Everybody needs good neighbors – especially ones who sell you solar energy Boffins looking into the Australian solar energy ecosystem say that sharing really is caring – and potentially profitable when homes with solar panels can sell their excess energy to neighbors at a preferential rate. "Under current conditions in Victoria, the feed-in tariff is less than 5 cents per kilowatt hour, while the …
I've got a 4kw array with 15.4kwh of battery storage, 12.4kwh usable (the rest is reserved to cover cell degradation over the 12yr warranty).
My 4 bed detached house uses in the region of 5500kwh of electric per year, we generate in the region of 4200kwh of electric per year (4256kwh in 2023, 3965kwh in 2024) and are on track for a record year this year breaking all records for generation. I'm WFH and spend a lot of spare time on computers too, we've got 3 desktops running during the day, and we cook with electric, only using gas for heating & hot water. So it's not unusual for the PC's alone to use up to 1kwh of energy for many hrs a day.
We spend around 6 months of the year off grid (less than 1kwh of import per day, as there's always some as load fluctuates) and we get 15p/kwh for export. We try to use as much as possible directly and only earn about £150 a year from export. But that's an extra £150 of the bills.
Last year we imported around 1800kwh of electric for the whole year and I consider last year a pretty poor year.
80% of our electric import happens between Nov-Feb.
We currently pay £100 a month to Octopus, and have a £962 credit with them. We typically get £200 a month gas/electric bills from Nov-Feb with the highest being £269 during extra cold weather. But last winter I beefed up the insulation in the loft and that seems to have helped a great deal too as part of the vaulted ceiling over the master bedroom had no insulation at all, and now has 400mm, whilst the rest was increased from 150mm to 300mm. I also insulated internal walls upstairs with acoustic insulation, and under the floor whilst doing some refurb work to master bedroom and ensuite... eliminating more cold spots above the front door. As I refurb more rooms, adding acoustic insulation to the last 2 internal bedroom walls.
Our yearly bills would be in the £2500 range for gas & electric and about £200 a month, as it stands, we pay £100 and build up a lot of credit over the last couple of years... and since my mum came to live with us, she throws her winter fuel payment (that she's just got back) on the bill too. The credit is so good, I'm going to see what it is in Feb 2026 and reduce the monthly payments probably to around £75. We are saving in the region of £1100-1200 a year inc any payments from export, and from Apr-Jul this year our combined energy bills have totalled £98 and August is looking like it will be around £25 (£13.50 as of the 17th)
If you can afford them without a loan, I cannot recommend them enough... I was lucky, We had money left over from the sale of 2 houses when we combined into 1 and it's paid for all of the DIY and refurb work we've done (Kitchen, utility, garage conversion, doors, windows, bedrooms & 2 bathrooms + the solar system). If you need a loan to do it, you won't actually be seeing those same savings, as the loan eats up as much as the lower bills provide.
Best thing I ever did... Now if only I can train my mum to understand that daylight does not equal 'entirely free electric' to turn of lights and TV's when she's not using them... but she's 79 and I don;t think that's ever going to happen. :)
My dream (if I won the lottery of course) is to build my own home, and whilst the initial construction wouldn't be eco friendly... it would be virtually off grid. Ground source heat pump to underfloor heating throughout, plenty of solar & battery, a solar water heating system and a small wind turbine... or even a hydro one if I was lucky to have access to flowing water. Just getting rid of gas for heating and hot water would save me around £600-700 a year in use and standing charges. The heating is turned off from May to Sept normally.
A few years back, I watched an episode of "Grand Designs" where a British family had asked a German "flat-pack" house builder (I think it was Baufritz) to construct a large home for them in a suburb of Bath (South-west England).
Being a modern German house, it was designed to be insulated and draught-proofed to the "Passivhaus" standard.
At the end of the programme, Kevin McCloud revisited the homeowners to see how it had turned out. When he asked about energy costs, the wife/mum replied that the family's gas bill for that winter had been £3.10.
This is why—as a former tech support and sales guy for a solar energy company—I tell my friends here in the UK that if you want to reduce your energy bills, spend money on insulating, draught-proofing and triple-glazing. Those measures will work in the winter and summer, night and day. Once you've done that, then look at solar.
I remember that episode, in fact that show is the whole reason I want to build my own house.
