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Not a great start to the year.

 

So far since we have been live we have been running under my estimates (Nov-97%,Dec-103%,Jan-86%,Feb-93%,Mar-90%)

 

There have been a lot of overcast days.

 

4.9 megawatt-hours in 5 months. Still very happy though :)

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So far I am about .78 mega Watt hours in almost six weeks - so its a bit down due to poor weather, but the system produces a bit even in really poor days. But about half of our production is feeding the grid whilst we aren't home. So on a very short average data model - it'll be saving us about $400 a quarter in Autumn and Spring - be interested to track what a full year's saving results in.

 

This saving I estimate would double if I had economical storage to re-use that 50% of power I am sending to the grid!

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I am at the half way point in our Autumn billing cycle and have noted one surprising trend. Our total consumption compared to this time last year is down about 16% since installing a Wattson and simply monitoring what we use.

 

This blew me away – the simple act of being overtly energy conscious has taken away a sixth of our consumption. So thanks to solar when I model what I am using now from the Grid it is in total 61% of what I used the same time last year (I am only consuming just under half of what I produce at present). Better still is and my consumption from the grid is now largely off peak at their cheapest rate - being 68% by volume or 41% by value!

 

So by my calculation our next bill should be around $392 – compared to the same time last year of $917 for this quarter. So at over $520 a quarter that is quite some savings!

 

I further modeled that with 9.6 kWh of intelligent battery storage I could save an extra $200 a quarter. So for me I can see that Solar looks like it really will be a winner given this trend continues!

Edited by g__day

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Small update as I close in on my first Mega Watt production. I have been modelling solar data a fair bit now, and this has improved my already decent Excel skills. My spreadsheet now punches out to the web in real time to get current production and works out where in the day I am relative to sunrise and sunset to better calculate and forecast real time consumption versus production.

 

For Excel - I'd never used the =now() function before or tried to strip a number out of text =SUMPRODUCT(MID(0&U14,LARGE(INDEX(ISNUMBER(--MID(U14,ROW($1:$25),1))* ROW($1:$25),0),ROW($1:$25))+1,1)*10^ROW($1:$25)/10) nor called a web page (the local IP address of the envoy gateway's Production page) to allow that earlier function (I got from the web) to strip of the current day's production figure in real time.

 

But the point to this is I have recalculated how much energy I could save on average if I stored all excess power into batteries to work out what price per kilo Watt hour the batteries would have to be to give a 5 or 10 year payback. Answer is a 1.2 kWh (Enphase proposed) battery would have to cost no more than $450 to have a 5 year ROI or $900 for a 10 year ROI. So thorough modeling for this time of the year shows batteries would save me a further $184 a quarter by load displacement - meaning I would really only pay for off peak usage.

 

The next thing to review is Power Shop - which allows one access to possibly 30% cheaper rates than AGL - so long as you monthly buy power in advance from them and get your forecast correct!

 

http://www.powershop.com.au/how-much-does-it-cost/

 

 

 

So the question now is will Enphase's calculators be as sharp as mine when it comes to pricing their technology for the Australian launch later this year. Fingers crossed

Edited by g__day

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Enphase say they will launch its Energy Storage and Management system in Australia in the second half of this year

 

http://enphase.com/wp-uploads/enphase.com/2014/10/Enphase-AC-Battery-Brochure-1.pdf

 

They promise solar installers they will have a calculator to demonstrate to folks the potential savings. So for me I model that each day on average for Autumn - I

 

1. Feed 9.3 kWh into the grid during the day for 8 cents a day

2. Consume 3.5 kWh in peak for 56 cents per kWh

3. Consumer 3.7 kWh in shoulder for 21 cents per day

4. Consume 14.8 kWh in off peak at 11 cents per day

 

So each day with batteries I could cover my peak, shoulder and a small amount of my off peak saving almost $2 extra per day. Do the sums and for a say an intelligent 9.6 kWh storage system I can see what the launch price would have to be. If Enphase's to be released storage energy calculator doesn't realistically model potential savings - then they might over estimate the price point they can try and sell this at!

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AGL just jumped into the act too. http://reneweconomy.com.au/2015/agl-fast-tracks-home-energy-storage-option-with-6kwh-battery-40348

 

 

But I think I will wait a few months and see what Enphase do first. A completely integrated, intelligent solar and storage management system that is web based is kinda desirable - so long as its keenly priced!

Edited by g__day

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price will be interesting.

 

I've just requested my Smart Meter info for the past year so I can get a better idea of my consumption patterns. I think it depends on your provider and state, but here in Vic you can request the 30 minute interval data that the Smart Meter sends to the provider. Based on that I'll get a better idea of usage patterns, especially overnight, and I'll be able to calculate how big a battery makes sense.

