This costed PV installation in Dublin looks at what the payback time was on the solar panels, what the process was like and how the apps are working out.
In this article we cover:
- House set up
- Background to PV installation
- System details including installation cost
- Energy use and payback time
- Apps and what would do differently
We live in a bungalow in north County Dublin and for us, the installation of solar panels was a logical choice. We had bought our first electric vehicle (EV), we had plenty of space on the roof, and I had recently retired so my lump sum meant we didn’t have to borrow to finance the work.
We were not very well informed about climate change, but we had a sense that it might be the right way to go. If it meant less use of oil purchased from countries with questionable human rights records, then so much the better.
The day we collected the EV, in November 2019, was actually the first day that public charging had to be paid for.
We followed up the purchase of the car with a change to a day/night electricity metre and the installation of our own EV charging point. We opted for a brand that seemed to be the best choice, at the time, to work with solar panels.
We delayed installation of the panels due to the limit of 12sqm that existed at the time, as our roof space allowed for more. I was told by a couple of government departments that a change was imminent, but I could not get a definite timeline.
In July 2020, we read of a case in Limerick where An Bord Pleanála sided with a resident who was instructed by the county council to remove panels that went beyond the 12sqm limit. On reading about this, we took the decision to proceed with 20sqm; placing more panels than allowed by regulations did not affect the grant. The panels are the cheapest part of the set up, and it amazes me when I see houses in new build estates with only five or six panels on the roof.
The set up
We obtained quotes from a number of different companies based on our average annual usage of 6,450 units (kWh). We have 20 panels, each 310 kWp, making a total of 6.2 MWp. They are divided equally between east and west. Whereas south facing is probably better overall, an east/west divide provides a better spread throughout the day, kicking in earlier and lasting longer.
We also opted for a battery and inverter with 5.7kWh of storage. In addition, we have a hot water diverter. The total cost came to €12,300 less a grant of €3,000. At the time, there was still a battery grant of €600. The grant application was approved in August 2020 and we received payment the following November.
The company that eventually did the work, based in Athenry, Co Galway, gave us the best quote and we were impressed by the representative of the company who visited us.
There was no hard sell. He provided the quote and the data about what we could expect. No money
was required upfront. The company helped with the grant application and paid for the Building Energy Rating (BER) assessment. This went from C3 to B2 following the work.
I am delighted we chose this company as Brian Graham, Colm Conneely and everyone we dealt with could not have been more professional and helpful. The work was carried out during Covid but the lads followed the guidelines exactly. It was apparent during the installation that they were experts in what they were doing, and the results have proved this.
Energy use
From installation in August 2020 to the middle of September 2024, the panels have produced over 21MWh of energy. Of that, we have consumed 82 per cent ourselves and we are 53 per cent self sufficient.
Our pre-panel usage of 6,450 units has increased a lot due to the purchase of a second EV and the change from a gas to an electric hob. We also heat the water in summer mainly using the power produced by the panels.
Payback
All things considered, we are very happy with the results achieved. We do send a small amount back to the grid for which we get paid 20c per unit. This is taxable over a certain amount, so it is wise to have two names on the electricity bill to maximise the tax-free portion.
Our battery app estimates that our savings from the panels are over €4,830 since installation. Our payback time is looking like eight years at the moment. This is dependent on having inputted the correct electricity costs into the app.
We have not kept the figures up to date, so our savings are probably greater. The payback figure does not include economies made from not buying petrol and not using gas to heat the water during the summer.
Apps
On the minus side, we do find that we have become obsessed with our phone apps. We use the battery app to monitor solar production, the current load, and the state of the battery.
We’re not quite at the stage where we shout “quick put on the dishwasher now” but the app does suggest when certain tasks should be completed.
The other app we use is one that allows us to set times for charging the car and heating the domestic hot water. Being able to do all this remotely is a real advantage. The big discussion in our house is deciding whether to charge the car or heat the water.
In fact, as we earn more for sending surplus energy back to the grid than we pay for nightmare electricity it makes more sense to charge the car at night and profit from the grid feed-in tariff.
Hindsight
Having gone through the process, we often reflect on what changes we would make if we were to start again. Looking back, we would definitely opt for more battery storage. In summer, the battery can charge during the day and power the house at night. At present, we rarely make it through the night without using some grid power.
In winter, load shifting allows us to charge the battery using cheap night rate electricity for use during the day. However, high usage items like ovens can eat up battery power very quickly. We can still add an extra module to what we have, and we’ll probably do so in the future.
Another item for consideration is a changeover switch where we could power the home in the event of an outage. Currently, we have access to a couple of sockets coming directly from the battery which we typically use for the TV, a lamp and the broadband router when there’s a power cut.
A proper changeover switch would add more functionality although the battery we have currently would not last long trying to power the whole house.
Suppliers
Charging station
Zappi installed by Nigel Daly, evchargingstations.ie
PV insaller
Solar Home, solarhome.ie
Panels
Bisol
Battery
Alpha ESS
Hot water diverter
Eddi
Timer app
myenergi