Energy Storage in Batteries & Thermal Technologies
You will be better educated on Energy Storage once you understand the difference between Power (kW) & Energy (kWh), This Page explains kW & kWh in Detail.
IMPORTANT: To Extend the cycle life of your batteries, the most important thing is Not to discharge more than 80% of the Battery Capacity ! e.g. If using a 10kWh battery, that means Consume no-more than 8kWh energy before re-charging, that will provide a longer Cycle Life, and it's said that constantly Over Charging Lithium batteries past 90% can also reduce the life of your batteries !
So, if you consume say 15kWh Energy per Day, add 20% =18kWh would be ideal, obviously the more Energy Storage you invest in, the longer it will last through extended Bad weather.
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Micro Grids are ALL installed "Behind-the-Meter", and those installed with the correct sized Energy Storage can operate independently of needing State Grid Power, all that is require to replace the State Grid Power a small $1'400 4.2kW Silenced Generator to provide additional Power to black-out proof your premises through extended Bad Weather.
All of our customer replaces the need to remain state grid connected, however it is import to invest in at least the kWh of Energy Storage that you consume between Solar-sunset & Sunrise !
An ON-Grid System basicly uses an Inverter that is legally allowed to Export Excess Power not being Consumed into the State Grid for a Feed-in-Tarrif (FIT).
However, it is Not really financially worth remaining ON-Grid unless you are Generating at lease 12kWh of Excess Energy each Day (375kWh Month), as the $30 month charged to Remain State Grid connected equates to 12kWh of Energy you have to Gift to the Retailers, that don't actually Pay for the Energy you Consume.
The big rip-off is, those that Purchase Power from the State Grid between Solar-Sunset & Sunrise commonly pay the full Power Rate, and during extended Bad Weather! By simply connect a Generator that is Automatically Started by our Inverter on the Days where Solar does not generate enough Energy, commonly OFF-Grid People with the Correct kWh Energy Storage say; They only use a Jerry can of Fuel each Year, that is 10 times Cheaper than Paying $360 year to Remain State Grid Connected!
We believe it would be a lot Farer & Simple if the State Grid Charged & Paid the same Rate for Importing & Exporting Energy from Solar, Wind and Aqua Prosumers, as well as removing the Deceptive fees to remain State Grid connected !
Customers need to take a leap of faith, and simply Go OFF-Grid, as Batteries are the main key to instantly becoming Energy Independent, commonly one or two 10.24kWh Battery is enough.
If a Retailer tells you Batteries are to expensive & takes to long to payoff.
Walk away & Shop around !
The main reasons behind that statement is either there Profit margin is high, or commonly most Solar Retailers Push to sell you an over-sized Solar Array, as there main focus is to get YOU to sign over YOUR 7 years of "Small-scale Technology Certificates" (in 2024 each: STC=$37 value), that can add up to over $4'000 for what is a easy Days Work installing your Cave-man Rooftop Solar system.
NB: A 6kW Solar Array's STC Credits equates to *$3'500~$4'000 depending on your location, BIG Profit for what commonly should only take 4~6 hours for two people to fully install either 9x 700W or 14x 435W or 18x 330W Solar Panels on a Roof-top!
Cave-Man Lead Acid Battery (LAB) are still the Cheapest Energy Storage Technology, but only have a 60% Depth Of Discharge (DOD), meaning 10kWh will only have a Usable 6kWh or Energy!
*In 2023 our Cost per kWh for Energy Storage Technologies;
How does Energy Storage work ?
Energy Storage is principally used to provide Power from Solar Sunset to Sunrise, and through extended periods of Bad weather, and if the Batteries get to low, an inverter with an Automatic Generator Start Function (AGS) will Start the Generator, we recommended a YiY and LUX Hybrid inverters as they do.
If you have a battery bank, all Power generated by Solar, Wind or Aqua first goes into a Hybrid inverter and first starts Charging your battery bank, and simultaneously the Inverter converted the the batteries energy into AC Voltage and powers your premises, and if you are Grid Connected, any excess energy can be Exported for a Feed-in-Tarrif (FIT) or Sold via P2P Energy Trading platform.
Commonly energy storage is for Consumption at Solar-sunset through to Sunrise, where solar generation starts again.
