Following on from the previous short post about our experiences of a new Ground Source Heat Pump system a year after its installation, here’s an even shorter post about how our solar PV array has performed a year on from when it was installed.
(For earlier posts about our solar PV installation, read these…)
Our installation comprises of 20 x Linuo 195Wp monocrystalline PV panels mounted on Schüco Lite rails connecting to an SMA SunnyBoy SB4000TL-20 inverter. The installation was specified, supplied and fitted by the excellent Greenday Renewables based at Fort Dunlop, Birmingham.
The original estimate for the total annual output of our installation, based on historical local climate and meteorological data, was 3,560 kWh. Our actual output for the first year has been 3,585 kWh which I’m pleased with given how much poor weather we’ve had this year.
As we managed to secure the higher Feed in Tariff (FiT) rate of 43.4p/kWh at installation time (which increases every year as it is index linked) we have generated an income of around £1,700 for this first year, plus any additional savings from not having to import as much electricity by using our own generated electricity as much as possible. Based on these figures the system should have paid for itself within 5 years.
Being a true geek, one of the first things I did after the system was installed was to set up some automated logging and reporting of data acquired from the inverter by connecting to its bluetooth interface. This data logging solution has evolved over time but is now implemented using the open source sma-bluetooth project running on a Raspberry Pi single board computer with a USB bluetooth adapter, storing captured data in a MySQL database and producing real-time web accessible charts using PHP and the excellent Highcharts library.
I look forward to reporting on how the system has performed after it’s second anniversary!
A couple of days after posting about the latest record day from my solar PV installation, the record was broken again! A new record of 26.69 kWh for the day.
In fact, the last 6 days have all produced over 22 kWh for the day.
And finally, another comment on the performance of my ground source heat pump. With the recent hot weather the heat pump has been on an average of only 1 hour a day – in fact yesterday it didn’t come on at all! All helping to save me money 🙂
Today our solar PV installation generated 25.07kWh of electricity, a new record beating the previous high of 21.69kWh.
This is what the graph from my automated data logging looks like:
As you can see there was unbroken sunshine all day although it only peaked up to around 3.1kW which reduced the overall output for the day. We’ve seen the system peak at over 4kW so I hope as we get later into the year we will see higher daily totals due to the higher peak output.
[ An interesting side note to this – our ground source heat pump was only on for 4 hours today, whereas during colder weather we can expect it to be on around 10 hours a day. I assume this is because of the high temperatures during the day and the obvious much reduced demand for heat. Let’s hope this this is a good indication of typical behaviour during the Summer months. ]
It’s been a glorious early Spring day today with continuous sunshine from dawn til dusk, and as a result it’s also been our highest solar PV generation day since the system was installed just over a month ago. You can see this from the chart produced by my automated data gathering and chart generation tool running on my Linux server:
As you can see we generated a total of 20.81 kWh of electricity throughout the day, peaking at an output of 3.17 kW at around 1:30pm. With the feed-in tariff (FiT) rate now confirmed as 43.3p/kWh for our installation and a deemed export rate of 50% of generation at 3.1p/kWh, this makes a total daily income of £9.27. That doesn’t include any savings on electricity that we were able to use ourself during that period instead of having to import it from the grid.
Although it’s still early days for our system and we are only just into Spring, things are looking promising for meeting or exceeding the estimated output for the system over the next year.
In the space of 6 months we’ve gone from having nothing to do with renewable energy to now having a ground source heat pump providing hot water and heating for our house, and as of today a solar photovoltaic (PV) array generating electricity for our consumption and export of any surplus back to the grid.
Our solar PV installation consists of an array of 20 LINUO 195W (peak) monocrystalline silicon panels arranged in landscape orientation on our 30° pitch South facing roof feeding back into an SMA SunnyBoy 4000TL inverter. It is rated at 3.9kWh peak and has an estimated annual output of 3,560kWh.
The supply and installation was carried out very efficiently and professionally by Greenday Renewables based at Fort Dunlop, Birmingham. Thanks to them for managing to get the installation completed before the 3rd March cut-off for reduced Feed in Tariff rates.
Within a few minutes of the installation being completed and the inverter powered up, it was generating electricity at a peak of 2.5kWh! Almost exactly on cue, after a day and half of dark skies, wind and rain, the sun came out and shone brightly 🙂