Has anyone setup a solar battery array for home supply?
There seems to be a bit of movement in this area and we are thinking it's the right move in the next year or two prior to retirement to get rid of the $1K/quarter electricity bills.
I see new 7Kw and 10Kw lithium iron battery cells coming soon but I'm wondering if anyone has done it already. I'm guessing some of the country folk may be the first. I don't want to disconnect from the grid as we can still get off peak super economy power at under 13c Kw to charge batteries. But running the house off local batteries and solar to charge them is very appealing.
Hi
You should already have a grid tie solar system already
say 7-10Kw of panels
will reduce your power bill to $0 with maybe even a payback from your supplier
We lived off grid on solar panels/ diesel generator for a few years...
The life of the storage batteries and the efficiency of the invertor was always problematic.
If you remain connected to the grid your "service provider" will still hit you for the supply charges whether or not you use any energy.
I assume you've aware of the Tesla powerwall gear? I did some quick sums and it looked okay for deferring your solar generation into peak usage period, but not particularly good if you were trying to defer off peak grid power into peak usage times (due to the losses going from AC>DC>battery>DC>AC). But they were very back of the envelope calcs.
I have been thinking of the same thing, we are a four person household, two of which are home every day and $1000 a quarter would be a nice change!
The way I see it, batter storage is about to become a very good thing to have. I see time of use pricing structures in all of our futures so where we are, being stuck with electric cooking it will suddenly make cooking dinner a very costly exercise (Which with a 7 year old in the house you can hardly defer to after the peak rate will end)
Solar with enough capacity to cover the daytime consumption plus enough freeboard to charge a battery system that would then get us over the peak time without dipping into the mains would potentially be a big cost saver. Just have to do the sums to ensure that it is not a matter of pinching money off the power retailer to give it to Tesla.
I understand that savings can be made which obviously we all want, but when there's no customers left to pay for the infrastructure, they are going to seriously shaft everyone just for having the supply available whether you use it or not.
Just like they do with water supply; the water pipe running past your empty block is enough for them to levy the charge in some states - not sure about all.
It stands to reason, if they're obliged to provide a service, then someone has to pay.
Hi Robin, we had our 5kW solar put in in 2011 just before the 50c feed-in finished so our thought process was different to what yours would need to be. The process we went through was basically:
1. Calculate energy usage of appliances including standby, in our case the big ticket items were aircon and pool pump.
2. Maximise benefit of solar by minimising daytime usage (thereby getting feed-in maximised) and running most things at night. To do this we changed the timings on the pool pump etc. Also worth looking at things like doing fewer, but larger washing loads.
3. Estimate savings on bills to work out payback period to see if it was worth the effort. I came up with a conservative payback period of 8 years. In practice it worked out a lot less.
If you are not getting a feed-in rate greater than the peak rate I think it would be more beneficial to run things off solar during the day and minimise usage at night which would be from the grid. You may need to estimate solar generation taking account of panel efficiency and inverter losses to work out which appliances you can run together so as not to draw on grid power. This may vary during the year because of increased sunlight but also because solar panels often become less efficient at higher temperatures.
Our experience has been that the inverters supplied by our well known Qld electricity supplier have not been reliable and we have had 2 fail, both within warranty fortunately.
It has been an interesting exercise and our power bills have reduced by around 60%, this reduction takes account of tariff changes, in effect I have eliminated the price variance in the calculation.
When our 50 cent feed-in rate finishes I will have another look at when and how we run the appliances. It's an interesting exercise and I think worth doing to satisfy yourself one way or another.
Maybe look up "Josh's house". Josh is a presenter on ABC Gardening Australia and local Perth resident who has set about building avery low energy footprint house. He recetnly installed a battery system and there was much fanfair about it, so there is probably good information available about what he used/did.
Me personally, we have our 5.2kw of panels being installed next week - grid connected so will receive 8c/kw for anything surplus. We don't have a fixed service charge in WA, so it's relatively common people have $0 power bills and get paid back money when they have grid connected panels.