Energy storage systems all have different size footprint, capacity, efficiency and cost per kWh, the best battery systems will provide good value for money and last many years past there guarantee period and cycle life, allowing you benefit long after passing the investment break-even point, from there onwards it will be all savings!
The New bread of Hybrid Super Capacitors (SC) Modules and the new bread of Sodium-ion (Na-ion) Battery Technology will become a big disruptive force in the near Future of Energy Storage for Residential & Commercial Consumers.
Below image, is only One way to Configure a Micro Power Grid.
Micro Power Grids are BEST installed as an Island, Independent & Separated from any State Grid Distribution Infrastructure, for those Connected to a State Grid Power Meter/Box, YOU have to Gift over $375kWh a Month to pay for the Connection Fee to remain State Grid Connected !
A smart Energy Minister should Mandate NOT to Charge Prosumers, e.g. Persons that Provide, Consume & Feed there Clean Energy into the State Grid Infrastructure.
Prosumers "SHOULD NOT BE CHARDED a Connection FEE, if already Connected!
People are charged upwards of $10'000 per Power Pole to bring State Grid Power Lines, you can legally run your own Underground Cabling if you want, and that will be a 1/3 the Cost of a New connections!
Think of the State Grid as an Extension Lead from a Coal Generator !
Well it is Really! As the State Grid Power infrastructure Mainly draws Power from Coal Fired Generator (Steam Turbines in many Cases), the Imbecile Scott Morrison Blocked a Natural Gas exploration of PEP-11 application, a Block of underwater land that could possably turn the East Coast of Australia GREEN with one source of Natural Gas, that has been escaping/leaking East of Newcastle for Hundreds of years.
Natural Gas is a lot BETTER Option to process Rare earth materials, Steel, Aluminium, Nickel etc. etc. products, that we Buy back as Solar Panels, Batteries, Inverters & Components to make all goods, even Plastic’s.
Assuming YOU ARE HERE to Become Energy Independent OR looking to Earn an ongoing Income stream.
Then invest from $15'000 on Equipment, and start down the path to become initally Energy Independent, by purchasing DART-6 or DART-08 Unit & 20kWh Energy Storage, and a single or three phase Generator to match your exsisting Power, this will be cost approx. $20'000 with installation.
Below image shows what would suit 90% of Australian Homes/Premises that Consume up to 100kWh of Energy per Day for a Large Energy Consumer, an Auto Start Generator Replaces the State Grid Power when Needed, NEEDED being the Key Word, as most MPG's (Micro Power Grids) are reported to only use two Jerry Cans of Fuel a Year, if the MPG is set-up Correctly, based on Consumption or Need.
be installed by what AC Connecting Inverters & Batteries
.::. AC Connected System .::. DC Connected Systems .::.
|Click Image to Enlarge.
How many kWh Energy Storage is require to become Energy Independent ?
Three Simple Options are;
- Purchase at least the kWh Energy Storage you Consume between Solar Sunset & Sunrise.
- The better option is to Purchase Energy Storage equal to or Greater than your heaviest Daily Energy Consumption, as commonly with extended Bad weather you will have 3~5 Days of uninterrupted Power, as even in extended bad Weather your System will be Generating Energy and charge your batteries.
- Obviously having a DART Solar Tracker fitted with a Wind Turbine atop the Solar Racking will Generate substantially more Energy, as commonly during Bad weather, there’s usually abundant Wind.
All that is largely dictated by your Daily energy consumption and Energy Storage required.
The minimum energy storage capacity should be what you consume between Sunset to Sunrise, obviously the larger capacity the better as that greatly extends the life of most battery, OTHER than Super Capacitors Energy Storage Modules have a 100% Depth of Discharge (DOD) without Damage.
This is a good FAQ document on Battery Sizing to read (.pdf)
Example: If your premises consumes 15kW of energy/power per 24hr day, and 5kWh between sunset to sunrise, then a 5kWh battery would be smallest, where a 15kWh battery should provide nearly 24 hours power security or greatly assist during sustained bad weather. Additional energy is easily generated by a small cheap Silenced 3.5kW Gen-set to totally black-out proof your premises.
No matter what battery storage system you purchase, you should Calculate the following;
- The Battery cost per kW: The less you pay for quality batteries the quicker the break-even into profit period is accomplished.
- Battery Life: Is calculated using the manufacturers energy Throughput or Cycle life figures;
- Throughput: If the manufactures energy Throughput is 55'000kWh ÷ 15kWh usable battery energy = 3'666cycles ÷ 365days = 10years.
