20 years ago that was a valid argument against solar power. However in 2012 that myth is pure BS. Hopefully this post can set the record straight.

How much Energy is required to make a solar power system?

The process of creating solar panels, like any manufacturing process, requires a number of inputs.  The fundamental ingredients that make up a solar cell include the minerals silicon, aluminium and gallium. These must be mined, smelted and transported to the factory. The factories require energy and the lots of component parts from disparate locations and multiple parts producers.  After assembly the cells assembled into a solar panel must be transported to a local, Australian distributor, then onto the installers and finally your roof.

And don’t forget that more energy is consumed in the installation process, and in the manufacture of wiring and devices that support the panel.  Finally, when the panel has come to the end of its useful life, there is the energy that goes into disposal which may included dissembling for parts and/or landfill costs.

Andrew Moore from PE International, in a 2010 Australian study found that the production of the solar PV cell is the most energy consumptive part of the process, accounting for 85% of energy use in the lifecycle of the product.

The inverter amounted for 7% of the energy and the framing and wiring 4%.

The remaining 4% came from transport.

Feeling guilty about shipping your premium solar panels over from Germany?

Don’t! To ship a panel from Germany to Australia only adds 2% to the energy required to make a complete solar system compared with getting a locally made panel!

What is the energy pay back period?

Moore found that PV systems installed in Australian cities paid back their energy debt accrued in production in 1.7-2.3 years.  1.7 years for sunny Perth up to 2.3 for not-so-sunny Hobart.

How much Greenhouse Gas is emitted for solar electricity?

Moore calculated that solar electricity contributed about 96% less greenhouse gas emissions than grid coal-based power.

So there you have it – solar power really does make sense from a whole-of-lifecycle perspective. And your average solar panel system produces less CO2 averaged over its lifetime than your farting cat (probably).

And as technology improves and efficiencies of the solar cells goes up, the energy paybacks are only going to get better.

Going solar now really is part of a virtuous circle – buying solar supports the ongoing development of the technology – which increases the performance and reduces the cost of future solar panels. Someone should tell Clive Palmer and his pals…

References:

Bourzac, K. (2009). Mining Fool’s Gold for Solar. Technology Review, 112(6), 80-82.

Moore, A. (2010). The solar lifecycle test. ReNew. 109, 46-48.

Wayne Swan's budget was good for solar

Debate continues to rage in the press over the last week as to whether or not Treasurer Wayne Swan’s much lauded Budget 2012 is good for the future of solar power in this country. The Treasurer’s delivery and demeanour gave no real hint of the speech being one that could be considered pro or anti renewables and solar pundits have split over what the Budget will mean for the Australian solar industry.

One of the first cabs off the rank was the Australian Solar Energy Society’s (AuSES) John Grimes who delivered a glowing assessment of the Treasurer’s work. Here’s a snippet:

The Federal Budget delivers on the Government’s commitment to a clean energy future. If fully implemented as outlined in the Budget, the Clean Energy Future package will supercharge solar through the combination of a carbon price, renewable energy target and the Clean Energy Finance Corporation.

Mr Grimes went further saying the Budget “… provides the basis for investment in Big Solar right across Australia.”

Great to hear eh solar fans? However as the week wore on, more (some would say better reasoned) analysis pointed to the fact that, far from a new dawn, this may be yet another lost opportunity for the government to support renewables. As that well-known barometer of reason the Solar Quotes Facebook Page began to reflect some disquiet and disbelief, so did other highly-regarded columnists.

Giles Parkinson, in an article in Renew Economy, described the Budget as a “revenue and renewable neutral” document. He explained for for all its bluster over renewables, the federal government has failed to deliver one major solar project that it can call solely its own and hinted that this budget didn’t seem to be about changing that outlook anytime soon.

While the Government was under tremendous pressure to deliver a budget in surplus, a task in in which it succeeded, the cost of balancing the books may well be at the cost of any meaningful investment in the future. High on the list of these are meaningful investments in the future of the country such as solar and other renewable projects.

