Home battery storage systems...

[NikNak]

As the title says...

Has anyone got one or thinking about having one installed.?

Is it coupled to a solar pv array or just stand alone.?

What size do you have.? is it big enough for your day-to-day household requirements, or in hindsight do you wish you'd gotten a bigger size.?

Any info you'd care to share.....



Nick

 

[hairy]

A neighbour has a couple of 100W panels in the roof of his greenhouse, and is thinking about one of the small turbines off Amazon for a few hundred quid, connected at first to a 500Wh lithium "powerbank" battery, but now to one maybe twice as big. The first one had limited charging input capability. He just uses it to charge the multitude of 18v tool batteries he has and to give a small back up during powercuts.
On a bigger scale from campervan to domestic off grid, this seems to be a knowledgable chap even if he doesn't think lithium batteries will solve all the worlds problems HandyBob's Blog

 

[Rorschach]

Why do you want it?

 

[Woody2Shoes]

I'm spending my "eco" funds on insulation and controlled ventilation first. By the time that's done, the capacity and costs of units on the market will have improved. I have loads of room for solar PV/HW panels. I would not consider a wind turbine under any circumstances.
You may learn something, if you haven't seen it already, from the irrepressible Robert Llewelyn's experiences with a Tesla Powerwall (and other "eco bling") in his house -

 

[NikNak]

I would not consider a wind turbine under any circumstances

Ditto.... I used to head up a team that built the tooling for turbine blades, that part was interesting, the rest of it.... pffff

 

[Woody2Shoes]

Ditto.... I used to head up a team that built the tooling for turbine blades, that part was interesting, the rest of it.... pffff

Yes, in the right place offshore at a grid-scale, absolutely. Inland, in SE England at a domestic scale, absolutely not.

 

[RichardG]

I have 8kW of solar panels and a 13.5kW Tesla power wall on order, there’s a shortage so probably won’t be installed until Sep/Oct. I spent some time doing a spreadsheet to calculate the cost/benefit before making a decision. One huge benefit of the Tesla battery over the others is the special energy plan it has for it’s customers of 11p per unit import/export and no standing charge, no other battery currently has this option. This will turn our electricity bill into electricity income as over the year we’ll generate more than we use.

Our energy supply has also been a bit flakey so being able to run off-grid is a huge reassurance, especially as we have a pumped sewage system.

 

[paulrbarnard]

I ran my workshop on solar and wind for several years before I got mains run out to it. I only got the power put in as I moved out of a rented office and now use one end of my workshop as a home office.
I only used the power for lighting and it worked a treat. I have two 100w panels and a 300W turbine. I have these feeding into a CTEK DC/DC charger and have a 110AHr AGM battery. I have the lights divided into 4 circuits with dimmers so that I could manage the power consumption. The battery box has a monitor on it that shows how much run time I have left in the battery. I also have a 1000W inverter which was used for the odd time I needed 240V. The lighting still runs off of the solar even though I have mains available.
The wind turbine does contribute a little in the winter, when the panels are boarder line. It is far less useful than the solar panels though.

 

[D_W]

Haven't seen anything here other than:
1) very wealthy people with a powerwall (which couldn't possibly pencil out yet given the tesla cost - but generally those are in areas where there are tiered electricity rates, and that may help. Higher tier rates in california can be 40 cents per KW hr and the companies have a horrid setup to pretty much steal money from larger customers just because those customers have the means to do it. That is, once you get above a certain level, you're paying 40 cents plus taxes and fees plus a 20 cent surcharge).

OK, I just looked that up as I recall someone on another forum saying they had a $500 electric bill per month in CA for what's probably a 3000 sq foot house. I couldn't imagine how their consumption could be that high, but learned later that they said the high tier could be 50 cents a kw/hr at the time.

on the eastern seaboard here, electricity is 11c per kw/hr and it's about 16 or 17 cents where I am (old electric company and high rates due to older distribution system that needs lots of attention.....and high benefit costs for the employees).

At any rate - type 2 for storage (a relative of mine at a remote location running a transmission tower, as well as some off grid folks in rural areas who don't want to pay to be hooked to the grid and are homesteading. In suburban areas here, you're not allowed to be off the grid, off water, etc, all of those utilities are mandatory). Type 2 storage is old school with deep cycle lead acid batteries and a nod toward lower consumption. The house/homestead has to be built around the lower consumption with backup generation and what most would consider hardships (conserving when sun supply is low, and nothing like air conditioning, etc).

Not sure if what I'm saying under 1 above is clear - for heavy users, panels and powerwall type setups don't supply all power, they keep users from getting into upper tiers and surcharges. California at one time (and maybe still) offered incentives to have customers lease panels based on established consumption with the result being much lower cost than just paying actual rates, and at the end of the lease period, the panels are just given to the property owner.

It may sound odd to add the powerwall given the tiers are established based on total use, but most places in CA also have varying rates by time of day, so the wall and panels work together to lower your grid use and avoid backing you into doing things like overnight laundry.

