A Solar PV installation journey
The total production for the month of December is just over 89kWh which is more than the SAP average energy production analysis predicted for this month, and therefore compensates to some extent for the smaller than expected production in November.
The lower than expected production last month, as mentioned in the previous post, may have been due to some extent by tree shading, but the average sunshine hours for the month of November were only 57.2 (based on Met office date for Oxford) - which is less than the 30 year average value which is 64 hours - so this will have affected the results as well.
Below I've shown the monthly data for both November and December, along with the 'short' month for October since the installation only went live on the 25th/26th.
More next month !
I've now had my first full month of operation and all the detailed daily energy production values are shown in the graph above.
The total production for the month is just 84.65 kWh which is well down on what the SAP average energy production analysis predicted for this month.
This may be because the month was below average for sunshine hours - or, as I suspect, it may be because I have a bit of a shading problem from trees at this time of the year. When the sun is very low in the sky, as it is at this time of the year, there are some trees quite close to the house that shade the roof quite early in the day - and whilst the trees are deciduous the leaves have stayed on the tree quite late into the month this year.
I will have to wait until later in the month to get the sunshine hour data - so I will report this next month.
Below I've shown the monthly data and obviously October is low since the installation only went live quite late in the month.
The FIT contract arrived in the post yesterday - which was a surprisingly quick turn-around since SSE had indicated that it could take up to 4 weeks.
Completing the contract was a very straightforward process with two copies of the document being provided, one for me to keep and the other that I just needed to sign and put into the post using the supplied postage paid envelope.
Also provided were very clearly details of how the generation meter readings should be taken once a quarter and emailed to SSE. So now I need to wait until the end of December to make my first formal generation submission after which I should receive my first payment.
I am still monitoring the system very closely with measurements being recorded every 5 minutes and the graph on the left shows the daily power generation performance from 25th October until 6th November.
It is difficult to judge whether the performance is on-track until there is a lot more data, but it looks about right - since the SAP design suggested a daily average for October to be about 7.2kWh and for November it would be about 4.7 kWh per day.
I will continue to report the system's performance over the coming months.
The Fronius inverter has a facility to log all the performance data on a USB stick.
This is installed in a small pull down 'tray' that is on the bottom of the inverter to the right and is 'opened' by undoing two knurled thumb screws as shown in the image on the left.
The USB stick can be seen inserted into the system in the image on the right.
It is very important to run through the correct USB removal process and you shouldn't just pull it out since data could be lost (just as could happen when removing a USB from an ordinary PC)
The data can be logged at different intervals from every 5 minutes through to every 30 minutes and at the moment it is set to just 5 minutes to get the most data over this initial working period.
The data is created as a CSV spreadsheet file which can be imported into Fronius software, that is a free download, for analysis and storage.
The screen shot on the left is from the Fronius system and shows how the the power generated varies enormously through the day - peaking at about 2.8kW, with the system only 'kicking in' just before 9.00am in the morning and is pretty much shut down by about 4pm - and a total just short of 6kWh being generated.
This is much as expected, even on a reasonably sunny day like today, since at this time of the year the sun is not very high in the sky even by midday.
The FIT application needs to be filled in and submitted as quickly as possible after the commissioning of the system, and certainly within 5 days, and my supplier Firegrass pointed me in the right direction to get this done.
The application was made to SSE (Scottish & Southern Energy) and all the following information was available from their web site here:
- a useful summary pamphlet produced by DECC available for download here
- the SSE FIT Terms & Conditions downloadable from here, and
- the actual Application Form downloadable from here
A useful tip pointed out to me by Firegrass was that at the bottom of the Application Form there was a somewhat odd note that said:
"You will only be eligible to receive FIT payments from the commissioning date if you have provided a written request before this date"
So to avoid any doubt about not being entitled to FIT payments from the very start of service I sent an email to SSE on the 20th October, advising them that a new system would be commissioned on 25th October.
Filling in the Application Form after commissioning was straightforward enough but it needed to be accompanied by the completed MCS certificate, a proof of ownership declaration as well as a utility bill (for proof of identity).
Fortunately Firegrass supplied me by email with both the MCS certificate and a proof of ownership document as PDF documents, and I could also get a utility bill as a download from the supplier's web site, so all I had to do was scan the filled in Application Form and I was able to submit everything by email very promptly earlier this morning.
