Archives

So, you have just decided to go green with Solar energy for your share of environment care. And solar rooftops system was your obvious choice, be it a residential or a commercial building. You are all decked up to call an expert on the solar rooftop system.

But pause for a few minutes and bear with me to understand that even if it’s your known dealer, a few things will always be kept undisclosed because of many Terms and Conditions that companies apply. Before diving, let us first understand the scenarios and the models available in the market.

The first model is an ON-grid system in which the rooftop solar systems is connected to the grid. An inverter is present to convert DC power (generated by Solar panels) to AC power to power the loads (AC/fridge/fan etc).

The first model is an: On-grid system. It has 5 scenarios.

1. Solar Generated = Required Load

(Solar power runs the loads completely. Although the Grid is available and the power from solar is sufficient).

2. Solar Generated > Required Load

(Solar power will support the existing loads first, and then export the excess power to the grid)

3. Solar Generated < Required Load

(Herein, load completely consumes the solar power. The rest of the power required by the load is compensated by the Grid)

4. Solar Generated = O

(At night-time, no generation of solar power. Herein, the load imports the power from the grid.)

5. No Grid is available.

(During a power cut, the solar inverter shuts down to keep the people fixing the grid safe).

The second model is an Off-Grid. This model replaces the grid in its entirety. Rather a battery is used which acts as a bank to store the excess power generated during the daytime. During less generation or no generation of solar power, in place of the grid, the battery sends its power to the loads.

The third model is a Hybrid system wherein, both On-grid and Off-grid systems work in tandem. This model is advantageous in two ways: one, you do not need the grid. And two, when the battery becomes full, the excess power is sent to the grid.

Now the real deals are:

1. The Tale of Two Metering 

In 1st and 3rd variants where the use of a grid is present, the possibility to generate revenue from the excess power is the exact area to focus on. Usually, the customers or the users give in to the temptation of getting paid by the power companies, once the users start generating excess power. Well, it just happens that nothing can be further from the truth. Let us see how.

There are Gross Metering Systems and Net Metering systems. The GMS system provides a pre-determined “Feed-in-tariff‘ for the power generated through solar. The generated solar power is completely exported in the grid. From the grid, the household loads are operated.

Unless you get a competitive ‘Fee-in-tariff’, better to opt for the Net Metering. Net metering, on the other hand, is what you use. Meaning that the solar power generated is first supplied to a home or business electricity needs. The power left after load consumption is exported to the grid and electricity retailers then pay you.

2. Reducing Efficacy

In general, all the companies try to convince customers and users that solar panels do not need much maintenance. This is true marginally. Weather conditions reduce the efficacy of panels each year by 1 percent. By the end of the 15-20 years, a significant reduction occurs in the panel’s efficiency.

Maintaining the panels in harsh weather is good for health maintenance. Talking to the dealers and experts to manage the efficiency of equipment over a period of time can be a good decision.

3. The Dilemma of Leasing

Lastly, due to the high rewards of exporting power to DISCOMs, the system of leasing roofs are catching up. But be aware that it has its consequences too.

Roof lease can hurt the valuation of your property. Installing a solar system in either residential or commercial places is a long-term (usually 20-30 years) investment and responsibility. It is crucial to consider your living tenure. If not, buyers of such properties usually shy away and you can lose your real value of the property.

People are usually duped into solar leases, by costly installations to several lease terms. Leasing is a cheaper option with little or no money to buy, but when you lease, the company in the contract which owns the system might take away the system once your lease term ends.

Make sure, you weigh the terms and cost between the total lifecycle cost of the lease and the benefits you would reap from ownership.

Related Read: How to Choose the Best Solar PV Installer

Opting for sustainable resources is indeed a great choice. And we appreciate those who have adopted these resources or are thinking to adopt one.

While these resources have no such limitations whatsoever, the only time when you might face a mild issue is- during its solar power output.

Since you are doing a great job already, let us help you understand the seven factors that reduce your solar power output.

1. The sun’s angle:

Your solar system cannot perform well without the power of the sun. One of the prerequisites is to have sunshine; if not in abundance then at least considerably good. In situations when the sun is low in the sky, your system will automatically produce less power.

2. Solar panel’s orientation:

Believe it or not, but the orientation of solar panels has a great impact on the sides they face. Roof orientation facing east or west will always generate less power compared to the ones that face north and south.

The logic is simple- if there is less sunlight reaching the panels then drop in power output will get affected.

3. Clouds & haze:

It is not like the solar panels do not work on cloudy days. They work like they normally do; however, they do not perform well as they would do on a bright sunny day. It is estimated that solar panels generate about 10 – 25% of their normal power output on a cloudy day.

4. High temperature & heat:

It may come as a shock to you when you discover that ‘the stronger the sun is, the less energy the solar panels produce.’ Well, it is said that at a certain point, the excessive temperature can cause a reduction in the energy output from the installed solar panels.

The solar panels are tested at 25°C under the Standard Test Condition therefore when the temperature goes high, the output gets affected directly.

The amount of energy produced by a solar panel is calculated by multiplying the current and the voltage.

5. Wind & humidity:

The sunshine heats the panels, but a breeze helps the panel to cool down, thus impacting its efficiency. In the case of humidity, there are high chances of tiny water droplets/water vapor to get collected on solar panels.

These droplets reflect/refract sunlight away from the solar cells, ultimately reducing the amount of sunlight hitting them.

6. Shading, dirt & bird dropping:

Most of the solar photovoltaic panels consist of several cells that are wired together into a series. When a small part of the panel comes under the shade, the performance of the solar panel significantly reduces.

A similar obstruction occurs when dirt, bird droppings, or leaves partially forms shading over the panel.

7. Microfracture in panels or fault in inverters:

Contradicting the natural factors; the system problems can also affect the overall efficiency of the system. Microfractures aka microcracks are small cracks that appear in solar cells.

On the other hand, the problem related to the inverter can arise when the inverters are installed incorrectly or due to their incorrect programming. This happens rarely though!

Moreover, the inverters come with a warranty of 5 to 10-year so, if there is a problem related to the inverter, then you can get them fixed under free warranty service.

Related Read:   5 Maintenance Tips for Your Solar Panels