Solar options for home in 2022

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#3490789 14-May-2026 09:48

50% deposit is not uncommon for most trades. Go through the recent reviews of the company you are dealing with on both google and there Facebook pages. A lot of them are active with install updates on their social media so it gives you confidence they are getting at least recently completed business.

Do whatever you want to do man.

t0ny

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#3490791 14-May-2026 09:52

I paid 2K to lock things in. Than 60% when they installed the inverter. No payment was made when they installed the panels (new build so they installed panels first). Rest when everything was turned on.

kangaroo13

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#3490808 14-May-2026 10:46

mark0x01:

What is a good "over commit" of solar panel to inverter and grid export limit.

Mainpower have approved a 7.0 kW export limit.

The Inverter is rate at 8Kw, but I'll only be getting 7Kw of panels to start and no battery.

Background load is around 1Kw/H for most of the day.

As others have said - oversize the array. Size for winter. Depending upon where you are in the country and the details of your panel orientation, you may struggle to even reach half the peak rating on winter days, i.e. 3.5kW daily peak out of 7kWp of panels. If you're trying to heat up a 3kW hot water system, it doesn't leave much overhead. (My experience, ChCh with N and W facing arrays at ~25deg).

Incremental cost for panels I found to be around $420 each (6 mths ago). Even off just the feed in tarrifs, the payback period on that incremental cost is likely to be less than the rest of your system (for me esimated at <4 years).

Most inverters can go +50% on the panels. Some more (e.g. SigEnergy, +100%).

If you're cost constrained, it may make sense to drop down an inverter size and upsize your panels - e.g. a 6kW inverter with 8kW of panels. For a residential installation, an 8kW inverter is on the larger side, unless you're planning to charge an EV. Inverters also work more efficiently near their rating.

Paul1977

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#3490815 14-May-2026 11:30

mark0x01:

What is a good "over commit" of solar panel to inverter and grid export limit.

Mainpower have approved a 7.0 kW export limit.

The Inverter is rate at 8Kw, but I'll only be getting 7Kw of panels to start and no battery.

Background load is around 1Kw/H for most of the day.

We went a 10kW inverter with 11.76Kw of panels. We could have squeezed another couple of panels in to bring it to 12.74 kW, and in hindsight I wish we had.

Ours was installed late April, and the highest generation we've had is about 8kW (but only for very short spikes), a bit under 7.5kW seems to be the typical peak on a sunny day at this time of year for us. Our setup is 5.88kW panels NNE (26.2 degree roof pitch) and 5.88kW panels WNW (20 degree roof pitch). Hopefully will be better in summer with the sun higher in the sky.

I'd say go at least 10kW (I'd consider going even higher) of panels on an 8Kw inverter. As others have said, extra panels are cheap at the time of initial install.

Paul1977

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#3490817 14-May-2026 11:37

razor2000nz:

Just wanting to get peoples thoughts on deposit amounts, is 50% the norm in this industry? Seems like they use your deposit to buy the product. But if they go bust your deposit is gone as you are unsecured.

With Harrisons we paid $1000 (refundable) to lock in pricing pending finance approval from bank. Once finance approved this was topped up to 50% (presumably non-refundable, but I didn't ask).

sen8or

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#3490818 14-May-2026 11:39

Also, allow for plenty of time before you start getting paid for exports, our power company (Genesis) seems to be moving at a glacial pace when it comes to configuring / changing the meter. Job put through 29/4 (advising 5-6 days for meter reconfig or 2-6 weeks for meter replacement). Followed up 11th May, received back "due to an unusual number of emails.........." reply, then got an email yesterday advising of further delays, and another 5-6 days for reconfig or 2-6 weeks for tech visit.

Only saving grace is that we are in a fairly low export period with just 90Kwh exported since install, at least its not during summer when I expect that figure to be much higher.

I'd hazard a guess if it was a meter that was going to earn them more money, the service level would be a lot better.....

Paul1977

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#3490820 14-May-2026 11:49

sen8or:

Also, allow for plenty of time before you start getting paid for exports, our power company (Genesis) seems to be moving at a glacial pace when it comes to configuring / changing the meter. Job put through 29/4 (advising 5-6 days for meter reconfig or 2-6 weeks for meter replacement). Followed up 11th May, received back "due to an unusual number of emails.........." reply, then got an email yesterday advising of further delays, and another 5-6 days for reconfig or 2-6 weeks for tech visit.

Only saving grace is that we are in a fairly low export period with just 90Kwh exported since install, at least its not during summer when I expect that figure to be much higher.

I'd hazard a guess if it was a meter that was going to earn them more money, the service level would be a lot better.....

In order to secure a good 2-year rate with PowerEdge before pricing increased we had to move to them a month or so before our solar was actually installed. Meter was remotely upgraded for exports about a week after we switched (well before the solar install) so exports being recorded from day one. Haven't seen them reflected in an invoice yet though.

Downside was the PowerEdge plan isn't great if you aren't exporting anything, so wasn't good for the month or so after the switch while still waiting for the solar install.

fastbike

527 posts

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#3490898 14-May-2026 14:26

LightbulbNeil:

mark0x01:

What is a good "over commit" of solar panel to inverter and grid export limit.

