I just earned $1 for selling 1kWh back into the grid.
Actually, I just earned $3.20 from selling half the storage in my Tesla Powerwall 1 during a ‘Grid Event’ back on 7 March, which brought my daily earnings from selling back into the grid to $5.62.
Not exactly a lottery win, but not to be sneezed at. Plus, I had the satisfaction of being part of the growing number of households who are helping to keep the lights on in suburbs when the grid is in trouble or when the spot price is unstable.
It was only the second “grid event” to impact Canberra this summer (last time was in November 30), but it’s something I am banking on happening more before they fix the east coast grid and/or Canberra goes 100% renewable in 2020.
It’s like betting against the economy, but with energy.
Doubling down
But I didn’t just bet against Canberra’s high growth in electricity prices (albeit off the lowest base) and the likelihood of black outs.
This was an effort to shore up the rising cost of living tide in the nation’s Capital – rates, gas, electricity, petrol, interest rates all going up with only a 3 per cent real increase in my salary (most Federal Public Servants don’t even get that).
So in December 2016 I went against the ROI-fixated ‘Solar-First Batteries-Second’ old hands and became part of Canberra’s Virtual Big Battery – a partnership between Reposit and the local ACTewAGL energy company – and spent $17,500 on an install that included:
Positives
After 12 months, I am happy to report that my 25 panel solar array and medium sized battery set-up (together some better demand management) has meant my wife and I have cut our electricity bill down from $2,100 per annum to just under $32 average per month (~$384 per annum).
Even though I own a pool and have a Carrier Heat Pump from last century (think 13kW draw when I use the element), my power bill is now the only bill I eagerly await – landing a $20 in credit in spring.
In summer my best day generated 44.5kWh in the nation’s capital:
I am now a full solar zealot and will tell anyone who will listen that the sun puts out these things called photons and that solar panels capture these photons and an inverter turns it into usable power for my household, the grid and my battery.
Plus I am an avid listener to the Energy Insiders and Solar Insiders poddies, and I trawl the Crap Solar Facebook page.
Negatives
Loss is the most powerful human emotion – measured at four times that of happiness. Seriously.
And although I know that it all works out the same in the end according to this ‘oversizing’ Solar Quotes article by Finn Peacock, it just irks me to see my SolarEdge clipped at 5kW on those hot windy summer days.
That is, unless the battery is still charging and then my system will produce up closer to near the 6.5kW maximum. See the 5.7 kW peak when the battery was still charging (orange chart below).
And how many times do I check my Reposit app? Well, suffice to say they should hand out free marriage counselling with every app, as I have been known to monitor the system and send my wife a text asking her if she is using the oven.
‘Tipping point’
Many are holding off, but I wanted to get in and see how it all works.
The ACT government’s $3,000 subsidy meant I bought the T1 at what some experts are calling the ‘tipping point’ of approximately $700 per kW of storage. Again, these are the same experts who are calling batteries a financial chimera and only applying the ‘payback period’ cost benefit analysis.
But there is one economic principle you can’t avoid – opportunity cost.
To fit the battery in to my budget I eschewed the premium LG 320 watt panels – forgoing the extra 11c feed-in tariff earnings from these more powerful panels – for betting against the network and a desire to be part of Reposit’s Virtual Big Battery solution.
Plus, I just dug the idea of sitting here at night with everything powered from my Powerwall.
The right installer
I still don’t get how energy moves through powerlines, or how Wi-Fi works, but I just know it does. So I leveraged outside expertise and got my three solar quotes, spoke to friends with solar and chose an installer who did a site inspection and has a local shopfront.
And I reckon I got it mostly right by going with these two trade-offs:
What’s next for the future sailor?
Yes, more is better. But as much as I want to bathe my roof in modules and slap up more batteries, I want to optimise what I already have.
I’m a more educated urban energy prosumer – one that both consumes and produces energy. Gone are days of me accepting the best ‘off-the-shelf’ energy bundle I could buy – with their time limited discounts and lack of customer service.
Now I want an Expert Battery, not just a Smart Battery; a battery that cycles twice a day and off-peak charges according to the BoM weather and my own usage patterns and equipment – and one that does this more consistently.
This means Reposit writing a better algorithm and having the time to tailor it to my household – which requires economies of scale.
Hopefully the crowd can help provide this scale-up, with DC Power spruiking the power of collective bargaining to improve service offerings and deliver a ‘VIP experience’ for prosumers.
So my next step has been to register my interest in DC Power’s crowd funded ‘Solar-As-A-Service’ offering to squeeze more out of my solar system.