 

[D_W]

As a gauge for economy - mennonites here in PA in the center and east of the state where the sun is better tend to have arrays, but no batteries. Mennonites also tend to be fiscally very sound - if they don't have some kind of locally arranged battery setup, it's because it doesn't make economic sense. If they have a panel array (they usually just have them out on a tube steel structure rather than putting them on their houses - something most landowners here think looks bad - my FIL won't actually get them on his roof because they'd be on the front of his house and he doesn't like the way they look, and BIL who drives a tesla won't have them installed freestanding on his property for the same reason - I wouldn't have thought there were that many men with thoughts like that, but I guess even saying that now is a banned thought). Mennonites keep neat properties, but don't forgo utility, either.

At any rate, economy apparently in having a lower cost more utilitarian array setup, but not adding the batteries here where power is a flat rate regardless of time of day or consumption level .

 

[hairy]

It's windy enough here (58N 6W approx) to make a turbine plus most likely a lead acid battery bank big enough to run the house a possibility. A neighbour was a registered installer, suggesting £23000 for a 3.5KW machine connected to the grid. The limit for that was downsized here from 5KW because the local grid can't use it or export it, too much already. But hopefully much cheaper just to charge batteries.
About a mile from here a domestic turbine had the blades blown off. They also need annual servicing.
Roof mounted solar panels would I think be bonkers here, but ground mounted, and especially hydro ones, might be good. Our house is super insulated and triple glazed, I'm growing my own firewood so cutting the electric bill would make the biggest difference to our outgoings. Not if a turbine gets blown away though

 

[Droogs]

@hairy What!!?? Do you live on the Calmac ferry MV Loch Seaforth?

 

[Dabop]

I been living offgrid (third time in my life) for the last year and a half in Australia- this is a 'temporary' setup to supply power to my shed and caravan- only 3kw of panels (1.5kw north, 1.5kw west) feeding 10kwh of LYP batteries (half my future house bank) and a 8kw 12v inverter (stayed with 12v for this as I already had the inverter and also the caravans lights, fans, tv and waterpumps for the sink and shower are 12v)

Once the house is built, then the rest of the panels (18kw in total, 72 secondhand ex gridtie panels- 6kw facing east, 6kw facing north and 6kw facing west on the roof) feeding a 20kwh (16x 400ahr LYP lithium battery bank ie 48v) and a 12kw LF inverter

Even my current 3kw is (just) adequate, even in winter- I run 2 laptops (1 24/7), bigscreen TV plus the little 22cm in the vans bedroom, fridge, cook on electric stove and microwave, griller and air-frier, a string of battery chargers for the tools for the house- I try and do all my cooking before sunset- I can easily run smaller stuff like the microwave and the airfrier etc off the batteries, but prefer not to do so (can even use the LPG stove in the van at a pinch, but I am still on the same 9kg bottle I bought a year and a half ago)

The thing is to go for high voltage series strings with quality MPPT inverters- mine will actually start charging (very small amounts, but still charging) BEFORE the sun is even up- by that I mean I am getting pulses about once a second of 1/4A into the bank when no part of the sun is even visible above the horizon yet, just the 'dayglow' of the sky lightening to blue...

This shows the effectiveness of a decent high voltage array coupled with high voltage input MPPT controllers....

In any case, unless it is for a shortterm project- forget about any of the Lead/Acid type batteries- long term, LYP lithium cells are better value for money, and to all and intents, basically maintenance free- fully sealed and all I do is once every few months, clean the dust off them... In terms of performance and value for money, L/A might be cheaper initially, but the lithium ones I selected will last me over 20 years, and allow me to use 3/4 of their rated capacity while doing so
This is something that causes a LOT of offgrid failures- with L/A- only half the rated ahr written on them is actually available unless you want a VERY short lifespan ie few months, and to get up to the 1500-1800 cycles, you can only use 10-15% of their rated capacity- ie you need to buy ten times more than you 'calculate' your needs to be to get that 1500 cycles... Mine are rated at more than 7000(!!!) cycles at 70% DOD ie I overrate the calculated capacity by 30% to achieve those 7000 cycles/20 years...
Suddenly those L/A don't look so cheap.... lots more of them and replaced far more often...

Home sweet home- temporarily...

 

[Droogs]

I would love to know how big a system would be needed to run a 3 bed house and a fully equipped workshop. IE a wksp with a decent table/panelsaw, lathe, extraction, planer, thicknesser etc plus an 8x4 capable CNC along with all the lights. Considering the cnc would be doing its thing while you got on with something else using machines for stock prep etc. Anyone any ideas?

 

[Speaker]

Have a look at “The EV Man” on YouTube. He has done two pretty good videos on his installation (Solar PV + Batterie) in Yorkshire.

 

[RichardG]

I would love to know how big a system would be needed to run a 3 bed house and a fully equipped workshop. IE a wksp with a decent table/panelsaw, lathe, extraction, planer, thicknesser etc plus an 8x4 capable CNC along with all the lights. Considering the cnc would be doing its thing while you got on with something else using machines for stock prep etc. Anyone any ideas?

It's almost impossible to go off grid in the UK using only Solar panels as they produce so little energy in the winter when you most want the power. To give you an idea in July a 10kW (28-30 panels) Solar array in Edinburgh generates 1225kWh, in December 167kWh.

