Conversion calculator for Weights & Measurements.

That largely depends on whether you want to remain enslaved to paying the deceptively named energy Retailers, for over inflated "state grid" energy prices, this page explains this in way more detail.

If you want to get an idea of how long it takes to recover the Investment cost for your own energy system, then click here and enter the details on your largest electricity bill, then you will instantly see what is required to produce more electricity than you use, that plus being able to store all excess energy, before even thinking about exporting your energy, that is the key to true independent energy!

Most people already off-grid will either be storing there energy or using some form of direct generation.

Having a battery storage capacity larger than your daily kWh usage, simply allows you to charge your batteries, be it with Solar, Gen-set, Wind &/or Aqua generation.

For FREE advice on planning your energy system, click here & enter your information to get a FREE system evaluation, we will get back to you ASAP to discus your needs based on the information you supply, we don't pressure anyone to purchase, we simply arm you with the knowledge of what may best suit your needs in relation to your consumption, location, and using any natural resources at your location.

No, not necessarily!

However, electricity Retailers require that you don't feed energy back into the state grid that has come out of anything that does not come from Renewable energy &/or you expand/upgrade your existing solar system or inverter or add Wind or Aqua generated energy to your system.

The main reasons behind that, is the deceptively named "Electricity Retailers" make over 40% commission on your total electricity bill, so if you have a small bill, and a over-sized system, the Retailer make very little from administering your energy bill.   Remember all electricity Retailers do Not actually pay for the energy you use, they simply compete to send you a bill and skim handsome profit at your expense!

Here's the thing though - most systems can be configured to never send electrical energy back to the grid.  Instead, you would be smarter to stored your excess energy to only be delivered to your premises as 'self consumption'.

So, if you want to pay the Retailer the $30 odd a month to remain connected to the state grid for security reasons, then one way to implement this is to get your system installer to prove to the Electricity Retailer, evidence your battery system is genuinely incapable of exporting energy to the grid, by installing an additional device in the circuit, called a 'zero export control box' (hence your system is not classed as a 'generator' in their narrow minded view. This device independently measures the energy flowing to and from your premises and will disconnect your battery inverter if it ever tries to export energy to the grid.

If you are seeking to install a battery system and want to avoid losing an existing Solar Feed-in Tariff, make sure you raise this request with your installer, and ask them to draw up a suitable proposed installation diagram, the industry calls this a Single-Line Diagram (SLD), that demonstrates the scenario suggested here. This is a Z-Cell diagram showing how the system works and this is then submitted by your installer to your 'Electricity Retailer', seeking their prior approval to create your Battery system in a manner that will not result in you losing your Feed-in Tariff.

Should your current Electricity Retailer reject your request to install battery bank, firstly contact your ombudsman or simply give that Retailer the flick and use a more forward thinking Retailer, as there a New bread of Peer-to-Per (P2P) Energy Trading evolving in Australia.

Yes, in Australia there are several forward thinking company's that now use the same type of proprietary software that allows you to sell your excess energy from your Solar & Battery system at a far better rate than the feed-in Tariff (Rebate) offered by the 'Electricity Retailers'.

Grid operators are shifting their stance and now actively seek to purchase energy on demand from home & commercial battery owners. This allows energy to be exported back to the grid from your battery bank at times that the grid operator is prepared to pay you a premium to do so.

There are several companies in Australia providing this service, and more are rolling out this service as the state grid struggles to dealing with unreliable renewable wind energy, like what happened in South Australia in early 2017.

This is a slow process that is gathering momentum as we speak, as other than Nickel Iron (NiFe) and Super Capacitor battery technology, all other battery technologies struggle to provide over a 10year life span, although Australian RedFlow battery's may be one such battery.

Feed in Tariffs (FIT) first started in Australia in 2008 when a 44c feed in tariff started in South Australia.

The price of solar in 2008 was a way more expensive then it is now. Since 2008, the price of solar panels have dropped around 80%.

Since the sudden drop in the price of solar panels, Governments around Australia have responded by changing the level of FIT payments.

Some FIT around Australia were applied to the entire amount of solar generation (gross FIT), and other FIT's were paid on unused solar electricity exported back into the grid (net FIT).

Below table summarises January 2019 status of FIT around Australia.

So, if you already have a solar array, why would you bother gifting your energy to the deceptive retailers for little return, you would be a LOT better off self-consuming the excess energy you harvest, simply done by simply installing a battery bank with a kWh capacity equal or larger than the energy you use after hours!

A lot of people, included energy professionals, don't fully understand the difference between kW and kWh.

If you are one of them, this article should set you straight !

Energy calculations and energy saving, become much easier when you understand the difference between a kW and a kWh.

You first need to decide on whether you are simply looking to reduce your power bill, and remain Enslaved to the 'electricity Retailers' or to become totally energy independent!

Either way, the solar array kW size largely depends on the Type of solar array you install, whether it be Dual-axis (DART), Single-axis (SAT) or Fixed-Tilted (FT) Racking, as these three Racking types generate vastly different daily energy between them.