- Cycle Life: If the manufactures Cycle life is 3'500 times ÷ 365 = 9.6 years.
NOTE: There is only one battery on the market that guarantees 30'000+ Cycle life, these are Super Capacitor (SC) batteries.
There is a New Commercial Thermal Energy Storage Technology (TESS), called 1414° TESS unit, the directors of the company have stated "it will be 1/10th the cost of large Commercial Energy Storage solutions like TESLA". This system would be very suitable for storing energy spillage, what would be normally wastes energy, and be very suitable for Community Energy!
If you already have Solar: You are way ahead, as your break-even point to re-coup your Battery investment will commonly be between 1~3 years depending on the kWh battery capacity!
So, remember when investigating in a micro grid, you need to purchase a Hybrid Bi-directional inverter (not a solar inverter), Hybrid inverters are compatible with variable input voltages, and cost from $900~$6'000 depending on the brand and kW rating, if you intend to operate 3 phase power, you can purchase single 3 phase inverter or three separate single phase inverters, depending on what you are trying to accomplish.
The latest energy storage technology are Dry-cell Graphene Super Capacitors (SC) Modules, they also have the highest Energy Density of 55Wh/kg, and come with a Cycle life of 50'000 times or 12 years guarantee.
Nickel Iron NiFe batteries provide the longest proven cycle life with no likelihood of failure from fire & explosion, and cost $550 kWh.
Lithium-Iron phosphate (LiFePO4 = LFP) batteries offer lower energy density and also lower cost $550kWh, these batteries are widely used in electric tools, medical equipment, and other roles.
LiFePo4 chemistry offers a longer cycle life than lithium-ion batteries. LiFePO4 batteries have a very constant discharge voltage, where each NiFePo4 cell voltage stays close to 3.2V during discharge, until the cell is exhausted. They allows the cell to deliver virtually full power until discharged, and simplifies or even eliminate the need for voltage regulation circuitry.
NB: Lithium-ion battery technology is Not as Safe as Lithium-Iron) can pose unique safety hazards since the TESLA battery contain a flammable electrolyte and may need to be kept pressurised. An expert notes "If a TESLA battery cell is charged too quickly, it can cause a short circuit, leading to explosions and fires". Because of these risks, testing standards are more stringent than those for acid or electrolyte batteries, requiring both a broader range of test conditions and additional battery-specific tests. There have been battery-related recalls by some companies, including the 2016 Samsung Galaxy Note-7 recall for lithium-ion battery fires.
We highly recommend Lithium Iron Phosphate (LiFePo4) and Nickel Iron (NiFe) batteries, as they are the Safest & Cost less per kW, where NiFePo4 have the lowest cost per kW of under $550kW, followed by NiFe that have a proven track record and last over 30+ years, with some lasting over 100yrs, NiFe batteries don't use Lead or Acid, they use a cheap & readily available Electrolyte composed of Potassium hydroxide and Lithium hydroxide, that is reported to last minimum 7~10+ years, and when the electrolyte need replacing it only cost 5% of the battery cost, electrolyte replacement refreshes the batteries for the next 10 years !
Nickel Iron (NiFe) battery Electrolyte:
- Potassium hydroxide (1.2g/cm3) is an inorganic compound with the formula KOH, and is commonly called caustic potash.
- Lithium hydroxide (20g/L) is an inorganic compound with the formula LiOH. It is a white hygroscopic crystalline material. It is soluble in water and slightly soluble in ethanol, and is available commercially in anhydrous form and as the monohydrate (LiOH.H2O), both of which are strong bases. It is the weakest base among the alkali metal hydroxides.
As a long term Investment, there are only a few battery types that provide long term reliability, in the following order, Nickel Iron batteries, NiCd batteries (download.pdf), and possibly the new Australian RedFlow bromide batteries(worlds smallest Flow battery), Tesla Powerwall-2 Lithium-ion batteries, all are able to be used for Residential & Commercial applications.
NEWS: In January 2018 an Australian company 1414° degrees introduced a "Molten Silicon Energy Storage System" (Not a battery). This is a Commercial 10MWh Thermal Energy storage system (TESS). Currently there smallest unit is 10MWh system, with an approx. footprint size, of a 40' shipping container and twice as wide, only designed for Large scale applications (250+ homes), a 1414° 200MWh system is the size of a two story building, currently these storage systems are Not for households, however it is claimed that a 10~50kWh system, if developed will only require 70cm3 for the molten core of Silicon (Si).
