I have been working at Loughborough University on the Low Effort Energy Demand Reduction (LEEDR) project. Chatting with a few of the researchers there I heard about a one-day workshop to stimulate debate on energy supply and demand within the UK. This was organised by students and researchers of the London-Loughborough Centre for Doctoral Research into Energy Demand, with the PV workshop being facilitated by Dan Quiggin of Demand Energy Equality.
The day involved a very practical session building a low cost solar PV panel, a session of games relating to the energy chain in the UK and a debate on the issues surrounding UK sustainable energy.
It was a great day where I met lots of interesting and motivated people, learnt some practical skills and got inspired. Here are some photos from the day and some information on building PV panels. I will be running a workshop to build a solar PV panel at the Nottingham Hackspace. Drop me an email if you are interested in attending.
Building a solar PV panel workshop
The first activity was to build a low cost solar PV. Dan has been working on an open-source guide to this process. Here are a few photos of the workshop.
A finished solar PV panel.
Basically the main frame is an old window frame. This is cleaned up and re-painted/preserved.
A window frame ready to become a solar PV panel.
Broken and slightly damaged solar PV cells are used. They are sorted into similar size pieces. Tabbing wire is soldered to the front and the back (positive and negative connections). Cells are arranged in series to give higher voltages (each cell generates at around 0.6-0.7V).
Arranging the pieces into cells.
Soldering to the back of the cells.
Tabbing wire (for interconnections to the cells) and a flux pen (to ensure the soldering works well and makes a good connection).
Testing the cell.
Building a solar PV panel like this was a very interesting learning experience and highlighted the PV construction process. The objective was to try and produce PV modules at a lower cost than commercial panels. At present the cheapest commercial is around £1 per watt. This process gets the cost down to around £0.50 per watt, according to Dan.
While a very good learning process, I have a few issues with the long-term sustainability of these modules. Commercial panels come with a guarantee of power production for 20 or even 25 years. I would be surprised if these modules would last that length of time, even with repeated preserving. Things like water ingress, damage to the cells etc would have an effect. Although it would be very good to test this. Dan has an array of 500Wp which has been installed since October 2011 and he is monitoring its output.
Other people who are doing similar things include:
- The Low Impact Living Initiative Build a PV panel course, run by Norman Phipps. This is a slightly more expensive construction process, but the cells are fully sealed within the panel.
- MAKE magazine had an article on building a 20Wp solar panel in Vol. 12. You will need to buy the magazine to get this article. It used a 20Wp kit from this company in the US.
- REUK has some info on solar PV kits here
- Know Your Planet have a build your own solar panel kit available here. They also have info on making solar phone chargers.
- There are loads of YouTube videos such as this one. Do a bit of a search to find all the info.
Cutting solar cells
One of the things we did not try in this workshop was cutting the solar PV cells into mor uniform pieces. I think this would be a good idea to do so that the modules are more even and we can fit more PV cell area into a give space. It would also help standardise the tabbing connections.
It is difficult to cut a crystalline cell, as they have a tendancy to shatter. Here are some videos of processes to cut the cells. Most use a dimond cutting disk and a rotary tool (such as a Dremel etc). I tried this by hand but the cells can still shatter, hence you also need some form of jig to hold the rotary tool.
- DIY solar panel with linear cutter – really nice panel made here, also cutting with a CNC machine
- How to cut solar cells – Similar technique to above with diamond cutting disk.
- The video above also has an Instructable to go with it.
- DC to power – Dicing solar cells. Slightly different way – milling them rather than cutting, with a diamond mill bit.
- Green Power Science – Info about making your own solar panel, but nothing on cutting the cells
- Robrt Smith Build your own PV panel – a number videos with a full panel build. Really in-depth, but he uses pre-cut PV cells.
- Information about soldering the tabbing wire.
- Instructable to build a controllable PV cell cutter.
Sustainable energy games
The participants were split into two groups and each group was also involved with some sustainable energy games and activites. One of these was looking at the full supply chain for both electricity (from coal) and heating (via gas). The other game was based upon David MacKay’s book, Sustainable Energy Without the Hot Air, which is free to download and I recomend everyone to read.
Looking at our fossil fuel supply chains in their entirety really brings home how complex they are.
I had a really interesting day, learning some new practical skills and hearing some interesting arguments and discussion. Many thanks to the organisers and all on the LoLo course.