This is a single solar panel DART-1 Prototype we designed for people with low daily energy consumption, it uses a single 500W Panel and Generates 5kWh/p energy per day, using Two panels will generate 10kWh/p per Day.

So, if you just want to reduce your Daytime power consumption, commonly you may only need a solar array to harvest approx. 50~70% of your 24 hour consumption, as obviously after Sunset you will be purchasing your energy from the utility company, or be using a Generator etc.

EG: With 15kW daily consumption (15'000 watts), lets say you need a solar array to harvest 10kWh energy to replace your daytime consumption, this is where DART stand on there own, as they harvest Peak energy for 10 hours per day, so divide 10kW by 10 hours =1kw solar array is required.

Now, if you purchase 380W panels, divide 1'000W (1kw) by 380 =2.63, so you only need 3x 380W panels to cover you daytime power consumption!

If you are looking to install Tilted Rooftop array (the least efficient), you will only harvest approx. 5 hours of Peak sun, that equates to 10kW ÷ 5 hours =2kw (5x 380W) solar array is needed, rounded up to 6x 380W solar panels.

If you are looking to become Power independent read the next question.

If you don't have a Solar system with a Hybrid Inverter that can Island or Energy Storage installed, the simple answer is NO.

However, read the information on this page, as we explain in more detail what can be accomplished with different equipment configurations!

What is the "government STC rebate" ? STC stands for Small-scale Technology Certificate, which the system owner can claim when an eligible solar power system is installed, the owner will receive a financial rebate deposited into there bank account.

Sorting through the Maths of other Solar Quotes can be bewildering, especially if you find there are massive price differences, and most do not supply an itemised cost breakdown, making it even harder to analyse what you are getting for your money.  So, we will explain what is behind the Quotes.

In 2020 most solar Retailers sell 300W, 60cell solar panels, so a 6kW array needs 20 solar panels, and you will find there price include a solar ONLY inverter.

The reason behind most Retailers selling 6kW solar arrays, as mentioned several times, is so the Retailer can maximise there profit by getting you to sign over your $3'500~$4'500 STC Rebate to them.

Retailers make claiming STC's sound like it's a difficult process, where in fact the customer (You) can claim the STC rebate by filling in a simple one page STC Claim form, where you supply your bank deposit details, then the Aggregators will pay the STC credits directly into your bank account.

These is our standard STC Registration Form.

Below is a common breakdown of the 6.5kW TV solar special & those annoying Google Adds you get bombarded with.

1. Most advertise a 6.5kW Installed Package Deal comprising of 24x 270W solar panels for $3'300, BUT that price is Deceptive, as they require you to sign over your STC Rebate, they claim for 10years.
2. So, lets do the Breakdown: $3'300 less $300 solar only inverter, leaving $3'000 ÷ 24 = $125 each =$0.46 Watt.  BUT (RP $195 +to cover GST and handling etc. to you i.e. $224 per panel. TOTAL cost of 17x $244 x 21 panels = $4547
1. Working out the rebates from your given Info 315W x 21 panels =.6.615 KW sys Gympie could be solar Zone 2 (1.536 ), STC assignment for 10 years for 2020, so STC generated is 6.615 x 1.536 x 12 = about 122 certificates generated presently the STC value estimated at $34 at worst case i.e. 122 x 34 = 4148units. Its NORMAL to give less than $34 per STC (to cover risk in case STC fall in price and cost of STC generations), So everyone set their own discount - This is not regulated
2. In one case quoted as, $3744 from 122 STC i.e. $3744 / 122 about $30 per STC PANEL NET COST ($4547 - $3744 ) is $803
3. Price of Hybrid Inverters warehouse estimated $1300 RRP.
4. Cost of railing is approx. $10 per panel, so $10 x 20 = $200.
5. Bit & Pieces i.e. Balance of System (BOS) under $500 (isolators, AC & DC cables, brackets, labels etc)

So, a saving of $6162 - $2400 = $3222, the RRP is therefore $3338 + $3222 = $6560

Many Solar Company Charges inc. fancy overhead, Installers, Admin, logistics.

If you PAY $9500 to cover Panels, Inverter, Railing, BOS the rest is RETAILING COST $9500 minus (803 +1625 +410 +500) $9500 -$3338 Company PROFITS & COST is $6162.

Every SOLAR RETAILER is Different - NO RIGHT OR WRONG !

There price, Our price & Your Choice !

Larger companies have fancy high overhead, Secretary, Support Team, Logistics, Accountant, Agent commission fees & Most have those annoying Google (Ad) Advertisement Costs that you pay for in the end, as they don't have decent websites.

On the other hand, CEC installers are Certified Electricians, and should provide better price structure, as many are Contract installers & do business from their SOHO (Small Office Home Office) or Van, and commonly don't have any fancy overheads.