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Probably only one, D. 10kwh is a fan heater at Max for 5 hours. You probably aren't going to do that, and it only has to last a night (lowest demand time) before recharging anyway.

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I have just stumbled across the analysis from g _ day. I have done the same over the last fortnight and have never seen such a helpful summary anywhere. So accurate and without bias. I have come to the same conclusion and just signed up for a 10kw JA310 KW system with enphase-250 micro-invertors. My family are very high energy users and thanks simply to analysis I have reduced my electricity usage. I am looking forward to the results and can not wait to read the analysis when the enphase solar battery storage battery pricing is announced.

once again thanks to g-day

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Probably only one, D. 10kwh is a fan heater at Max for 5 hours. You probably aren't going to do that, and it only has to last a night (lowest demand time) before recharging anyway.

So not enough to run the fish tank, the hot water and everything that's on standby?

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Probably only one, D. 10kwh is a fan heater at Max for 5 hours. You probably aren't going to do that, and it only has to last a night (lowest demand time) before recharging anyway.

So not enough to run the fish tank, the hot water and everything that's on standby?

 

 

Mate, if your standby shit uses that much juice, you fucken well need to clean up anyway. :p

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$3500 USD that's for a 10kwh pack, not sure how many you'd need for a house?

 

As a percentage cost of an overall solar solution it's a fair whack, but it does increase the payback substantially.

 

For most people, the aim is to reduce the amount you take from the grid to zero without over-investing. So a system with a battery wan't to produce slightly more than they are consuming so that the battery is slowly recharged during the day, but not a shit load more.

 

When you start to look at the savings you can make by moving more appliances to electricity (like hot water) and possibly even an electric car, it gets exciting :)

 

Of course everything costs money, so you need to make sure you don't invest so much it pushes the payback period out to buggery.

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Probably only one, D. 10kwh is a fan heater at Max for 5 hours. You probably aren't going to do that, and it only has to last a night (lowest demand time) before recharging anyway.

So not enough to run the fish tank, the hot water and everything that's on standby?

 

 

Mate, if your standby shit uses that much juice, you fucken well need to clean up anyway. :p

 

:)

 

 

Yeah I have NFI how much juice we use....shouldn't be that much, we don't have the TV on during the day nor the aircon etc. Though since the hot water unit got replaced last year I have noticed a HUGE drop in our power bills. It's all academic for now as we don't own a roof to put the panels on anyway. :)

 

 

 

$3500 USD that's for a 10kwh pack, not sure how many you'd need for a house?

 

As a percentage cost of an overall solar solution it's a fair whack, but it does increase the payback substantially.

 

For most people, the aim is to reduce the amount you take from the grid to zero without over-investing. So a system with a battery wan't to produce slightly more than they are consuming so that the battery is slowly recharged during the day, but not a shit load more.

 

When you start to look at the savings you can make by moving more appliances to electricity (like hot water) and possibly even an electric car, it gets exciting :)

 

Of course everything costs money, so you need to make sure you don't invest so much it pushes the payback period out to buggery.

 

Sometimes though it becomes the better option from the get-go, I mean if it's going to cost 50K to connect your block up to the grid I reckon you'd be better off putting the money into alternative energy and avoiding the grid altogether.

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I chatted with AGL today on line - they are planning a 7.6 kWh, standalone unit that can't be utilised in pairs or more of similar sized units :( They inform me it is Lithium Ion based technology that can last 10 years or 5,000 complete charge / discharge cycles (which is something I wasn't aware any battery - even deep cycle could do). A line in a brochure of theirs infers their system is allowed to be charged both by solar or by off-peak grid; but the online session died just as the fact finding got interesting!

 

I don't plan to ever go off grid - but I sure want to use 100% of what I produce. Having produced over a Mega Watt now I can see my expected bill should be short of the $400 mark - versus over $900 for the same time last year. Even with a lot of crappy weather I have exported 583 kWh to the grid - at 8 cents per kWh - and that is energy I would love to self consume during peak (and/or shoulder times) - hence the wait for storage solutions pricing and usage limitations!

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So far this year I've pumped 1.79 mWh into the grid. If I could store and use that myself I'd be a happy little vegemite!

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The tesla home battery is looking like a great idea. Might have to get panels on the roof here. :) Thanks for your detailed posts too.

