Getting Returns While Consuming Energy Is Now Possible With Solar Panels

Getting Returns While Consuming Energy Is Now Possible With Solar Panels

Can solar panels deliver a return? The answer is yes. Solar panel systems are becoming more popular than ever, as people and companies switch to solar power usage both at home and for commercial purposes.  

The energy generated by solar panels is the cheapest, most efficient, and environmentally friendly source of renewable energy available worldwide. Besides, the PV systems and solar panel kits will play an essential role in the future of power generation. The consumption of solar power will also reduce and sometimes even replace fossil fuel and nuclear energy usage. 

The lifetime of the first solar panels was short. Today, PV systems have about 20-25 years lifetime. So, solar panel cost is also an important factor when calculating solar panel return on investment. 

Solar panel systems provide clean solar energy throughout the day, and with energy storage systems, you can store your extra power for overnight usage. Generally, the solar, wind and hydro energy technologies require up to ten days of storage. While most non-renewable energy technologies require no storage as the fuel is already a storage. Nuclear energy and coal also need some storage. 

Energy Returned Per Unit Of Photovoltaic Panel Surface

Energy return on investment (EROI) is a useful metric when evaluating the long-term viability of energy-dependent systems. Hence, we should consider the methods, applications, and analysis when learning solar energy and solar power technologies.

The concept of energy return on investment has a long history dating back to studies in 1960 on the efficiency of the energy by D. Smith. 

To calculate the energy returned, there are two possible ways. The first one with a pyranometer does not consider reducing irradiation, accordingly the accumulation of bird droppings and dust, surface damages, aging, and weather changes (frost, snow, humidity). The energy returned in this case is about 20% lower and is about 80 kW he/m2 yr.

With the second way, it is possible to calculate the module’s electricity production per square meter. It is needed to determine the operational lifetime of the solar panel system installed. Nowadays, many solar panel companies give a 25-30 year warranty. All the damages due to transportation and weather conditions are not calculated. 

However, all the external factors, including humidity, snow, passing clouds, should also be accounted for. 

So, with a 25-year lifetime, the total energy returned over a lifetime will be 88.1 (kW he/m2 yr) times 25, which is 2203 kW he/m2.

Methodology For The Calculation Of The Energy Invested

To calculate the total energy invested, you should first define the system under investigation. The energy system’s life cycle has several stages, including the production and manufacturing of the components, transportation, manufacturing, installation, and maintenance. So, the quality of energy produced is essential as well. 

There are many methodological issues for the calculation of the EROI analysis. We will discuss two of them. 

The first one is the IEA methodology (EROI(IEA)) that uses the principle of the energy required to collect the energy to be returned. This methodology is more appropriate for comparing various solar panel and solar system technologies than determining the efficiency of the solar systems as an energy source. The reason for this is the fact that PV technologies are material, labor, and capital intensive. What does that mean?

The PV module’s average weight is 16 kg/m2, and the weight of the support system, inverter, and the balance of the system is about 25 kg/m2. However, the weight of concrete and some chemicals used (elemental gases, dopants, photolithographic chemicals, etc.)  is not included as being too small. Besides, the concentrated hydrochloric acid weight required for the production of solar silicon is 3.5 kg. So, the total weight of the PV module panel area becomes: 

16 kg (module)+25 kg (balance of plant)+3.5 kg (significant chemicals)=44.5 kg/m2

The consumption of material resources using PV technologies is 64 times of nuclear energy. It also affects the energy of the transport.

What for labor, the renewable energy industry, and mostly the PV industry creates many workplaces. The photovoltaic systems are about seven times more labor-intensive than other energy resources.

The capital resources of photovoltaic technologies are about 40 times that of fossil fuels. 

Considering that the PV technologies are material, labor, and capital intensive, the winter period’s capacity factor is deficient. So, this methodology is only suitable for comparing different photovoltaic technologies.

According to the second methodology, called the extended EROI (EROI(EXT)), the energy must collect, deliver, and use that energy. It was derived from H.T. Odum’s works in the concepts of net energy and emergy that are all the energy and material resources utilized in energy generation. In 2010, Murphy and Hall said that a technology with an EROI(EXT) less than five should be considered unsustainable.

Calculation Of The Energy Invested For The PV System

When calculating the energy invested for the photovoltaic system, we should consider integrating the PV-generated electricity into the grid, the labor, and the capital requirements. 

Total Energy Invested

In calculating the energy for the photovoltaic systems, research and photovoltaic industry development are not included. The utility company workers, the energy loss due to the excess energy production is also excluded. 

So, it is needed to stabilize the grid system on summer weekends when there is more excess energy available or disconnect water turbines using the river water. 

What Is the Solar Panel Payback Period?

Installing solar panel kits at home is a significant investment. It will eliminate your electricity bills, help you save with solar panel tax credit and other incentives,  and even increase your property value. To make the final decision whether to install a solar panel system, you can consider various metrics. The solar panel payback period (ROI) is one of them. ROI estimates how long it will take to make you back your solar investment. 

To calculate the solar panel payback period, you should know the total costs and annual benefits of going solar. Dividing your combined costs and yearly benefits, you will get the number of years you will need to get your payback. After that, all the savings are your financial gain. In the United States, the payback period is more than eight years. For example, if your solar panel installation cost is USD 20,000 and will save you USD 3,500 yearly on your bills, your payback will be 5.7 years.  

By comparing quotes from different solar panel companies and estimating the payback periods, you can learn your solar investment value and make the right decision for your home PV system.

Author of a publication: Irene Abgaryan 

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