# What is the best way to use solar panels?



## basilio (2 March 2010)

The British Government is introducing a Gross Feed in Tariff of 44 p for every kwh of electricity produced by  domestic PV set ups or wind micro turbine. It will be coming in on 1st April.

At this stage the biggest complaints are from  groups that think the government should do "more". But why in hell are the British considering supporting PV panels  in  an environment that just doesn't make best use of their capabilities and  that in a  micro scale is fundamentally less efficient than larger plants?

George Monbiot takes this proposal apart piece by piece and at the end there is very little left.

There are also some excellent comments in the public forum at the end.



> *Are we really going to let ourselves be duped into this solar panel rip-off?*
> *
> Plans for the grid feed-in tariff suggest we live in southern California. And at £8.6bn, this is a pricey conceit with little benefit
> 
> ...




http://www.guardian.co.uk/commentisfree/2010/mar/01/solar-panel-feed-in-tariff


----------



## GumbyLearner (2 March 2010)

basilio said:


> The British Government is introducing a Gross Feed in Tariff of 44 p for every kwh of electricity produced by  domestic PV set ups or wind micro turbine. It will be coming in on 1st April.
> 
> At this stage the biggest complaints are from  groups that think the government should do "more". But why in hell are the British considering supporting PV panels  in  an environment that just doesn't make best use of their capabilities and  that in a  micro scale is fundamentally less efficient than larger plants?
> 
> ...




Thanks for starting the thread and cheers for the link basilio. 

This is the fallacy of decomposition yet again.(what is good for the middle classes is good for everyone?) Not the case if you cannot afford the technology. Again we have a headline grabbing government scheme that does little to invite the majority to participate and of course based on a deontological ethical emphasis to science, that ignores the consequential school of ethics in light of a program that just means more will pay higher taxes because they don't have the financial means to upgrade to more expensive technologies. Also marketing technologies that provide little in the way of benefit.  

It seems to be another bull**** rip-off joke that makes bureaucrats look good and does little to allow the taxpayer to participate for future benefits to themselves financially and for a cleaner environment! IMHO


----------



## marklar (2 March 2010)

outside?


----------



## Smurf1976 (2 March 2010)

Here in Australia, the idea of a Feed In Tariff (FIT) has been outright rejected in Tasmania but generally is being implemented in the other states.

What it amounts to is a subsidy. In rough terms, bulk wholesale electricity is worth 4 - 5 cents per kWh with household retail rates of 15 - 20 cents per kWh (roughly - it varies between states and retailers). Most of your household power bill is for distribution (poles and wires in the suburbs) plus a bit for transmission and retail. Electricity itself, straight from the power station, is comparatively cheap to produce.

So why the high rate FIT in most states? In short, it's a politically motivated subsidy. It doesn't scale to mass adoption of the technology because at its' heart is a reliance on the majority (without solar panels) subsidising the minority (with solar panels). It falls in a heap financially if more than a small minority choose to install solar.

The concept has been rejected in Tasmania due to the above and on account of the reality that electricity generation is surely the most intensively studied policy area over the past 4 decades. Bottom line is that new bulk electricity generation at above 5 cents / kWh just doesn't have a a market since most electricty use (about 80%) in the state could either be relocated overseas (60% of total demand) or replaced with wood / gas / oil. 

Indeed it is a fact that 30 years ago oil did have about half of the subsitutable energy market and wood held a similar share 20 years ago. So there's just no point economically in building new high cost generation since there's no market for the power produced, other than by means of a subsidy - itself a very hotly debated point over the past 40 years.

The other states have different situations with a greater share of non-subsitutable or relocateable load and as such the issues with rising costs are less. But solar still only works with a subsidy.

What many fail to grasp is the scale of the subsidy. The network and retail costs (distribution etc) that make up half your bill are not in proportion to the volume of electricity consumed. That is, they are much the same for an all-electric house with a $1000 bill as they are for an all-gas house with a $100 bill. The costs avoided by you installing solar panels on your roof are not much above the wholesale bulk electricity price, not the much higher retail rates.  

At present, the high consumption users subsidise the smaller volume users. That is why the industry has always promoted higher levels of consumption - profit increases disproportionately to any increase in per-connection consumption.