That and I will use some of my GridCredits to appease the ROI Gods and swap out my pre-historic Carrier Heat Pump and switch my gas hot water over.
Then I will start future proofing again by buzzarding the electric vehicle market to find my ‘second battery’ – because those Texas oil fields aren’t filling up again any time soon.
Roger Rooney is an author and a Smart City technologist who is into his second year of living with battery augmented rooftop solar.
This post was published on March 14, 2018 9:52 am
An update on how Victoria's State Electricity Commission is rolling out their one-stop-shops for home…
In our final episode for the year, SunWiz's Warwick Johnston on the highs and the…
Regulator report finds that little-understood but increasingly common demand tariffs can add up to $800…
Have you heard the one about non-solar homes paying the cost to networks of accommodating…
Four good quality solar panels - costing around $500 - would produce enough power for…
The gas war still burns: “We need to think about how to stop misinformation going…
View Comments
Welcome to the SPA (solar pedants anonymous)!
You know you are a life member once you start calculating watts generated per kW installed capacity per hour of operation.
Oh goodie, another acronym that suits me. I'm sure support groups are popping up everywhere for this one.
The others? MAMIL and BOF
Just trying to be all-pro!
Do you mind me asking who your energy provider is? I see you get 11c feed in tariff but to get grid credits through Simply energy I had to accept a much lower 6.5c/kw and since the events were rare it wasn't worth me being on it so I changed back to ACTEW and am getting 11c/kw but with no GC. just got my first positive return on my power bill so wont be going back unless they are now matching 11c.
Actewagl offers .11c under contract (which I reckon is irrelevant these days) so get reposit to hook u up - actewagl and Reposit teamed up back in November for a trial —!no announcement yet on future but I expect it to continue
People further interested in discussing home energy matters can join in at My Efficient Electric Home, now with >2,700 members. Of course our Members are big fans of One Step Off the Grid and Renew Economy! https://www.facebook.com/groups/996387660405677/
Thanx Tim, I have just applied! :-)
Agreed, lose the Carrier ASAP. A new heat pump AC for about $1400 fitted would be a good investment.
Love it…This is what we all should do…Death to Big Power – who cares they are owned by foreign companies or governments….I have joined Sonnen Flat – I am in rural NSW
Roger, Thanks for sharing your joy, for I too am a member of the club and just love it, especially when I receive $210 credits/Q and nothing owed. As a solar expert I hope you will take my advise as to water heating, don't even consider a heat pump, it will add to your load everyday. Instead go an Evacuated Tube Solar Hot Water system, very close to zero annual cost, under $30 p,a. Edson make the best. 15/20yr warranty.
If you would like further info contact me on this avatar.
Hi solarguy, how much it cost you for the Edson system? I'm thinking to ditch my gas (I already have 3kW panel and PW2). Adding more panels a bit stretch to my overcrowded roof already, so this might be an option.
Hello Rusdy, Prices start from $4,340 before rebate of $1,369 for system only.
Thanks. I wonder why not install more PV with electric water heater?
Seeing that you already have an overcrowded roof, the SHW collector can be put on a pitching frame on a south roof, facing north. You would need to much PV to do the same thing and won't work on mostly cloudy days as an E.T. SHW system. Collector only needs 4sqm of space.
Simply put a big hot water system in and put a timer on sub board so water is heated from solar during day..
Solarguy, please try to keep your comments respectful and constructive.
You can request that from me Sophie, but have you looked at the nasty comments from this Rob Kuys git. Threats of violence is surely a more serious offense, not to mention the very bad language that went with it.
Why haven't his comments been removed? And why haven't you mentioned anything to him on this forum, at the very least?
Roger, larger rated output of panels doesn't necessarily mean more output per square metre of panels. If your panels are more efficient, that would make a difference. However, size, in this case, doesn't matter. :-)
I've embraced the energy efficiency pathway,$1 saved equals $5 not spent on hardware?
Gouging Corporate Gas (GCG) was sent packing and the savings invested in my own personal insulation,ie,a down jacket.Washing machine is used ~once every 2 weeks for those things too cumbersome to be washed by hand.Hand washed gear is spun dry where necessary.
Hot water is turned on manually ~1 hour every 3 days.Showers ~2-3 minutes.
LED lights of course and I really should give up on extended tv watching,it's not good for mental health.
Monies not spent on solar hardware currently earning 7.7% p.a.
Daily electricity useage <5kWhr/day.No heating (I'm in Canberra) just better camping gear;I consider my house to be a high spec tent.
Death to conspicuous consumption...When my list of simultaneous partial differential equations point to an inflection in the cost benefit curve,I might jump aboard with a modest 1.5kW system.Am I missing something?