Our house uses about 13kWh per day in winter and that's with no electric heating, so about 400kWh per month, so the Solar doesn't even come close to generating half what you need. In the summer you have 3 times the power you need. Looking at the Solar data for each month you would be OK from Feb to Oct providing you have enough battery storage to store all the energy during the day for use overnight and the inverter is powerful enough to meet your peak energy usage, that's a big assumption.

 

[D_W]

The same is true where i live in the states. Our solar factor is 0.7. In the southwest, it's 1.3. WE get about 54% of the solar out of a given array that the southwest does, but it's not just as simple as that as humidity/haze and cloud formation from being in a valley create stretches without significant solar energy (so the problem isn't solved by just doubling the panels).

There are a few houses here with grid tie-in, which makes more sense. As the panels get cheaper, even places like where I live start to be able to offer packages for lease where the cost of the array setup can be financed by switching payment from the utility to the backer for the solar setup. The way this works is that you're still ultimately paying net to the utility, but the backer who sets up the solar array and leases it guarantees a delivery or a certain amount of power and a market for your excess if you have some, so as long as your consumption stays similar, you have an idea of what your costs are (typically about the same cost as utilities, but with a 2 or 3% inflation increase built in). The lease packages have a term, and you're generally the owner of the equipment at the end of them (always as far as I've seen so far - what is the third party debt purchaser going to do with a 20 year old pile of system parts).

 

[D_W]

I thought someone mentioned wind here, but I guess it went away. I've got a relative (now deceased) here who in the first eco go around installed a large 10kw turbine on a 90 foot tower. He built the tower, installed everything and bought only the top part of the turbine (and was trained in electronics in the navy).

I don't know how reliable turbines are now, but within a couple of years, he was making regular trips to the top of the tower to fix the turbine or find that he needed to bring it off of the tower for more extensive work.

It ran some fraction of the time at a reasonable % of capacity. On the utility scale, turbines seem to be getting very cheap. At the individual level, I think it would be hard to make them pencil out at a utility rate, at least based on what I've seen.

Said relative's 10kw wind turbine was a lot more stout than what I see these days and had a lower rated wind speed, but sat idle a lot of days as the startup speed was around 10 miles per hour. He had a commercial location adjacent to his property and the hopes were that it would defray some of the lighting costs. I don't think it ever did, but it was worth a shot.

 

[Bod]

This system of solar panels, and batteries, suppling mains quality electric, is common on Narrowboats', all be it small scale.
What is needed is a good understanding of how to charge the batteries properly, Lithium batteries, have very different requirements to Lead acid.
Good quality Pure Sine wave inverters' are needed for modern electronics. A proper multi stage battery charger, to maintain the batteries over winter, as Solar panels produce next to no charge during the British winter, and the batteries will suffer great damage if left less than fully charged, over that period.

Bod.

 

[Dabop]

I would love to know how big a system would be needed to run a 3 bed house and a fully equipped workshop. IE a wksp with a decent table/panelsaw, lathe, extraction, planer, thicknesser etc plus an 8x4 capable CNC along with all the lights. Considering the cnc would be doing its thing while you got on with something else using machines for stock prep etc. Anyone any ideas?

That's exactly what mine will be doing once the house is built- the house will be a 4 bedroom one with all electric cooking, electric HWS, led lighting, and aircon (must here where I am in Australia- summer days can hit 43C plus for days on end and in summer nights will often be over 25-30C as well)
The workshop will be in the shed I am currently living in (in the caravan), with cnc plasma cutter, cnc mill, plus all my other tools (lathe, various grinders, welders etc etc)- I budgeted to never run my bats over 70% DOD ever to give a 20yr + life expectancy- most nights they will never run above 25-30% DOD- even with me running several ceiling fans 24/7, and leaving the TV on overnight (I need noise to sleep- strange as it might sound- I have rather bad tinnius from years of industrial work- eh??? WHA????- and find the background noise from the tv makes it easier to sleep)

My entire system cost under $18000Au, with the batteries making up the majority of that- $11500Au- but as I said- they will probably outlive me.... 20 years plus expected life expectancy (and I believe they will get it- this particular brand of batteries has been on the market here in Australia for over a decade with some severe usage with some owners- one guy has a set he uses in an EV for over a decade with still negligible performance drop- the panels I paid $1960 Au for 72 250w secondhand gridtie panels ie 18kw in total, I actually got over a kw chucked in for free- the installer I bought them off couldn't be bothered unstrapping the pallets to take off the excess!!! (his yard was literally full of pallets of them from upgrades and insurance jobs...) Plus the inverter (48v, 12kw continuous, 20kw peak) and 4 atm- 8 eventually 3kw multivoltage solar controllers to under run them for long life and no possibility of overvolting them in cold weather

I wanted to run offgrid anyway- but in my case it actually made economic sense to- to run the 1/2km to my house location from the street lines outside- it would have cost me a grand total of $42k AU, with a load limit of 8kw single phase (rural SWER system)- instead I have a 12kw offgrid solar system for $18k- and no bills...
No brainer LOL