Later note: have just received (Monday 31st Oct) acknowledgement of receipt of the application from SSE - which says that they should process it within 4 weeks and then they will send out a contract for me to sign.
Day 2 of the installation and the roofing team have cracked on to complete the installation of the panels on the roof.
It looks a bit like Meccano with each of the panels bolted onto the rail framework that was fixed to the roof yesterday.
Man-handling the panels is a bit tricky since it is quite windy today, but whilst the panels looked enormous when they were on the ground they seem to have shrunk once they are up on the roof.
Fortunately it is nice and sunny today, although we've had the odd heavy shower.
With all the panels now on the roof, the electricians were back and the DC cables from the panels are finally connected to the inverter.
The inverter comes already configured with default settings that suit most installations, but there was some minor set up. Importantly the inverter has a USB connection so that it will 'log' data on a continuous basis, so I had bought a couple of USB sticks that I could 'rotate' to collect the data, and one of these was inserted ready to go.
But unfortunately by the time everything was ready to go the sun was already going down so the panels weren't generating enough power for the inverter to start-up.
The generation meter, shown above, was therefore still on its initial reading, which wasn't quite zero, so "00000.69" was the reading that I took for the important FIT application form which I need to complete and submit as soon as possible.
The main installation started this morning with two teams of two doing the work: one pair to do the electrics and a second pair to do the work on the roof.
The electrical work consisted of tapping into the existing distribution box in the utility room shown in the image to the left of the boiler (I'll have no excuses for not decorating the utility room once the installation is done - been putting this off since the new boiler was installed.
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By luck there was a spare 'circuit' available in the distribution box, so this is where the feed from the Solar PV 'generator' will supply elecricity to the main house network, or if it cannot be used in the house it will automatically be 'exported' back out into the main electricity grid.
Moving upstream the feed goes through various isolation switches and importantly through the generation meter; these are both shown to the right of the boiler. The generation meter is a critical component since this is what 'clocks' how much electricity in kWh has been generated - and will be read at intervals in to order claim the Feed In Tariff income.
Going further upstream the feed passes out through the wall to trunking that was installed on the outside wall going up to the loft level.
From here it then enters the loft space where is goes through another isolator before connecting to the inverter which has been fixed to the end gable wall inside the loft.
Shown in the image on the left, the final step upstream is through another isolation/connection box, shown bottom right, where in due course the DC connections from the solar panels themselves will be made.
The electricians finished their work fairly quickly, and had done as much as they could by about mid-afternoon, since the layout of the house made this aspect of the installation pretty straightforward.
The roof work however was slower going and not helped by occasional heavy showers!
What needed to be done here was the careful laying out and fixing of the rails and hangers that each of the panels would be attached to.
The fixings for solar panels are now very standardised and the methods well tested and established, but the work was quite painstaking to ensure that everything was prepared accurately and securely.
By the end of the day all the fixings were prepared but there was no time to start fixing any panels in place.
More tomorrow !
As part of my planning permission research I had ascertained that Building Regulations would not be required for the works "provided the installer is registered under Part P of the approved document", which they were.
But as part of the overall system installation cost, Firegrass also included a structural survey to ensure that there were no issues associated with the increased load on the roof, etc.
As my property was relatively new and certainly in pretty good condition I had assumed that this would be just a cursory inspection.
However the structural engineer spent quite a bit of time carefully looking at all aspects of the roof construction and, much to my surprise, he did find a number of issues. These were all associated with the original construction, where some aspects of the way the individual roof trusses were cross-connected for rigidity, was not done to the required codes.
Fortunately it wasn't anything very serious, and the rectification was something I could easily do myself, and I wasn't required to do the work before the installation was carried out - but I have to say I am actually quite pleased that such a thorough job was done!
A final consideration for my choice of supplier was that they should be a member of REAL. This organisation was set up by the Renewable Energy Association to not only establish quality standards but importantly to offer various insurance schemes.
This was important since I have decided to go with a small local company Firegrass Energy Ltd for the installation, because as far as possible I always try to support local businesses. As they are a member of REAL they then pay for a "Deposit and Advance Payment Insurance Scheme" which means that the deposit I need to pay when ordering would be covered by insurance should they 'go bust' before the installation is complete.