There was an attempt to unravel the entire pricing structure in Tasmania in 1994 with full implementation in 1995. The end result was outrage from subsidised consumers (mostly shack owners and those at work all day) once the truth was laid bare for all to see (and pay). The scheme was actually implemented, then progressively rolled back between 1996 and 2010 when the last remnants disappeared completely. Politically it was an outright disaster and a significant issue at a state election so it won't likely be repeated anywhere in Australia anytime soon.

But all that said, I do have solar PV panels on my roof. Why? Because you, the taxpayer, paid 100% of their cost and I'm not one to knock back money headed my way. They are absolutely profitable for me as an individual consumer, since I paid none of the costs and take 100% of the profits, but they are not profitable for society as a whole in purely financial terms.

If you want renewable energy then large scale hydro or wind are really the only means that are even close to profitability in most cases. There are project-specific exceptions, but in general it's hydro and wind that are viable along with localised use of firewood etc. Hence hydro dominates global (and Australian) renewable electricity generation, followed by wind with everything else making a minor contribution.


----------



## alphaman (2 March 2010)

My father-in-law used to run a coal power station. He told me coal is actually not very efficient anyway and he won't be surprised if solar electricity eventually becomes cost competitive.


----------



## basilio (3 March 2010)

Thanks for the input Smurf. I think it reinforces argument that Monbiot makes that under the current pricing and subsidies widespread PV panels on suburban roofs is misguided and a waste of public and private money.

But the point is that this whole process of making, selling and fitting countless suburban PV systems is profitable. Which just shows how counter productive our economic system is in trying to deal with long term sustainability issues.

BUT in a another context one could see how widespread suburban PV could be worthwhile. Consider a new generation of  (alleged)  low cost thin film solar panels across thousands of square meters of factory roofs, farm buildings, school roofs, community buildings - in fact any large building with roof access and the right orientation. 

Consider solar farms on land that may not be suitable for  high value agriculture but has plenty of sun.  I suggest that these are the places we should be directing our efforts.


----------



## Happy (3 March 2010)

basilio said:


> ...
> 
> Consider solar farms on land that may not be suitable for  high value agriculture but has plenty of sun.  I suggest that these are the places we should be directing our efforts.




Single level shopping centre car parks would be good place too.
Customers would have cool cars when they come back in the middle of summer and dry access to their car during heavy rain and possibly more pleasant during heavy wind.

Solar energy is under-utilised especially in Sun burned country like Australia


----------



## basilio (3 March 2010)

> Single level shopping centre car parks would be good place too.
> Customers would have cool cars when they come back in the middle of summer and dry access to their car during heavy rain and possibly more pleasant during heavy wind.




That's very clever Happy. Could be a nice little earner for the shopping centre as well.  And it would also be a good promotion point.They could even collect the runoff water. (I could see problems with the construction. On the other hand an engineer might point out this was relatively simple regulation construction.)


----------



## Smurf1976 (3 March 2010)

If you are going to do it on a large scale (that is, a solar power station) then solar thermal technologies would be a lot cheaper than putting panels on roofs. 

Solar towers - in operation it's basically an upside down hydro scheme using air as the working fluid rather than water. Inflow (heat) and storage at the bottom goes through the turbines with discharge at the top - like hydro but upside down and it's hot air rather than water. It's a simple concept that should work very well in a location such as Australia. Having storage means it keeps working after the sun goes down, an important consideration when you realise that the second highest period of electricity use is on Winter evenings.

The other one is to use concentrating mirrors to produce steam to drive conventional steam turbines. That ends up being much the same as any coal or nuclear plant (and some gas or oil-fired plants) except for the heat source being the sun. 

And if we are going to use PV panels, then again having concentrated light at a large centralised power station makes it cheaper.

Fundamentally, the economic problems with rooftop PV are two-fold. Firstly, PV isn't a financially cheap technology. Secondly, and this is a big one, lack of scale drives costs per unit of output up massively. You couldn't run a viable coal-fired plant in your backyard because it would be uneconomic per unit of output and it's the same with anything. Mass production lowers costs - economics 101.


----------



## alphaman (4 March 2010)

It's not about the current cost. No government would bother subsiding the solar industry if the cost is expected to stay the same.


----------



## basilio (6 March 2010)

George Monbiot has taken a real hiding from his analysis of the new Feed In Solar Tariffs scheme in England.  He's written other piece responsing to the criticism and expanding on his arguments against the promotion of  domestic PV as the dominant renewable energy source.