Or am I being too harsh readers? Your thoughts?

A solar inverter is like any other electronic device in your home and it will produce some Electromagnetic radiation and potentially Radio Frequency interference. There is a standard that all approved electrical devices in Australia are required to meet (C Tick) but it does not guarantee zero emissions.

The school is out on exactly what harm can occur to human beings from electromagnetic radiation but solar inverters do emit it, so if you are concerned ensure that your inverter is installed well away from living areas – as a rule Electromagnetic Radiation drops off very quickly as you move away from the source and is reasonably easily blocked by obstructions.

As a general rule, the biggest problems stem from Radio Frequency interference on AM or HAM radio because they rely on weak and variable signals with large antennae, which are particularly susceptible to interference of any kind but it doesn’t rule out solar for radio buffs.

Good installation practices to minimise EMR and RFI

The number one rule for EMR and RFI prevention are first and foremost – determine the real cause. Is it the inverter or something else? A simple hand held battery powered AM radio is a great tool to determine where interference is coming from.

Once you have found your source you can then revert to the golden rules – shielding, cancellation, filtering and suppression. Careful routing and location of the DC cabling (twisting them is a good general tip too) is a good idea and the location of the inverter can make a big difference.

Although it is dangerous to generalise, lower cost inverters (or other products such as power supplies) tend to have less filtering and EMR/RFI reduction equipment built in and are likely to cause more interference.  Some quality inverter web sites talk about their testing and the lack of EMF that is produced as a result of clever design; so some companies clearly invest more heavily in these types of issues.

So if you are really concerned about RFI or EMR, then I would strongly advise paying a few hundred dollars more to upgrade to an SMA / Aurora / Delta or other top quality European inverter from a brand that has had decades to tweak their designs. And make sure you ask the installer about the issue to weigh up his experience of this issue.

Reducing radio frequency interference is, at best, a “snipe” hunt but choosing quality gear and using installers who understand the issue will go a long way to minimising any impacts.

Solar Panels: About to be Big In Japan?

As Japanese anti-nuclear activists celebrate the closing of the country’s final nuclear reactor, making Japan temporarily nuclear free, a power revolution of another sort is set to begin in the Land of the Rising Sun.

While debate rages over whether or not the country should remain permanently nuclear free, rumblings from the country’s once-mighty Ministry of Trade have hinted at the emergence of a renewable-led energy sector. Your correspondent’s memory seems to recall that it was this ministry (also known as METI) which was in the driving seat of planning the great Japanese industrial and export-led economic post-war “miracle,” culminating in the booming success of the 1990s.

While the Japanese economy has since lost some of its shine, falling into a recession during the “lost” decade of the noughties, signs of a recovery were certainly there before the tragic social and economic losses wreaked by the devastating tsunami of over a year ago.

Readers won’t need to be reminded of the weeks of suspense for the Japanese people as the Fukushima reactor began its meltdown, spewing radioactive waste into the surrounds risking lives and livelihoods. However will some good come out of such a tragic event? The country is no stranger from fighting back from seemingly impossible odds and it is here that the Ministry of Trade has apparently stepped up to the plate to once again help revive the country’s economy.

This time though, it seems the ministry may be promoting a sea change in attitude towards renewable energy, with a proposed feed-in tariff policy that makes any offered by Australian state and federal governments laughable.

As always with Japanese policy, once done it means things are not done by halves. Just read the below quote from the renewable energy magazine Renewable Energy World.com on the magnitude of the policy change should it be implemented.

In what may be the most significant renewable energy policy development worldwide in years, Japanese authorities are circulating proposed feed-in tariffs that-if confirmed by the Minister of Trade later this month-could lead to a crash renewables program.

Equivalent to putting the country on a war-time footing following the Fukushima nuclear disaster, the unusually high tariffs will lead to a massive rush of renewable energy development.