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AGL are providing a bit more information on their storage solution. What I have learnt so far is:

  1. It's sized at 7.6 kWh fixed – and you can only have one unit per house.
  2. It's maximum output is 2 kW per hour
  3. It's Warranted (sub- performance risk coverage unknown) for 10 year of 5,000 cycles (unclear if that is full depth charge / re-charge or not)
  4. It's lithium Ion based
  5. It can integrate (to some extent) to most solar systems
  6. Supplier have a basic economic calculator that AGL are not willing yet to share with residential consumers
  7. It can be recharged either from Solar or the Grid (but its unclear if AGL allow you to re-charge from the off peak grid and do load displacement)?

A bit more here if the link at the bottom is readable for all. I wanted to know from AGL:

 

  1. Is the control system rather intelligent, user programmable, real-time monitored, providing web based reporting every 15 minutes and closely integrating the solar production, energy storage and grid consumption?
  2. If a typical use case might be half the 7.6 kW going to feed evening peak and half going to feed morning shoulder use – I calculate this could save $680 a year – so when is the expected payback period for a unproven, 10 year maximum life system?

 

Actually that analysis is a bit harsh – because you could discharge the 7.6 kW in the morning, recharge possibly during the day and discharge again in the evening at peak off set, then re-charge again that evening during off peak (if that's allowed) meaning you would reach your 5,000 cycles possible late in year six! By my calculations on this it shows possible real world savings of between $800 - $900 for six years if used nearly optimally and the gear does all its supposed to every day...

 

Interesting times ahead!

 

https://community.agl.com.au/t5/Solar-and-Renewable-Energy/When-will-AGL-launch-a-customer-Energy-storage-solution-sizing/m-p/61/highlight/false#M10

 

PS My real time monitoring sheet

 

11203617_853499974725173_746220612339085

Edited by g__day

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I appreciate that there are many new companies promising a storage solution ( Tesla, Enphase ....) but have yet to clarify pricing. There are many companies already connecting batteries and advertising their products. They appear to be reasonable in price and promise a reasonable return on investment. particularly the gel battery set ups.

Does anybody recommend a company or a setup. www.setec.com.au is a local Victorian one that I have seen but there are many.

Any thoughts would be appreciated... Personally I can not wait to see the enphase pricing but expect to be disappointed and having to look at the options I mention above

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I would say its 3-6 months too early to recommend a winner yet. You need to know:

 

1. Whether the electricity provider will allow any (or only their own storage solutions to be recharged from off peak grid) - that allowance if their kinda improves the value of a solution by maybe 50% as it allows a battery to be used twice per day - kinda like doubling the useable capacity of the storage solution (but you pay for the night time charge and can only use it to off set the morning shoulder peak, whereas the evening peak use is offset ###against your free solar over production.

 

******************** Update from AGL - they will definitely allow their system to be recharged overnight from the off-peak grid! ***********************

 

2. One needs to well understand the amount of power they need to shit on average both evening and morning

 

============= The maths is interesting now - morning shoulder displacement until solar came online could be from off peak grid top up and even peak use could come from stored excess solar during the day - meaning the battery cycles twice per day, almost halving the size of storage you need for a day's displaced, cheaper supply!

 

3. The intelligence of the storage controller versus your needs has to be assessed!

Edited by g__day

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Key update from AGL on whether any storage solution can be re-charged from the Off peak gird = YES!

 

This means when sizing any solution you can allow for overnight recharging - to cover peak morning load - meaning when sizing a solution you only need to size it to cover evening load!

 

https://community.agl.com.au/t5/Solar-and-Renewable-Energy/Will-AGL-allow-all-storage-solutions-to-recharge-their-batteries/m-p/82#M17

 

Re: Will AGL allow all storage solutions to recharge their batteries overnight from the off peak grid Options

 

 

Thanks for your question Matthew.

 

Our objective is to let you take control of your own energy. If you want to use off-peak to charge your battery that’s great. If enough people want to do that we’ll work out a way to make it even easier.

 

We can’t comment on what other energy solution providers or their chosen battery manufacturers (like the ones you mention) will allow you to do. We are choosing a number of battery systems we think are best for Australian conditions, and integrating them to provide a complete solution.

 

We think most customers will want to simply “set and forget” or they may want us to optimise the charging and discharging for them on a daily basis. Of course there may also be customers who want to define their own profile, and within the constraints of safety and warranty, we will let you do that.

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So there is a bit of a conspiracy theory that has some legs, that electricity companies are using satellite images to determine who is using solar panels, and hiking their rates up accordingly.

 

I say the theory has legs as my partner worked at Aussie Solar for a couple of years and this was the scuttlebutt around the industry, based on reports from consumers complaining that some months after their solar installations, their rates jumped by 25% or more, when their neighbour's rates stayed static...

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