DIY ESS - Already 2 Years of 24/7 Service with Solar at Home !

Yes, it's been 2 years yesterday, since I started producing & storing my Solar surplus at home for re-use whenever necessary, during the day, or in the evening when the sun goes down
http://www.myelifenow.com/2013/07/starting-first-full-day-of-solar.html



My Energy Storage System was actually working several months before that, and my Solar Panels where installed on the roof almost 9 months before too, but I was waiting for my solar contractor to complete the install with his own special inverter, which was too delayed in the end, so I asked him to installa regular one, and we agreed on an 3kW SMA unit

Once installed, I could finally generate my own solar electricity, and my ESS being ready and tested, it worked right away seamlessly :)
http://www.myelifenow.com/2013/07/uni-solar-pvl-sma-inverter-finished.html



That was two years ago, and it has been doing great over time: No breakdown, no Battery problem (I read so many things about sceptick folks on this), it has been working like a charm



With less solar generation during winter, I used the Forced Charge function to charge from low cost electricity at night, to help push low cost energy back into my home grid to help heating, lighting and cooking



As we can see on the Wattson / EnergyHive portal where my generation & usage data are collected in real time, it is saving around 250 EUR per year (over the last year), and since the price per kWh goes up all the time, it will save evne more in the future
http://wattson.energyhive.com/dashboard/diyesskit



My ESS has been registered on the DOE - Department Of Energy - Global Energy Storage Database back in July 2013, few days after, under PRojet Reference 720
http://www.energystorageexchange.org/projects/720


But wait, there's more ...

A second unit, called Mini ESS, based on 3 Nissan LEAF battery modules, installed in october, has helped store and save even more, at night during winter, and now from 11AM to 4PM, harvesting during the peak production period of sunny days



Also I am in the process of building and testing a second version of this DIY ESS, called DIY ESS V2 with Enphase, because it will use the famous Enphase Micro Inverters - M215 or M250 - for more efficiency
It's design & build should be simpler, but it is not ready yet ...



With the new Tesla PowerWall, Enphase AC Battery coming, it really shows everyone that Energy Storage is a serious business and a perfect complement to solar and/or wind installs, at the residential level !

To Celebrate this 2 years milestone, I decided tho slash the DIY ESS Kit price and remove 100 EUR from it, dropping from 249 to 149 EUR ! (Kit #2 is also reduced by the same amount of course)

Also the Kit Building Documentations are now available to anyone FOR FREE on the DIY ESS Kit website ! "All our Patents are belong to you" ;)
http://www.diyesskit.com/p/documentation.html   (look for the "=> Get the PDF File" links)



To have more info about the Kit and why not build your own, go to:

http://www.diyesskit.com
or
http://www.storeyourenergy.com


Now, you can start building your own DIY Energy Storage System for your Home !

My Mini ESS with LEAF Batteries gets an Enphase M215 Micro Inverter ! and becomes my DIY AC Battery ;)

In a way this like getting my own Enphase AC Battery ;) well, sort of ...



If you recall, I have been testing 3 LEAF Battery Modules for 6 months, then put them into a 6-bottle wine crate along with a Charger and Grid Tie Inverter to make what I called a Mini ESS - Energy Storage System -

Since November 2014, it has been running 24/7, for more than 4 months, until last weekend when a strange smell caught my attention while it was pushing power back into our grid in the morning, after its usal night low TOU rate charge cycle; It must be a vented capacitor, leaking inside .... It happened on another of the SUN-250G grid tie inverter I am using since the beginning of my Energy Storage activities

During last week I stumbled across an ad for 18 used Enphase M215 - 2 years old - Micro Inverters at 79 EUR per piece, and decided to give it a try; I already did try to use them last year but realized the US version will not work in France (split phase/single phase & 60Hz/50Hz)

I got in touch with the seller, a professional in Solar and Wind, who was nice enough to deliver 2 units for free saturday morning at home; In our email exchange I learned that they need to have a profile flashed into them before they can operate, and this is done during their first comissioning via the Enphase Engage gateway, using power line communication



So the 2 units I got have this profile already inside and he told me they should operate just fine, once they have DC through their MC4 connectors and the grid with 230V AC on the other end of the Enphase Engage cable - which I already got last year, EU version -



I quickly took my Mini ESS downstairs, unscrewed the cover, and connected the Battery pack to the  DC side using crocodile clamps and MC4 connectors, plug the AC side to a wall outlet, through a wattmeter, and turned main switch to the GTI - Grid Tie Inverter - position



After a long 2mn and 20s, and different status LED colors, it started producing 235W :) ! which is normal but I was happy to have working units now, opening my Storage experience new horizons ...



