Which solar panels are best?
Posted by Chris Jardine on 25 April 2013 at 12:10 pm
Choosing the best solar panel is a bit like choosing the best sandwich for your lunch. What’s better for you – a BLT or a cheese and pickle sandwich? Well, the cheese sandwich wins in terms of lower calories and lower fat, but the BLT contains more protein and more vitamins and nutrients from the vegetables. So it’s a difficult multi-faceted decision, and one that could be argued either way. And that’s even before you’ve looked at salt content, sugar content, sustainability of packaging, carbon footprint, ethics and welfare standards in the supply chain, etc, etc.
It’s much the same for solar panels, with many different criteria that can be used to judge products, and it can be difficult to get good information from installers. This is because the installers themselves are subject to intense marketing pressure from manufacturers of solar panels, with the manufacturers trying to tie down installers to using their particular product. They will do a sales job on the installer by promoting the key benefits of their product. And often, the installer will just then repeat these same benefits to sell to you the customer.
Unfortunately this doesn’t mean that these benefits used to sell panels are either particularly important in the grand scheme of things, or particularly unique among all the products out there. Most common is choosing a cheap product that is perceived as easier to sell (PV customers tend to be price sensitive), and then talking up its warranties, or other attribute. It’s quite easy to mislead here – something I call the “Men’s Health” effect; going back to our food analogy, nutritional information in men’s lifestyle magazines will often say something like “This doner kebab contains more vitamin B2 than a grapefruit”. Whilst this may be technically true, it can certainly mislead the overall benefits by focussing solely on one minor attribute. When choosing a solar panel you need to be able to read between the lines in a similar way.
Some of you, I’m sure, will be reading this blog hoping for a definitive list of the ‘best’ modules. It’s not possible I’m afraid, as it depends on how you value the different judgement criteria. In the same way, I couldn’t give you a list of the healthiest sandwiches without knowing if you value calorie intake more highly than salt content.
So how do you make a judgement? Well a ‘bad’ installer will choose a product, perhaps on the basis of price alone, or because they like what the manufacturers told them, or because they get good supply chain terms. They will then try and sell you the positive attributes of the panel chosen. A ‘good’ installer, however, will have used their expertise to undertake a full technical assessment of the different products, warranties and prices and provide you with a balanced argument in favour of their chosen product. For example, in my company we rated 30 manufacturers against cell efficiency, measured outdoor performance, long-term degradation, brand value, warranties, speed of supply chain and company ethics and only sell product that scores highly in most, if not all of these aspects. This is a much more nuanced assessment, and I’ll be using future blogs to talk through the details of these different panel attributes more explicitly.
From the customer point of view, it’s still difficult to find the best product for you, because at face value all you will hear is different installers claiming the product they use is the best. So you need to do a little digging. Here are my top tips for you to at least see who’s done their homework and who hasn’t.
• Ask why they recommend the panels they do. If they only give 1 reason why, be sceptical – one positive attribute does not make a good panel, but several is much more reassuring.
• Ask how they chose what panels they offer? How comprehensive has their decision-making process been?
• Cost isn’t everything. If you are being sold a particular product just because it is cheap then that may not be best value in the longer term.
So go careful when choosing what make of solar panel you want for your house. And make sure your potential installer has looked at product choice as carefully as you.
Also in this series:
More information on solar PV from YouGen
About the author: Chris Jardine is technical director of Joju Solar and teaches on the MSc course in Environmental Change and Management at Oxford University.
If you have a question about anything in the above blog, please ask it in the comments section below.
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