Solar Panel Regrets

[rennix]

I'm wondering if anyone has any regrets with installing their Soalr Panels please? Or wished they had known differently when installing their solar panels?

[_Steve]

Hi, I appreciate your reply. We have a somewhat odd circumstances , we are on TWO phases, as the house has in slab heating. We were moved ( no say in it ) by AGL to Time of Use rates when THEY decided the metres weren't working. To be frank, the whole 'it's nothing to do with the customer' approach is what I find the most outrageous. Anyway, I must say there have been a number of benefits, one being we have more flexibility with when we can use the in floor heating now ( the obvious caveat being we may pay more per KWh used ). Previoulsy the floor was only available over night. I find your replies and comments are always relevant and helpful.

[Lester]

Ah, underfloor heating, 2 phases.

You have a normal circuit for the general use, and a CL (controlled load) or off peak for the floor heat ??

You might have 2 meters, or some of them can do both normal and CL I beleive.

Ok, this is not unlike ours, where we had a circuit for normal usage and CL for the HWS, which used to only come on in the then off peak about midnight to 0600.

We are 3 phase here, and the solar was put in on 2 phases, with 2 x 5kwh inverters and a relatively balanced split between the 11.23kw of panels.

When we got the upgrade from analogue meters (and timer) to the new digital meter, SAPN (here in SA) put on what I expect was like for like, and the HWS put onto CL TOU, which . . .

. . . being separate from the main meter with general usage TOU and solar feed, meant that it was not in any way affected by the solar, we were charged for every kwh used for HW.

We found this out not long after it was all up and running, and left it for about 12 months.

It was costing up about $12.50 a week, or $160 or so a quarter.

Not good, so we considered options.

Put the HWS onto the normal usage meter and the CL is then defunct, and either :

1. Install a Catch Power unit, that can smart shift HWS usage to solar hours when there is enough solar to power it year round, especially important in winter and shoulder periods, and if not enough power, it can smart heat the HW when the cheapest tariff time comes around.

For us this is 0000-0600 at 8c/kwh.

About $1000 + install cost, maybe $1500 all up ?

or . . .

2. With the HWS on the normal circuit, install a timer on that, where we can set if for whatever times of day we like.

Cost $380, all up, which we did a couple of months ago.

The thought behind that was that, while we can set it for say 1000-1500 most year round and get it heating on solar alone, the 3.6kwh HWS usage would likely cut into usage above solar production in more costly times of day, say the wife doing a wash, or the kettle / stove going on, etc.

This would be most relevant in winter and shoulder, with much lower production, especially heavy cloud / rainy days.

So instead, we set it for 0100-0500 during our cheap early morning rate, so that old $12.50 HWS cost a week, now cost $4 a week, or $52 a quarter.

I'm happy enough with that for now, and one day we'll probably get a battery and make all that irrelevant. 

So, if you are happy with your underfloor heating on a CL, and it's not too much of a cost, that's great.

If you want to cut it down a bit, the timer thing might work out better if you have a rate low enough to undercut CL tariffs (ours had 4 different times of day, 3 different rates !).

Or when getting solar on, you could consider the Catch Power too, it really is a great unit that can save anyone with solar and a electric HWS, underfloor, pool pump etc heaps plus the set and forget hassle. (Or maybe a battery which could make all other steps unnecessary.)

All the best with your solar decision, make sure you get as much kw as you can on the budget and roof space, that's the new rule for most of the solar sales / advice websites with low panel cost now, and even overrides perfect north aspect.

We have panels east, north, and west, and get good morning / afternoon production too.