After running fine for an hour or so, the external temprature is only reaching 32°C, no fan required, no noise (you have to put your ear onto it to ear something), it's just great !


It pushed a steady power for 3 hours or so ... nice !



Sunday morning: now let's swap the 2 GTIs and make this Enphase M215 fit inside the box


After trying different positions and measuring the length of DC wires, I cut them and soldered them to their MC4 connectors


Voila ! DC side is wired and fits inside the crate :)


This new layout will leave the 10A charger outside, and I decided to hang it in the back, less vibrations this way


After testing both Charging and Discharging, I put my Mini ESS back upstairs, next to its big brother in the living room, right in time before night rate kicks in ...


It charged during the night, and this morning pushed all this stored Energy back into our home grid for 4 hours in a row, helping the heat pump warm up the apartment and breakfast consumption



Notes: After realizing it takes the M215 2mn and 20s to initialize and start producing power and I was disappointed first, because it takes only few seconds for my SUN-250G to start doing the same! Thinking over this during the weekend I tried leaving the DC side ON, and it worked, now reducing the startup time to 15s, much better !
Also there might be the fact that I am not using the Envoy GAteway, and the M215 might be waiting, trying to connect to it before producing ...

Well I still have to learn about that part, but overall this is a huge step towards more Efficiency and this is key !

All about my 2 DIY ESS : http://www.myelifenow.com/search/label/DIY%20ESS 

Follow my 2 ESS units 24/7 live: http://wattson.energyhive.com/dashboard/diyesskit

Reposit Power : Store Solar Energy & Trade it with Grid

A Canberra-based company is to introduce new technology that it says could help turn electricity markets on their head – by allowing households to buy and sell electricity on the market.

The buying and selling of electricity has hitherto been the province of large or specialised companies such as electricity retailers. But Reposit Power says that homes and businesses can and should be able to trade electricity with the help of battery storage, and production facilities such as solar panels.

Reposit Power plans to install battery storage in six homes around Canberra to run a six-month pilot of its technology, known as GridCredits. The Australian Renewable Energy Agency is contributing $445,000 to the $900,000 project.

Reposit Power says GridCredits is a world-first energy storage program that will put consumers in the driving seat and will "transform the grid forever."

Spokesman Luke Osborne says the technology will allow households to "buy low and sell high" – adding a new layer of possibilities to homes that have solar and storage. He says this will enable some households to virtually eradicate their bills and still remain connected to the grid by doing what the retailers do – maximising their earnings on the market.

"A lot of what retailers do is buying services from peaking power stations. Consumer with storage and solar panels can provide the same services themselves," Osborne told RenewEconomy in an interview.

"What we are doing is when it makes sense – households can be a seller, and then buy electricity at a low price."

Reposit Power is interested in using similar technology for wind farms and solar farms and for large businesses. "This is the alternative to going off-grid – households can be energy independent, at the same time as making the whole grid cleaner," Osborne says.

"Networks should be a platform for trading and exchange of electricity, so tariffs should be structured to encourage this, not to prevent it, or that will accelerate the death spiral of the grids.

"This is about households being able to go head to head with the major companies."



Reposit Power hopes to be able to broaden its rollout by mid next year, when this initial program is complete, and when it has convinced the Australian Energy Market Operator that households or businesses can be a "reliable source of power", as AEMO requires.

ARENA CEO Ivor Frischknecht said the new technology would allow consumers to gain more value from their rooftop solar PV installations. He said that one in five houses now use solar power.

"This substantial rise has made it vital to find solutions to better manage how residential solar systems operate in our electricity grids," Frischknecht said.

"Reposit's GridCredits system can control and store solar energy. This gives consumers access to their own power overnight and at peak times, reducing their demand on the grid.

"It also allows energy to be sold back into the grid by placing bids into the market, turning residential properties into micro power plants."

Frischknecht said that storage would help network operators manage demand more effectively by delivering stored power into the grid at peak times, and Reposit's technology will also help smooth out the variable delivery of solar energy.