> *There is no 'green treachery' in questioning this solar panel rip-off*
> 
> *We do not have a moral obligation to blindly support inefficient, expensive renewable technologies *
> 
> ...



http://www.guardian.co.uk/environment/georgemonbiot/2010/mar/05/solar-feed-in-tariff


----------



## Purple XS2 (6 March 2010)

Smurf1976 said:


> If you are going to do it on a large scale (that is, a solar power station) then solar thermal technologies would be a lot cheaper than putting panels on roofs.
> 
> Solar towers - in operation it's basically an upside down hydro scheme using air as the working fluid rather than water. Inflow (heat) and storage at the bottom goes through the turbines with discharge at the top - like hydro but upside down and it's hot air rather than water. It's a simple concept that should work very well in a location such as Australia...




At which point it's apropos to mention Enviromission - EVM, a listed company which 'promotes' the solar tower concept. They're yet to build anything, and while I suspect the company will never be anything more than hot air (sorry - ironic simile unavoidable), one never knows. I watch with interest, do not hold.

As for Photo-Voltaic panels, I used to live in a shack beyond the civilized pale of (Tassie hydro-) electricity, and relied on PVs charging into big batteries for lighting. I struggle to believe domestic PV panels will ever make a cost-effective contribution to an established grid.

But hey, if I could get a set for free?   Memo to Smurf: are they still giving it away for free in Hobart?


----------



## Smurf1976 (6 March 2010)

Purple XS2 said:


> As for Photo-Voltaic panels, I used to live in a shack beyond the civilized pale of (Tassie hydro-) electricity, and relied on PVs charging into big batteries for lighting. I struggle to believe domestic PV panels will ever make a cost-effective contribution to an established grid.
> 
> But hey, if I could get a set for free?   Memo to Smurf: are they still giving it away for free in Hobart?



Here's some figures...

Suppose that every single electricity consumer (household, business) installs a 1kW grid connected PV system. In Tasmania, that would cost just over $2 billion and would produce electricty worth about $12 million per year or 2.5% of the state's total electricity consumption. The panels have a realistic working life of around 40 years, with major maintenance (replacement inverter, at a cost of about $2500 each) after 20 years (assuming you're using high quality equipment).

Alternatives:

Wind - $300 million to build plus around $7 million a year to keep it going (though there's a lack of certainty over long term operating costs and lifespan - the industry hasn't been around long enough to be really sure of this). Lifespan around 30 years in theory with significant parts able to be reused for a replacement installation at the same site.

Hydro - Very site specific but for an average site $300 million for equivalent output. It has a lifespan of around 70 years prior to requiring significant maintenance and an overall lifespan of several centuries. Operation is unmanned and essentially zero cost on a day to day basis.

Coal - Around $90 million for a plant to produce that output, plus $11 million a year in fuel and operating costs. Cost based on a share of output from a larger scale plant. Lifespan 30 years after which major maintenance is required, 60 years life in total.

Gas - Around $60 million to build plus around $7.5 million a year to operate. Lifespan 30 years, after which it's scrap metal. It's not a long term option however, as fuel costs seem likely to rise substantially.

Those costs are for Tasmania where hydro and wind have a comparative advantage compared to those technologies applied in the other states. Gas and especially coal have a comparative disadvantage versus the other states due to local factors, primarily related to scale, site location and coal quality. 

Now before anyone points out that solar panels ought to be better in the other states than in Tas... Solar panels need light but they don't like heat, hence the difference in output between Sydney (for example) and Hobart isn't anywhere near as large as you might expect. Less sun here maybe, but less heat too and that's an advantage.

In short, solar is not financially attractive for society as a whole at anywhere near present costs. It can however be profitable for individuals if they receive enough subsidies. 

As for free panels - no, I'm not aware of anyone doing completely free PV system installations in Tas at the moment.


----------



## tas devil (24 September 2010)

I'm new to this forum, and would like to know if I can clear up a theory. 
that is, that our politicians here in Tasmania all lie.
Recently I looked into getting PV panels to offset our rising power costs. 
unlike the reports published recently in our local paper, 
The claim is we have the third cheapest electricity in the country !
Now what I would like is an idea of what your costs are in comparison.
Our last bill consisted of
 'fixed Charges' $65.79 (this is regardless of using any power) 
Meter -Tariff 31 $0.20.8230 cents / KWH( Light and Power )
Meter - Tariff 42 $0.125580 cents / KWH (Hydroheat)  
So in summary, we pay, calculated on our last account overall a rate of *64.25 cents / KWH -Now that's cheap !?*
particularly when all we have to do to produce our power is to turn on a tap -Hydro... God must have put up the price on rain !
Can anyone top this? Or is there anyone who can tell us if the PV panels are going to be of benefit, the only thing I've discovered is that the 'smart meter' is installed free of charge, probably won't last as the government will find a way of charging for that too.


