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Generation data helps people make good decisions about solar PV

Posted by Aldous Everard on 9 November 2011 at 4:48 am

Recent cuts to the feed-in tariff make optimal performance of solar PV systems more important than ever, to maximise both investment payback and sustainability of energy supply. 

Many people who have solar PV systems installed want to know how their system is performing as an investment, and in comparison with other systems.  Now there is a tool available that does just that. The Microgeneration Database from the Sheffield Solar Farm allows you to log the generation data of your solar PV system and reports back on how it is performing.

The map above (click on the picture to enlarge) shows a comparison of the generation levels from systems around the UK in September this year.  Users can find their location and see how they're doing in comparison with their neighbours. There is a broad spread in performance across the country which does not necessarily relate to latitude.  

Those with under-performing systems may wish to find out why their system is failing. It may be due to issues outside of their control such as shading or roof orientation, or it may be that a safety switch has tripped, or the inverter has failed, in which case the report alerts them to this.

The report comes with a spreadsheet of data, so data-donors can compare their generation figures with others.  All data is provided since they started donating, so they can identify any trends in performance variability through time for their own, and others systems.

Informing the decision of PV buyers

The project shows those considering installing a solar PV system what is already being produced by generators in their area. This is important additional information on top of that provided by installers. Installers use the SAP (Standard Assessment Procedure) method of calculating energy generation, which assumes that sunlight at any location in the UK will be the same as in Sheffield, so it is not too accurate further from the centre of the country and tends to underestimate. 

The microgeneration database is real data so generators can see how the performance of systems changes through time. Weather is notoriously fickle, so while the generation database cannot predict your generation, you can see what has been achieved during the past years around the country.

Where from here?

It is still early days at the Solar Farm. The analysis method is rapidly developing, in order to find ever more useful methods of reporting. For example – once we have enough donors – the above map may show energy generation contours. Feedback is always welcomed so that the reports can be improved.  A new website has just gone live which makes it easier to donate data.  This website aims to make reporting more interactive for donors and prospective PV generators.

The Solar Farm is non-commercial. It is run from the University of Sheffield as part of the Shine project. Its objective is to educate and inform people about PV.  We do not use the data collected for any kind of marketing purposes, and the identity of donors is kept strictly confidential.

The quality of the data collected depends on our donors, so if you have a PV system installed you can donate your data, and become a part of a growing network of micro-generators who understand the impact they are making, towards a world of sustainable energy generation. 

About the author: As manager of the Sheffield Solar Farm. Aldous is passionate about breaking our addiction with fossil fuels, through renewable energy.

If you have a question about anything in the above blog, please ask it in the comments section below.

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1 comments - read them below or add one


boatsnipsComment left on: 31 October 2012 at 4:03 pm

The Sheffield University 'Micro-Gen DataBase' is a great source for comparing Solar PV generation - Aldous and his team 'standardise' donated data giving the ability to directly compare performance. In my case it assisted greatly in convincing my installer that all was not well and a system fault was rectified.

Mapping is now included allowing comparison with other donating installations in the locality - a further check.

The collated information is in standard 'spreadsheet' format at this time. Tonight another months data will be uploaded to the data base and the compiled results awaited! 

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