If you engage a local CEC Installer, ask what are there charges ? Their Charges will relate to there travel distance, So the Contractor(s) should have minimum charge &/or by the Panel cost at most $120 per panel for simple rooftop installation, i.e. 20x $120 =$2400 as a contract installer COST*.

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NB: If you install a DART unit, you will require approx. 30% less Solar Panels and a DART harvests energy for 11hrs day, instead of 4.5hrs for Rooftop installation.

As a DART unit is mounted on the ground, a Farmer or a handy person will be able to do most of the Foundation & Assemble work, the Conduit & Cabling to your meter box can be done two ways, above or below ground.

Please Note: We sell 375~500W Monocrystalline solar panels, as such a 6.5kW solar array only needs 17 modules (panels), and we only sell Hybrid inverters that are designed to interoperate batteries into a system at any time.

I hope this article enlighten you on HOW TO PRICE A SOLAR SYSTEM !

To Totally Eliminate your power bills you only need;

1. A Solar Array that Harvests the energy you consume in 24 hours.
2. Energy storage equal to the power you consume between Sunset & Sunrise, Obviously the larger the better!

As a general rule, 2/3 of Residential energy is consumed during daylight hours, and all excess energy not consumed, should be automatically sent to your batteries & stored for use after Sunset and through to the next Sunrise. ...It is that simple!

Batteries only store the energy that would either be fed into the State-grid or otherwise would be Wasted energy.

EXAMPLE: To negate a 15kWh of daily electricity consumption using a DART-4 unit, then 15kW ÷ 11 hours =1.36kW DART array is needed, rounded-up =4x 375W panels (1.5KW) Array is needed, then all you may need is a 5KW battery to store your excess energy to get you through to the next sunrise.

To negate a 30kWh daily consumption, you may only require 10kW battery storage to get you through the Sunrise, where your Solar will take over again.

In 2021, the cost of the Solar panels have dropped greatly over the last five years, to where the Installation costs are now being deceptively hidden Behind the 'Small-scale Technology Certificates' (STC) Credits!

The main reason the majority of solar Retailers advertise cheap 6kW+ solar systems, they are really chasing your 11 years of 'STC' credits by getting you to sign over your STC Credits, these are worth between $3'000~$4'000 in government REC rebate!

This is our STC Registration Form: Australian Micro Power Grids STC Form, however as over 95% of our Customers install there own Systems, we prefer they Claim there own STC's, easily done when the CEC approved Electrician passes there installation, the money is directly deposited into there bank account.

We accuse the majority of Retailers hiding the actual installation costs behind the REC Credits, that Customers can easily claim by filing a simple STC Form, and get the funds deposited into your bank account.

We don't market Roof-top Solar as flat or tilted Racking is the most inefficient at Generating solar energy.

We mainly offer DART Racking & SAT Racking as a 3KW DART Unit will harvest more energy than a 6KW Tilted Roof-top Racking!

TEST the below figures by using this Calculator;

1. DART: 8x 375W Modules =3KW Solar System, as DART Racking chases the Sun for 11 hours per day it Harvests =33kWh/p energy per Day!
2. FT: 16x 375W Modules =6KW Solar System, FT (Fixed Tilted) Racking is ONLY able to Generate Peak energy for 2~3 hours per day =30kWh of Generated energy per Day!

That should make it Obvious why we first & foremost offer DART Racking.

Click Here to see our system Cost Guidelines, that you can play with.

Owners of registered Solar systems are eligible to claim STC’s ("REC" Credits) themselves, providing the installation has been signed off by a CEC accredited installer within 12 months of system purchase.

This is our STC Registration Form: Australian Micro Power Grids STC Form.

Generally speaking Dual Axis Tracking (DART) provides up to 50% increase in efficiency over Flat mounted panels, as the panels are consistently being adjusting and pointing directly at the Sun.  These tracking units use Slew Bearings & Actuators that are expensive, however as they increase the efficiency, in turn these units reduce the pay-back period substantially.

Where Single-Axis Trackers (SAT) simply follow the sun as it crosses the sky, and provide up to 25% increase in efficiency.

There are several motorised designs, from industrial 12~24v self powered actuators, using commercial worm drive Slew bearings to cheap lightweight motors costing a fraction of the price, the cheap motors don't last and cause prematurely tracking failure.

Solar tracking systems require stronger than normal Racking frame to mount the panels, largely to be able to deal with adverse wind & weather conditions, as the pivot/mounting point is a very small area, compared to roof fixed flat racking.

Ground mounted DART & SAT trackers are the most widely used, this varies from using a concrete reinforced foundation, the more modern foundation method is using multiple Ground-Screws, that are mechanically driven into the ground, thus eliminate the need for Concrete foundations, with the added benefit of being easily removed & relocated if required.

DART's can also tie the Mast pole to the facade of a building, not as common is fixing a short pole with supporting legs connected to the Rafters.