----------



## Lantern (25 September 2010)

Just put 3.7KW (20 x 185W Trinas in to a 3.8 KW Sunny Boy) on my roof in  NSW. Expect about $3.5K per year income (legislated and tax free) untill 2017. Then just no more power bills.

Total cost to me was $8.5K. (I work for a solar company)

Absolute bargain. Probably the best investment I could ever make.

Lived on a stand alone solar power system for 20 years previously so know how to save power.

Also have solar hot water.


----------



## Julia (25 September 2010)

tas devil said:


> I'm new to this forum, and would like to know if I can clear up a theory.
> that is, that our politicians here in Tasmania all lie.
> Recently I looked into getting PV panels to offset our rising power costs.
> unlike the reports published recently in our local paper,
> ...




I'm in regional Qld and the names of the tariffs appear to be different.
Tariff 31 is just for the hot water heating and is charged at 7.92 cents per kWh excluding GST.

Tariff 11 covers everything else and is charged at 19.41 cents per KWH excluding GST.


----------



## Smurf1976 (25 September 2010)

tas devil said:


> I'm new to this forum, and would like to know if I can clear up a theory.
> that is, that our politicians here in Tasmania all lie.
> Recently I looked into getting PV panels to offset our rising power costs.
> unlike the reports published recently in our local paper,
> ...



I'll avoid commenting too much on my frustration with what's going on with power prices in Tas at the moment. I'll just say that we should never, ever have come to this and it was totally avoidable. Eric Reece, Sir Allan Knight and the thousands of workers who developed the Hydro from the ground up amidst very harsh physical and other conditions would turn in their graves if they knew of the outright mess that's been made of the industry by politicians and other fools these days. 

Smurf's solution is pretty simple. Combine the entire assets of the industry into a single entity which we'll call simply "the Hydro", the unofficial name in universal use from when it was formed in 1914 until the bureaucrats gave us Aurora and Transend as well. This will be a non-profit organisation, as the Hydro was for 80 or so years, during which time it employed more people both directly and indirectly, and was responsible for more economic development in general than anyone else. 

I note that Labor, Liberal, Greens and, surprisingly, even the Chamer of Commerce and Industry seem willing to at least consider this move - one of those rare things where basically everyone is fed up with the status quo. 

And then, most importantly, we need to put an engineer or other competent person in charge of it - not a career "CEO" or bureaucrat should remain anywhere in the organisation. And it doesn't need a "board" at all, at least not a board full of people who know very little about electricity. That will fix the problem and we can all go back to having hot dinners and stop this nonsense of pensioners shivering in the dark, critical production infrastructure not working for months on end whilst the bosses try to turn the power industry into a hedge fund and so on. 

Comparing tariffs between states is somewhat difficult however. Tasmania is the only state where Tariff 41/42 exists at all - anywhere else those loads would simply be charged at the full normal supply rate (or more commonly, people just use off-peak (or gas) for heating water). So a direct comparison is not that simple - most people use 50%+ of their total consumption on Tariff 42, and for some households it goes to a very high percentage.

On a more practical point however, the solar panels. At the moment you can get a 1.5 kW system installed for just under $2500 from Nu Energy. Meanwhile Origin Energy will install a similar system, using higher quality "brand name" components, for just under $3000 and offer 12 months to pay as part of the deal. There are other companies offering similar deals too.

The 1.5 kW system will cut your bills by about $380 a year assuming the panels face somewhere close to north (anywhere between NW and NE will be fine) and aren't subject to shade by trees etc. However, there are strong rumors that some sort of feed-in tariff (FIT) will be introduced, noting that this is a Green policy and that the Greens are part of the present government. The original Green policy is for double the normal rate to be paid for solar-produced power with gross metering (ie the rate is paid on all power produced by the panels). If it happens then that would double your return to around $760 a year. Don't count on it though - politics. Worst case if it doesn't happen then you'll still get the $380 (and no doubt a lot more with yet another power price rise coming in December this year).

