Viticulture in Ireland: So happy with our Solar PV

Our solar PV array on our shed

We've had solar PV for a couple of weeks now and we are totally addicted to keeping an eye on how much we are using, how much we are generating, how much we are storing, and how much we are selling into the grid. It's totally fascinating. We now have access to all the information we need to use our electricity smartly.

The app by Hwawei for their system (yes we installed a Chinese system) is quite sophisticated. The home screen shows where electricity is moving from and to graphically. You can see how much is being generated, how much is being stored in the battery, how much is being used in the house, and how much is being taken from the grid. There's a two-minute delay for the app to pick it up so we can basically see exactly what's contributing to the usage on most counts. The baseline usage is too much, but we have two fridge freezers and two freezers, plus bloody pumps for water and sewage that run too often.

Click on the battery in the app and you can see how full it is, and what is supplying it as well as daily charge and discharge, Click on statistics and you see daily, monthly, yearly, and lifetime stats. The chart at the bottom shows minute-by-minute energy use and generation which you can view in full screen. You can overlay charged from the PV, discharged from the battery, direct use of PV, and direct use of energy supplied by the supplier, for us Energia. With our recent Smart Metre installation, we switched to a Smart Plan. We pay €0.1917 for night rates (11pm to 8 am), 0.3579 for day rates (8 am to 5 pm, and 7 pm to 11 pm), and 0.3751 for peak rates (5-7pm). We get paid 0.24 per kWh for anything that goes into the grid. And when we get an eV, we can get a reduced charging rate of 8.15c per kWh PLUS the longest charging window on the market from 2am to 6am with Energia’s Smart Drive tariff.

We have set the system to charge the battery at 12-2 am at the night rate. I do at least one or two loads of laundry at 2-4 am with our new washer and dryer a couple of times a week which can be set to delay the cycle. The night charge on the battery carries us through morning showers and breakfast when the PVs start to kick in on most days. The battery recharges with PV during the day and the PV/battery covers most daily activities, even in February. If we run the dishwasher or washer during the day, we use some from each source.

We noticed that when we turned on the heat in the winery, that heater was using quite a bit of electricity so we turned it off during the day and turned it on at night for a project Alex was doing. Having the heat on round the clock to maintain 22-24C during fermentation was expensive last year. The insulation maintains the temperature in the winery during the day reasonably well, so perhaps we will moderate our use this year. It's all hugely valuable information we did not have access to before.

It's taking a bit of experimentation to balance out our use and optimise the system. The things we've found that use the most electricity are:

Water heater (scary amount)
Water pump (scary amount)
Kettle (also scary amount)
Oven
Dryer
Washer
Dishwasher
Microwave
Fridge/freezers
Sander/saw

Computers, TV and lights are minimal in comparison. That surprised me as I was always such a stickler for turning off the lights. It's taking a bit of time to see how each cycle draws and what is most efficient to choose.

That was just the PV system app. We also get data from esb Networks and Energia. The esb data is a week at a time and a week old so it's not as useful. The Energia tools are much more useful and the newest one presents daily figures. So you know if yesterday was high and you did laundry, that's what accounted for it.