“Massive rush?” “War footing? It remains to be seen whether or not the country follows through with a renewables policy that would leave other countries floundering in its wake, or revert to nuclear along with fossil fuel when it is politically expedient to do so. The internecine world of Japanese politics means that such proposals are often watered down beyond recognition (or not implemented at all) as the vested interests put the pressure on.

However led by the mighty METI, a turn around towards a more energetic (wrong word I know) renewable energy policy may well place pressure on the other renewable superpower of the region, China, perhaps kick starting a new, Japanese-led solar revolution.

And the implications for our country should such a policy go ahead? Watch this space.

Solar is compatible with 3 phase

Connecting solar power to a 3 three phase supply is entirely possible. But you need to decide how you are going to connect your solar system to the grid. Your 2 options are:

a) connect your solar system to only one of your supply phases with a single-phase solar inverter.

b) connect your system into all 3 phases of your supply with either a single, 3-phase solar inverter or 3 separate single-phase inverters.

There are a few tricks which you need to be aware of to ensure you make the right decision.

1) Three phase billing

As a general rule, despite the fact that you may use different amounts of energy on each of the three phases, the total energy used across all three phases will be added up to make your total bill.  Also you will generally pay exactly the same tariff on each of the 3 phases.

Now, depending on whether your home state’s Feed In Tariff is generous or stingy, you will want to either maximise or minimise the amount of solar power you export to the grid.

To do this you need to consider the total energy consumption across all 3 phases versus the total solar generation into all 3 phases, because it’s the sum of all 3 that will ultimately be billed (or credited).

Having said this, you should triple check with your electricity retailer – they each have different rules and regulations regarding how your system needs to be wired in to their grid. A good solar installer should know your local regulations.

So whether you are trying to make a dollar from exported energy or simply trying to maximise offsetting your consumption, the key is to remember the sum total of consumption and generation and match the system size to consumption levels depending on your objective.

2) Three phase load balancing

Having said the above, it is important to note that it is not unusual for the demand across phases to be unbalanced; i.e. a lot more load on one or two of the phases. For solar financial modelling this is less of an issue (due to the summed billing) however, from a technical perspective, balancing consumption and generation across the phases is a good thing for power quality.

I have seen cases where voltage is problematic on a particular phase causing inverters to trip out; for example where a large pump or cool room is on that phase and presents high start-up demands. In such a case, you should consider putting the inverter on a more stable phase; they don’t like unstable voltage or frequency at all.

Ultimately, a little bit of instantaneous and energy consumption demand analysis should be considered a pre-requisite to connecting solar to three phase systems. Your utility or perhaps a friendly solar installer can help with this. If you have three phase, it is even more important that you choose a qualified solar installer to talk to initially, instead of a less qualified solar salesperson – who probably hasn’t got the electrical background to understand the nuances of multi phase electricity supplies! 

Three phase versus single phase inverters

You can buy three phase and single phase inverters and often, you can put single phase inverters across (for example) each of three phases. The advantages and disadvantages depend on cost and how your phases are balanced. (Also you should be aware that 3 phase inverters start at about 8kW)

However, in an ideal world, you should be aiming for reasonable balance across the phases in both consumption and generation. Assuming that the cost of multiple single phase inverters is similar to a larger three phase unit, you do get the advantage of redundancy so, multiples could offer a slight advantage.

Your utility may have some specific advice depending on your situation and if you are lucky, you (or ideally, your installer) will find an interested electrical engineer at your utility that knows your area and is keen to improve power quality into the local grid.

PAYG Solar Too?

Have you considered installing a domestic solar system but have been put off by the initial cost? Then the recently-announced unveiling of a radical new pay-as-you-go plan in Australia may be for you.

