Help me understand how Solar is cheaper at home.

Hoyks

Well-Known Member
This is where I am really confused.
So why do people get 22 cents?
Because they had high FIT to encourage people to fit solar. As more people put panels on their roofs they wound back the FIT that you could get. Each state had their own renewable energy targets and tariff to match too, just to make it harder.

My sister got in really early and was getting something like $0.32 kW for several years, but now she's back to what us mortals can get.
 

Toyasaurus

Well-Known Member
One of the great things about the Tesla is the app.
Stores all sorts of info, How much power, where it`s going, what you use and how much the totals are in real time.
Yes I am sure of the totals.

We got in on the very first of the FIT, started at 60c. kw then went to 66c. kw.
Then when they shut it off it went to 6.6c.kw.
From memory that went for 5 or 6yrs.

Cheers. Ian.
 

boobook

Well-Known Member
Ok so there were definitely higher feed-in tariffs in the past, that seem to have gone down over time to what they are today. So old installations are one thing.

But for someone looking to buy solar today, what is the benefit of paying 30% more for all your electricity use, then only getting around 10 cents for feed in. It does not add up. I have had a few quotes and they are similar. You have to pay about 15 cents per kWH more for the electricity you use if you have solar.

I calculate that it will cost me 10% more for my electricity needs, plus $4,000 for the privilege of doing it in setting up costs off sent by some lower power use from the grid.

Where is the friggin payback? It is more expensive to go solar - period.

I must be missing something.
 

cam04

Well-Known Member
the idea is that you generate your own power during the day and try to focus your power hungry activities to daylight hours, therefore purchasing less power, no matter what the cost, and seeing a commensurate reduction in the bill size. Those of us with a higher FIT are the opposite in that we should ideally be selling the higher priced ‘green power’ into the grid during the day and then carrying out our power hungry activities at night using cheaper brown power. Saving the planet be dammed if the numbers add up a different way.
 

discomatt

Well-Known Member
63KW???? That's a hell of a lot. That's 262Amps at 240w.
In Vic, not sure about other states you are not allowed to feed anything like that back into the grid because in would have very detrimental effects on the transformers and booster stations, not sure what the max is.
Where is the friggin payback? It is more expensive to go solar - period.

I must be missing something.
No not at all, refer to post 4, its a con when you do the sums and work out all the carbon footprint
 

Colly18

Well-Known Member
My (admittedly uneducated) opinion is that home based battery storage, whilst a convenient solution for some, can't be environmentally responsible or sustainable in the longterm, given our large global population. I like the idea of pumped storage hydro-electricity, using excess solar power generated by day to pump water and hydro power by night or to meet demand.
What I do know is that we have fitted grid connect solar panels to our last 3 homes and consider the investment worthwhile in terms of reducing our electricty bills, adding to the home resale value and feeling like we are doing something positive for the environment (even if we aren't?).
 

cam04

Well-Known Member
In Vic, not sure about other states you are not allowed to feed anything like that back into the grid because in would have very detrimental effects on the transformers and booster stations, not sure what the max is.

No not at all, refer to post 4, its a con when you do the sums and work out all the carbon footprint
5 kw per phase in Qld For a 15 kw Max if you have 3 phase power on at home. A mate did it just for the solar farm he could put on the roof.
 

boobook

Well-Known Member
In Vic, not sure about other states you are not allowed to feed anything like that back into the grid because in would have very detrimental effects on the transformers and booster stations, not sure what the max is.

That sounds about right to me. But I simply can't imagine that anyone has a 63kW solar setup. That is massive. About 10M x 40M of panels.

These two are 60kW. it must be a very large house for 63kW :eek: Something doesn't add up to me.

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Keith B

Member
We have 10Kw on the roof facing north west and a 13KWh Tesla battery. I think our feed in rate is 11 cents and our buy price is about 28 cents per KWh. We pay a small bill in the winter months, which is pretty much made up for by credits for the rest of the year. The bottom line is that we just about break even on what used to be a $3,000-$4,000 a year power bill.
If the battery has to be replaced after, say 12 -13 years and the solar panels reach their 25 year life, our $29K expenditure will give an annual return of just over 9%pa. We are also immune from blackouts.
I can't get return that anywhere else.
Keith
 

Hoyks

Well-Known Member
But for someone looking to buy solar today, what is the benefit of paying 30% more for all your electricity use, then only getting around 10 cents for feed in. It does not add up. I have had a few quotes and they are similar. You have to pay about 15 cents per kWH more for the electricity you use if you have solar.

I calculate that it will cost me 10% more for my electricity needs, plus $4,000 for the privilege of doing it in setting up costs off sent by some lower power use from the grid.

Where is the friggin payback? It is more expensive to go solar - period.

There are a lot of assumptions, all based on what deal you can get or what you're paying now.
I looked at my last bill and I'm paying $0.22kW for supply, getting $0.11kW FIT and $0.93/day service charges. Going off the average charges I see in on websites pushing solar, right now I'm on a pretty good deal.