NB: If the solar energy is to travel a long distances (over 50mt), before reaching Hybrid MPPT inverter, batteries and charge controller, it may be worth while converting each solar panel from DC to AC using Micro Inverters, as AC voltage has far less energy losses than DC wiring over long distances, DC voltage travelling long distances requires purchasing expensive heavy duty multi-strand wiring to reduce energy losses.

This topic is covered here in more detail.

There are three main types of Solar Modules Racking.

Choosing the correct Racking types for the area of land you intend to use, can greatly influence the gross daily kWh/MWh of generated/harvested energy, and in-turn how quick your investment is retuned.

1) Dual Axis-solar Tracking (DART) Racking is the BEST by far, at Generating the most amount of energy per day.  There are two types of DART Racking, being Pole mounted DART and Horizontal mounted DART Racking, both follow the sun on two axis.

DART Racking & installation cost comes at an additional cost, that once installed will harvest over 130% more energy per day than any Fixed flat solar racking mentioned below, the additional energy generated by DATs will be ongoing for decades to come, so the additional up-front cost of DART will be recover by the additional energy savings in approx. 12 months!

2a) Single Axis Tracking (SAT) with a Vertical Azimuth axis rotation, these units looks identical to a DART, but only have one Slew Bearing that rotates the pre-tilted panel racking from east to west, SAT is the next best Racking option.  Because of the Racking & Installation cost approx. the same as DART, usually only one or two of these units are installed, and some design can be fitted with a manual Tilt adjustment between Summer & Winter, obviously that increase the energy generated.

2b) Single Axis Tracking (SAT) with Horizontal axis rotation with Tilted panel racking with horizontal east to west tracking is the next best Racking option.

2c) Single Axis Tracking (SAT) with Flat panel racking with horizontal tracking with No panel tilt, tracks east to west is the next best Racking option.

3a) Fixed Tilted Racking (FTR), usual Tilted North, East or West facing Racking is the first option many Installers go-to, this is usually based on a Cash-Grab as this racking cost is cheaper & very quick to install, the Con is "Fixed Tilted Racking" is way less efficient at Harvesting Energy than the above two racking types.

3b) Fixed Flat Racking (FFR), is the Worst of Racking & rarely used these days, unless on Industrial flat roofs, where the installers are to lazy to install Tilted Racking!

Excluding Land cost or Lease, a Commercial Fixed Tilted solar Racking Solar Farm costs starts from $1'000'000 per MW, that includes the supply & hiring of all equipment, machinery, electric sub-station, field Inverters, electrical wiring, conduit & 3m high perimeter security fencing with CREE Led lighting & CCT video etc...

Installing Dual Axis Tracking DART Racking adds additional cost to the build, the big payback is they Generate substantially more energy for the next 25+ years, and commonly that increases the Payback period by approx. 25% per year!

In our opinion, installing Single Axis Tracking SAT Racking is a wast of money, as a little extra spent on DART is far more beneficial, as the Generation is substantially better during Winter & Summer!

NB: DART Racking is the most expensive racking, however DART provides a yearly return from 25% on the investment cost due to the additional energy that is generated, and commonly there is only a 3~4 year break-even time period, with an ongoing income for the next few decades!

Cement foundation can cost more money and take more time & resources to install, where a modern Galvanised Ground Screw Foundations are quicker & far simpler to install, and these foundations can be easily removed if & when required, leaving the ground in the original condition and with no wastage!

Firstly, by replacing Cement foundations with Ground Screw Foundations for all Racking types, as well as the perimeter Security Fencing, the Installation costs of a solar farm are Greatly reduced for the following reasons;

1. There is No need to dig up the ground. (except for wiring conduit)
2. No Concrete used or needed.
3. No down-time waiting for concrete to cure.
4. No Re-bar & concrete mesh used or needed.
5. Ground Screws can replace the need for separate Earth lugs, as per AS3000 master electrical code.

The main saving using Ground Screws is time saves on Labour & Material costs, solar Racking & Fencing can be assembly & installed as soon as the ground screws are in place.

Labour is the Great unknown;

• Large DART units can be assembled at ground level & craned onto the mast.
• SAT Racking are way less complicated and thus can take less time to install.

The actual fixing of the Solar Panel onto the Racking is a very simple undertaking, as commonly there are only four (4) retaining screws, the two (2) DC plugs per panel, on any racking options.

There Elephant in the room for most solar farms is the Bureaucratic red tape that is forced upon solar farm investors/builders by Council's, that can cost upwards of $80'000 to undertake "Environmental Studies".  Here lies the issue, if you are going to till the land to Grow a Crop, you don't need any permission, as long as you are not de-foresting the land of large old-growth trees.

It appear smarter to tilled the Land for a crop and then apply for a solar farm afterwards.

A 1MW solar farm refers to the Array size, Not the hours of Harvesting, as each Racking type Generating varies greatly, use this 1MW Solar Farm Calculator to get a better understanding.

The following relates to the Energy Harvesting in the Sydney region;

• Using 270W solar modules requires 3'500 modules to obtain 1MW Array.
• Using 435W solar modules only requires 2'300 modules.
• That saves approx. $20'000, and also requires less Racking & Labour!

