How do I choose my solar panels? Solar Panel buying guide 2021
Choosing to install a solar system is a smart financial investment. But once you have decided to take the step to go solar for your house or commercial property, the next biggest question that arises is which solar panel to choose. In today’s world of datasheets and specifications choosing the right solar panel becomes a difficult task but there are a few generally agreed things you must look into while considering a manufacturer.
While choosing a solar panel, there are at least four factors that you must consider
- Temperature coefficient
- Panel Efficiency
- The manufacturer
This is one of the most talked-about features of a solar module that every salesperson talks about when they do a sales pitch to a customer. Making a purchase decision based on the wrong warranty would be disadvantageous to any customer. Every solar module has two solar warranties
a. The manufacturer’s product warranty
The difference between these two warranties is quite important. The manufacturer’s product warranty covers any fault or issues with the solar panel over a certain period. Entry-level solar modules give you a product warranty between 10-12 years. Premium solar panels give you a product warranty of more than 15 years. The manufacturer’s warranty in most cases is the only warranty that you will need to focus or base your purchase decision on.
b. The manufacturer’s performance warranty
The Performance warranty is a warranty given on the degradation experienced by a solar panel over a tenure. (Typically 85%- 90% at the end of 25 years). However, in practicality, 25 years or 30 years is too long a period for any form of guarantee, and measuring the performance over the life of the panel is a difficult task and it’s impossible as one needs to measure several parameters such as solar irradiance, module temperature etc. to even prove the claim unless it’s in a solar farm, a lab or a utility-scale PV project. This is why very minimal weightage can be given to the performance warranty of a solar product or rather ignore it completely if it’s for a residential or commercial solar installation.
2. Temperature co-efficient
One commonly overlooked information is the temperature coefficient of a solar panel also known as Pmax. The lower the temperature coefficient, the better the solar panel will perform under higher temperatures.
Typically, for any solar panel to work optimally, the temperature it needs is about 25 ° C. When in operation, a solar panel typically uses light( or heat from the light) and converts it to energy ( electricity). However, as is the case with most electronics, they hate the heat. Solar panels will always produce less energy when hot and produce more energy when it is colder. The temperature co-efficient will indicate how much degradation that will take place when the temperature goes up. With an increase in temperature of over 25 °C, one can expect the output to decrease by over 0.5%. In tropical climates like India, it tends to get very hot and stays hot for a long time. So, a good temperature co-efficient is vital in choosing the right solar panel.
3. Panel Efficiency
Every solar panel has a specific panel efficiency. Panel efficiency is defined as the solar panel’s output in wattage versus the size of the solar module. It has nothing to do with the conversion efficiency of the solar panel.
The importance of the property is in the sizing of the panels against the available space. For Eg. We can have two solar panels of 335 Wp. But the one with higher panel efficiency will be smaller than the other. Thus it is an important point to consider if your focus is on maximizing the roof space.
This also applies to when you are choosing between a poly module or a mono module, that produces the same energy. If one wants to maximize the power generation one can choose the mono module. But in the case that you have a lot of roof space and there are no space constraints, the poly module is still a good choice.
4. The manufacturer
Finally, the manufacturer behind the panel is something that one needs to beware of. With the volatility of today’s market and the world, especially after the start of the Covid-19 Pandemic many large manufacturers have gone bankrupt or are no more in existence. Thus, it is important to research who is sitting behind the warranty claims of the panel to determine whether they will be around long enough to see it through in case of any defect. It is always better to work with a company that has at least been in business for more than years and has good financial standing.
One popular way to identify whether a company has good standing is to look out for an Altman-Z score which gives an idea of which PV manufacturers are financially stable and are not a risk of going bankrupt.
This is critical information especially for commercial consumers who are looking at very large installations or MW size captive projects. Here is a link to a report compiled by a company called sinovoltaics. https://media-01.imu.nl/storage/sinovoltaics.com/2234/sinovoltaics-pv-module-manufacturer-ranking-report-edition-3-2020.pdf
Additional Local Factors
Another crucial factor that you might have to consider is whether the manufacturer has a strong local presence in India. If not, warranty claims and service requests can be tedious and quite a difficult process.
Choosing the right solar panel is difficult for many, Today there are so many options available in the market and a lot of conflicting information written on data sheets of solar panels which cause more confusion than clarity. Amongst them, the warranty, temperature coefficient, panel efficiency, and the manufacturer are the most crucial points to keep an eye on. We at Heyday ventures, deal with long-standing manufacturers with great warranties, temperature coefficients, and panel efficiencies. Click Here to know more about our Solar panels or free feel to contact us to clear your queries.