Comparing the performance of solar PV panels
Posted by Gabriel Wondrausch on 5 September 2011 at 9:45 am
You wouldn’t buy a pair of shoes without trying them on in the shop first. They may look great on the model in the advert, but that doesn’t mean they’re going to be the perfect pair for you.
The same principle applies to solar panels. Most of the panels and components that we use in the UK have been designed and tested in different parts of the world in very different conditions*. So, until they’re fitted to your property you have no way of knowing if they’re going to work well on your property? Or do you?
Well, luckily, you do, and I’ll tell you why.
At SunGift Solar, in Exeter, we think it’s essential that we know which solar panels ‘fit’ best in this part of the world, so we built our own test array. Using this test array we can see how the individual panels actually perform in real life – in real time.
Our monitoring system allows us to monitor each panel individually and chart the different outputs of each panel. This means that we can give our customers the best possible service by offering them products that are not just tried and tested – but tried and tested in the climate in which they’ll be installed.
It also means that we can install, test and monitor all of the preferred solar PV panels and components on the market.
Using the right equipment
Our test array uses Solar Edge technology, which allows us to use lots of different modules – a technology we are increasingly using on our customers’ installations. It would not have been possible to install the array using the more common method of having the panels connected in ‘series’ to one inverter, as the differing panel voltages would have caused problems.
The Solar Edge system we use includes ‘optimisers’ that have been installed on each panel. This allows them to work independently from one another, optimises energy output, and enables us to monitor the performance of each module. It then feeds back into a national-grid-connected central power box, which enables us to use an inverter and convert the DC voltage to AC voltage. This provides the highest conversion efficiency of greater than 97 per cent.
We fitted our test array in February 2011, and the results give us a clear picture of exactly what products will provide the best value for money for you if you’re thinking of fitting solar PV in this part of the country.
The test array consists of five different manufacturers’ PV ‘modules’ and gives location-specific results. The information from each solar panel is sent back to monitoring software, where our design team can assess their individual performance, see which ones generate the most electricity, and decide what product will do the best job for our customers.
Currently, we are testing the Siliken 245 Mono, REC 235PE, Sanyo HIT240, Conergy 225P, and Sharp NU185 modules, all of which are regarded as high quality systems with their own benefits. Our results show clear leads for both the Siliken and REC panels. This is quite an achievement, as they are currently the most cost-effective systems we install.
Manufactured in Spain, the Siliken 245 Monos may be the new kids on the block, but they have already won international acclaim for their high levels of efficiency and value. They won the 2010 Photon International tests, so we’re pleased to be one of the first UK installers to get our hands on them and check how they perform over here.
The REC 235PEs are also performing well, and we’re looking forward to testing the new REC 245 PE modules that are a top performing panel in leading industry tests. The test array has, in just under six months, generated a feed-in tariff revenue of £1,300. You can see a full comparison of all five systems in the results table above:
These results give us a great guideline as to how panels might perform best on a property in the Westcountry, or indeed the UK.
However, we’re also very aware that to be happy you want your shoes to fit you perfectly. That’s why, despite the results you see in the table above, the best idea is always to get a renewable energy specialist in to take a look at your property. That way they can carry out a survey, analyse your situation, and advise you on the very best solution to suit your needs.
You can see total up-to the minute results from SunGift Solar’s test array in Nadderwater, Exeter by visiting the online monitoring page.
* Technical bit: the standard test conditions for PV modules are 1000 W per m² at 25˚C cell temperature.
More information about PV panels from YouGen
If you have a question about anything in the above blog, please ask it in the comments section below.
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