Using Single-Axis Tracking (SAT) Racking, and using Ground Screw foundations or earth rammed Pylons, removes the need for Cement foundations & waiting for cement to cure.

Using Ground screws greatly reduces installation time, and the cost saved on labour, supplements the additional expense of any ground racking, not to mention the Additional 20% of energy generated by a SAT, than that of Fixed tilted racking.

The costs saving made by using the latest CEC approved 435W modules not only reduces the modules required by 35%, it also uses far less raw material like Aluminium, Glass etc..

Also, by using 435W modules you require less ground racking & pylons, and again this carries over to saving on Workforce labour & shorter installation Times.

If you are undertaking your first solar farm installation with new unskilled workers, you should not need to increase the figures below.

Installation times for Single Axis Solar Racking;

1. Set-up site with Portable Office, Lunch room & Toilet facilities.
2. Position shipping containers, machinery & material around the Site for easy access for workers: 3 people, 3 days =90 hours.
3. Install Permanent Security Fencing & Razor wiring: 3 workers, 5 days =200 hours.
4. Install 672 SAT Ground Screws with Tractor: 2 workers, 7 days =110 hours.
5. Install SAT Masts & Beams: 6 workers, 5 days =240 hours.
6. Install Slew Drives & Tilt Actuator bars: 2 workers, 2 days =40 hours.
7. Forklift Module pallets around site; 1 worker, 2 days =20 hours.
8. Install 2'300 Solar Panels: 10 workers, 15 days =2'200 hours.
9. Install DC Isolator Switch boxes: 2 workers, 3 days =60 hours.
10. Cleaning up of site rubbish: 2 workers, 2 days =40 hours.
11. TOTALS: Approx. 3'000 hours labour, 6~10 workers as needed.

Projected Breakdown: Labour can be extended from 5~10 days or longer if required, obviously dependant on delays due to bad weather conditions, machinery breakdowns & no-shows.

As you can see, great saving on time & labour is possible, by using Ground screws or Earth Ram Pylons.  Ground screw racking installations are now becoming common practice, largely due to the fact the land can be returned to it's original condition, way easier than a solar farm that used concrete foundations!

Worth noting: Fixed Tilted Racking nowadays, is way more time consuming & complicated, as they are like a huge meccano set, where thousands of additional parts/components are needed than Single-axis Racking system.

Dual-axis Solar Racking and perimeter Security Fencing, can all be installed using Ground Screws, greatly reducing the installation times & costs for all solar farms !

updated: Dec-2019.

This is something that needs to be discussed with the local Utility distribution company, as equipment will need to be based on the local infrastructure, as well as the MW feed-in voltage & capacity of the solar farm.

However, we have worked with several companies, and an 11kVa sub-station ballpark cost is from $100'000~$150'000, that cost does NOT include the Hi-voltage lines that connect to the Utility distribution infrastructure.

To be updated, come back soon !

Only if you really want to take full advantage of the energy you produce!

That includes any form of energy production, and if you already have a solar array and only get a measly $0.06 Feed-in-Tariff (FIT), you would be a lot better diverting your excess energy into a battery bank, then you will not get slugged $0.28kWh (400% more) by the Electricity Retailers after sunset, as having a battery bank allows you to harvest the energy from your batteries after sunset, it is that simple!

The energy companies don't really want you to become smart & independent, as they rely on your enslavement.

The larger your battery bank, the quicker your payback time will be, as long as you produce enough energy you will no longer need to pay the Electrical Retailer's prices, thus saving you paying $0.27 cents per kWh for energy after sunset, as you will be harvesting the energy from your battery bank.

In 2020 the talk of town is Super Capacitor (SC) Energy Storage Modules being the Future of Energy Storage for Residential & Commercial Energy systems for decades to come.

Our Recommendation in order of LONGEVATY is;

1. Super-capacitor Modules 50'000+ cycles.
2. Nickel Iron (NiFe) Batteries 3'600+ cycles.
3. Lithium Iron (LiFePO4) Batteries 10'000+ cycles.
4. Lead Acid Battery (LAB) 2'000+ cycles.

In order of Weight & Footprint size;

1. Super-capacitor Modules.
2. Lithium Iron (LiFePO4) Batteries.
3. Nickel Iron (NiFe) Batteries.
4. Lead Acid Battery (LAB).

Storage Technology COST per kWh;

1. Lead Acid Battery (LAB) $125 per kWh.
2. Lithium Iron (LiFePO4) Batteries $440 per kWh.
3. Nickel Iron (NiFe) Batteries $550 per kWh.
4. Super-capacitor Modules $1'000 per kWh.

If you really want to take full advantage of the energy you Harvest/Generate, then invest in a larger kWh capacity battery bank!

No, if you already have Hybrid inverter it is Plug & Play.