Mainpower have approved a 7.0 kW export limit.

The Inverter is rate at 8Kw, but I'll only be getting 7Kw of panels to start and no battery.

Background load is around 1Kw/H for most of the day.

Size your system for winter consumption. With an 8kw inverter , would reccomend 10kw of panels

5kw panels NE and 5Kw NW. This will give you the longest sunshine hours in Winter.

Panels currently are about the cheapest you will see them. Installing more later is not cost effective.

The inverter spec sheet will show total max PV input.

Put on as many as the roof will fit.

Otautahi Christchurch

richms

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#3490955 14-May-2026 17:26

Remember that panel voltage will be above the nominal nameplate Voc when its really cold too.

Richard rich.ms

fastbike

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#3490991 14-May-2026 19:52

richms:

Remember that panel voltage will be above the nominal nameplate Voc when its really cold too.

Not a huge problem here in temperate Aotearoa except in inland mountainous areas.

We did the calcs in 2024.

If it is a problem get an inverter with 3 or 4 independent MPPT inputs.

Otautahi Christchurch

Paul1977

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#3491206 15-May-2026 13:11

Just doing some comparisons and wondering if anyone who is with Mercury can answer whether or not GST gets applied to the export rate?

With PowerEdge it's applied as a credit to the pre-GST total, so you effectively get GST added even if you aren't GST registered. Not sure what happens if you wanted an actual pay out.

Mercury list all their prices as GST inclusive, except for the export rate which they explicitly state is GST exclusive.

I tried phoning Mercury to ask, but I don't think the person I spoke to could wrap their head around what I was asking. I.e. With their 11.1c ex GST buy-back rate, would I effectively receive a 12.765c inc GST credit per kWh exported?

LightbulbNeil

80 posts

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#3491213 15-May-2026 13:43

Paul1977:

Just doing some comparisons and wondering if anyone who is with Mercury can answer whether or not GST gets applied to the export rate?

With PowerEdge it's applied as a credit to the pre-GST total, so you effectively get GST added even if you aren't GST registered. Not sure what happens if you wanted an actual pay out.

Mercury list all their prices as GST inclusive, except for the export rate which they explicitly state is GST exclusive.

I tried phoning Mercury to ask, but I don't think the person I spoke to could wrap their head around what I was asking. I.e. With their 11.1c ex GST buy-back rate, would I effectively receive a 12.765c inc GST credit per kWh exported?

You will only get the gst for the export if you are gst registered.

Its the same with Meridian. I'm not gst registered. So I don't get the gst on the exported solar. I'm not paying gst for the sold or exported power either. Any solar exported I'm not claiming as income either.

My solar energy currently is not recognized as secondary income yet. But they may change the rules on that once enough people are on solar and are effectively enegy independent.

There is a company in Auckland that does pay you gst for the exported solar.

I'm not wanting to start any arguments with inland revenue either.

zenourn

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#3491295 15-May-2026 18:45

mark0x01:

What is a good "over commit" of solar panel to inverter and grid export limit.

Mainpower have approved a 7.0 kW export limit.

The Inverter is rate at 8Kw, but I'll only be getting 7Kw of panels to start and no battery.

Background load is around 1Kw/H for most of the day.

I’m in North Canterbury on Mainpower and just had a 24 kWp system installed. The minimum production per day this month has been 20 kWh, fully sunny day over 100 kWh. Max power of ~20 kW at midday peak.

General guide is to get panel capacity 1.2x inverter size. There will be minimal clipping with this.

mark0x01

22 posts

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#3491297 15-May-2026 18:49

richms:

Remember that panel voltage will be above the nominal nameplate Voc when its really cold too.

Thanks for all the useful feedback.

The Inverter has a PV max of 10Kw and I should just get 21 panels on the north facing roof spaces to give 9.8Kw.

I'll see if I can get the extras added at install time.

kangaroo13

106 posts

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#3491300 15-May-2026 19:29

zenourn:

mark0x01:

What is a good "over commit" of solar panel to inverter and grid export limit.

Mainpower have approved a 7.0 kW export limit.

The Inverter is rate at 8Kw, but I'll only be getting 7Kw of panels to start and no battery.

Background load is around 1Kw/H for most of the day.

I’m in North Canterbury on Mainpower and just had a 24 kWp system installed. The minimum production per day this month has been 20 kWh, fully sunny day over 100 kWh. Max power of ~20 kW at midday peak.

General guide is to get panel capacity 1.2x inverter size. There will be minimal clipping with this.

Clipping isn't really a problem though - tt is better to design to ensure sufficient energy over the winter months, even if that leads to substantial clipping in summer. Panels are relatively cheap, so over-provisioning the panels is relatively inexpensive (particularly done up-front when installers on on the roof). I would say 20% over-provisioning is pretty light on in most cases. But it does depend upon location, and panel configuration. If you're well south, with a low pitch roof, and don't have all your panels facing N, then there is a stronger case for over-provisioning, compared to a northerly location with better panel configuration.

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