Those prices for systems include supply of all panels, inverter, mounting kit, wiring etc as well as installation by a licensed electrician. Installation takes a full day typically, subject to weather (due to OH&S rules the workers can't go on the roof in the rain, and for practical reasons you don't want to be handling solar panels in high winds). 

The only thing not included is the new meter, but Aurora presently does this for free. Only catch, as with anything involving Aurora, is that they will take several weeks to turn up and actually do the work. *Note that you can not have solar panels connected to a Pay As You Go meter*. If you have PAYG, then you'll need to revert to standard metering and billing in order to install solar.

Personally, I'd go for it if you've got a suitable roof area and nothing preventing installation. Those prices are based on a tin roof - add $200 or so for installation on a tiled roof. If however you are one of the few who have an asbestos roof then forget it - for safety reasons you won't likely find any installer willing to put solar panels up there.

I got my system from Nu Energy. No hassles apart from the constant heavy rain on the day of installation. They still installed the inverter and did the wiring work, but had to come back another day to install the actual panels. There was no extra charge for the additional visit so it wasn't a major issue. System is working just fine. 

Happy to help with any questions about solar power, hot water etc.


----------



## pixel (25 September 2010)

alphaman said:


> It's not about the current cost. No government would bother subsiding the solar industry if the cost is expected to stay the same.




That's the crux IMHO, and the reason why I jumped at the PV offer a year ago. Initially for the same reason that Smurf installed his; but also because no matter how high or low the FIT is: *It will save the cost of about 1670 KWh per 1KW capacity per annum*. At the moment, that cost saving may only be about $350 p.a. - a payback period of about 10 years on the (taxpayer-subsidized) installation cost. But the power rates are constantly going up, and up, which simply means the time to recover the initial outlay will come down.

As regards production costs, Synergy (the former "Western Power") quotes 7c, which is the FIT they will pay us for any excess we deliver into the grid. In come the Taxpayers - bless their largesse - and top it up by an extra 40c here in WA. Which now makes it still more viable to add, say, 2KW production capacity at around $4,000 because that will at least double the power we feed in, while we use the rest to reduce our consumption at the going retail rate. Average the additional 3340 units at only 30c/unit, and the additional $4K will be paid off within 4 years. How many shares give you a better than 20% yield for the next 10 years? Guaranteed!

PS for Tas Devil: We had to pay for our smart meter - it was about $300.


----------



## Smurf1976 (25 September 2010)

pixel said:


> How many shares give you a better than 20% yield for the next 10 years? Guaranteed!



Indeed.

It may well be taxpayer subsidised, but from an individual perspective it is a very good return (tax free...) on a relatively safe investment that requires no ongoing effort. It just sits there saving me money.


----------



## pixel (25 September 2010)

Smurf1976 said:


> Indeed.
> 
> It may well be taxpayer subsidised, but from an individual perspective it is a very good return (tax free...) on a relatively safe investment that requires no ongoing effort. It just sits there saving me money.




"Tax-free" may have a little boomerang or sting in its tail.
According to latest noises from Centrelink, if you're a pensioner and receive more FIT credits than your consumption bill, you'll have to declare the "extra income" and have your pension reduced by 50% of that amount.

My neighbour, who recently installed a 1.5KW solar PV and spends much of the summer trekking around Australia, will definitely fall into that trap from time to time. And I'm pretty sure that the $9.44 or so per fortnight that Centrelink may squeeze out of his pension for 4 months of the year, will pay for all the admin and compliance cost to make it "fair for all".


----------



## nioka (26 September 2010)

I have installed a 4kw system. I chose 4kw because that was the best use for getting the maximum number of panels on the roof with the best aspect. 

The price after the govt subsidy of $7931 ( the subsidy is for the first 1.5Kw) was $12,995. The installation also required two inverters (included in the price). The alteration to the metering system cost another $220.

I have a deal with Country energy where they buy all the electricity for 60c a unit and I pay them 19.62c a unit for the power I use. The deal is for 6 years.

The salesman was over enthuastic in working out how much I would make out of the deal. The sun would have to shine brightly all day every day to reach his objective. The meter tells the total amount that I feed in and another reading tells me how much I buy back. After a few months I will have better idea of the actual economics. Even with partly cloudy days since the installation I am producing more than I am using. The next big drought will at least have some benefit.

 As electricity charges increase the profit margin will decrease however I think the system will have paid for itself well before then. At least I look forward to no electricty bills ever again.