If not, the cheapest option is to purchase a Hybrid Inverter or a stand alone MPPT Charge-Controller, a MPPT unit tracks the optimum voltage/current ratio form your Solar array, and can provide up to 30% increase in performance over other controller types, MPPT controllers support different voltages in and out.

If you want to increase the losses that occur in all energy production systems, caused mainly by inadequate equipment, wiring and the distance the electricity travels too the inverter, and then to your premises, you should purchase a multi-voltage Hybrid inverter.

The exception to that rule is if each Solar panel has it's own "240v Micro MPPT inverter", this way a shadow from a building, tree or shadow that partially covering one panel, it will Not effect the whole solar array as it would with all panels wired in series or parallel.

Maximum Power Point Tracking" (MPPT)

There is some confusion about the term "Tracking", there are two types;

Panel Tracking - is where solar panels are on a mount that follows the sun. The most common are Two axis & Single axis Solar Tracking. These optimise output by following the sun across the sky for maximum sunlight. These typically give you about a 15% increase in winter and up to a 35% increase in summer. This is just the opposite of the seasonal variation for MPPT controllers. Since panel temperatures are much lower in winter, they put out more energy. And winter is usually when you need the most energy from your solar panels due to shorter days.

MPPT Electronic Tracking - usually digital. The charge controller looks at the output of the panels and compares it to the battery voltage. It then figures out what is the best energy that the panel can put out to charge the battery. It takes this and converts it to best voltage to get maximum AMPS into the battery. (Remember, it is Amps into the battery that counts). Most modern MPPT's are around 93-97% efficient in the conversion. You typically get a 20 to 45% energy gain in winter and 10-15% in summer. Actual gain can vary widely depending weather, temperature, battery state of charge, and other factors.

Grid tie systems are becoming more popular as the price of solar drops and electric rates go up. There are several brands of grid-tie only (that is, no battery) inverters available. All of these have built in MPPT. Efficiency is around 94% to 97% for the MPPT conversion on those.

This section covers the theory and operation of "Maximum Power Point Tracking" (MPPT) as used in solar electric charge controllers.

An MPPT is an electronic DC to DC converter that optimises the match between the solar array (PV panels), and the battery bank or utility grid. To put it simply, they convert a higher voltage DC output from solar panels (and a DC voltage from Wind & Aqua generation) down to the lower voltage needed to charge batteries.

(These are sometimes called "power point trackers" (PPT) for short - not to be confused with PANEL trackers, which are a solar panel mount that follows, or tracks, the sun).

Here is where the optimisation or maximum power point tracking comes in. Assume your battery is low, at 12 volts. An MPPT takes that 17.6 volts at 7.4 amps and converts it down so that what the battery gets is now 10.8 amps at 12 volts. Now you still have almost 130 watts, and everyone is happy.

Ideally, for 100% energy conversion you would get around 11.3 amps at 11.5 volts, but you have to feed the battery a higher voltage to force the amps in. And this is a simplified explanation - in actual fact, the output of the MPPT charge controller might vary continually to adjust for getting the maximum amps into the battery.

Typical energy Curve of a Solar Electric Panel on the left, is a screen shot from Solar Software "PV-Design Pro" computer program (click on the picture for full-size image). If you look at the green line, you will see that it has a sharp peak at the upper right - that represents the maximum power point.

What an MPPT controller does is "look" for that exact point, then does the voltage/current conversion to change it to exactly what the battery needs. In real life, that peak moves around continuously with changes in light conditions and weather.

An MPPT tracks the maximum power (energy) point, which is going to be different from the STC (Standard Test Conditions) rating under almost all situations. Under very cold conditions a 120-watt panel is actually capable of putting over 130+ watts because the energy output goes up as panel temperature goes down - but if you don't have some way of tracking that energy point, you are going to lose it. On the other hand under very hot conditions, the energy drops - you lose energy as the temperature goes up. That is why you get less gain in summer.

MPPT's are most effective under these conditions;

• Winter &/or cloudy or hazy days - when the extra energy is needed the most.
• Cold weather - solar panels work better at cold temperatures, but without an MPPT you are losing most of that. Cold weather is most likely in winter - the time when sun hours are low and you need the energy to recharge batteries the most.
• Low battery charge - the lower the state of charge in your battery, the more current an MPPT puts into them - another time when the extra energy is needed the most. You can have both of these conditions at the same time.
• Long wire runs - If you are charging a 12-volt battery, and your panels are 30mt (100 feet) away, the voltage drop and energy loss can be considerable, unless you use very large wire. That can be very expensive. But if you have four 12 volt panels wired in series for 48 volts, the energy loss is much less, and the controller will convert that high voltage to 12 volts at the battery. That also means that if you have a high voltage panel setup feeding the controller, you can use much smaller wire.

Ok, so now back to the original question - What is a MPPT?

