameters of the plant to which it refers, in particular:
- Irradiance (I): Specifies the site where the plant is located. It represents the average annual value of solar energy impacting the earth per square meter of surface.
- Conversion efficiency (ec): Specifies the photovoltaic panels used in the system. It represents the amount of solar energy (irradiance) which is transformed into electricity through the photovoltaic effect triggered by the silicon modules panel. For panels used, this efficiency is 13%.
Starting from these values and multiplying them, it is possible to calculate the specific production Ps (per unit area) of the plant which, for example, in the case of the Scornicesti Solar Farm, is equal to 216 kWh/m2 per year.
The panel’s effective surface area (S), in terms of area of photovoltaic cells, is equal to 1.63 m2. From here, we derive the annual production of Pu from a single Power Unit that, again in the case of Scornicesti, is reported to be 0,350 MWh / y. This value represents the energy produced under optimal conditions from a single Power Unit, in one year of operation, and constitutes the basis of calculation of successive conversions.
Environmental parameter no. 1: CO2 emissions avoided
For the determination of the conversion factor between energy produced and carbon dioxide (CO2) emitted, must refer to the values determined by the International Energy Agency (2012) . These values refer to the emission generated by the production of a KWh of energy, in terms of weighted average of the different sources used for the production (% of use). The report is obtained a value of 502 gCO2/kWh.
Environmental Parameter no. 2: Trees Planted
An environmental parameter, figuratively easy to understand, is represented by the equivalency between the energy produced and the number of trees planted. To perform this step, we must first consider the amount of CO2 avoided, since each tree leads to reduced atmospheric carbon dioxide of an estimated value of 0.039 t CO2 / y  (for medium growth coniferous trees planted in an urban setting, not densely planted, and allowed to grow for 10 years). From this we achieve the conversion coefficient equal to 12.8 trees per kWh of energy produced by Power Clouds’ photovoltaic plants (4.48 trees per Power Unit).
Environmental Parameter no. 3: Water Saved
Producing energy from renewable sources can also clearly allow water savings compared to energy production with traditional sources. Water, in fact, is used in different phases of the production process in conventional power plants, while thanks to the use of photovoltaic technology, significant water savings are achieved. To be able to estimate the amount of water saved, reference is made to what is reported in a study on the analysis of the life cycle of water for photovoltaics, which correlates to energy production with a savings of 1.33 m3/MWh [3 ].
The following table summarizes the conversion factors used with reference to 1 kWh of energy produced by Power Clouds plants, and also in reference to a single Power Unit. Lastly for this, it distinguishes between the annual value and the estimate of plant’s entire life (considered in a precautionary manner, to 25 years).