In Vic at least the situation is reversed from what it was a few years ago. Rather than trying to size the system and shift your consumption around to maximize the power fed back to the grid (At what would be a long way from the peak use time, exactly when the DB and generators DONT want extra) it would not be better to move your consumption as much as possible into the peak generation time (Within the capacity of your system) to take advantage of the solar production yourself given that you now receive about one third as much for feed in than the typical cost per KWH. If you can not use it yourself, it will just never pay for itself.
Battery storage will hopefully soon be able to float you over the peak and while the losses involved would skew the sums, maybe even be useful to charge in the lowest tariff time and consume through the peak.
The vast disparity in feed-in rates really needs to be addressed, as currently it is a dis-incentive for residential solar investment to have one house getting 50 cents and the guy next door getting 5 cents which is a reality in some areas of the country. This evening up of the playing field needs to extend to the 'gravy' charges for just having access to the grid (grid connect daily charges for example).
Secondly, in positioning for future storage battery systems, just be aware you can do it now pretty easily and it doesn't have to cost the earth provided you are willing to use cost effective storage and curtail your usage to stay within the economic model it can support. If people want to have storage capacity for all the possible power they can use then there is no incentive for efficiency.
As an example, I have a 2KW return to grid roof top system, which as a single retiree pretty much covers any daytime usage (provided I limit my usage to one major appliance at a time - and that's important). I also have a private 'off grid' ground mount system of 500W of panels feeding a 500AH battery bank (made up of readily available 100AH deep cycle batteries). Check the photos attached. Ground mount is cheap it build if you use treated pine posts. This small off grid system is very useful for augmenting the grid connect system during the day - it runs my big shed and workshop, and it also provides all the power to my observatory, and most power to the house at night. It is dual purposed, in that some of the batteries can be used in my camper trailer power system when I go away to the dark site. In building the off grid system my goal was to minimise night time grid draw and it achieve this very well. For example, at night the off grid battery bank (through it's inverter) runs my household power needs (lights, and TV, stereo, ADSL router, PC etc). I run a single 10amp feed from my inverter down to the house and from that all my night time power is covered. You must use a separate cable system to the grid supply and cannot connect off grid power to the house AC wiring at any time.
Note that my entire system is approved by my electrical engineer son, no red neck engineering here.:
Dual purpose batteries where you can. Many people have caravan's, camper trailers, boats, etc with multiple 12V batteries - there is no reason that these can not be blended into the battery bank provided; you keep an eye of the output of each one and use similiar contructed batteries for all the 'toys'. A simple Anderson plug can bridge in a caravan power bank to a household bank (yes isolate them with a fusible link, etc) but it's not hard. Why have power storage sitting there to only be used a one a year when it could be used everyday. Connectivity does not have to be scary but you do need to be careful and provide adequate safe guards on any connection.
Lifestyle modification + solar can give you a great deal of indendence and position you to be ready for total withdrawal from the grid if you desire.
Unfortunately, while the did kick start solar PV in the market, the feed in tariff structure really is a pretty huge market distortion.
It doe not take much thought to see that when people were paying around 25 cents per KWH, but the feed in tariff was anything up to about 60 cents per KWH that it was going to be a problem sooner or later.
The only advantage is that it kick started the solar PV market (With all the bad things like cheap shoddy gear and fly by night installers) to the point where the cost of the equipment crashed and now it can hopefully sustain itself. Cost effective storage was the next bit of the puzzle now that feed in tariffs have returned to a bit more normal level. I am not sure what the actual margins are in the electricity market, but I would bet the price at Loy Yang is not much different to the feed in being paid now.
We had a 3 kw system installed home on the old system. We get the higher feed in tariff and another few years we will have finally paid it off. One thing that many who are only entering the market now seem to have forgotten is that pricing for systems as early adopters was huge. We paid nearly $9000 for our system. I know of several others who put in much bigger systems and they paid a big price. Suggesting there is a disparity for someone who buys a 3kw system now for $1800 -$3000 or so dollars really undermines those of us who helped the system develop by being early adopters. The incentive was listed as being only 17 years from the time of the introduction. I think we got in with about 15 years remaining. It made the switch affordable and removing that would punish us for doing the right thing early. So some might want to be a little grateful for those of us who paid the price early to help get the industry up and running.