The Power Point Tracker is a high-frequency DC to DC converter. They take the DC input from the solar panels, change it to high-frequency AC, and convert it back down to a different DC voltage and current to exactly match the panels to the batteries. MPPT's operate at very high audio frequencies, usually in the 20-80 kHz range. The advantage of high-frequency circuits is that they can be designed with very high-efficiency transformers and small components. The design of high-frequency circuits can be very tricky because of the problems with portions of the circuit "broadcasting" just like a radio transmitter causing radio and TV interference. Noise isolation and suppression becomes very important.

There are a few non-digital (that is, linear) MPPT's charge controls around. These are much easier and cheaper to build and design than the digital ones. They do improve efficiency somewhat, but overall the efficiency can vary a lot - and we have seen a few lose their "tracking point" and actually get worse. That can happen occasionally if a cloud passed over the panel - the linear circuit searches for the next best point but then gets too far out on the deep end to find it again when the sun comes out. Thankfully, not many of these around anymore.

The power point tracker (and all DC to DC converters) operates by taking the DC input current, changing it to AC, running through a transformer (usually a toroidal type of impedance coil, a doughnut looking transformer), and then rectifying it back to DC, followed by the output regulator. In most DC to DC converters, this is strictly an electronic process - no real smarts are involved except for some regulation of the output voltage. Charge controllers for solar panels need a lot more smarts as light and temperature conditions vary continuously all day long, and battery voltage changes.

Smart power trackers

Most recent models of Hybrid inverters have digital MPPT controllers incorporated and are microprocessor controlled. They know when to adjust the output that it is being sent to the battery, and they actually shut down for a few microseconds and "look" at the solar array and battery and make any needed adjustments.

Although not really new (the Australian company AERL had some as early as 1985), it has been only recently that electronic microprocessors have become cheap enough to be cost-effective in smaller systems (less than 1 KW of the panel).

MPPT charge controls are now manufactured by several companies, such as YIYEN Electric, Fronius, Vitron, SolaX, Outback Power, Xantrex XW-SCC, Blue Sky Energy, Apollo Solar, Midnite Solar, Morningstar and several others.

Solar cells are neat things, they are not very smart, neither are batteries. Most PV panels are built to put out a set voltage, nominally 12~38 volts. The catch is "nominal".

In actual fact, almost all "12-volt" solar panels (old technology) are designed to put out from 16 to 18 volts. The problem is that a nominal 12-volt battery is pretty close to an actual 12 volts - 10.5 to 12.7 volts, depending on state of charge. Under charge, most batteries need from around 13.2 to 14.4 volts to fully charge - quite a bit different than what most panels are designed to put out.

OK, so now we have this neat 350-watt solar panel. Catch-1 is that it is rated at 350 watts at a particular voltage and current. The BS-350 is rated at 9.48 amps at 38.39 volts. (8.99 amps x 38.39 volts =345 watts).

How do ultra-fast battery chargers work ?

Fast-charging creates a lag between voltage and state-of-charge that increases the faster the battery is being charged.  This can be compared to a rubber band lifting a heavy weight. The larger the weight, the wider the lag becomes.

The ultra-fast charge forces the voltage of a 1.2v NiFe battery to say, 1.4V/cell ceiling quickly, while the battery is only partially charged. Full charge will occur at a slower pace as part of saturation.

Try this Battery Charge/Discharge Calculator.

The short answer is Yes!  If you set aside the the initial investment cost of a proper silenced generator, you can produce cheaper electricity than the Retail State Grid price of 25cents kWh (bear in mind large commercial Hotels/businesses only pay $0.08c kWh for peak energy, and $0.04c kWh for off-peak energy).

With ever increasing electricity prices, it is currently easy to manufacture electricity @22c kWh using a 10kW Diesel generator.

NB: Operating as Diesel Gen-set on Waste Vegetable Oil (WVO) will greatly reduce the cost to under $0.05 (5 cents) kWh, and also Greatly reduce Green house pollution, as Vegetable oil in biodegradable !

For those that have the room & natural resources, and a bit of a Handyman, you should SERIOUSLY consider setting up Bio-Gas system

EG: With Diesel fuel costing $1.10 litre, a standard 10kW Diesel generator produces electricity at around $0.22kWh or less, the newer breed of inverter-generators use a small capacity engines, making them even cheaper to operate.

Yes, however residential, noisy, un-caged generators are commonly only used for short periods by tradesmen that need power on site or in emergency situation during blackouts, they are very noisy and for that reason are rarely used to charge a battery bank, and usually never utilise the actual kWh of energy that is produced whilst running!

These days most Diesel engines are only warranted for 6~12 months or 500~1'000 hours of operation (which ever comes first), even though most engines will run for many more hours if correctly maintained, brush-less alternators themselves very rarely fail.

So, all that need to be factored in if you are calculating the pay-back period before making a profit from your investment.

The Key to making the best use of any generator, is to charge a bank of batteries whilst the generator is running !

That largely depends on the engine capacity, fuel cost, working load and hours of operation.