According to an April 21 report in the Sydney Morning Herald, an American company, Sungevity Inc., has teamed up with Lismore-based solar installer Nickel Energy to set up an Australian subsidiary, Sungevity Australia, which offers free solar panel installation. The ongoing costs under the power purchase agreement will, according to the company, be less than the amount households pay at present for fossil fuelled electricity. The costs will increase in line with the consumer price index.

According to the report the scheme has taken hold in the United States and is now being offered in Northern New South Wales and South east Queensland though is slated to appear in other parts of the country in the near future.

Sungevity Inc’s president Danny Kennedy told BusinessWeek that the model had already been received well in the United States and the company, which owns a minority stake in the venture, is looking forward to testing it in Australia.

“We’re obviously seeing the success of the pay-as-you-go solar” model, Kennedy said. “This is going to be the first pay-as-you-go proposition to Australian customers.”

Kennedy added that the power purchase agreement is to be designed to be less than what some Australian households are currently paying for electricity.

According to the company’s website, the evocatively-named “Roof Juice” solar panel product works in the following way:

• The company will install the RoofJuice solar panels at no cost to you
• You buy the power the panels produce at a cheaper rate than what you pay for power now now.
• You pay no up-front cost.
• The company will guarantee the system’s performance

The site states the product will protect the punter from “future power price rises by selling you solar energy that’s generated on your very own roof.” In a carbon tax future this sounds an attractive way to both offset expected skyrocketing energy prices and reduce your carbon footprint. After all what more gratifying way of knowing you are contributing to a more renewable world than getting power from your own solar panels?

Has this got “winner written all over it” solar fans? Will this take our country by storm as it apparently has in the US?  Let us know what you think of the new plan and if you’d consider taking advantage of it. Join the discussion on our Facebook Page.

What's the payback?

In my previous 2 posts I looked at the concept and design of Hybrid Solar systems.

The main conclusion of those 2 articles was that

a) Hybrid solar rocks!

b) But you gotta pay for it!

So the question this post will try to answer is:

How Much Extra Does Hybrid Solar Cost?

and bearing in mind the extra costs:

What is the payback of Hybrid Solar Compared To Regular Grid Connect Solar?

So let’s look at the cost of a Quality 5kW Grid Connect system and then see what it costs to upgrade it to “Hybrid”.

Cost of a 5kW grid connect system (April 2011 pricing) :

5kW of good quality panels: $8,000

5kW inverter: $3,000

Racking and cabling: $1,000

Install: $2,000

Less Solar Credits (approx 165 STCs @ $25):  -$4,000

Total cost: $11,000

Cost of a 5kW Hybrid solar system:

5kW of good quality panels: $8,000

5kW inverter: $3,000

Power management unit: $3,000

Batteries (to store 10kWh):  $3,000

Racking and cabling: $2,000

Install: $3,000

Less Solar Credits (approx 165 STCs @ $25):  -$4,000

Total cost: $18,000

So, for  a 5kW system – expect to pay at least $7k more for the hybrid option.

So the question is – if you are going hybrid to avoid a miserable Feed In Tariff, like NSW’s 7c per kWh – then what is the payback on the extra expense?

Let’s crunch the numbers using my solar payback calculator:

Scenario 1 – Grid Connect System:

Key assumptions are : we export 50% of our solar power @ 7c per kWh, and we offset our electricity bill @ 26c per kWh with the other 50%.

(Read this article If you are confused about importing and exporting solar electricity)

The calculator looks at the cash-flow of this solar system for 20 years. It takes into account:

• electricity price inflation
• the “opportunity cost” of not having the cash you paid for the solar system in the bank earning interest instead
• power degradation over time as the panels age

For a system cost of $11,000 here are the results:

The payback calculations for a 5kW Grid Connect Solar System : 12 years

The payback of the 5kW grid connect system is 12 years when exporting half your power for a pitful 7c per kWh.

Scenario 2: 5kW Hybrid System.

The 5kW hybrid system comes with about 10kWh of battery storage. A 5kW system produces about 20kWh per day. So it should be capable of storing and shifting the 50% of the solar power that was previously being exported. We can use that power to offset our 26c per kWh bill instead. If this was to happen what would the payback be on the hybrid system?

