39 Comments
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Hana Craig's avatar

An absolutely awesome and hilarious article whuch echoes my family situation very well. Thank you!

Nigel B's avatar

We have had solar for 3 years now without a battery which are just not financially viable and we love having it. Our bill was $6 last month. It's well worth buying a Catchpower device which very cleverly diverts surplus power to your hot water cylinder before it sends any back to the grid. Given hot water can be up to 30% of the bill this makes huge sense and your cylinder then acts like a low cost battery. The interesting thing we have found is that people only ask how long it will take to pay it off. My reply is always that's a small factor compared to the immense satisfaction of doing something worthwhile for our struggling planet. Why our crazy government is building a gas terminal in Taranaki at vast expense instead of subsidising solar never ceases to amaze me but I suppose most of them and their mates have fuel company shares to go with their rentals.

Mark Graham's avatar

Thanks Jesse!

Currently getting quotes and face a similar challenge with my wife. Hopefully you’ll be able to do what I struggle with.

And we’re also looking at getting an EV, though every 2nd hand one we had watch listed has sold in the space of a few days and the dealers we visited today have none and people pouring in through the door.

Stephen Reynolds's avatar

I think a winning pitch for the solar installer is not the pages and pages of financial and ROI charts and data but "Here are three ways to pitch this to your nearest and dearest." As Jesse suggests, Claude could help here. In our experience the clincher for my wife was meeting the installer and gaining confidence from hat he said and how he said it. This is the flaw in the on-line sales pitch model and the real advantage for the local installer.

Sophie S.'s avatar

Went fully off the grid a few years ago and must say I do not miss the power bills. It's hard not to feel a tiny little bit smug when there's a power outage in the neighbourhood 😄

Diana Jones - diana-jones.com's avatar

Brilliant, thanks for all your research and insights. I’d love installing solar in nz homes to be easy and economic. It sounds like we are still a long way from this. Your article goes a long way to making the numbers work, now it’s accessing skilled experienced installers and having panels available. What is hard about that?

Debra's avatar

Lol. I did welcome the glossy sales pitch many page proposal I received ... for not-for-profits orgs in the right areas that own their buildings check out some great potential granting opportunities with https://welenergytrust.co.nz/grants/other-support-available

Jonathan Tonkin's avatar

Love this piece, Jesse! Super helpful.

Victoria Smith's avatar

This was such a funny and incredibly helpful article Jesse. Thank you.

Stephen Reynolds's avatar

Great article, Jesse. Pretty much our journey. My two points are;

1. Panels are sooo cheap and grunty now, just put as many on your roof as can fit no matter which they face except possibly due south. This will be overkill in summer but, hey winter's coming!

2. Why do we get so hung up on payback with solar? When you renovated the bathroom did you chose the tiles based on their ROI? No you didn't, and I know even a basic bathroom reno costs a whole lot more than 40 solar panels and an inverter. And eventually the panels are paid off and give you FREE power. No bathroom tiles ever did that.

Jesse Mulligan's avatar

Hey Stephen I love your thinking. A few years ago when I started kayak fishing I used to spend a lot of time wondering whether the fish I caught would eventually pay for the equipment I'd bought then I realised ... I am actually having fun out here! Nobody asks a bird watcher when the birds will pay back the investment in binoculars. But I don't think the analogy is quite right with panels/tiles. Solar panels are optional and only (or at least mostly) installed for financial reasons; tiles (or something like them) are necessary and have aesthetic and utilitarian value in their own right. There must be a better analogy though I'm not sure what it is. Either way I respect the point you're making!

Rob Purdy's avatar

Much to talk about! Great article looking forward to the results

Andrea Preston's avatar

We’re considering it but in winter a large part of our load is at night time due to the heat pump. But don’t want to fork out for battery, any ideas?

Jesse Mulligan's avatar

Might be worth uploading power bills to GPT (Claude) and letting them work it out? We have a pool and spa so guarantee plenty of daytime load!

Jenny Sahng's avatar

Putting a little timer on other loads like the hot water, washing machine, dishwasher etc. to run during the day is the way! Then even if your heating is drawing from the grid at night, you can still achieve a good % of your electricity consumption from solar.