[_Steve]

Wow, lot of relevant points there !
Firstly, we are in Mount Gambier, so just down the road 🤣
I’m still getting my head around it all, but we have two phases, and two metres ( that much I get ! ).
We have the whole of house split between the two phases & metres.
And now, we have three TOU prices for general use and three for the controlled load ( which for us is only the floor ).
So, I don’t know how, but I assume the metre can some how tell when the electricity is going to the floor and when it’s not…
We have received a quote from a very reputable local electrical contractor and they mentioned the Catch Power ‘box of tricks’ and this was a definite missing part of the puzzle for us, as we have had two heat pump hot water units die on us ( the most recent lasted just six years) so we will never have another one of them.
So, we will get a ‘traditional’ hot water unit and use the Catch Power box to its fullest. The electrician also mentioned it could send solar to the floor, so, that’s all sounding good.
Except with the house we have, being designed to be take advantage of passive solar heating, we realise when we will most likely need the floor running, will be after sun set.
Which draws our thoughts to a battery….

What you say about the timer for HWS t’s up with what we were thinking we’d do = use cheap rates at night ( via a timer ) then Catch Power box during the day.
We hear you, re getting as many panels as possible, I’m starting to understand the logic !!


Purely out of interest, these are our current rates we pay, and they have actually come down ( not a lot, but still down ), from 12 months ago. Oh ! To be paying 8¢/kWh !!!

Peak
46.54 c/kWh
Shoulder
39.18 c/kWh
Off peak
31.87 c/kWh

Controlled load Peak^
41.68 c/kWh
Controlled load Off peak^
23.13 c/kWh
Controlled load Shoulder^
18.39 c/kWh

Supply charge
137.86 c/day


Steve .

[Lester]

Steve, I'm guessing your 2 meters will be set up like ours were set up.

Main meter for general use and solar feed (when that's installed).

CL meter for HWS and floor heat, or maybe heat pumps are operating differently on main meter circuit, I'm not that familiar with them.

Whatever there, but you can talk to the sparky / solar quote people and really nail them down for the best options based on the AGL plan (or other retailer) that might suit your new setup best.

TBH, I found AGL is the best or at least there are no better offers in SA for us, even before the the EV plan with cheap rate there are plenty of other retailers, but little difference in overall cost when compared equally for rates and supply charge.

One has to remember, different states and even regions (some states have more than the one electricity supplier) can have very plans and rates / offers, supply charges etc.

I take it the floor is on more (or only ?) in winter ??

So there is a switch for that or timer already ?

Or is it just on all the time on a set temp year round, and uses a thermostat to control on / off ?

Do you know what power that draws ?

The HWS we have is traditional, some have one element, some two, maybe depending on size . . . ours is 250lt, 3.6kwh single element, it only comes on for about an 3/4 hour most early morns about 1am, and later in early morn before 5am it comes on a little top off for maybe 10 mins, seems to draw about 3kwh most mornings for that, and we have HW through the day no problems . . . 2 of us, not big users of HW, just a nice long shower, dishwasher used on solar, it heats its own water, minimal kitchen HW use.

Battery install aside . . .

The Catch Power is the perfect setup for the HWS on main circuit, to make sure you can run that on solar as much as production will allow year round, so long term you will save a packet with that investment, and doing it same time as the full install, you will no doubt get the install etc very much less than doing it later.

The floor heat, maybe leave on CL and get a timer on that to come on during shoulder ??

A lot depends on draw, you could also have that on mains if reasonably low draw and leave the Catch Power to do its thing on solar, then timed to override in CL shoulder if needed in dead of winter etc.

A battery is good for normal fairly low draw after solar hours use, they shouldn't be used for things like high draw HWS, EV charging, or other such.

Taking an approx 10 - 12 kwh usable battery down to maybe min 20% SOC is best for longevity, and for us, a battery of that size would only go down maybe 6kwh for a nights full use (EV rate time included, but not for the sons EV).

When son is home with his EV, we'd have to make sure that is charged on the 8c rate, and not a battery, as that uses 7kw + a little of the usual early morn usage.

So for 6 hours of EV charging that comes to 40kwh or so, too much for a home battery, but then that's all programmable where the power comes from via a battery configuration . . . a battery could also be charged at 8c if desired, good for winter if solar is bleak.

What plan are you on ?

Have you checked this is best one for your area / usage ?

Those rates should include gst, and are much higher than ours.

It could be a regional thing.