To find out, I simply changed the price of the system to $18,000, and changed the % of electricity being exported from 50% to 0%. Here are the results (with the changes to the calculator inputs highlighted):

5kW Hybrid Solar System pays back in 11 Years

With those (very big) assumptions, the payback comes out at 11 years! Hybrid solar appears to be a better investment…woo hoo!

But.. it isn’t that simple I’m afraid…my experience is that the batteries in such a system will need replacing after about 10 years.

Luckily our calculator can handle that. I originally programmed it to include the option of replacing the inverter after a number of years. If we use this option to show us the effect of replacing $3,000 of batteries after 10 years, then the payback comes out at 13 years. One year longer than the non-hybrid system:

New batteries after 10 years add 2 years to the payback

So in this example – assuming the batteries last 10 years, and cost you $3,00 to replace (many people would argue that batteries will reduce in price drastically in 10 years), your hybrid system is a slightly worse investment that non-hybrid.

But I’ve made a hell of a lot of assumptions:

• about how much electricity is exported
• what the feed in tarrif will be 10 years in the future
• how much electricity prices will rise
• etc, etc.

The long and short of it is that – the extra cash you spend on a hybrid system should pay for itself over about 10 years if the feed in tariff in your state is (and stays) very low. Combine that with the advantages of blackout protection, and the satisfaction of not giving almost-free electricity to the retailers and hybrid solar starts to look tempting. And as battery costs and the cost of the power management units come down, it is only going to become more viable.

Turbo Boost for Solar?

Some major news on a local technological breakthrough for solar cells this week folks. This, as always, gives your columnist the  opportunity for some more shameless cheerleading on behalf of Australian solar watchers, in the increasing wasteland of government support for domestic solar systems.

(For help, see Finn’s latest article on how to future proof your PV system from perfidious state and federal governments.)

To begin with the Mexican wave (or Sydney University wave to be more precise) part of the article. An April 18 press release from the university has stated that Associate Professor Tim Schmidt, from the university’s School of Chemistry, has partnered with colleagues from the Helmholtz Centre Berlin for Materials and Energy in Germany, to develop what they describe as “turbo for solar cells”.

The breakthrough technology is a “… photochemical upconversion that allows energy, normally lost in solar cells, to be turned into electricity,” according to the release.

If, like me, you are wondering what the “upconversion” technology means, the university helpfully explains that it is the process “which harvests the part of the solar spectrum currently unused by solar cells, [and] eliminates the need for costly redevelopment of solar cells.”

Associate Professor Tim Schmidt describes the work as providing a “benchmark” for future development of the upconversion technique.

“We are able to boost efficiency by forcing two energy-poor red photons in the cell to join and make one energy-rich yellow photon that can capture light, which is then turned into electricity,” Associate Professor Schmidt said.

“We now have a benchmark for the performance of an upconverting solar cell. We need to improve this several times, but the pathway is now clear.”

The pathway to solar cell efficiency includes an expected rise to 40 percent efficiency says the university.

The upconversion technique with regard to solar cells has been developed by the teams for a number of years and more information on how the technique works is available here:

http://iopscience.iop.org/1742-6596/185/1/012002/pdf/jpconf9_185_012002.pdf

The Australian Solar Institute, which provides some funding for the venture, describes the breakthrough as a fine example of collaboration between German and Australian solar scientists. We can’t argue with that! Congratulations folks.

Hybrid Solar Too?

In my previous blog post on hybrid solar systems (aka grid connect with battery backup) I promised to follow up with a post that went into more detail on the costs and give examples of inverter hardware that can be used to make such a beast.

I’ve realised that if I go into the costs and paybacks then this blog post may be longer than War and Peace. So in this post I’ll cover the hardware and I’ll save the financials for next time.