----------



## drsmith (26 September 2010)

Smurf1976 said:


> Here's some figures...
> 
> Suppose that every single electricity consumer (household, business) installs a 1kW grid connected PV system. In Tasmania, that would cost just over $2 billion and would produce electricty worth about $12 million per year or 2.5% of the state's total electricity consumption. The panels have a realistic working life of around 40 years, with major maintenance (replacement inverter, at a cost of about $2500 each) after 20 years (assuming you're using high quality equipment).



At that rate of return, we might as well just toss the banknotes directly into the furnace of a coal fired power station and save on the environmental footprint of manufacturing the solar panels.


----------



## davidhover5 (10 October 2010)

Unless their is a dramatic increase in efficiency and reduction in price for solar panels, they will have little effect on the bigger picture for energy use.

Im quite interested to see the possible future of thorium nuclear reactors, considering Australia has one of the largest reserves in the world, and it is 200 times more efficient than Uranium. 
In addition to this it breaksdown within a few hundred years compared to a few hundred thousand years, and the nuclear waste cannot be harvested as weapons.


----------



## fiftyeight (8 October 2014)

I was speaking to a mate at work today, he is looking at buying a block but it has no essential services. We were discussing the different options for electricity.

Solar during most days but what to do at night? 

Smurf in another thread mentioned pumping water up a hill using wind. I was thinking maybe he could use a solar water pump that pumps all day and then use this stored energy all night/cloudy days. Not efficient but I wouldn't think it would need to be.

Has anyone used or seen this idea on a small/personal scale?

Thanks


----------



## Smurf1976 (9 October 2014)

For a normal household situation where mains power is not economically available, the simplest option is to go for solar and batteries.

Solar generates power during the day, and yes it will do that even when it's cloudy, and charges the batteries in parallel with the load (via an inverter).

With the big reduction in panel costs, it's reasonably economic these days to oversize the panels such that the batteries reach full charge on all but the worst of days (in which case they'll recover the following day). The end result, as long as we're talking about moderate amounts of power, is a stand alone fully self contained system.

As for pumped hydro, it certainly works as an idea and on a large scale it's around 70% efficient at storing energy. We do have 3 large scale pumped storage operations in Australia (Tumut 3 (NSW), Shoalhaven (NSW) and Wivenhoe (Qld)) but it's certainly possible to do it on a small scale if you've got the right topography. That said, for a household system then I'd stick with batteries unless you've got an actual source of water (creek, river) so as to make conventional non-pumped hydro your major energy source (in which case it leaves solar for dead in every way).

For 99.9% of such situations, batteries and a few extra panels above that theoretically required is the way to go.


----------



## pixel (9 October 2014)

Smurf1976 said:


> Indeed.
> 
> It may well be taxpayer subsidised, but from an individual perspective it is a very good return (tax free...) on a relatively safe investment that requires no ongoing effort. It just sits there saving me money.




Here is an update after 4 years of use:
We started with 1KW and upgraded to 2KW a year later, when the 40c/KWh FIT came into force, thanks to the State Government of the Day 
I kept a spreadsheet with all power bills since installation, summing up units consumed, exported, and charges/credits for each. The spreadsheet also tallies the units produced.

Results as per 12/09/2014, the date of our most recent power bill
Total units *imported*: 17,832 for $3,646 giving an average 22.4943c/KWh
Total units *exported*:    6,855 for $3,196 credit = averaging 46.6354c/KWh
Total units *produced*: 13,816, which leaves
Total units *consumed*: 6,961, saving $1,592 at the rate of 22.4943c/KWh for imports

Operating costs for meter upgrade and bi-annual service fees amounted to $598. giving a 
Net Profit of $4,165, or 53% of the combined installation cost.

Not quite the 20% annual ROI, but even 13% beats bank interest hands-down.
I guess if we did the laundry at night or before dawn, we could've used less power during the day, exporting a few more units at 46c and importing them at night for 22c; the difference might run to $1/week, or may be nothing at all. So, let's not worry about could've should've would've... I'm happy with the results.


----------



## cynic (9 October 2014)

Just last week I experienced yet another delightful (>4 hours) power outage during my trading time. This has become an increasingly annoying and frequent occurence (sometimes several times a month and usually of similar or greater duration) these past few years. 

The deterioration in service reliability, combined with the exponential increase in the associated power bills, has been increasingly frustrating me to the point where I'm seriously tempted to tell the suppliers to go FTSE themselves and ditch their pathetic service altogether.