The house I bought a few years ago, is about 25yrs old, and was built on the cheap for what is classed as an 'executive' style home. So as we've been renovating and updating it, we've found that the floors between ground/first had no insulation at all, neither did any of the stud walls upstairs. So as I'm making repairs and adding extra sockets, along with reboarding the ceilings to get rid of the patterned artex... I'm filling the internal walls with acoustic insulation. Increased loft insulation by doubling it, we also did the garage roof space when we converted it and the old utility room into a bedroom & ensuite for my mum, so there's 150mm PIR in the floor, 150mm in the walls and 400mm in the loft above.
I'm also replacing windows here and there. Done a bedroom and a bathroom, as well as new doors front, back and patio... there's two massive windows in the lounge and master bedroom and we've been quoted £5000 just for those two, have to punt that down the road into next year... Got other priorities like replacing the knackered old conservatory for one with a warm roof.
Sounds like you're making good progress, TDM. Upvoted!
I forgot to mention to anyone who might be interested, that there's a natty device that diverts any excess solar power generation to your immersion heater; so instead of selling excess kWh's for peanuts (or worse, giving it to the grid for nothing), you can "store" it as hot water in your tank, which you can still benefit from after the sun's gone down.
It's called a 'power diverter' and the two brand names that I used to deal with are the Energy Recovery System or 'ERS' from PowerFlow and the Solar iBoost from Marlec.
Or, just set a timer on your immersion tank to come off "cheap rate" overnight and only allow it to heat up between 10.00 and 16.00 from sunshine.
Newer systems should have a tempering valve to mix cold water in with the hot set to max on the thermostat. Older systems can have one fitted to allow the heater to be turned up to max without scolding you.
Saves more energy and is simpler putting the HWS on a timer fuse than a power diverter.
Very similar experience and numbers - with the difference that I have a 10 year interest free loan to pay for the infrastructure (6.5kW panels and 10kWh battery), installed just over 2 years ago.
Well worth it and looking to break even after around 8 years.
So let me get this straight: energy companies could just buy your excess solar at 5c, resell it at 28c, and laugh all the way to the bank - but that would be too obvious, too honest of a racket. Instead, they’ve engineered a system where your surplus electrons must be purified through seventeen layers of “grid services,” “balancing markets,” and “network charges” before they re-emerge as “premium renewable energy” on your neighbour’s bill.
They don’t buy your power because then the trick would be too transparent. They need the fiddles: the hidden levies, the creative accounting, the ability to cry poverty while posting record profits. The greenwashing is just a bonus - a coat of paint on the tollbooth they’ve built around something that literally falls from the sky for free.
But remember: they’re not gouging you, they’re empowering the transition.
I wonder if this is the real reason for the forced deployment of smart meters....
With an old-style meter, read once a year, the import and export rates will always be exactly the same.. If you produce 10MWh in a year (exporting the bit you don't use, i.e. running the meter backwards during sunny spells) and consume 10MWh/year, then your bill would be zero, except for the standing charge.
But with a smart meter, they can give you asymmetric pricing and play arbitrage.
Australia is moving to 5 min metering across the country so it tracks spot prices closer.
Also unspoken is the remote command disconnect of solar generation [it runs through a separate contactor on the meter] plus the ability to take you instantly offline completely if you don't pay your bill.
So let me get this straight: energy companies could just buy your excess solar at 5c, resell it at 28c, and laugh all the way to the bank
Nah, that would be too easy, won't it? Just do as the Dutch do. There too there is a huge push to get folks on "smart meters", because...
The old meters just started to run backwards when you delivered power back to the grid. But "oh dear, that puts pressure on the grid". Or, more PR conform: "We deliver you the service of transporting your energy". So... now, if you generate solar energy with your solar panels, the ones you paid for and put on the roof of your home, and you feed that power back to the grid... we of course will charge you for doing that. No worries, we can charge you too for any power of your panels you yourself use, and if you don't reach a certain level, we conveniently adjust your tariffs! What..? You made some money selling your solar energy? Ah! Hello, we are your servants of your local tax office, you need to pay us!. BTW since you need a "smart meter" so we all know how much you need to pay us all, Dutch government now passed a law making making it criminal not having one.
Does it surprise you that the cloggers now just turn it all off on sunny days?
The tariff difference is indeed odd. Incredible margins for the electricity companies.
Here in Nordics the common electricity market exchange pricing goes both ways. You buy and sell at the spot prices - the prices for the next 24 hours are public. The electricity companies add their own margin, but with my leccy contract the margin is 0,60 cents / kWh, so nowhere near those Aussie numbers.
