What are the benefits of installing rooftop solar system?

Reduction of energy bills – Installing solar power plant can help to save substantial amount of money on electricity bills. Per unit cost of energy generated from the solar plant is comparatively cheaper to energy purchased from the utility. Use of underutilized roof area – Installing solar plant on the roof is most effective way to utilize roof. This not only increases the value of the home but also offers multiple financial benefits. Participation in building modern Indian power system – Installing solar power plants supports creation of distributed power generation network and reduces need for extensive use of fossil fuels. Reduce power losses – The energy can be produced though solar power plant on your own roof and can be consumed within your building, which limits transmission losses. Renewable energy source – Unlike fossil fuels and natural gas, the sun is a source of energy that is renewable. Going solar reduces our dependence on the fossil fuels. Shrink your carbon footprint – Going solar reduces the CO2 emissions, the leading cause of climate change and global warming.

Read More


How does temperature affect solar panels?

Solar panels react differently to the operating temperature. The efficiency of a solar panel decreases as it increases above the ambient temperature. Each solar panel has a temperature coefficient (which is defined in datasheet of panels). The temperature coefficient represents the rate at which the panel will underperform at each increase in degree Celsius (°C). Most panels have a temperature coefficient of between -0.2% /°C to -0.5%/°C, when tested under standard laboratory conditions, where ambient temperature is set to 25°C. For example if the temperature coefficient of a particular type of panel is -0.5%, then for every 10C rise, the panel’s output power will reduce by 0.5%. [Source: Youtube] [Publisher: altE Store’s Educational Video Channel]

Read More


What renewable energy is?

Renewable energy resources are naturally replenished on a human timescale Amount of feasible to utilize energy  is much smaller than the energy available Renewable energy is the energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat (1). This is the most obvious and popular understanding of the renewability understanding.  The concept of renewability was invented to highlight the difference between renewable energy sources and fossil fuels. Please note that fossil fuels once burned will be lost forever and burning leads to carbon dioxide emissions, not to mention methane emissions associated with extraction. The graph below compares the energy content of various renewable energy sources.  The energy potential of hydropower (nascent most popular renewable energy source) is a point of reference, please note that energy generation potential of the hydropower plants is relatively small when compared to other renewables – for example, amount of solar energy available on the Earth is almost 3 000 times bigger than the hydro-energy available. Availability of the different renewable technologies, https://www.nrel.gov/gis/re-potential.html  The abundance of the energy source does not mean that the energy would be effectively utilized. For example, geologists were well aware of the existence of gas in shale rocks, but the extraction was technically impossible. Due to technological development, previously unreachable energy sources (shale gas) appeared to be one of the cheapest fuels, revolutionalizing energy markets and setting new rules for international politics. There are factors determining the […]

Read More


What are the sources of energy?

classification of energy sources depends on the  viewpoint (purpose) the most obvious distinction comes from the climate change influence.   Energy sources can be characterized in multiple ways, depending on the point of view and purpose. The first, the most straightforward classification way, would be grouping by the physical form of the energy. Forms of energy The “physics” perspective distinguishes mechanical energy, chemical energy (embedded in the inter-molecular bonds), electromagnetic energy, thermal energy,  nuclear energy, gravity, electricity etc. A very good example of available mechanical energy is tidal energy generated by the Moon – the Moon, due to gravity, attracts water, and the tidal energy (wave) power plants can convert kinetic energy to useful mechanical or electricity. The example of the source of chemical energy can be coal or natural gas, where the energy is embedded in inter-molecular bonds. Once the bond breaks out, the chemical energy is released to the environment. The chemical reaction cannot be reversed without energy delivery – so we can say it is a one-way process. Nuclear energy comes from the nuclei of atoms – for example, fission is the nuclear reaction of atom division, atomic physical bonds are breaking and excess of energy is released to the environment.  An example of nuclear fusion is the thermal fusion of hydrogen to helium, taking place inside the Sun. Electromagnetic energy is embedded in the electromagnetic waves. Depending on the length of the electromagnetic wave, it can be thermal radiation (relatively long length electromagnetic waves), light, ultraviolet, […]

Read More


What is “MNRE Benchmark Cost”?

“MNRE PV benchmark cost” is a reference costs used by Ministry of New and Renewable Energy, Govt of India for calculation of subsidies applicable for rooftop solar systems. The value provided by the Ministry can be both, higher or lower than actual/average cost of the rooftop solar system. The benchmark costs only sets up the maximum cap for subsidy. If the investment cost is lower or equal benchmark cost the subsidy is calculated using the formula (1) Subsidy = % subsidy * investment cost, if (investment cost<= benchmark cost) If the investment cost is higher than  benchmark cost the subsidy is calculated as follows   (2) Subsidy = % subsidy * benchmark cost, if (investment cost> benchmark cost)   Example 1:  If MNRE subsidy is up to 30% of the benchmark cost. Let us assume that the benchmark cost is 45 Rs./Wp of installed capacity. So maximum value of the subsidy can be calculated from the formula: Subsidy = 30% * 45 Rs. = 13.5 Rs./ Wp In other words even if the real cost is 100 Rs., investor would enjoy 13.5 Rs./ Wp of subsidy. For investments which are less expensive or equal to benchmark cost, the 30% subsidy will be disbursed, for costlier investments the subsidy will be relatively smaller.   Example 2: If subsidy is 30%, benchmark cost 45 Rs./ Wp, Actual cost 40 Rs./Wp Subsidy share = (30% * 40 Rs./Wp) = 12 Rs./Wp   Example 3: If subsidy is 30%, benchmark cost 45 Rs./ Wp, Actual cost […]

Read More


What is the role of lightning arrestor in solar PV systems?

Lightning can strike anywhere at any time without warning & it can be destructive even when if it does not strike directly. The energy released by a lightning discharge is one of the most common causes of fire. Therefore, personal and fire protection is of utmost importance in case of a lightning strike to the building. Lightning arrestors are designed to absorb voltage spikes caused by electrical storms, and effectively allow the surge to bypass power wiring and the PV system.

Read More