6 years ago I had a 4kWp solar PV system put on my roof.
Just lately I've had a bit of extra time on my hands (can't think why?), and took a look at the solar production...
In 6 years the production meter has just ticked over to 20,000 kWh. That's about 3,300 kWh per year.
The Solar iBoost immersion heater diverter has just recorded 4,000 kWh diverted to hot water.
Free hot water and next to nowt gas used between April and November. I like free.
The electricity bills show that my average billed amount is about 1000 kWh per year. That's the amount I imported from the grid.
So I send the lecky co. shedloads of lecky for which they pay me about 18p per unit (kWh), and I take 1000 units from them for which I pay about 15p per unit.
So how come I still get a bill?
Well I'll tell you. The solar panels don't provide enough peak power to stop that import meter wheel from going around, so on a dull day putting the kettle on costs me. Likewise, all the power I use at night is imported. Even on a bright sunny day, like just about every day since lock-down started, I end up importing about 1 kWh just to cover lights, kettle, TV, radio, computer, fridge, and phone charging, etc.
In winter, naturally, this increases to about 4 to 6 units per day on average. This means that my estimated electricity usage is about 6 units per day, or 2000 kWh per year, the solar panels produce 3300 kWh per year, so am I running a carbon neutral house?? Once again the answer is no, because most of my heating comes from burning about 6000 kWh of gas per year.
What I could do with is a bank of batteries, Tesla Powerwall-like that charge during the day, cover the peaks in power demand, and keep the lights on and the fridge running at night. These are available, but at a price, so not yet.
What size to get? It looks like I only need about a 1kWh size to cover my present lecky usage during the sunny months, so maybe a typical 3 kWh unit would suffice...but suppose I go over to the dark side and get a lecky car?
My solar panels produce about 20 kWh per day between May and September.
A charge-up on one of those babies will eat all of those sunshine units, and that's assuming I leave it at home all day, turn the hot water over to gas, and cut down on the cuppas! Is a bigger battery store the answer? Got to say, a 20kWh store, if it even exists, would be mega money, and take up more garage space than the car, so that's a non-starter.
I suppose I'll just have to wait for the flux capacitor....and might as well have a cuppa while waiting.
Just lately I've had a bit of extra time on my hands (can't think why?), and took a look at the solar production...
In 6 years the production meter has just ticked over to 20,000 kWh. That's about 3,300 kWh per year.
The Solar iBoost immersion heater diverter has just recorded 4,000 kWh diverted to hot water.
Free hot water and next to nowt gas used between April and November. I like free.
The electricity bills show that my average billed amount is about 1000 kWh per year. That's the amount I imported from the grid.
So I send the lecky co. shedloads of lecky for which they pay me about 18p per unit (kWh), and I take 1000 units from them for which I pay about 15p per unit.
So how come I still get a bill?
Well I'll tell you. The solar panels don't provide enough peak power to stop that import meter wheel from going around, so on a dull day putting the kettle on costs me. Likewise, all the power I use at night is imported. Even on a bright sunny day, like just about every day since lock-down started, I end up importing about 1 kWh just to cover lights, kettle, TV, radio, computer, fridge, and phone charging, etc.
In winter, naturally, this increases to about 4 to 6 units per day on average. This means that my estimated electricity usage is about 6 units per day, or 2000 kWh per year, the solar panels produce 3300 kWh per year, so am I running a carbon neutral house?? Once again the answer is no, because most of my heating comes from burning about 6000 kWh of gas per year.
What I could do with is a bank of batteries, Tesla Powerwall-like that charge during the day, cover the peaks in power demand, and keep the lights on and the fridge running at night. These are available, but at a price, so not yet.
What size to get? It looks like I only need about a 1kWh size to cover my present lecky usage during the sunny months, so maybe a typical 3 kWh unit would suffice...but suppose I go over to the dark side and get a lecky car?
My solar panels produce about 20 kWh per day between May and September.
A charge-up on one of those babies will eat all of those sunshine units, and that's assuming I leave it at home all day, turn the hot water over to gas, and cut down on the cuppas! Is a bigger battery store the answer? Got to say, a 20kWh store, if it even exists, would be mega money, and take up more garage space than the car, so that's a non-starter.
I suppose I'll just have to wait for the flux capacitor....and might as well have a cuppa while waiting.