With a battery you can theoretically - and in practice - accumulate cheap power and sell it when the price gets higher. For example, today the kWh spot price at Nord Pool will fluctuate between 0,02 and 8,78 cents.
During summer the price can often be negative so you better just use it yourself: charge the batteries, turn your storage water heater to 11, charge your car and mine bitcoins. OTOH, electricity is more expensive in winter and in January 2024 Finland had a cold spell combined with a couple of electricity plants having technical problems - the price climbed to over 2€/kWh for one hour and the daily average was around 1€/kWh. Average for 2024 was about 5c/kWh.
You can also make static electricity price contracts (usually for at least a year), which may be better if you expect the exchange prices to get higher in the future. The electricity you generate at home will still be sold at the spot price.
> a hell of a differential.
In classic tariffs, distribution often costs more than generation. Yes if I literally delivered my excess to my neighbor, 300', that is only a $9,000 line amortizing under $1K over a decade+. But Jimmy's got the same sun as I do, and more roof (17 car garage), so distribution can more than eat any differential.
I don't know when or where their got there numbers but I pay twice as much at 3:01pm and I only get $0.01 feed in and I'm on the high side of the feed in with some people getting 1/10 of that. I'm in Ausnet territory in Victoria.
Would be really interested to see how this is actually achieved.
I like the idea - a lot - but there are some considerations - regulatory, safety, insurance, practical - I am sure there are others.
You cannot use the grid to share - as then you would just be paid the export tariff. So do you have a private distribution infrastructure to one neighbour - or a few?
Building your own power sharing infrastructure will need to be done properly - not an extension lead slung across a fence - or it becomes a safety risk.
Does this impact the insurance policy? Probably a new one for them, but I can imagine what they would say.
Do you have neighbours you would be able to do this with - and not fall out with???
Grid connection to one point.
Meter. Both ways.
Connect 5 or whatever houses to that point, with a meter for each.
Feed in the solar (etc) at houses, or all into that point between the meters, and meter each input.
Now adjust input and output prices to suit.
Energy is more valuable in the right place at the right time, and everyone using a grid is invited to contribute to the maintenance of it.
We have ≠ 2kW on the far side of the county about to be fed in, along with many MW in the same field, eventually we get a trickle of money via the supply company that buys the power.
The panels on the roof have more immediate arrangements.
We draw power when we put the kettle on in summer, but 5 houses in a row usually wouldn't.
> I like the idea - a lot - but there are some considerations - regulatory, safety, insurance, practical - I am sure there are others.
This is why we have have people who know what they are doing. There are around 3000 pages of direct regulation and standards an electrician is expected to know before he can install a new circuit breaker.
> You cannot use the grid to share - as then you would just be paid the export tariff. So do you have a private distribution infrastructure to one neighbour - or a few?
Consider apartments, condos, sausage flats, houses on common driveways or plazas, that all have a single point of entry
> Building your own power sharing infrastructure will need to be done properly - not an extension lead slung across a fence - or it becomes a safety risk.
So? Building your house is likewise a regulated activity that must be done properly.
>Does this impact the insurance policy? Probably a new one for them, but I can imagine what they would say.
"Does it comply with the Electrical Safety Regulations and applicable standards, and is it installed by a qualified person?"
>Do you have neighbours you would be able to do this with - and not fall out with???
Yes. But you don't need to manage this yourself. A body corporate or a company like Octopus could easily manage direct interconnect billing as well as the grid connect billing.
Exactly.
Unless you setup a separate side grid to connect you with neighbors (or a single cable to connect you with one neighbor) this isn't going to work, because even ignoring safety/regulatory issues else the utility is not going to allow you to use their grid to sell power to your neighbors because it isn't in their financial interest.
Another objection is that when your neighbor needs electricity is very often going to be when you also need it, so you need to oversize your battery storage to have enough to handle your neighbor's needs along with your own. Let's say your neighbor is willing to pay enough that you get payback on that extra battery capacity in six years. Sounds great, right? What happens if prices fall and he decides to get his own battery system two years in to save money vs paying you? Now you have that oversize system without any payback.
The way I look at it any sort of payback for capacity you aren't using and will never/almost never use is gravy, but you need to decide on sizing etc. based on your needs not anyone else's. If the utility is willing to offer an installation time rebate worth more than the full upgrade cost in exchange for being able to use that excess capacity they "bought", fine. If that payment comes in the form of feed-in tariffs that are subject to change, I'll treat them as being worth $0 and size my system according to my needs alone.
