Buying solar is a bit of a ho ha with lots of offers and a mixed bag of “deals” a lot of which are not worth the money as they have some rather large short comings. But what could you get for £2000?
Going too small when buying solar tends to not work out well, as I have been dealing with quite a few small solar problems this weekend. the main issue was undersized battery and undersized solar array.
If you do the installation then you will save a lot of money, but where do you start?
10kWh battery is a good place to start, that will set you back £1400. We would have to go for the Growatt hybrid inverter which is 3kw coming in at £420, and 3 solar panels coming in at £172, and giving you 1.2kw of solar power.
We have a problem here in that we would be missing a few bits, like the roof mount system, scaffolding to get on the roof and any tools as well as the PV cable. excluding the tooling and scaffolding, that comes to an additional £164 so we are now over budget £156. if we say £200 for scaffold we can now rework the numbers.
Perhaps you would do away with a battery?
If you have dual rate power tariffs then you may not want to price drop here.
if you have 10kw of battery storage, you can fill your battery for around £0.08kWh. If your normal rate is £0.24kWh meaning that you will save £0.16kWh or £1.60 per battery cycle. That’s £584 per year to make a clear point on this.
What is the new figure with just one 5.1kwh battery?
£1706
What if we have one battery and extend the solar?
With this option, you could add £294 in solar,
Adding another 3 panels would come to £266.16 and give you 2.4kw of solar over the 6 panels.
How is the total?
£1972.16
How would this system perform?
You would have to consider the performance and where the power would be and what time.
Having 2.4kw of solar would mean that you could get 12.8kWh a day on average during summer but with a peak of 19.2kw, in winter you would get around 3.12Kwh a day.
What you have to consider is that you will use the battery and therefore need to charge the battery, so if your day time use is around 3kwh (roughly ours) about 4kwh will be exported in the summer days.
But you could add the battery later! 5.1Kwh Battery
Keep in mind the night use, lets say the night is 14 hours.
5.1/14 would mean that the average hourly load would need to be less than 364wh.
If you are like our house hold you will use around 3.5kW between 3-7, giving you a new night average of just 145wh, to give give you some idea, ours is 247wh.
Small battery = less life?
Yes the DOD of a battery ( how far or much you use it) will reduce the cycle life, the 10kWh battery gives that little bit more and the battery is set up to try to preserve itself to give you around 6000 cycles which is 16 years of life. Discharging the battery to a low level would drop the battery life to around 5.45 years.
read this article
What would winter be like?
Generally poor, of you have a dual tariff then for around 90 days of the year, you will be grid charging the battery. The solar should produce some power to lower your bill, but you would need to look into the low rate tariffs. This is where two batteries really work for you saving money.
£2000 solar ROI.
We consider this a small ish system as it sits somewhere in the middle. Therefore ROI should be less than 4 years.
£2000 at 0.24kWh is 8333kWh
Annual Solar 3432kWh
ROI 2.42 years
How much would installation be?
Around £414- £630. it could be a little more, but this is a good estimate of the installation costs.
How much extra does it cost to get paid for export?
Around £886.20 costs vary from place to place.
You would need to export 22,155kWh to reach zero for the cost of the export. Its not worth it in our opinion. You could add the second battery for less.
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