As I said in the previous post, your motivation for spending more on a hybrid solar system will likely be either:

1) You want backup power when the grid goes down.

2) You want to minimise your electricity exports due to a painfully low or non-existent Feed In Tariff in your state.

3) You may want to maximise your electricity exports due to a very generous FIT in your state (Hello Queenslanders!)

4) You may want to “shift” the peaks in your grid electricity usage due to a Time-Of-Use electricity tariff. This would involve charging your batteries at a low tariff and using your battery power + solar at peak times to avoid paying the peak electricity rate.

(And even if number 4 is not relevant to you know, I’d bet my mountain-bike that sooner or later everyone will be forced onto a time-of-use tariff.)

Now, I could go through every possible combination of hardware for every possible combination of the 4 requirements above. But the post would be so long and repetitive that even the hardiest solar geek would probably tune out.

So instead I’ll present for your delectation a system that can be configured to do all the above. Which I would argue is the most future proof solution anyway. Because recent history in NSW has shown us that we can’t trust the State governments to keep their word on Feed In Tariffs and it seems obvious that time-of-use electricity charging (you pay more for your electricity at peak times of the day) will become the norm very soon.

Hardware Required for a future proof, super-duper mega, mega configurable  Hybrid Solar System:

First let’s look at what goes into a standard grid connect system:

1) Solar Panels

2) Inverter

3) Everything else: Wires, Racking, Disconnect Switches, fuses etc.

A Hybrid Solar System needs all the above and more. The extra hardware needed is:

Power management unit (box of electronics)

Inverter that can talk to the power management unit (or is integrated into it)

Bank of Batteries

An example of a “power management unit” that will do the job and has all the configuration options you’ll probably ever need is the 5kW Rich Electric SuperCombi.

Makes the coffee too?

This sucker can be configured to:

• Allow you to disconnect fro the grid and still have power.
• Charge the batteries only when electricity is cheap.
• Minimise grid power usage when electricity is expensive.
• Discharge the batteries when electricity is expensive.

And the joy of having such a configurable system is that if, in the future, the government changes the rules you can re-jig your system for maximum profit!

If, for example, the government came to its senses and introduced a “time of use feed in tariff” where you get paid more for exporting energy at peak times, you could configure the SuperCombi to buy the electricity when it is cheap, push it into the batteries and sell the same electricity when it is expensive (ideally along with all your solar power).

To connect the whole caboodle to the grid you would have to combine the SuperCombi with a Grid Tie Inverter from the same manufacturer (e.g. Rich Electric’s SolarWorx GTI). The reason you need to use this particular inverter is that it can talk the same language as the Supercombi so that they can work together and do all the smart stuff listed above.

And don’t forget that you will need at least 200Ah of 48V batteries which will give you 9.6kWh of electricty storage to play with.

Here is how all the bits connect together (at a very high level):

The SuperCombi is the brains of the system and can probably feed the cat too.

As you can see, everything goes through the SuperCombi.  To cut a long story very short, this box of electronics has the ability to be programmed to follow any kind of logical rules based on the state of the batteries, solar panels, grid connection, or time of day. It uses this logic to route either the:

• Solar Power
• Battery Power
• or Grid Power

or any combination of the three to either charge the batteries, power the home or export to the grid.

It can also be configured to only power the “essential circuits” in the house if the grid goes down – to extend the time you can run on the battery bank.

Essentially your solar system has been transformed from a rather simple electrical system, to a sophisticated computer controlled power management and battery backup system. This means that if you are looking to install Hybrid Solar, it is essential that your installer/designer has both the “Off Grid” Clean Energy Council Accreditation (so he knows how to handle the batteries), and also has good experience of the hardware being used, as it gets pretty technical pretty quickly, even for a Chartered Electrical Engineer like yours truly.

Next Week: I’ll add up the costs of the solar hybrid system compared to Grid Connect and also crunch some numbers to see what the payback is for the extra expense incurred