"You cannot use the grid to share"
I am guessing that because in AU the distribution (poles and wire) are separated from the energy generators which are in turn separated from the wholesalers and retailers that a communal power entity arranges access to the distributors assets (as it is a consumer already pays a separate itemised supply fee) and subsumes the role of the retailer. As long as the participants aggregate feed-in is greater than their usage the billing for use is largely arbitrary - any excess power can be written off.
In principle the participants in a communal power sharing arrangement wouldn't need to be adjacent or even in the same city but presumably connected to the same distributor which very roughly means the same state.
Currently we get 3¢/kWh and paying 32¢kWh but since our usage is mainly during the middle of the day the PVs supply that and heats the hotwater. If we added an 8kWh battery our imports would be close to zero but with TCO of battery and the distributor's supply fee probably not a net win although the government subsidy might tip the balance.
Having lived on acreage in a regional area I can see a lot of residents going off grid as they have the space for 20kW PV arrays and matching batteries and generally already have diesel generators for the frequent [grid] outages expected during the summer storm season.
How that will play out is not entirely clear.
As mentioned, you would have to build your own grid, and attach it as the primary, maintaining the existing grid as a secondary source, in order for this to work.
The issue here is the greed of the power company.
There is considerable line loss between power generation and your home. If you sell back the power at the same price you would pay for it, the electrical company would still make quite a bit of money.
In other words, the solution here is political. The power company is operating a monopoly. Demand legislation that you can simply run the meter backwards.
Lines companies have a largely fixed cost to provide infrastructure. Because people really don't like having to pay really big standing charges, they tend to use a margin on the energy sold to make up the income.
In a solar future with no import-export differential, the standing lines charge has to become much higher, and people disconnect from the grid because with solar and batteries, they are better off adding PV over-capacity and saving $15000 over 10 years of standing charges.
This process is already well underway in rural areas**, but this year it has started happening in urban areas.
**Lines engineer told me that less than 1/4 of new houses in a particular rural area are connecting to the grid, and more have disconnected than connected. The lines companies are trying to get the universal service obligation removed, as they can't pay for replacement when the existing wires and poles age out.
"As mentioned, you would have to build your own grid, and attach it as the primary, maintaining the existing grid as a secondary source, in order for this to work."
Not really - there is at least one power retailer in NZ that allows you to sell your PV surplus to your second home or a family member. The catches are that both places need to be with the same retailer and you pay (I think) 10c/kWh transport fee, but it can still work out as a better deal for both parties and there's no restrictions on how far apart the two endpoints are..
Well that is how mine started 20 some years ago. They are slowly boiling the frog. They changed the deal (they can, they run the grid) to you pay me 12c/KWh and we pay them 12c/KWh, which seemed the same as net. Slowly they've raised the water temp. We are now at utility pay me 9 and utility charge me 15. Mind you that includes the electrons I use that are generated by my panels never seeing the grid. Without a dedicated ckt with batteries, you are their *itch when they decide.
How the Aussies share power:
"Virtual Energy Networks"
SolarQuotes is a mine of information for Aussies interested in Solar (and renewables generally).
www.solarquotes.com.au/blog/ven-virtual-energy-network-mb3248/
The only one I'm familiar with is "LocalVolts"
You can in theory contract to sell or give your power to anyone else in their network or sell it on the wholesale market.
In theory, there is no difference between theory and practice.
Not having any friends, I just buy and sell through a wholesale portal called Amber Electric. That has its own issues though.
I got quoted for solar and battery syorage recently and as others have pointed out, just getting rid of gas means the removal of the standing charge pays back 10% of the total install cost. The gas boiler service savings will additionally pay for a few Kwh of electricity a day over the winter months.
At the most recent election there was a very well hidden election promise that strata companies would be able to share power between them. Perfect for my situation where we have 3 units... we could chip in a buy one big battery and feed all three of us off my 5kW rooftop. But when the draft legislation came out, it turned out only to apply to apartment buildings.... so the strata company can put panels on the roof and sell power the residents. Worth pointing out that in WA the energy company that rips us off is owned by the state govt so they have little incentive in improving things.
ps get a heat pump for hot water and program it to run from 11am to 3pm :-)
This is the answer. Back before solar everyone was reliant on big generators. Now we can make and store our own electricity. It's a game changer.
Within a few years the big gens ability to game the wholesale power market will be gone (they should've been taken to court for this already!).
Cheap rooftop solar and home batteries is the future. Australia is leading the way towards a decentralised grid.
