Two weeks ago saw a red letter day for our build when Mark and I became film stars for the day!!.
So what you might ask was this all about? As I mentioned in my previous blog (The Tale of Two Batteries) we purchased our solar PV system from Callidus https://www.callidus.co.uk/
A few weeks ago Steve Frost, the Director of Callidus, called me to explain that Victron Energy, https://www.victronenergy.com/ the makers of the Inverter we are using, had asked CALLIDUS if they could film our installation for product publicity. We readily agreed as we were told it would mean more free drone images of the house. However we also had to accept to be interviewed as part of the film.
The day of the filming dawned and we nervously went to the site. Mark sporting a fresh post lock-down haircut and one of his wonderful West African shirts, me hiding behind a lock-down fringe secured with Kirby grips to keep it off my face!
Jono the film maker was an ex-BBC producer and was absolutely charming. He quickly put us at ease and we had great fun watching the Callidus Team working on the installation.
In addition to the footage of Ubuntu, and the chats with Mark and myself, the film provides extensive technical detail about the system we have installed. I will therefore not reiterate all of that here. However I will briefly outline when and why we decided on our Solar PV system.
A link to the film, currently featuring on the front page of Victron’s website, can be found here: https://youtu.be/zgZ0cHq-NfE
When Mark and I embarked on building Ubuntu we had not planned to install Solar PV immediately. The technology is developing rapidly, so we were minded to wait for a period before investing. This would give us an opportunity to assess the overall thermal efficiency of the house and also would enable us to benefit from new product lines.
However we realised there was one flaw in this approach. The roof which we have installed is made of single ply membrane from PROTEC. https://www.protecroofingltd.co.uk/flat-roofing Whilst it is possible to retrofit Solar Panels to this type of roofing after installation it is not recommended as you are potentially breaching the integrity of the roof which impacts on the warranty. We therefore decided to install solar PV during the build so that the mounts could be incorporated into the roof during installation. This meant that we had to decide on which panels to use as they require different mounting dimensions.
At this point we met Steve and Donna from Callidus. We quickly realised we had found a local company that could demystify the world of Solar PV, provide an excellent service, very good products and great value for money. They are also great fun to deal with. We were fortunate that Steve was able to do a deal for us on the latest range of Q Cell Solar Panels – the Q-Cell QPeak Duo Blk G6+. Manufactured in Germany these at the time of purchase were the only panels (apart from LG) that offered a 25 year product warranty and 25 year linear performance warranty. (Most Solar PV only provide between 10 to 15 year performance warranties). The technical data sheet for the panels is here: https://www.q-cells.co.uk/fileadmin/user_upload/download_area/Solarmodule/datasheets/Q.PEAK_DUO_BLK-G6plus/Q_CELLS_Data_sheet_Q.PEAK_DUO_BLK-G6__330-345_2019-09_Rev02_EN.pdf
At that stage we were minded not to purchase a battery as again the technology is moving so rapidly – driven in part by the shift to electric vehicles. However, as mentioned in the previous blog (The Tale of Two Batteries), due to the necessity of ensuring continuity of supply during power outages and the zero rating VAT we get when batteries are installed as part of the new build, we decided to install batteries now. These are supported by a Victron inverter.
The tables below give an idea of the potential return on our investment. In this I would say that Solar PV is not a quick return investment but it does mean that we are reducing our impact on the environment by using cleaner energy and it enables us to be more self-sufficient which in these uncertain times is no bad thing. It is far too early to assess how the entire system will perform but I look forward to monitoring this over the course of the next year and providing updates as we finally move into Ubuntu to live.