Generally speaking, when Diesel fuel costs $1.10 litre, a 10kW generator produces electricity for $0.22 per kWh, so in one hour a 10kWh Diesel generator will produce approx. 10kW of energy and cost $2.20 per hour to operate, where a 25kWh Gen-set will use approx. 5.25 litres in an hour, and costing $5.77.

To get a better understanding, use this Gen-Set Calculator and set it to whatever sized Gen-set is need to produce the energy you require, keep in mind you are better off using a generator to operate in short bursts to top up/charge a battery bank via a High Amp Logical controller or Charge controller.

In general stationary generator engines can run on Diesel, LPG, NG, PJ8 etc. and in general are fuel efficient and cost effective.

However if you can locate a free source of WVO better known as Used/Waste Vegetable oil, then you will have the ability to produce electricity at around 1 cent kWh, that equates to only costing you $0.42 cents per day or $12.00 per month operating a 10kW generator for 4 hours per day, 7 days per week, or as needed.  Meaning if you don't have or want a Solar Array, you may want to consider simply purchasing a 10kW Silenced Generator and a Battery bank larger that your daily kW usage!

For example: To charge a very large totally flat 48kW NiFe battery bank, takes approx 4 hours or less, a smaller battery bank may/will require less than an hour to charge each day, then you can harvest the energy at night and save yourself paying $0.27cents per kWh!

It all comes down to using the natural resources in your area, you may be able to purchase pure vegetable oil from a Farmer or Co-op, then you won't need to filter the oil, saving you even more time.

The linked calculator below shows the Carbon footprint generated and Fuel Cost per week and year for a various fuelled engine.

You can enter the amount of fuel you use and the cost of the fuel. Click here to use this Green House calculator.

There are several types of Aqua/Hydro generators, from small up to large kW Vortex type generators, that could power dozens of houses.

1) Vertical Pelton hydro generator uses water gravity forced through jet(s) that turns a pelton wheel that turns a generator, this can start with as little a flow as 0.1~10 litres per second with a Head pressure from 30~130mt, several Pelton generators can be operated from one large diameter PVC type pipe that draws water from upstream, thus giving you far more kW of energy produced from reasonable little water flow.

2) Horizontal Turgo (TRG) uses the same method of water supply but with Jets turning a similar wheel or propeller, but the generator is above the propeller, where a vertical shaft drives the generator.   Both these generators can be scaled up to commercial size.  

3) Low Head (LH) generators are also common and usually require a trench or Large hoses to divert/draw water from the main stream/river flow, into a sleuth type structure, where the water is returned to the stream via a plug type hole where the water only needs to drop 1.1mt to return back to the stream/river.

4) Vortex generators are similar in water flow as a LH type generator, in fact a vortex generator is a large scaled LH generator, the main difference is the size and volume of the water that actually rotates slowly causing a water vortex in the centre of the round shaped pond.   Vortex generators can be scaled up to power a town if several are placed along the river, one after the other.  The larger the vortex pond volume the stronger the turning force created, and that allows for very large kW generators to be used along the stream with every 1.1mt drop.

Biogas is produced when micro-organisms digest organic matter (biomass) under anaerobic conditions (that is, in the absence of oxygen).

This process produces a mixture of gases – primarily methane, some carbon dioxide and small amount of other gases such as hydrogen sulphide.

Bio-Gas and Bio-Methane are virtually the same type of Gas, the gas is collect from the breakdown of vegetable matter from the inside of a low pressure bladder type vessel.

These units easy to assemble and are also transportable if required.  They come with may equipment options that make the job simple and almost hands free.

The Family Size 1.2M³ Membrane Biogas Plant is the smallest Plant;

• Fermentation Capacity: 0.5m³.
• Gas Storage Capacity: 0.5m³.
• Biogas Production: 0.5m³/d.
• Electricity: 0.75 kWh/d
• Footprint: 98cm x 98cm x 114cm (WxDxH)
• US$500.00 +sea freight.

The Larger size 3.5m³ Membrane Biogas Plant;

• Fermentation Capacity: 1.7m³.
• Gas Storage Capacity: 1.3m³.
• Biogas Production: 2.0m³/d.
• Electricity: 3.0 kWh/d
• Footprint: 156cm x 120cm x 195cm (WxDxH)
• US$900 +sea freight.

For a large household there is a double 3.5m² biogas digester system, where the household sewer system is plumbed & processed directly into the system, the Bio-Gas produced can be used to operate equipment like Bio-Gas Gen-Set, Stoves, Rice Cooker, Lights.  Additional equipment like Circulating pump, Food Waste Shredder, Sewage pump with knife, Flow Meter, Heater for cold weather, and other equipment is available, a full Bio-Gas package deal costing approx. $2'300.

If you have a garden with a supply of vegetable matter &/or even animal waste, the above system can easily process the organic waste, and you end up with a Rich Liquid Fertiliser that can be safely used on your garden, plants & crops etc.

The smaller 1.2m³ Plant would be suitable to fit into a Motorhome that has 1m³ footprint, and be a self contained plant, or ideally suited for smaller residential Bio-Gas Plant.