Trying to reduce our bills by installing Solar in Brisbane - Seeking Financial Advice

[teenagedatheist]

TLDR: With the increased power costs and increased expected heat this coming year, I've been contemplating the idea of installing a 10kwh solar system on my house here in Brisbane for $5000 in hope to create a zero monthly electricity bill, and I'd greatly appreciate your thoughts and advice on this matter.

Here's my situation in full:

Solar System Offer:
-Keeping in mind that installation prices have dropped but aware of making sure the installion is done well and that even thoigh I hear that 1 kwh = 4kwh/day, im unsure if this is based more on a 4.5 hour day
-Also keeping in mind the rule of thimb that what ever they say you'll produce, you're more likely to only get 85% of this anount in kwh production. [kwh=amount/(0.1*0.85)
- Found an offer for a 10 kWh solar system at $5,000, including installation.
-Payback model is interest free $110/fornight
- Expected solar production: 250-300 kWh per week, considering current weather conditions.
- Brisbane receives an average of 6-6.3 hours year round of sunlight daily, which is quite good.

[b]Current Electricity Usage:[/b]
- In July (coldest month): We use around 10 kWh/day.
- In February-March (hottest months): Our usage spikes to about 14.5 kWh/day.
- Maximum daily export capacity to the grid is 10 kWh, with a reimbursement rate of $0.08 per kWh.
- We buy electricity from the grid at a rate of $0.25 per kWh.

My Questions:
1. Do you think a 10 kWh solar system is sufficient to reduce our annual electricity bills to zero, considering the variation in solar production and our usage patterns throughout the year?
2. With our surplus electricity being reimbursed at $0.08 per kWh and a purchase cost of $0.25 per kWh, does it make financial sense to go solar atm¿

I'm eager to hear your experiences and insights, especially if you've dealt with a similar situation. Any advice on sizing the system correctly and optimizing savings would be invaluable.

Thank you in advance for your help?

 

[homeowner]

@teenagedatheist That's so cheap I'd be questioning the quality of the parts and installer. I paid closer to 17k, got 4 quotes too.

In Melbourne with massive shade issues on a good day I get 1kw=5kw

 

[rucgieb]

@teenagedatheist Assume that feed ins will go to 0 soon.

Otherwise my advice would be to oversize panels if you can afford to (hoping batteries will get cheap in the distant future)

Also would recommend getting a quote from positronic solar.

 

[teenagedatheist]

@rucgieb Ok. Good info. Cheers

 

[minsc]

@teenagedatheist I'd be very very wary about the price you have been quoted. that's extremely cheap

 

[briben1976]

@minsc not sure why you were downvoted i am a solar retailer and that looks like a scam

interest free is only to the customer (the retailer pays) so that system is only netting the retailer like 4500 for a 10kw system

no chance in hell you will get a 10kw system fully installed for that money

and on interest free to boot

look into repayments most interest free 5kw systems i look at for clients come out closer to 10 000- 14 000 after all repaymments and costs

 

[lcb]

@minsc I got a 13.2kW panels and 10kW inverter for $6.3k in Brisbane - this ain't far off

 

[freeforthetaking]

@rucgieb The moment feed ins get turned to zero is when I will cut my solar panels from the grid.

 

[macon]

@teenagedatheist A 10kW system may well reduce your bills to zero or near it, but it does depend on a number of factors, such as how much self-consumption you manage and what your daily service charges are. In Vic, most people get the largest system they can connect to the grid. This is because the price doesn't go up proportionally as the power increases - bigger system tend to be cheaper per watt. My daily service charge is $1.09.

In a low FiT (Feed in Tariff, what you're calling reimbursement) environment the key is to use your own solar output as much as you can and minimise what you buy from the grid. This is called maximising self-consumption. So, you try to do your energy intensive stuff while the sun is shining because it's better to use it than sell it to your suppler for $0.08 only to buy it back later for $0.25.

And I would definitely get more quotes. $5k is too cheap.

Also, electrical power and energy units are a bit weird to get your head around, but basically, a kilowatt (kW) is a measure of power, while a kilowatt hour (kWh) is a measure of power over time.

If you have a device that uses 1kW and you run it for an hour, it will have used 1kWh. If you run it for 5 hours, it will be 5kWh. Generation works the same way, so grid connected systems are described using the peak output of the panels, which is in kW, and the amount of energy they produce over a period of time is measured in kWh.

 

[teenagedatheist]

@macon Appreciate all of this info. Cheers