With this safeguard and from the very informative and friendly style of Firegrass, and of couse an acceptable price, I placed the order on 26th September, and was pleasantly surprised to receive the REAL insurance ceritificate through the post just a few days later.
A Microgeneration Certification Scheme (MCS) accredited supplier will design a Solar PV installation to the Government approved standard (SAP 2009) and will supply the details of the design as part of their quotation since it underpins the financial analysis for the annual return on investment etc.
You can do your own calculations however by using this web site.
As can be seen in the screen shot on the left all you have to do is to use the google map facility to pin point your location and fill in some basic parameters in the form provided.
You can select a PDF output and then the "Calculate" button will produce your design, as illustrated on the right.
This will not only show you the likely annual total electricity production but also the likely average daily output for each month of the year.
An important consideration for the installation of a Solar PV system is planning permission - which is something you have to sort out for yourself.
The good news is that in most situations the installation of Solar PV on a roof will be what is known as a 'permitted development' and, so long as specific conditions are complied with, planning permission is not required.
Looking at the key conditions, I had worked out that my property was not in the formal Conservation Area of Marlborough, and the short listed suppliers I was talking to could self-certify that their work complied to the necessary building regulations.
However this was clearly a complex area and as I wanted to be quite sure, I contacted the county planning department who were very helpful. As a result I submitted a formal enquiry, which was subject to a small fee, where I had to define the type of installation I was proposing and its details. What proved useful here was a schematic diagram produced by one of the potential suppliers which is shown above and because I could submit all my information via email there were no delays in the post - and in a very few number of days I gained confirmation that it would be a 'permitted development'.
Looking back at my electricity bills I had been growing more and more concerned that the bills were not only steadily going up, but they were also not very seasonal, i.e. each monthly bill was pretty much the same winter or summer.
I had already swapped all of my lighting to new low power bulbs, and having installed a real-time meter to be able to 'see' my consumption on an immdiate basis, it was clear that most of my 'base load' consumption was due to 'gadgets' of one sort of another; primarily the large amount of computer equipment that runs all day long as part of my business which I run from home.
My minimum goal therefore was to supply my base load consumption and with the amount of roof space that I had available I wanted to investigate installing the maximum amount of solar PV capacity. To benefit from the highest Feed in Tariff this meant a maximum installed capacity of 4kW so this was my target.
Contacting potential suppliers was very straightforward since there are a lot out there now, and I opted to look at both national and local suppliers - although I would prefer to choose a local supplier if they met all my criteria - which were:
- must obviously be a Microgeneration Certification Scheme (MCS) accredited company and installing MCS approved equipment - otherwise I would not be eligible for the Feed-in-Tariffs
- should be able to provide as complete a 'turn-key' supply as possible
- my research suggested that a complete installation price should be at or about £3000 per installed kW of capacity i.e. about £12k for a 4kW system - but it should be noted that prices will continue to come down as time goes on
- must be able to demonstrate credible knowledge of all aspects of the installation and to provide contactable references for successful installations in the area
Once potential suppliers started to provide information things started to move very quickly !
Having been thinking about it for too many months, I have finally committed to look seriously at a Solar PV installation at my property. Solar PV, where PV means photovoltaic, is the technology that allows sunlight to be converted into low voltage DC electricity, which is then converted into the normal higher voltage AC electricity with an electronic device called an inverter.
This technology has been around for a very long time but in recent years, as the volume of installations has increased, the engineering and installation methods have become much more standardised and there are now a lot of suppliers offering 'packages' of one sort or another.
Getting going with this project has been prompted by a much publicised 'review' of the Government backed Feed in Tariffs that is now underway. The Feed in Tariffs, or FiTs, are the way that householders can gain an income from the renewable energy that they generate when they install Solar PV, and it is expected that the review will conclude that the tariffs should be reduced early next year - so I had to get a move on!
To get up-to-date on Solar PV, the first thing I did was to check out both the Energy Savings Trust and the DECC web sites, and then I needed to:
- Work out what size system would make sense,
- What budget I would need,
- Understand what the planning permission issues were, and then
- Contact some potential suppliers
In this series of blog posts I am aiming to document each of the steps I am undertaking and the issues that arise so that others can learn to some extent from my experience.