Smurf1976 said:


> ...For 99.9% of such situations, batteries and a few extra panels above that theoretically required is the way to go.




In your opinion, what type/s of battery would one typically choose for storage?


----------



## fiftyeight (9 October 2014)

Thanks Smurf, much the same answer I came up with googling. He has already started looking for a block with a water source.

I have passed on your suggestions about renewable energy in the Nuclear thread to anyone who will listen


----------



## fiftyeight (9 October 2014)

Thanks Pixel


----------



## skc (9 October 2014)

I am looking at installing solar for our house. In addition to saving power bill, I want to have solar as backup for my trading computers. 

Some questions if I may:
1. As blackouts often happen during a storm, I'd imagine that there is no solar electricity generated during a storm?!
2. How much battery storage will I need if I want to continue to use my computer, 4 monitors and modem running for, say 4 hours? 
3. How much do battery storage cost? Do they need to be replaced regularly?
4. Any recommendations for Brisbane solar company?

Thanks


----------



## Smurf1976 (9 October 2014)

cynic said:


> In your opinion, what type/s of battery would one typically choose for storage?




There's three options that I'd consider depending on application.

LiFePO4 (lithium iron phosphate) = the current "state of the art" way to do it and "on paper" has a lot of advantages. It's a less proven technology, relatively new versus the others which have been around for ages, but can also be discharged a lot more heavily without damage when compared to lead acid. If $ isn't a consideration then LiFePO4 all the way....

Gel (lead acid) = old tech but a very "set and forget" option that doesn't really need maintenance. Main advantage over LiFePO4 is the very proven, predictable nature of them. They're heavy and so on yes, but they just work without much fuss. If it must work, and you're risk averse, then Gel is your friend.

Flooded (lead acid) = old tech, high maintenance and best avoided by anyone not keen on tinkering with things. But that said, _if_ they're properly maintained then they'll last a very long time and can end up being the cheapest option. A lot of hobbyist / tinkering types love them for this reason. They're reliable as such, and cheap - as long as you don't mind having to keep them topped up regularly. They're definitely not a "set and forget" option and not well suited to being regularly moved around either (unless permanently mounted in a vehicle etc).

Stand alone household on solar = LiFePO4 would be the "modern" way but also the least certain in terms of lifespan. Gel or flooded lead acid are less risky financially in that sense, you can be fairly confident of their lifespan, although they're inferior as such.

Backup to mains = Gel or AGM would be the easy option. Or you could use LiFePO4 if you're keen.  

Gel and AGM (Absorbed Glass Matt) are both variants on the same thing - a sealed lead acid battery. Gel is somewhat more durable but has a slower discharge / recharge rate than AGM. Hence the use of AGM in things like computer UPS' with a small battery designed to last 15 minutes while you shut things down etc. AGM handles such a rapid discharge better than Gel does. But if you were going to size the battery to keep the system running for hours then there's no such advantage - and in that case the longer lifespan of Gel wins out.

There are also other battery technologies, eg NiFe (Nickel Iron) but you're not likely to consider those for home use. They do have some applications however, and the primary benefit of NiFe is their very long lifespan - we're talking 25 years or so. Downside = expensive and inefficient. But they're extremely robust which is the good point.

Something that cuts across all of this is the type of battery itself. An SLI (Starting, Lighting, Ignition) battery (commonly known as a "car battery") won't last long if deeply discharged. It will work yes, but a car (or truck etc) battery will have a short lifespan if it's being deeply discharged on a regular basis. It's designed to provide a huge current for a few seconds to start the engine, then be immediately recharged. It won't like running your computer all day. In contrast, a proper deep cycle battery is the opposite - it physically can't produce the high current that a SLI battery can, but it will survive many, many more discharge and recharge cycles in a solar or backup power application.

So Deep Cycle is what you want in any application for backup power, solar etc.

There are also such things as "marine" batteries and various other things. Typically, they're a hybrid - designed to be sort-of deep cycle but still put out a lot of current to start an engine. Leave them where the name implies, on boats, and stick to proper deep cycle batteries for solar etc applications.


----------



## Smurf1976 (9 October 2014)

I'm running out of time now, but will make a post on backup power for trading etc computers in the next day or two.

In short though, YES it's quite easily doable and that applies regardless of whether you want to use solar or just store mains power in a battery for use during the blackout. It can be done either way.


----------