This in turn would allow more renewables to be connected to the grid.

Reposit Power was co-founded by energy industry veteran Dean Spaccavento and scientist Lachlan Blackhall. The company says the two "shared a vision for allowing consumers to trade their electricity while contributing to a safe and cost-effective grid."




Source: Renew Economy

Buidling a Mini Energy Storage System - ESS - to Store More Energy at Night during Winter

You probably followed my AESC / LEAF Battery Modules adventures since last March: Ordering them from Las Vegas, Bottom Balancing them, Wiring them in Series and Testing them for month in my bedroom with a 24V 10A LiFePO4 charger and a SUN 250G Grid Tie Inverter

Here is a link to all these previous posts on the same subject : http://www.myelifenow.com/search/label/AESC+ESS+leaf

In October I finally decided to pack of this "mess" into a compact Mini ESS - Energy Storage System - and below are the steps I went through, using a Bordeaux 6-bootle wooden crate - we are in France ;) -



This small unit is now upstairs in the living and used every day and every night, mostly to store as much Energy as we can at night when Electricity is half price during 8 hours with our TOU plan from EDF

This Mini AESC / LEAF Battery Modules ESS is storing 1.5 kWh of Energy at night and is pushing it back into our home grid during the day :)



So I started with these 3 LEAF battery modules, wired in series, and tested over 6 months



The idea was to find an enclosure that fit the modules almost perfectly and I thought about a 6-bottle wine crate to do the job


Warning: be extremely careful when using metallic tools with exposed battery connections !! a short could cause massive damage to you since the power output is HUGE !



So it fit almost but the tabs were sticking out a bit, an opening would be necessary anyways to access them to be able to check the voltage and access the connections when needed

Let's cut out this window


and pill up the 3 AESC modules


Now it is time to dismount the whole charge and discharge control system and install it inside the box, on top of the modules: it is made of a dual relay programmable voltmeter, and 2 Tyco Kilovac contactors - overkill for this system, but it's always better -



I did not want to put all these components directly on top of the modules so I added a small piece of wood, cut it to fit in length and did not cover the whole surface to let the modules breathe a little even if they do not heat up at all, they just get lukewarm towards the end of the charge around 4.1V per half modules



After came the fitment of all the rest: the 250W Grid Tie Inverter, same one used in my big DIY ESS upstairs, a 10A 24V - actually 29.2V - LiFePO4 charger and all the cables and wires
The 2 Kilovacs will face each other taking minimum space like this


Then we need to rewire the modules in series, but this time with connections using new 6mm lugs, add the main breaker in the middle of the pack for safety - and long time storage -


Soldering all the cables, using 2.5mm2 solid copper, too big for carrying 10A in both charge and discharge modes on short distances, but it is always better - and I can always double or triple the current later upgrading with other chargers and grid tie inverters -





First test after rewiring everything : it works, good !



At this point I brought the Mini ESS upstairs and put it next to the big one


I quickly protected exposed connections with a plastic cover, switched on the charger and it completed its first night charge - using half price electricity -


I forgot to talk about the main switch which simply allows, OFF in the center, Charger ON upper position, and Discharge through the Grid Tie Inverter in lower position
Bot Charge and Discharge modes are cut off automatically when the upper and lower Pack voltage limits are reached : 24.9V for full down to 21.6V for empty (6 half modules with voltage from 4.15V down to 3.6V)

The next week end I looked for a way to cover the whole unit and found a plastic box cover that fit perfectly


Tall wood screws will be perfect to hold it in place leaving some space to let the warm air from both charger and GTI get out


I screwed the small plastic box cover on the connections and this should be fine to protect - small holes will be drilled to be able to check the modules voltage, even if this is not moving at all, as I learned during the last 6 months test period -
The main DC breaker here is used to break the pack in two if unusual high current is reached in case of a short circuit for example, and to avoid any drain of the voltmeter if the Mini ESS is not used for long periods of time - holidays for example -


Now it remains here in the living room, next to the other ESS which has been running for a year and a half now with solar


Here is the UStream channel where I can watch both Generation and Net Usage at home anytime remotly (link on the upper right)




and screenshots of the Wattson Anywhere portal providing graphs (link on the upper right too)






So this little unit is helping the big one by adding an extra 1.5kWh of storage at home


and they both try to keep our NEt Usage as close to 0W as possible ;)