I was paying a bit more on my old plan, but based on the fact that cut my bill in 1/2 and I was paying approximately $650/quarter, my $5000 system has been paid off in around 4.5 years. If I use power during the day, it costs me nothing, if I don't, then I get around $0.30/hr while the sun is up.

One of those things that you won't make money from it, but it costs you more not to have it.
 

boobook

Well-Known Member
Thanks @Hoyks.

I have 2 questions.
1) Are you in Vic or elsewhere, this stuff seems very state specific. Even wholesaler specific.
2)If in Vic who do you use for electricity.

Thanks
 

Kippie

Moderator
One of those things that you won't make money from it, but it costs you more not to have it.

That's the key! We all need electricity, so the question is how do we get it. Depending on the size of your own PV system you cover part or all your electricity use. The alternative is that you pay the electricity companies for the supply. Whichever way, it's going to cost you. So how to reduce that cost?

I don't rely on FIT to do my sums, because the investment horizon is 20 years. During those 20 years the FIT will go down. In fact, in our previous house we got $0.60/kW and in our current house we get $0.11/kW. But in the meantime the cost of PV systems have more than halfed whilst the cost of grid supplied electricity has increased. I do my sums based on actual and forecast power use.
 

Outrage

4x4 Earth Contributer
I expect that's 63 kWh over for a 24 hr period. Toyasaraus said he has an 8.25 kW system. I know a number of areas limit you to around 5 kW systems.

Whether solar is worth it or not depends on a number of factors. Particularly your energy usage and usage patterns.

For me, my bills (no solar) are about $200 a quarter, so only $800 a year. Average daily usage is about 4 kWh with most of my energy usage being evenings and weekends. Say I put in a 3 kW system, I'd be sending most of my power into the grid, then buying back in the evening.

Scenario 1: 100% usage from grid, 100% feed in to grid.
My current supply charge is $1.13/day or $412 per year.
Usage is about 1460 kWh per year (4 kWh per day), lets say cost is $0.4/kWh if on solar. Booboks number on first post. (Note that I currently pay $0.25/kWh after pay on time discount. I don't know if solar plans still have discounts).
Usage cost is $584 per year.
If I fed into the grid a daily average of 6 kWh in winter (2 hours equivalent of full sun) and 18 kWh in summer (6 hours of full sun), that's 4380 kWh per year.
At a feed in tariff of $0.12, I get back $525 per year.

So I'd end up paying $470 per year in bills. Let's assume it cost $3000 to purchase/install.

I was paying $800 per year before solar. I'm saving about $330 per year. So 9 years to break even.

Scenario 2: 50% direct usage
If my usage patterns changed and I could supply half my energy usage directly with solar each day (so 2 kWh per day direct). I only end up paying for 2 kWh per day and feeding in 4 kWh in winter and 16 kWh in summer.

My year total cost ends up about $266, saving $534 per year, with a break even in 5.5 years.

Scenario 3: Tesla powerwall.
This would add about $10,000 to the system, but I'd be able to have 100% direct usage from solar. So 0 kWh from grid, with feed in of 2 kWh in winter and 14 kWh summer.

My year total cost ends up about $62, saving $738 per year, with a break even in 17.5 years.. Such a battery system makes no sense for me, but a smaller battery would improve this (or larger solar system to get a higher feed in amount), but not be any better than no battery. It can gain energy security though.

I really depends on usage, and balancing the system with your needs. Put in too small a system with poor usage pattern, and the break even period can be very long (may never break even).
 

Toyasaurus

Well-Known Member
Sorry guys, I should have been more specific.

I ment I can generate up to 63kw summer, 20+kw in winter.
That is what the system generates over the period sunrise to sunset.
Not all of this goes to the grid, I was told by the company I bought the system from that they cap capicity at 7kw per hr.
I wanted to know the differance going to 10kw of panels would make, not worth it, you can only feed so much into the grid.

My next thing is to replace my on demand gas hot water system with a heat pump storage unit, we have bottled gas not NG.

The current govt BS is that they are reducing the cost of power, wait until they close the next power station in 2021.
The state can hardly meet the demand now, the price will skyrocket.

Cheers. Ian.
 

boobook

Well-Known Member
Ian, as outrage says, I think you must mean 63kW hours per day. A different thing and much more likely.
 

boobook

Well-Known Member
Here is some more stuff they only tell you in the fine print.

1)If it is a sunny day, and lots of people have solar in your area, your system will be turned down or off by the energy company to stop over voltage in an area. On cold sunny days, systems will run about about 20% of capacity or not at all. On a hot day when Aircon is on, it will be more like 70 to 100% depending on how many aircons and solar installations there are in your area.

2)If there is a power outage for any reason, you will lose power. This is called anti-islanding and designed so fire authorities can cut the power to your house and not get electrocuted when they spray water everywhere. Some special battery systems support islanding - power when there is a blackout but you must get a special system and register it from what I can see.

This isn't as simple as it looks on the surface.
 

Toyasaurus

Well-Known Member
Yes I forgot the h.
Islanding is automatic with Tesla.

After the fires and blackouts down here lots of people bought gensets thinking they could just plug them in and go for it.
That came to a screaming halt.
Same thing has to have an islanding system to be legal.
 
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