Cindy's avatar

Thanks for this - all makes sense from my own previous research, although as you say solar panels have improved over time, so being up to date is vital. I have a small battery that I use for car camping & portable solar panels that can recharge it, as well as the cigarette lighter in the car while driving. In the event of a power cut it would run my freezer for day or so. Last year I tried to get my other rigid solar panel installed on the roof with a feed to this battery but the person who quoted the job suddenly stopped responding & I lost motivation - obviously wish I had persisted now! In the summer this panel gets good sun at ground level, but in the winter only the roof is clear from the shadow of the neighbour's roof, hence the need to elevate it. Sounds like it will be harder than ever to get it done now with the increased pressure from those eager to get more autonomy!

I really can't afford a full install, but perhaps a Lotto win might change things! Would be happier if they would stop increasing the base rate for low users FFS 🤬 Being punished for being careful is counter-intuitive, no matter their reasoning.

Carolyn's avatar

I’m in Canada and we installed solar panels on our house a year ago. Canada had a “Greener Homes” program with a grant and loan; they ended the grant just after we’d gotten it. Even though our roof is snow-covered for part of the year, we are still ahead for the year on generation vs consumption. Every bit we can do helps.

Leave No Regrets's avatar

Good humorous post on a serious subject. Well Done!

Lindsay Wood's avatar

Thanks heaps, Jesse, for an insightful post on your PVs. Good on you for taking the plunge, and I love your annotated image of your power use/generation.

I’d like to point out that, for anyone wishing to install a battery in the future, it’s worth investing up front in a “hybrid” inverter, which would then allow their system to keep running on batteries when the main power system was down. (The point being that when there’s a fault on the mains, to avoid feeding power into a faulty grid, PV systems have to shut down unless they have a hybrid inverter that allows them to switch over to running off batteries alone.)

Plus, topically with current petrol and diesel prices, you're clearly tuned in to charging your EV during PV generation, so you're likely running it at a phenomenal 2-3 cents/km! (Rule of thumb: divide your powerco's "solar buy back rate" by 5. So if the rate is 12 c/kWh that works out at about 2.4 c/km driving., i.e. what you lose in buy-back by charging your car).

Jesse Mulligan's avatar

Thanks Lindsay and for your guidance over the years. We did get a hybrid inverter, is that worth noting in the piece do you think? Easy to make an edit. Does your 2-3 cents/km include the new RUCs?

Lindsay Wood's avatar

I do think it worth mentioning hybrid inverters, Jesse, to spare people a possibly significant additional expensive at a later date (he says from costly personal experience!)

And thanks for checking in on RUC - my lack of clarity, sorry, as I was just talking energy costs. RUC works out at 7.6 c /km additional. So RUC + electricity off your PVs may be around 10c/km; petrol @ say $3.50 (inc road tax) works out about 35c/km - still a huge differential. (I'm currently updating our Clearcut tool to compare EVs, fossil fuel cars, and hybrids, with a view to making it freely available.)

Jesse Mulligan's avatar

Thanks! I'll add something now. 25c/km means around 40,0000 km for a $10,000 second hand Nissan Leaf to pay itself back? Am I doing those numbers correctly? I should subtract most mechanic charges too I suppose? Understand there are other good reasons to walk away from fossil fuels including supply volatility and environmental impact

Lindsay Wood's avatar

In simple terms based on daytime charging of PVs, yes, but it does get fairly complex fairly quickly - e.g.what is the finance rate? (There can be much better terms for EVs). How are the generally higher maintenance costs for combustion engines factored in? Has the range of the Leaf dropped to a point where public chargers (at higher costs/kWh) will be needed more frequently (which in turn relates to the sort of usage the car will be put to - just short round-town or a lot of longer trips etc).? The usage pattern also determines whether charging is always able to be offset against the solar buy-back rate - people who charge at night won't do so well.

Kiwi Rebel's avatar

My parents put solar hot water panels on their roof in the 1980’s when it was all the rage. Of course people thought they were crazy. I wonder how much they saved in the 40 years they owned that home? I’ve just signed up for a free Off-Peak power plan and put a switch on my water heater so that it only heats during those hours (I don’t own the roof) which cut my power bill substantially.