Super Capacitors (SC) built for Energy Storage:
Super Capacitors are the latest in Energy storage devices in 2020, although SC Technology is more expensive per kWh they make a great addition to any existing energy storage system.
NB: Super Capacitor can be wired in Parallel as long as both are the Same DC voltage, It is NOT recommended to wire SC Modules in Series
DC Voltage can vary from 12V up to 750VDC, New Dry-cell Super Capacitors banks is NOT a chemical battery as such, Super Capacitors can Instantly release the total energy stored, unlike a conventional batteries that have 60~80% lower DOD, and restrictive energy release!
So why would we use a Capacitor bank ? Well, if say a Water Heater, Oven or equipment that requires high amps to start, then instead of placing the Initial High load on your battery bank, the combination of Super Capacitor & Battery bank simply Shares the Load/Draw of power, eliminating the load on your batteries, thus extending the life of your batteries, and Super Capacitors Charge back-up in a matter of a few minutes, compared to batteries, thus SC are ready for work first.
Charging Energy Storage:
Besides solar, wind or Hydro, an inverter with AGS (auto-generator-start) function, does NOT really require a Generator larger than a 3.7KW as that is what the State Grid supplies to all single phase connections.
A cheap silenced caged 4.2KW Generator is the most economical methods to instantly increase your power production, Generators with starter motor can be automatically started by an inverter with AGS function.
Remember: Whilst a fuel generator is triggered to start, the BMS (battery-management-system) will first supply power to the Batteries with all spare energy charging your Energy Storage system, this way very little fuel is wasted, most generator can be programmed to automatically start & shut-down as programmed by the Inverter, be it for just a short time several times a day either based on SOC or Battery Voltage to simply charge the batteries to get you through until sunrise.
Can I use a Battery bank to load-shift ?
Yes, energy storage connected to the Grid, allows households without Solar to take advantage of cheap off-peak electricity prices. The idea is to charge the batteries during off-peak times, and then use the stored energy during peak times. This is known as Load-Shifting – But it doesn't make much financial sense unless there is a substantial difference between the day and off-peak power rates!
All batteries can off-set whatever kW of energy they store, for example, a premises with a 10kWh battery bank, consuming 10kWh day, can charge the batteries in approx. 4 hours @$0.28 to $1.12 per day using the inverters' 120A Battery Charge circuit (or power from a generator can be used), so charging the batteries at off-peak rate of $0.07 c/kWh cost $0.28 per day. This gives a saving of $0.84 per day, or around $310 per year.
Super Capacitors (SC) Energy storage technology is superior to all other energy storage technologies, including NiFe, LiFe, LiFePO4, and obviously Cave-Man Lead Acid batteries!
Will battery storage become cheaper ?
Yes, the costs of battery used for energy storage have been falling at a rapid rate and forecasts are for this trend to continue as more and more households adopt them. For example, the cost of battery storage fell 14% every year on average between 2007 and 2016 and it's expected that prices will halve again within the next five years.
As of January 2021, single unit purchase Calculate Cost per *kWh;
- 10.24 kWh Lithium iron phosphate (LiFePo4) battery cost $5'150 ÷ 10.24kW =$500 per kW.
- 9.60 kWh Nickel iron (NiFe) battery cost $7'650 ÷ 9.60kW =$800 per kW.
- 8.50 kWh Super Capacitor (SC) Graphene Modules cost $8'160 ÷ 8.50kW =$960 per kW.
- 10.0 kWh RedFlow Bromide battery cost $10'000 ÷ 10kW =$1'000 per kW.
Clearly leaving LiFe & NiFe batteries well ahead of thee rest in price and proven reliability, with NiFe reported "as new" after 30+ years!
Solar panels are also getting cheaper, with a 75% drop in price over the past five years.
With the global market for solar panels and battery storage expected to grow ten-fold by 2020, the demand for battery systems like Nickel Iron (Non acid), RedFlow (Bromide) etc. should have flow-on effects on prices as economies of scale kick in.
* approximate figures, less for multiple purchase, as single Unit Purchase is a Lot dearer.