As to the battery system. This will be our plan in the next 5-6 years once the system costs reduce down a lot. There is little incentive right now to jump in early while costs are quite high. We will try to increase our current system to around 11-15kw with a new inverter/s to suit and a battery system that will store around 85kw of power. The thinking here is that it will prevent the need to be on the grid entirely, provide several days back up power in the event of cloudy weather and I will be asking the power connection to be removed altogether. This will negate supply charges and power cuts when the annual black outs occur. The current cost of such a system is not even worth considering and since we have the larger feed in tariff I am content to stay where we are at present. I like the idea of going totally solar and more so I like the idea of preventing being gouged wholesale by suppliers. SA still has the highest power charges in the country and it appears set to increase further in the next year. Not to mention the actual benefits to the earth I will be providing by not burning coal (the poisons created from making the solar system are another matter though but we have to start somewhere). So my suggestion Robin is to wait off if you can. Get a larger storage system when it is affordable. Right now the system I mention above would cost around $85k.
I understand your thoughts Paul but unfortunately your argument is wrong. To buy into solar today at the current transfer rates a pay back period of 50 years is almost unachievable. The only saving to be made is to actually change your lifestyle and use the energy you generate and not to allow any to return to the market. To pass energy into the market only extends the period required to gain any return on investment.
I just love this comment:" Suggesting there is a disparity for someone who buys a 3kw system now for $1800 -$3000 or so dollars really undermines those of us who helped the system develop by being early adopters." What a load of codswollop. You bought when you did because you could see a dollar in it and could afford it. To say you helped the system develop to where it is now is a fact now it is financially stupid to buy into the system at 6 or 8cents a kilowatt hour. at 68 cents for 20 years it was a good deal OK.
Quote:
Originally Posted by Paul Haese
We had a 3 kw system installed home on the old system. We get the higher feed in tariff and another few years we will have finally paid it off. One thing that many who are only entering the market now seem to have forgotten is that pricing for systems as early adopters was huge. We paid nearly $9000 for our system. I know of several others who put in much bigger systems and they paid a big price. Suggesting there is a disparity for someone who buys a 3kw system now for $1800 -$3000 or so dollars really undermines those of us who helped the system develop by being early adopters. The incentive was listed as being only 17 years from the time of the introduction. I think we got in with about 15 years remaining. It made the switch affordable and removing that would punish us for doing the right thing early. So some might want to be a little grateful for those of us who paid the price early to help get the industry up and running.
As to the battery system. This will be our plan in the next 5-6 years once the system costs reduce down a lot. There is little incentive right now to jump in early while costs are quite high. We will try to increase our current system to around 11-15kw with a new inverter/s to suit and a battery system that will store around 85kw of power. The thinking here is that it will prevent the need to be on the grid entirely, provide several days back up power in the event of cloudy weather and I will be asking the power connection to be removed altogether. This will negate supply charges and power cuts when the annual black outs occur. The current cost of such a system is not even worth considering and since we have the larger feed in tariff I am content to stay where we are at present. I like the idea of going totally solar and more so I like the idea of preventing being gouged wholesale by suppliers. SA still has the highest power charges in the country and it appears set to increase further in the next year. Not to mention the actual benefits to the earth I will be providing by not burning coal (the poisons created from making the solar system are another matter though but we have to start somewhere). So my suggestion Robin is to wait off if you can. Get a larger storage system when it is affordable. Right now the system I mention above would cost around $85k.
Agreed Doug, to put it simply (assuming you have no storage capacity) If your feed in rate is above the tariff supply rate then you are better off doing nothing during the day, feeding into the grid and running appliances at night. Vice versa if your feed in rate is less than the tariff supply rate.
All those old contracts should be torn up. The federal government needs to step in as there needs to be a national program, with a single buy back rate that can justify the business case for homeowner investment. They can call it 'Direct Action for Homeowners' or whatever. Recent adopters are just subsidising the old contracts. I agree there is no incentive to feed back to the grid in the current environment, and suspect that's exactly how the (State owned or now commerical) power companies want it.
