Solar Buyers Should Be Reassured With These Test Results

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Solar Buyers Should Be Reassured With These Test Results

In a world with planned obsolescence and firms going belly-up without warning, it’s reasonable to be a little cautious when it comes to buying technology. Solar is no exception to this rule, with naysayers of the technology pointing to solar panel degradation rates, claiming that the technology won’t be efficient enough to justify the cost multiple years after the installation. More importantly, in long term surveys of existing users in the US, the highest dissatisfaction has been tracked back to solar installers and some manufacturers, that effectively went out of business, leaving users wondering about their warranties. Considering the stage of the solar evolution here, there is no reason why that wouldn’t be an issue in India as well.

The good news is, solar panels deem to be delivering on their efficiency promise after multiple years, as demonstrated by Hespul, an organization focused on facilitating the development and deployment of renewable energy and energy efficiency technologies in France. Responsible for the installation of solar panels into France’s energy network in 1992, a small 1KW worth sample of their 31 year old solar panels were recently removed and tested, producing electricity at an impressive79.5% of their initial rate. That is better than promised actually. Thus, even as degradation rates have averaged under 0.7% in this case, studies in the US have also returned numbers close to those. That’s better than the 0.8% degradation that is usually projected by most installers we spoke to. Keep in mind however that degradation rates might speed up after 7-10 years slightly.

The smaller degradation rates underline just why return on investment in solar is one of the best among renewables to invest in. On average, the money saved from not paying for electricity because of solar has an ROI of 10% plus now even in places with relatively lower irradiation levels. By contrast, for the average Indian house with a setup of 2kW, solar has an ROI of about 3-5 years, way before the solar panels begin to lose any significant efficiency loss.  That explains the speedy uptake of solar in Australia for instance, where a combination of subsidies and reports from early adopters spurred a massive boom in rooftop solar till last year.

A word on solar warranties.

Potential customers should understand that panels come with two types of warranties

  • Product warranty that covers defects in design, material, workmanship and manufacture. These involve replacement of the panel by the manufacturer, especially relevant for the initial years, when any defect can be expected to show up
  • Performance warranty: This guarantees a minimum level of performance (power output) over time. While we have seen in India accelerated degradation and performance drops beyond the normal, these have been caused by higher pollution or poor maintainance mostly.

Performance warranties are usually 25 years, although some brands have gone as far as 30, even 35 years. Thus, a 540 watt solar panel has 85% power output warranted at year 25, means it can deliver almost 460 watts output after year 25.

All in all, for users today, solar is one of those things that you can buy into without too many qualms, as long as you buy it from a good vendor. While buyer’s remorse might still kick in if a new, more efficient panel gets unveiled the next week, we’re at the point where panel efficiencies are high enough to not worry about losing money. Solar panels are even more durable than we give them credit for, lasting way beyond their rated lifespans in many cases. And if the panel manufacturer was to go out of business, well, the panels might yet outlast them.


By Yash Singh

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